A dilation catheter system comprises a guide member, a dilation catheter, and an image sensor. The guide member includes a shaft comprising a distal end and a proximal end. The shaft further defines a longitudinal axis. The dilation catheter is movable relative to the guide catheter member and comprises an expandable dilator. The expandable dilator is sized to fit within one or both of a Eustachian tube or a passageway associated with a paranasal sinus. The image sensor is configured to provide visualization within anatomy of a patient. The image sensor is integral with the guide member.

In some instances, it may be desirable to dilate an anatomical passageway in a patient. This may include dilation of ostia of paranasal sinuses (e.g., to treat sinusitis), dilation of the larynx, dilation of the Eustachian tube, dilation of other passageways within the ear, nose, or throat, etc. One method of dilating anatomical passageways includes using a guide catheter to position an dilation catheter within the anatomical passageway, then inflating a balloon disposed on the dilation catheter with a fluid (e.g., saline) to dilate the anatomical passageway. For instance, the expandable balloon may be positioned within an ostium at a paranasal sinus and then be inflated, to thereby dilate the ostium by remodeling the bone adjacent to the ostium, without requiring incision of the mucosa or removal of any bone. The dilated ostium may then allow for improved drainage from and ventilation of the affected paranasal sinus. A system that may be used to perform such procedures may be provided in accordance with the teachings of U.S. Pub. No. 2011/0004057, entitled "Systems and Methods for Transnasal Dilation of Passageways in the Ear, Nose or Throat," published Jan. 6, 2011, the disclosure of which is incorporated by reference herein. An example of such a system is the Relieva® Spin Balloon Sinuplasty™ System by Acclarent, Inc. of Menlo Park, Calif.
Alternatively such dilation catheters may also be employed using a similar method for the dilation of a Eustachian tube located adjacent to the paranasal sinus of a patent. A system that may be used to perform such procedures may be provided in accordance with the teachings of U.S. patent application Ser. No. 14/317,269, entitled "Vent Cap for a Eustachian Tube Dilation System," filed Jun. 29, 2014, the disclosure of which is incorporated by reference herein.
A variable direction view endoscope may be used with such a system to provide visualization within the anatomical passageway (e.g., the ear, nose, throat, paranasal sinuses, etc.) to position the balloon at desired locations. A variable direction view endoscope may enable viewing along a variety of transverse viewing angles without having to flex the shaft of the endoscope within the anatomical passageway. Such an endoscope that may be provided in accordance with the teachings of U.S. Pub. No. 2010/0030031, entitled "Swing Prism Endoscope," published Feb. 4, 2010, the disclosure of which is incorporated by reference herein. An example of such an endoscope is the Acclarent Cyclops™ Multi-Angle Endoscope by Acclarent, Inc. of Menlo Park, Calif.
While a variable direction view endoscope may be used to provide visualization within the anatomical passageway, it may also be desirable to provide additional visual confirmation of the proper positioning of the balloon before inflating the balloon. Alternatively, it may be desirable to eliminate the endoscope altogether when patient anatomy proves too small and/or tortuous for full visualization using such an endoscope. In either case, this may be accomplished using imaging sensors positioned on either the guide catheter or the balloon catheter, or both the guide catheter and the dilation catheter. Such imaging sensors may be positioned within or near to the target area and be used to visualize the target area.
It may be desirable to provide easily controlled inflation/deflation of a balloon in dilation procedures, including procedures that will be performed only by a single operator. While several systems and methods have been made and used to inflate an inflatable member such as a dilation balloon, it is believed that no one prior to the inventors has made or used the invention described in the appended claims.
The drawings are not intended to be limiting in any way, and it is contemplated that various embodiments of the invention may be carried out in a variety of other ways, including those not necessarily depicted in the drawings. The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention, and together with the description serve to explain the principles of the invention; it being understood, however, that this invention is not limited to the precise arrangements shown.

Guide catheter with image capture and light emission features


A bearing structure for motors is provided, wherein a rotary shaft is supported by a pair of rolling bearings for rotation with respect to a housing, said rotary shaft being mounted on said pair of rolling bearings for slidable movement in the axial direction thereof.

1. Field of the Invention
The present invention relates to a bearing structure for motors in which rolling bearings are used.
2. Statement of the Prior Art
Where it is required to accurately position a spindle that is an output shaft of a motor in a thrust direction and rotatably support said spindle while preventing its rattling, as encountered in the case of, e.g., a direct drive system for disks that are recording media for information carrying signals, the spindle is supported by rolling bearings, while the rolling bearings are biased by a spring in the thrust direction to apply a pilot pressure thereto.
Typically, FIGS. 8 and 9 show two conventional bearing structures for motors in which a pilot pressure is applied in the thrust direction of rolling bearings.
Referring to FIG. 8, a spindle hub 1a is fixed to an upper end of a spindle 1 that is an output shaft of a motor, and inner rings of two rolling bearings 2 and 2 are fixed around upper and lower portions of the spindle 1 with a sleeve 3 interposed therebetween. At a lower end of the spindle 1, there is fixed a rotor case of the motor by means of a mounting screw 6. An outer ring of the upper bearing 2 is fixed into a central hole in a housing 9, whereas an outer ring of the lower bearing 2 is fitted into the central hole in the housing for relative movement in the axial direction. Between the outer ring of said lower bearing 2 and a step of the housing 9, there is interposed a pilot pressurization spring 4 for applying downward and upward biases to the outer ring of said lower bearing 2 and the housing 9, respectively.
The bearing structure shown in FIG. 8 is called a constant-pressure pilot pressurization system wherein the pilot pressurization spring 4 fluctuates depending upon the relative movement between the outer ring of the lower bearing 2 and the housing 9 so that a constant pilot pressure is always obtained.
In contrast to the conventional bearing structure shown in FIG. 8, such a sleeve 3 as employed therein is removed from the conventional bearing structure shown in FIG. 9. As illustrated in FIG. 9, an outer ring of a lower bearing 2 is fixed into a central hole in a housing 9, and between a rotor case 8 of a motor fixed to a lower end of a spindle 1 by means of a screw 6 and an inner ring of a lower bearing 2 there is interposed a pilot pressurization spring 7 for applying downward and upward biases to the rotor case 8 and the inner ring of the lower bearing 2, respectively.
The conventional bearing structure shown in FIG. 9 is referred to as a constant-position pilot pressurization system wherein the pilot pressurization spring 7, once positioned, is restrained from vertical fluctuation.
A problem with the bearing structure shown in FIG. 8 is that since the inner rings of the upper and lower bearings are fixed in place through the sleeve located on the inside of said inner rings, the accuracy of the sleeve has a considerable influence upon axial or planar vibrations.
In the bearing structure shown in FIG. 9, a central constricted portion of the rotor case is located in the inner rings of the bearings to determine the central position of the rotor case, so that when mounting the rotor case in place by means of a mounting screw, said constricted portion of the rotor case tends to come in contact with the inner rings of the bearings. When the constant-pressure pilot pressurization system is applied to this bearing structure, the resulting pilot pressurization tends to be unsatisfactory due to a frictional force occurring between said constricted portion of the rotor case and the inner rings of the bearings. This is the reason that applied to the bearing structure of FIG. 9 is the constant-position pilot pressurization system wherein both the inner and outer rings of the upper and lower bearings are fixed to the spindle and housing. According to this pilot pressurization system, the inner rings of the bearings have to be fixed to the outer rings thereof under a certain pilot pressure, and difficulty is encountered in providing a confirmation of whether or not the certain pilot pressure is applied, once the inner rings of the bearings have been fixed to the outer rings thereof. This structure is also lacking in reliability, since the pilot pressure is maintained by the bonding of the inner or outer rings of the bearings. For that reason, there is proposed a structure wherein a pilot pressurization member is located in opposition to the inner rings of bearings and an axial push is given to said pilot pressurization member with a jig to apply a pilot pressure to the bearings, whereupon said pilot pressurization member is fixed to a spindle with the use of a screw. However, this structure is troublesome to assemble and regulate, costs much and is disadvantageous for making the bearings thin.

Kabushiki Kaisha Sankyo Seiki Seisakusho


An intentionally activated frangible bonding system comprises a frangible adhesive, adhesive primer, composite material matrix, and/or the like, having a polydispersion of at least one additive spread throughout the frangible bonding material. The additive degrades a bond provided by the frangible bonding material, upon application of a specific energy to the frangible bonding material. An energy emitter is configured to selectively direct the specific energy toward a structure or assembly comprising components bonded by the frangible bonding material to degrade the frangible bonding material bonding the components for disassembly.

An adhesive layer is often required and desired to attach or bond two or more structures together in order to form an assembly that performs a function. As an example, a rotor blade of a rotorcraft is manufactured through several different adhesive bonding operations of many individual components to form a final blade assembly that will help give the aircraft lift while maintaining its structural integrity throughout all flight conditions and environments. Since the individual components of an assembly are shaped differently, made of different materials, and/or are affected differently by the various operational conditions, they wear and degrade at different rates. Also, a layer of primer, or the like, may be applied to the underlying structure and/or the overlaying structure may be applied to help ensure adhesion. Additionally, or alternatively, composite materials, which comprise at least one structural material and a matrix material, are used extensively in modern aircraft.
Aircraft are often required to fly in extreme environments such as sandy desert, rain or thunderstorms, around saltwater and/or in combat zones. In the case of rotorcraft, exposure to the elements can cause significant damage to rotor blade components over time, which often leads to repairs or replacement. Common damage that results in subcomponent removal of rotor blades includes erosion to the leading edge metal abrasion strip, ice protection failures to the heater blanket disposed beneath the metallic abrasion strip, impact damage to the upper and lower skins that cover the afterbody surfaces of the blade, and the like.
It is common to remove, repair, and replace certain damaged or degraded components of an assembly while reusing others. However, the methods of disassembly used today can be unsafe, labor-intensive, costly, disordered and damaging to the underlying or adjacent structure. In the case where removal, repair, and replacement of the damaged or degraded component is too difficult or costly, beyond economic repair, the components are often scrapped and replaced.
Traditional methods for disassembly of bonded components have involved the use of heat or other temperature degradation or embrittlement, electrical degradation, or mechanical disassembly of such components using force and/or sharp tools, all of which often cause damage to components intended to be salvaged. In the example of the removal of a damaged rotor blade component on a rotorcraft, the process is typically an operator-dependent and time-consuming process. Such removal of a damaged rotor blade component often employs a method that requires a high degree of craftsmanship and may be physically exhaustive. Various methods for removal of a damaged rotor blade component have been developed over the years. Such methods have been characterized as "messy," requiring specified tooling and support equipment, unsafe, risky in terms of both operator safety and/or potentially incurred damage to the component or assembly. Further, such removal of damaged rotor blade components may be limited to facilities with certain resources and infrastructure. With these existing methods of rotor blade component disassembly there is often unintentional damage incurred to the remaining structure of the blade. This may lead to increased cost for rework, and in many cases, scrapping of the component(s). As a typical, specific example, it is almost impossible to remove a good metallic abrasion strip without damaging it in order to replace a failed heater blanket that is disposed beneath the abrasion strip, at least in a reasonable amount of time. Conversely, in the case of an eroded abrasion strip, the removal process typically damages the underlying heater blanket, which may be functional and not in need of replacement.
These issues with the difficulty of disassembly of such components may be considered to result from design considerations for such a blade, expecting an abrasion strip and heater blanket to stay on the blade indefinitely. Just like all bonded structures, producibility and performance concerns revolve around strong and durable adhesion. Hence, as discussed above, good rotor blade components are often sacrificed during the removal process of a single damaged or failed part.
A specific example of removal of a failed heater blanket or eroded metal abrasion strip, using heat gun, wedges, hammers, chisels, and the like, includes an operator using the heat gun to soften the underlying bondline in order to slip in wedges under the edges of the metallic substrate all the way around the abrasion strip. Then, a large hammer or mallet is used to apply force to the wedges in order to locally dis-bond the abrasion strip. Pliers or mandrels may also be used to help peel back the metal of the abrasion strip, such as in long narrow bands (i.e. in can key strip opening fashion). Once the abrasion strip is removed, the thin heater blanket layer is chiseled away. Then, the remaining heater blanket material and adhesive remaining on underlying components is sanded down, in attempt to reveal an undamaged rotor spar or sheath underneath the heater blanket. Often, the hammering of wedges or chiseling leads to damage to spar or sheath plies, resulting in a scrapped part or rotor blade, particularly if a local repair to the spar or sheath plies is not sufficient. This removal of a failed heater blanket or eroded metal abrasion strip is a time-consuming, unclean, and costly method for rotor blade component removal that does not always result in success.
In another specific example of removal of a failed heater blanket or eroded abrasion strip using dry ice, wedges, hammers, and the like, there is more potential for successful abrasion strip removal, while preserving the underlying heater blanket. Therein, a dry ice bath is used to lower the temperature of the metal substrate of the abrasion strip. This method requires more, typically a considerable amount of more, special tooling and equipment that is tailored to the specific blade in order to acquire consistent cooling across the abrasion strip to be removed. The dry ice can be dangerous to personnel and must be handled with care. This is also a very tedious and operator dependent process when done correctly. The temperature of the metal must be tightly controlled for successful removal, so the time in the dry ice bath must be closely monitored. The part, or overall blade structure, can be permanently damaged if left in the dry ice bath too long. The cooling of the metal causes thermal contraction/expansion such that the part (metal adhesion strip) moves relative to the underlying blade structure. The idea is to create a clean disbond with this process, without damaging any components. When a clean disbond is not accomplished, sometimes hammers and wedges are used at the part edges. There is still considerable room for error in this process and it may not save any time or cost over other methods, such as use of a heat gun, as described above, use of an electrical current to degrade the bond, or the like.

Selectively activated frangible bonding system


A unified data access mechanism can provide transparent access to data that is either stored locally or remotely. Application programs can direct data requests and data modifications to this singular component without foreknowledge of where the data is stored. The unified data access mechanism can work in concert with a synchronization mechanism that can maintain data synchronization between local data and remote data. Requested or modified data can be identified as stored locally or remotely based on the namespace of the data. If the data is stored remotely, the user credentials associated with the user's process space within which the application program is executing can be utilized to identify, and then provide, relevant authentication information to the remote data store, should it be required.

For modern computing devices, including traditional personal computers, as well as personal digital assistants, cellular telephones, and the like, network communicational abilities have become ubiquitous. As a result, an increasing amount of information utilized by such computing devices is obtained from storage devices that are physically separate from such computing devices, and with which communication is established through one or more networks. Similarly, an increasing amount of information created by such computing devices is often stored, not on a storage medium co-located with the computing device itself, but rather on storage media that are physically separate from such computing devices and communicationally connected with such computing devices through network communications.
Information stored on, and utilized from, networked storage media, such as the storage media of one or more server computing devices, can provide benefits over locally stored information. For example, information available from networked storage media can be accessed by multiple different computing devices, often simultaneously, thereby enabling greater sharing and collaboration efforts. Similarly, information stored on the storage media over one or more server computing devices can receive the practical benefits of the support provided to those server computing devices including, for example, data redundancy, data backup, uninterruptible power supply, and other like benefits. Unfortunately, however, information stored on, and utilized from, networked storage media can likewise have drawbacks as compared with locally stored information. Most notably, access to a network through which the networked storage media can be communicated with may not always be available. Additionally, the provision of data across a network can be subject to various delays that are typically not present when the data is stored on a storage medium that is local to the computing device. Such delays can include network throughput, network latency, and the inability of the networked storage media to supply data in an efficient manner to a large number of requesting clients simultaneously.
Traditionally, the developers of software application programs must decide in advance whether the computer-executable instructions that comprise their software application programs will attempt to access data that is stored locally on the computing device on which such computer-executable instructions are executing, or whether they will attempt to access data that is stored remotely, such as on networked storage media. Different function calls and access methodologies are typically utilized by such developers depending on where the data that their application programs are attempting to access is stored.

Transparent access mechanism for local and remote data


Marksmanship training apparatus is used with air guns or weapons firing blank cartridges and comprises a housing member with an attached muzzle alignment tube for insertion into the bore of the barrel of the weapon and includes sealing apparatus around the muzzle alignment tube to minimize leakage of gas between the bore and the muzzle alignment tube and to prevent the gas from pushing the muzzle alignment tube out of the bore. The housing member includes a switch which is activated by the gas to complete an electrical circuit positioned in the housing to cause light energy to be emitted from the housing member.

1. Field of the Invention
The present invention relates in general to new and improved apparatus for use in marksmanship training. More particularly, but not by way of limitation, this invention relates to apparatus for removably mounting on small firearms and the like to project a beam of light onto the spot where the firearm is aimed at the time the firing mechanism of the firearm is activated.
2. Description of the Prior Art
It is well known that the best way to develop firearms marksmanship is actual firing at the target where the results are immediately visually perceptible. The firing of live ammunition is expensive, noisy, incurs certain risks and may just not be feasible in certain situations.
Various prior art devices have been devised which substitute the emission of light for the discharge of live ammunition to train one in the accurate aiming and firing of various types of firearms. Unfortunately, many of the prior art devices suffer from one or more major limitations. For example, many such devices are bulky, unwieldy and otherwise difficult to use. Many require modification of the firearm to accept the training device and render the firearm (at least temporarily) inoperative to fire live ammunition. None are known at this time which operate with air rifles or pellet guns.
Some of the prior art devices use laser implementation with their inherent dangers, particularly to eye damage. For example, U.S. Pat. No. 3,938,262 discloses a laser weapon simulator for firing a laser pulse in response to the firing of a blank cartridge. Pawls are attached to the housing of the simulator which is attached to the rifle by clamping onto the flash suppressor. U.S. Pat. No. 4,678,437 discloses a self-contained substitute cartridge which emits a pulse of light upon closure of a switch resulting from energy received from the firing pin of the firearm. U.S. Pat. No. 4,234,911 discloses an optical apparatus adapted for insertion into the open end of a hand-gun barrel. A piezoelectric crystal produces an output signal in response to the hammer impact to cause an LED to output a pulse of light. U.S. Pat. No. 3,367,516 discloses a radiant energy emitting unit for a cartridge cylinder of a revolver and an elongated lens tube adapted to be received within the barrel. U.S. Pat. No. 3,510,965 discloses an electrically actuated light bulb and focusing lens which inserts into the barrel of a revolver. When the trigger is pulled, the firing pin strikes the cartridge unit in the chamber for completing the electrical circuit.
This invention is intended to provide a solution to various prior art deficiencies which include the requirement to make a temporary modification of the weapon. Some prior art units use laser light with its inherent danger. The prior art does not provide for marksmanship training apparatus to be used with air rifles or pellet guns.


A method for estimating a fracture aperture in a formation penetrated by a well includes obtaining at least one of a vertical resistivity (Rv) and a horizontal resistivity (Rh) of the formation; obtaining a mud resistivity (Rmud) or a matrix resistivity (Rmatrix); and estimating the fracture aperture. The estimating of the fracture aperture may be performed by solving the following two equations:Rv=Vhf·Rm+(1−Vhf)·Rmatrix and 1/Rh=Vhf·1/Rmud+(1−Vhf)·1/Rmatrix,wherein Vhf is the fracture aperture.

1. Field of the Invention
The invention relates generally to oil and gas exploration, particularly to methods and systems for estimating fracture apertures in the formations and for assessing fracture aperture changes in response to well stress.
2. Background Art
Fractures in the formation may be storage sites for hydrocarbons or they may enhance permeability of formations by connecting pores that might contain hydrocarbons. Therefore, identification and characterization of fractures is an important part of formation characterization. Fractures are cracks or surface breakages within rocks. When there is relative movement (displacement) of the rocks across the fracture face, the fracture may be referred to as a fault or joint, depending on the relative movement. For convenience, "fracture" will be used in a general sense in this description to include fractures, faults, joints, or other similar geological features.
Locating the intervals where the borehole intercepts large and/or numerous fractures (e.g., fracture swarms) is important to characterize the fractured reservoir and to optimize completion and production operations.
Determining natural fracture aperture is also essential to estimate permeability in Fractured Reservoir Formation. In the case where fracture is the primary, or an important contributor, to the reservoir storage, natural fracture aperture is also essential to determine the formation porosity.
Various methods have been proposed to detect fractures and estimate their aperture from resistivity log (Sibbit and Faivre, 1985, "The Dual Laterolog Response in Fractured Rock," Transaction of SPWLA 26-th Annual Logging Symposium, 1985, Dallas, paper T), borehole image (Luthi and Souhaite, 1990, "Fracture aperture from electrical borehole scans," Geophysics, 1990, vol 55; Cheung and Heliot, 1990 "Workstation-based Fracture Evaluation Using Borehole Images and Wireline Logs," SPE 20573), and sonic measurement (Hornby and Johnson, 1986, Winkler K, Plumb R., "Fracture Evaluation using reflected Stoneley Wave arrivals," Geophysics, 1986, vol 54.).
Seismic data is commonly used for acquiring information about subsurface structures. Changes in the elastic properties of subsurface rocks appear as seismic reflections. Such changes in the properties of the rocks typically occur at boundaries between geologic formations, at fractures and at faults. For example, U.S. Pat. No. 3,668,619 describes the rotation of a logging tool having a single acoustic transducer that senses the reflected acoustic energy to detect fractures. U.S. Pat. No. 5,121,363 describes a method for locating a subsurface fracture based on an orbital vibrator equipped with two orthogonal motion sensors and an orientation detector.
Sonic measurements are sensitive to natural fractures (Hornby B. et al, 1986), but also to stresses and local borehole damage, making it difficult to use them systematically to quantify fracture characteristics.
In addition to seismic or sonic measurements, other measurements have also been used to locate fractures. For example, U.S. Pat. No. 4,802,144 uses the measurement of hydraulic impedance to determine fractures. U.S. Pat. No. 2,244,484 measures downhole impedance to locate fractures by determining propagation velocity. Resistivity tools are particularly useful in this regard. Similarly, U.S. Pat. No. 6,798,208, issued to Omeragic, which discloses a method for detecting a fracture in an earth formation using a propagation tool. The method includes the steps of producing electromagnetic fields using a transverse magnetic dipole (TMD) transmitter in the tool; measuring corresponding voltage signals detected with one or more TMD receivers in the tool; determining harmonics from the measured signal responses by shifting the responses (e.g. by 90 degrees) and performing an addition or subtraction using the shifted response.
Separation between shallow and deep laterolog readings has also been used as an indicator of natural fractures (Sibbit and Faivre, 1985). It is often used to help distinguish natural and induced fractures after those fractures have been picked on borehole image (Cheung and Heliot, 1990). However, this type of measurement does not provide any quantitative assessment of the fracture extent and aperture.
Borehole images allow one to identify, pick and characterize individual fractures as seen on the borehole wall. Techniques exist to quantify the aperture of each fracture based on the images (Luthi and Souhaite, 1990; Cheung and Heliot, 1990). However, those measurements have a very shallow depth of investigation, making it difficult to differentiate the natural fracture characteristics from the borehole damages.
The sensitivity of multi-component induction measurement to a fracture has been demonstrated by numerical modeling and field examples. (Wang et al. 2005) Discussion centers on the sensitivity of coplanar-coil (XX and YY) and co-axial-coil (ZZ) measurement to fractures. The numerical modeling is for one individual fracture, with application primarily to hydraulic fracture.
Because fractures often contain hydrocarbons, identification and quantification of the fractures in formations penetrated by a well can provide valuable information for optimal production of the wells. Therefore, it is desirable to have methods that can detect and quantify the presence of fractures.

Method and system to estimate fracture aperture in horizontal wells


Modulated signal A is transmitted from a first antenna, and modulated signal B is transmitted from a second antenna. As modulated signal B, modulated symbols S2(i) and S2(i+1) obtained from different data are transmitted at time i and time i+1 respectively. In contrast, as modulated signal A, modulated symbols S1(i) and S1(i)′ obtained by changing the signal point arrangement of the same data are transmitted at time i and time i+1 respectively. As a result the reception quality can be changed intentionally at time i and time i+1, and therefore using the demodulation result of modulated signal A of a time when the reception quality is good enables both modulated signals A and B to be demodulated with good error rate performances.

An example of a conventional communication method that uses multiple antennas is the communication method known as MIMO (Multiple-input Multiple-Output). In multi-antenna communication represented by MIMO a plurality of streams of transmit data are individually modulated, and each modulated signal is transmitted simultaneously from a different antenna, thereby increasing the data communication speed.
In this kind of communication method, the receiving side must separate and demodulate a plurality of modulated signals multiplexed together on the transmission path. Therefore, in communication using multiple antennas, demodulation precision has a major influence on the effective data transmission speed.
An example of a heretofore known technology that improves modulated signal reception quality on the receiving side and improves the effective data transmission speed when performing multi-antenna communication is a technique whereby space-time block codes are transmitted as described in "Space-Time Block Codes from Orthogonal Design" IEEE Transactions on Information Theory, pp. 1456-1467, vol. 45, no. 5, July 1999.
These space-time block codes will be explained briefly using FIG. 1. As shown in FIG. 1B, a transmitting apparatus has antennas 5 and 6, and transmits a signal simultaneously from each of antennas 5 and 6. A receiving apparatus receives the simultaneously transmitted plurality of signals with an antenna 7.
FIG. 1A shows the frame configuration of signals transmitted from antennas 5 and 6. A transmit signal A is transmitted from antenna 5, and at the same time, a transmit signal B is transmitted from antenna 6. Transmit signal A and transmit signal B are composed of symbol blocks in which the same symbols are placed a plurality of times so that coding gain and diversity gain are obtained.
This will now be explained in more detail. In FIG. 1A, S1 and S2 indicate different symbols, and complex conjugates are indicated by "*". In space-time block coding, at time i, symbol S1 is transmitted from first antenna 5 and symbol—S2* is simultaneously transmitted from second antenna 6, and then at time i+1, symbol S2 is transmitted from first antenna and symbol S1* is simultaneously transmitted from second antenna 6.
At antenna 7 of the receiving apparatus, a signal is received in which transmit signal A subjected to channel fluctuation h1(t) between antenna 5 and antenna 7, and transmit signal B subjected to channel fluctuation h2(t) between antenna 6 and antenna 7, are combined.
The receiving apparatus estimates channel fluctuations h1(t) and h2(t), separates the original transmit signal A and transmit signal B from the composite received signal by using those estimates, and then demodulates the symbols.
If space-time block coded signals are used at this time, when signal separation is carried out maximal-ratio combining of symbols S1 and S2 can be performed regardless of channel fluctuations h1(t) and h2(t), enabling large coding gain and diversity gain to be obtained. As a result, reception quality—that is, error rate performances can be improved.
As a different modulated signal is transmitted from each transmitting antenna in multi-antenna communication as described above, it is ideally possible for the data transmission speed to be increased by a factor equal to the number of antennas compared with a case where a modulated signal is transmitted from a single antenna. However, if the precision of separation and demodulation of the modulated signals is poor, the effective data transmission speed will decrease.
In contrast, when space-time block coding technology is used, the reception quality (error rate performances) of the modulated signal transmitted from each antenna can be improved, enabling a decrease in data transmission speed due to degradation of separation and demodulation precision to be suppressed.
However, a drawback with the use of space-time block coding technology is that, while reception quality (error rate performances) certainly improves, transmission efficiency decreases. That is to say, since S1* and—2* transmitted using space-time block coding are demodulated as S1 and S2 by the receiving apparatus, the same information is transmitted twice at time i and time i+1, and transmission efficiency decreases proportionally.
For example, in a general multi-antenna communication system, symbols S3 and S4 differing from symbols S1 and S2 are transmitted at time i+1, and therefore four symbols S1 through S4 can be transmitted in the period from time i to time i+1. That is to say, considered in simple terms, data transmission efficiency when using space-time block coding technology decreases to half that of general multi-antenna communication.

Transmitting apparatus, transmitting method, receiving apparatus and receiving method


A flywheel includes a wheel having a composite rim structure with multiple radial layers of steel material. Epoxy type adhesive can bond the multiple layers of stainless steel together.

Composite flywheels can include fibers, or filaments that are wound into a wheel and bonded together with adhesives. Such fibers can be metallic wires. The size, or speed of composite flywheels having metallic wires is typically limited to being relatively small, so that the wires and adhesive do not delaminate from each other.


Disclosed are devices and methods for loading an intrauterine device (IUD) with a thread or suture engaged therewith into an insertion device. The devices and methods are suitable for use with an automated knot tying system.

An intrauterine device (IUD) is an object that, when placed in the uterus of a female, acts as a birth control device to prevent pregnancy. Two types of IUDs are commonly available, copper-containing devices and hormone-containing devices that release a progestogen. Hormonal containing devices are considered to be a different form of birth control and may be distinguished in the literature by the term intrauterine system (IUS).
IUDs are typically inserted into the uterus using an insertion device or instrument. See, for example, U.S. Pat. No. 3,783,861 to Abramson for Inserter for Intrauterine Devices issued Jan. 8, 1974; U.S. Pat. No. 3,794,025 to Lerner for Intrauterine Device Saddle Inserter issued Feb. 26, 1974; U.S. Pat. No. 4,920,727 to Ristimaki et al. for Cassette System and Apparatus for Manufacturing an Active Agent Liberating Capsule for Subcutnaeous Use issued May 1, 1990; U.S. Pat. No. 4,949,732 to Spoon et al. for Apparatus for Insertion and Fixation of an Intra Uterine Contraceptive Device to the Uterine Fundus issued Aug. 21, 1990; U.S. Pat. No. 5,084,004 to Ranoux for Process for Intra-Uterine Fertilization in Mammals and Device for Implementation Thereof issued Jan. 28, 1992; U.S. Pat. No. 5,370,129 to Diaz et al. for IUD Inserting Apparatus issued Dec. 6, 1994; U.S. Pat. No. 5,400,804 to Helle et al. for Method and Equipment for Installing a Medicine Capsule on a Support issued Mar. 28, 1995; U.S. Pat. No. 5,785,053 to Macandrew et al. for Inserter for the Positioning of an Intrauterine Device issued Jul. 28, 1998; and US 2013/0014762 A1 to Deckman et al. for Intrauterine Systems, IUD Insertion Devices, and Related Methods and Kits Therefor published Jan. 17, 2013.
During manufacturing of the system various challenges arise loading a threaded IUD into the distal end of the IUD insertion device such that the IUD is ready for deployment during use.

IUD loading devices and methods for inserting an IUD into an insertion device


A method for hydraulic fracturing subterranean formation whereby at least part of the fracture is propped with proppant material essentially in the form of elongated particles having a shape with a length-basis aspect ratio greater than 5, preferably such as metallic wire segment. The remaining part of the fracture may be propped with conventional non-metallic proppant. Fracture conductivity is optimized.

This invention relates generally to the art of hydraulic fracturing in subterranean formations and more particularly to a method and means for optimizing fracture conductivity.
Hydraulic fracturing is a primary tool for improving well productivity by placing or extending channels from the wellbore to the reservoir. This operation is essentially performed by hydraulically injecting a fracturing fluid into a wellbore penetrating a subterranean formation and forcing the fracturing fluid against the formation strata by pressure. The formation strata or rock is forced to crack and fracture. Proppant is placed in the fracture to prevent the fracture from closing and thus, provide improved flow of the recoverable fluid, i.e., oil, gas or water.
The proppant is thus used to hold the walls of the fracture apart to create a conductive path to the wellbore after pumping has stopped. Placing the appropriate proppant at the appropriate concentration to form a suitable proppant pack is thus critical to the success of a hydraulic fracture treatment.
Sand, resin-coated sand, and ceramic particles are the most commonly used proppants, though the literature, for instance U.S. Pat. No. 4,654,266, also mentions the used of walnut hull fragments coated with some bonding additives, metallic shots, or metal-coated beadsxe2x80x94nearly spherical but having a passageways to improve their conductibility.
The proppant conductivity is affected principally by two parameters, the proppant pack width and the proppant pack permeability. To improve fracture proppant conductivity, typical approaches include high large diameter proppants. More generally, the most common approaches to improve proppant fracture performance include high strength proppants, large diameter proppants, high proppant concentrations in the proppant pack to obtain wider propped fractures, conductivity enhancing materials such as breakers, flow-back aides, fibers and other material that physically alter proppant packing, and use of non-damaging fracturing fluids such as gelled oils, viscoelastic surfactant based fluids, foamed fluids or emulsified fluids. It is also recognized that grain size, grain-size distribution, quantity of fines and impurities, roundness and sphericity and proppant density have an impact on fracture conductivity.
As mentioned above, the main function of the proppant is to keep the fracture open by overcoming the in-situ stress. Where the proppant strength is not high enough, the closure stress crushes the proppant, creating fines and reducing the conductivity. Sand is typically suitable for closure stresses of less than about 6000 psi (41 MPa), resin-coated sand may be used up to about 8000 psi (55 MPa). Intermediate-strength proppant typically consists of fused ceramic or sintered-bauxite and is used for closure stresses ranging between 5000 psi and 10000 psi (34 MPa to 69 MPa). High-strength proppant, consisting of sintered-bauxite with large amounts of corundum is used at closure stresses of up to about 14000 psi (96 MPa).
Permeability of a propped fracture increases as the square of the grain diameter. However, larger grains are often more susceptible to crush, have more placement problems and tend to be more easily invaded by fines. As the result, the average conductivity over the life of a well may be actually higher with smaller proppants.
In an effort to limit the flowback of particulate proppant materials placed into the formation, it was disclosed in U.S. Pat. No. 5,330,005 to add some fibrous material, mixed with the proppant material. It is believed that the fibers become concentrated into a mat or other three-dimensional framework, which holds the proppant thereby limiting its flowback. The fibers can be of glass, ceramic, carbon, natural or synthetic polymers or metal fibers. They have a length of typically about 2 to 30 mm and a diameter of between 10 and 100 micrometers. According to U.S. Pat. No. 5,908,073 the flowback is prevented through the use of fibrous bundles, made of from about 5 to about 200 individual fibers having lengths in the range of about 0.8 to about 2.5 mm and diameters in the range of about 10 to about 1000 micrometers. It has also known from U.S. Pat. No. 6,059,034 to add to blend the proppant material with a deformable particulate material. The deformable particles may have different shapes such as oval, cubic, bar-shaped, cylindrical, multi-faceted, irregular, taperedxe2x80x94but preferably with a maximum length-based ratio equal or less than 5, and are typically spherical plastic beads or composite particles comprising a non-deformable core and a deformable coating. In another embodiment claimed in U.S. Pat. No. 6,330,916, the particles may comprise ground or crushed materials such as nutshells, seed shells, fruit pits, and processed woods.
It should be emphasized that in all of the four above-mentioned U.S. Patents, the proppant itself is constituted of essentially spherical particlesxe2x80x94most typically sandxe2x80x94intermingled with a material that may be elongated. This reflects the general understanding of this art that angular grains fail at lower closure stresses, producing more fines and thus reducing fracture conductivity. On the other hand, round and uniform-sized grains result in higher loads before failure since stresses are more evenly distributed.
Adding fibers or fiber-like products to the products may contribute to a reduction of the proppant flowbackxe2x80x94and consequently to a better packing of the proppant in the fracture. Additionally, they contribute to prevent fine migrations and consequently, to prevent a reduction of the proppant conductivity but there is still a need for a new type of proppant that will lead to higher conductivity.
It is therefore an object of the present invention to provide a new type of proppant and improved methods of propping a fracturexe2x80x94or a part of a fracture like for instance the extremity of the fracture closer to the wellborexe2x80x94whereby the proppant conductivity is improved and thus, the subsequent production of the well.
According to the present invention, a fracture is propped at least partially with a proppant consisting of an elongated particulate material, wherein individual particles of said particulate material have a shape with a length-basis aspect ratio greater than 5, and consists for instance of short metal wire segments for example.
Advantageously, the invention is compatible with techniques known to enhance proppant conductivity such as the use of conductivity enhancing materials (in particular the use of breakers) and the use of non-damaging fracturing based fluids such as gelled oils, viscoelastic surfactant based fluids, foamed fluids and emulsified fluids.
Another feature of this invention is that imaging the fracture geometry is substantially improved when these elongated particulate proppants are metallic or have some metal content. Tools such as resistivity tools, electromagnetic devices, and ultra long arrays of electrodes, can easily detect this proppant enabling fracture height, fracture width, and with processing, the propped fracture length to some extent can be determined.

Conductive proppant and method of hydraulic fracturing using the same


A method of installing a security system includes placing a security device at an installation location. An air-borne signal is transmitted to the security device. An indication of a quality of the signal as received by the security device is displayed on the security device.

1. Field of the Invention
The present invention relates to surveillance systems including wireless security devices, and, more particularly, to the installation of surveillance systems including wireless security devices.
2. Description of the Related Art.
Surveillance systems, also known as security systems, are known to include wireless security devices, such as wireless motion detectors, wireless door sensors, wireless window sensors, wireless smoke detectors, etc., for monitoring a secured area of space. The wireless devices each bi-directionally communicate with a central controller via radio frequency (RF) signals or some other type of wireless and/or air-borne signals. Obviously, the performance of the security system is largely dependent upon each of the wireless security devices having strong reception of the RF signals transmitted by the central controller to the wireless security devices. Thus, each wireless device in use by a security system must be installed at a location where such strong RF signal reception is possible. That is, the wireless devices must be installed at locations that are free of electromagnetic shielding and other conditions that may cause poor radio frequency reception.
The identification of locations that yield good radio reception involves some trial and error. Typically, the central controller is installed at a location that is convenient for the user, and the wireless devices are mounted at locations where the detection of intruders is needed. Although some consideration may be given to the RF reception between the central controller and the wireless devices, the detection of intruders is the primary factor in deciding where to mount the wireless devices. After the wireless devices have been mounted, the installer walks to the central controller and operates the system in order to determine, among other things, whether the RF reception of the wireless devices at the mounting locations is acceptable. If not, the wireless devices are relocated and the process is repeated until an acceptable level of RF reception by the wireless devices is achieved. A problem with this approach is that mounting the wireless devices, even temporarily, is time consuming and typically requires holes to be drilled in the walls. Thus, each time a wireless device is relocated, the holes and other wall damage from a previous mounting must be repaired. Another problem is that the installer must return to the central controller each time the RF reception at a new location of a wireless device is to be tested. The walking back and forth between the relocated wireless-devices and the central controller is a time-consuming aspect of the installation of the surveillance system.
Another problem is the adequacy of the location of the central controller for RF communication with mobile wireless devices, such as panic devices and keyfobs, is rarely tested. Such testing would require a first installer to walk around the premises while activating the mobile wireless device, and a second installer to man the central controller and monitor the changing quality of RF reception. Thus, the location of a central controller is typically chosen for the convenience of the user without any testing of its suitability for RF reception.
What is needed in the art is a method of installing a wireless security system without the installer having to mount the wireless devices on walls in order to test the RF reception of the wireless devices at the mounting locations. What is also needed is a method of installing a wireless security system without the installer having to repeatedly walk between the mounting locations and the central controller in order to test the RF reception of the wireless devices at the mounting locations. What is further needed is a method of easily testing the RF reception characteristics of a location of a central controller.

Method of installing a wireless security system


A retrofit heat pump system for a water heater is disclosed. The heat pump system includes a plurality of evaporators to increase the efficiency of heat exchange for the system. The system can also include a plurality of condenser circuits used to heat the water of an existing water tank. A fan disposed in a housing of the heat pump system can draw air across the plurality of evaporators and exhaust cool air external to the heat pump system. The cool air can be exhausted into duct work associated with an air conditioning system of the home. The disclosure also describes a refrigerant distributor for providing uniform liquid refrigerant to the plurality of evaporators.

Efficiency ratings have always been a main concern for water heater manufacturers. One reason for this can be attributed to the fact that the water heater is the second-most energy consuming appliance in a typical household, trailing only the heating and air conditioning system in the home. A hybrid heating system has been developed recently that aims to increase the efficiency of the system without compromising the heating efficiency and recovery time of the water heater. The hybrid system includes a traditional water tank, which can be either electric- or gas-powered, and an additional heat pump combined within a single system. The two systems (i.e., traditional heating and heat-pump heating) can work in tandem and adjust according to water heating needs. For example, the heat pump is highly efficient and can be used in an energy saving application. Electric or gas heating elements are less energy efficient but provide a great amount of heat. The two can be used at the same time to reduce recovery time when hot water is in highest demand.
The traditional hybrid system has a number of limitations regarding its ability to be widely adopted, however. First, gas-powered hybrid systems are not a universal solution for energy efficient water heating, because many localities have enacted regulations that ban the use of gas water heaters. As the reduction of greenhouse gas emissions becomes more of a concern over time, the use of gas-powered water heaters may become less prevalent.
Second, electric water heaters require a large power load to heat the heating elements within the water heating tank. Because of this, the water heater is connected to a 240V power supply to provide the power needed to heat the water. Typical hybrid system shares a common power supply, meaning the heat pump system also runs on 240V power supplies. Requiring a 240V power supply is also not optimal for widespread use.
Third, the hybrid system does not provide a solution for consumers that do not wish to purchase an entire water heating unit. Stated otherwise, a customer may to wish to increase the efficiency and/or heating capacity of their existing unit without having to purchase a new appliance. What is needed, therefore, is a system that can work with both gas and electric water heaters, that runs efficiently with a limited power load, and that can be used as a retrofit application to add heating capacity to existing water heaters, either at the manufacturer level by adding the system to existing designs or at the customer level by retrofitting an already-installed water heater.

Retrofit heat pump water heating systems


A method and superalloy component for depositing a layer of material onto gas turbine engine components by atomic layer deposition. A superalloy component may have a ceramic thermal barrier coating on at least a portion of its surface, comprising a superalloy substrate and a bonding coat; and aluminum oxide (Al2O3) layer may be deposited on top of an yttria-stabilized zirconia layer and form a bonding coat by atomic layer deposition. The yttria-stabilized zirconia layer may have a plurality of micron sized gaps extending from the top surface of the ceramic coating towards the substrate and defining a plurality of columns of the yttria-stabilized zirconia layer. Also, atomic layer deposition may be used to lay an aluminum oxide (Al2O3) layer over a tantalum oxide (Ta2O5) layer on a silicon-based substrate. Using atomic layer deposition to coat the gas turbine engine components permits conformal coating of the columnar surface to permit gap expansion and contraction without sintering of the columnar surface or spalling of the coating, and form an oxidation resistant bonding coat.

This invention relates generally to thermal barrier and environmental barrier coatings for metallic and ceramic substrates and in particular to thermal barrier coatings and environmental barrier coatings that are resistant to sintering and oxidation damage for components in gas turbine engines.
As gas turbine engine technology advances and engines are required to be more efficient, gas temperatures within the engines continue to rise. However, the ability to operate at these increasing temperatures is limited by the ability of the superalloy turbine blades and vanes to maintain their mechanical strength when exposed to the heat, oxidation, and corrosive effects of the impinging gas. One approach to this problem has been to apply a protective thermal barrier coating (TBC) or environmental barrier coating (EBC) which insulates the blades and vanes from higher gas temperatures and hot gas corrosion, and to apply an interfacial bonding coat between the thermal barrier coating and the substrate to inhibit oxidation. The TBC for metallic substances typically consists mainly of ZrO2 ceramic, which is known to have low thermal conductivity and therefore reduces the substrate temperature under gas turbine engine operating conditions. Typically, the ZrO2 ceramic TBC contains additives to stabilize the crystalline structure and prevent the phase transformation as the TBC goes through temperature cycles. The most common additive for stabilizing the zirconia is Y2O3.
For high performance turbine blade and vane applications where the surface finish and lifetime of the coating are important, Electron Beam Physical Vapor Deposition (EBPVD) TBC is often used to coat substrates. Furthermore, to have low thermal conductivity, it is desirable that the TBC contains pores or other microstructure features that can scatter phonons. Typically, the EBPVD TBC will have an outer ceramic layer that has a columnar-grained microstructure. Gaps between the individual columns allow the columnar grains to expand and contract without developing stresses that could cause spalling. Strangman, U.S. Pat. Nos. 4,321,311; 4,401,697: and 4,405,659, discloses a thermal barrier coating system for a superalloy substrate that contains a MCrAlY layer, an alumina layer, and an outer columnar-grained ceramic layer. Duderstadt et al., U.S. Pat. No. 5,238,752 and Strangman, U.S. Pat. No. 5,514,482 disclose a thermal barrier coating system for a superalloy substrate that contains an aluminide layer, an alumina layer, and an outer columnar-grained ceramic layer.
A problem with columnar-grained ceramic layers is that when exposed to temperatures over 1100 degrees C. (2012 degrees F.) for substantial periods, sintering of the columnar grains occurs. As the columnar grains undergo thermal expansion, the columnar grains impinge upon each other. The gaps between columnar grains close as adjacent, columnar grains bond together from sintering. Once the gaps become closed, the ceramic layer can no longer accommodate the thermal expansion and may spall or crack. The same problem also exists in plasma sprayed TBC, in which the pores and gaps in the typical laminar structure are sintered at use temperatures. In addition, sintering of the TBC increases the thermal conductivity of the coating, which is undesirable, since the thermal insulation property of the coating degrades and the temperature in the substrate increases. Frequent maintenance of turbine components is required due to the tendency for sintering of the TBC which causes the TBC to spall or crack and increase thermal conductivity. Conventionally, after about 100 cycles, turbine components must be removed to blast away the TBC or the EBC and then the turbine component is coated again. If a coating could be made more resistant to spalling, cracking and increases in thermal conductivity, then costly disassembly and maintenance may be minimized.
There have been attempts in the prior art to solve the problem of sintering of columnar grains in the EBPVD TBC or pores and gaps in the plasma-sprayed TBC. For zirconia-based TBC, one of the methods is to incorporate a material such as Al2O3 into the gaps or on the columnar grain surface. In principle, the existence of alumina in the gap or on the grain surface inhibits the sintering of the columnar grains, and can extend the lifetime of the EBPVD or plasma sprayed TBC. However, coating methods in the manner of the prior art tend to produce a coating that does not conform to the topography of the columnar grains. Instead, the coating adheres to only the top surface of the columnar grains. This can significantly reduce the effectiveness of the sintering inhibiting property of the coating. Another problem associated with the prior art coating on the top portion of the TBC is the thermal expansion and modulus mismatch created by the inhomogeneous distribution of the coating, which can shorten the bonding life of the TBC on the substrate.
Another major problem with a common TBC, such as a TBC containing ZrO2, HfO2 and Ta2O5, is poor oxidation barrier properties. These materials have the strong tendency to be in non-stoichiometric quantities with oxygen deficient structure. With the inherent high oxygen vacancy concentrations in these materials, oxygen atoms can move rapidly inside the materials. As a result, oxygen atoms, ions and molecules can diffuse easily from the environment through the TBC down to the bonding coat region, and attack the bonding coat and substrate underneath. Because of this poor oxygen diffusion barrier property, a TBC containing ZrO2, HfO2, or Ta2O5 is not effective at all in protecting the substrate from oxidation at high temperatures. Because of this problem, the substrate needs to be protected from oxidation by a bonding coat, such as alumina, platinum, platinum aluminide, and the like. However, even the bonding coat cannot sustain the oxidation attack for long, and a common failure mechanism of TBC is directly due to the formation and growth of thermally grown alumina due to oxidation at the interface between the substrate and the TBC.
The prior art is not specifically intended for high performance applications under extreme conditions, and some suffer from one or more of the following disadvantages:                a) non-conformity of coating layers.        b) inability to sustain high temperature conditions.        c) increased spalling and cracking.        d) subject to excessive oxygen diffusion.
As can be seen, there is a need for an improved apparatus and method for turbine components comprising inorganic layers applied to ceramic layer coatings that are resistant to sintering, conform to columnar grain topography, withstand higher temperatures and extreme conditions, resistant to oxygen diffusion, and minimize spalling and cracking.

Atomic layer deposition for turbine components


A system for managing an insurance scheme includes a calculation module to, on the occurrence of an insured event for an insured person, calculate a subsidy for expenses for the insured person or a nominated beneficiary. The subsidy is calculated by accessing data defining a plurality of categories of expenses and determining for each category a spend amount. The spend amount is either an average historical spend amount over a period of time prior to the insured event or an actual spend amount for a period of time after the insured event. A percentage is then calculated using the insured person's participation with a wellness program. Finally, the amount of the subsidy is calculated by multiplying the percentage by the spend amount. A payment module effects payment of the subsidy to the insured person, the nominated beneficiary or a third party goods or services provider.

The present application relates to a system and method of managing an insurance scheme.
The present invention may be implemented by a traditional life insurance plan operator for its members or may be implemented by another party.
Conventionally, insurance policies such as life insurance policies operate on the basis that an insured person, sometimes referred to as an insured life, pays a premium to the life insurer, and the life insurer pays a predetermined sum, referred to as the sum assured, to the insured life or his/her beneficiary on the occurrence of an insured event. Typical insured events are the insured life suffering disability, contracting a dread disease or dying.
However, it will be appreciated that the processing and finalising of the payment can take some time, in some cases up to several months or even years. In this instance the insured person may have short term financial difficulties if they are dependent on this payment.
A system and method of addressing this is therefore required.

This patent is subject to a terminal disclaimer.

System and method of managing an insurance scheme


A cutter blade (17) for a finger joint cutter head (10) which includes a cantilevered cutting tip attachment. A cantilever pocket (20) is formed in the fillet area of steel backing member (18) to receive and hold the inner end of a hard material cutting tip (19), such as tungsten carbide. Cantilever pocket (20) has tapered sides which diverge outwardly and a rounded vertex or pocket bottom. Cutter tips are elongated to extend well into cantilever pockets (20). Each cutter tip is attached within a pocket (20) and along the joint surface of steel backing members (18), using a sandwich braze, to form braze joints (21) and (22).

1. Technical Field
This invention generally relates to finger joint cutter heads which are mounted on a rotatable shaper spindle, such that the cutter head cuts finger joints in the edges of wood products for joining two such products together. More particularly, this invention relates to a cutter blade for use in a finger joint cutter head. Cooperating finger joint cuts are used to join two pieces of material, generally wood, together to form one continuous larger piece. Finger joint cutting is an economical process to produce a long piece from a number of short pieces by providing matching or cooperating surfaces at the ends of the pieces which can be fitted together and glued.
2. Background
U.S. Pat. No. 3,951,189 to Cromeens, incorporated herein by reference, discloses an apparatus for carrying out this process. Generally, a finger joint cutter head is mounted on the spindle of a shaper apparatus through which the shorter pieces of material are fed.
U.S. Pat. No. 5,005,619 to Jensen, also incorporated herein by reference, discloses the details of the construction of several cutter heads. Generally speaking a plurality of individual claw-shaped cutter blades are stacked one on top of another to form cutter blade assemblies which in turn are annularly secured via bolts between the top and bottom plate of the cutter head. The top and bottom plates are attached in parallel spaced relation to an arbor collar. The top and bottom plates extend radially outward from the arbor collar.
Initially, the individually cutter blades were simply machined from a high speed tool steel. The actual cutting surface or tip was simply a ground surface of the tool steel. These blades had a very limited life and had to be regularly sharpened because of the high speed, high temperature and abrasive nature of their use.
In response to this problem, harder cutting surfaces or tips, such as tungsten carbide, were attached to the cutter blade to serve as the actual cutting surface. FIG. 2 of the drawings illustrates this prior art cutter blade, generally designated as one. Prior art cutter blade 1 has a high speed tool steel backing 2 to which carbide tip 3 is attached via a silver alloy braze joint 4, or other suitable attachment mechanism. As can be seen from FIG. 2, the innermost end of carbide tip 3 is rounded to mate with the fillet on backing 2. This cutter blade configuration represents the current state of the art.
While this cutter blade demonstrates tremendous improvement over the previous all steel cutter since it does not require the frequent resharpening, it is still prone to failure. Because of the different expansion coefficients of the carbide material and steel backing, a carbide tip must be carefully attached to the steel backing. This is especially true since heat is generally used to accomplish the attachment process, as in brazing or welding. Currently, a copper strip which is clad on both sides with a silver alloy braze material is used to bond the carbide tip to the steel backing. This so called "sandwich" braze helps prevent bond failure or cracking of the carbide as the two distinct materials are cooled at the end of the brazing process. The copper strip acts as a mechanical stress buffer.
As can readily be seen from FIG. 2, the area of carbide tip 4 which is actually bonded to steel backing 2, this surface of the backing member is hereinafter referred to as the cutter tip attachment surface, is approximately equal or slightly greater than the actual cutting surface presented by the blade. This is unfortunate in that virtually all of the force generated during cutting is transferred through the braze joint to steel backing 2. This fact, when coupled with the high temperatures generated during the cutting process, results in an unacceptably high failure rate of the cutter blades.
What is needed is a cutter blade for finger joint cutting which does not require frequent sharpening and which prolongs the life of the cutter blades. It is, therefore, an object of this invention to provide a carbide tipped, or other hard material tipped, finger joint cutter blade which is not as susceptible to failure.


A method, apparatus and system for fusing real-time ultrasound images with pre-acquired medical images are described.

Various types of medical imaging modalities are available to the diagnostician and medical practitioner. These modalities each have comparative benefits and comparative drawbacks in different applications. So, one modality may be useful for one type of testing or one aspect of imaging, and another modality may be useful for another type of testing or imaging aspect. As such, there it is often the case that more than one imaging system may be used in medical imaging for the purposes of diagnosis, or treatment, or both.
One useful type of medical imaging involves spin-resonance imaging known commonly as magnetic resonance imaging or MRI. MRI imaging devices have evolved significantly and now provide real-time scanning with excellent resolution and detail. Often, MR scanners provide a plurality of 'two-dimensional' images, or image slices, which can be examined directly, or may be reconstructed using suitable reconstruction software (e.g., a graphic user interface (GUI)) to replicate a three dimensional image on a two-dimensional display.
While MRIs provide excellent imaging capabilities, invasive testing during MRI scanning can be complicated and expensive. For example, in many cases, it is useful to obtain a tissue sample via a procedure known as a biopsy. Unfortunately, while the resolution and real-time imaging provided by the MRI is useful in properly identifying a region of tissue to sample, biopsy procedures would take a great deal of time using the MRI modality. This translates directly into increased patient cost.
Ultrasonic imaging is another useful modality for medical testing in imaging. Ultrasound (US) imaging, among other benefits, allows for comparatively fast imaging, fostering in-situ testing (e.g., biopsy testing) and treatment. While US image resolution has greatly improved, it remains inadequate for certain testing and treatment procedures.
There is a need, therefore, for a method, apparatus and system that overcome at least the shortcoming of known imaging devices and methods discussed above.

System and method for fusing real-time ultrasound images with pre-acquired medical images


A water jet mechanism with composite control light-emitting modules, particularly a car water jet mechanism equipped with multiple light-emitting configurations for optional switching control, the base comprising a front assembly unit for installing the water jet assembly; a rear assembly unit, providing at least two accommodating grooves, each installed with a light-emitting member, in electrical connection with a module option control that supplies power for driving control, the module option control is optionally controlled to drive two light-emitting members to independently light or flash, or both simultaneously, to obtain single-color light or multiple-color decoration and enhancement of driving safety, and alarm effect by flashing lights.

A conventional water jet mechanism for cars generally involves the installation of a water jet assembly or valve in a casing, whereby a motorist switches on or off the water jet mechanism to spray water or a cleaning liquid onto a windshield, and a wiper moves to brush off dirty matter from the windshield. In other words, the conventional water jet mechanism has only a liquid spraying function. But, the water jet device is located at an engine hood that has the best position for front vision. Mere liquid spraying function could not develop full and effective utilization, such as identification of a driving vehicle, an emergency alarm signal, or such effects.
Another type of light-emitting water jet mechanism for cars has been disclosed in Taiwan Patent No. 454725 and U.S. Pat. No. 6,305,618, wherein;
The water jet mechanism for cars disclosed in Taiwan Patent No. 454725 relates to a depressed groove at a front of a ball valve of a fixing unit, inside the depressed groove being a flattened water jet hole, at two ends of the depressed groove being semi-circular flap blocks, thereby using a U-shaped regulator of the depressed groove and the flap blocks inserted and rotated to adjust the direction of jet, and the flattened water jet hole to obtain a larger area of water jet area, and at a rear of the fixing unit being an LED alarm lamp, emitting light to serve as a safety enhancement and a beautiful decoration; in such a structure, however, though an LED lamp is installed, it give out a single-color light that flashes on and off, serving as mere a decoration. Because the luminosity of the LED lamp is quite limited, its mere light provides inconspicuous effect as an alarm signal.
The water jet mechanism disclosed in U.S. Pat. No. 6,305,618 relates to a spray nozzle installed at a rear end of a transparent base, at a front end of the base being a lighting component, which lights on during the spraying process or when the cleaning liquid is used out; such structure and its operation only when a spray liquid is used out has merely an indicative function advising the user of water spraying function and when the liquid needs topping up, it does not has the function of alarm to alert the motorist or other people beside him of an immediate emergency situation, or the function for enhancing driving safety during nighttime.
The present invention of water jet mechanism with composite control light-emitting modules has a base comprising of a front assembly unit for assembling a water jet assembly; a rear assembly unit providing at least two accommodating grooves, each accommodating a light-emitting member, and a module option control electrically connected to supply power and enable activation, thereby the user operates the module option control to drive two light-emitting members to independently or simultaneously emit light at the rear end of the water jet mechanism, creating a regular light, or colorful lights flashing on and off; which serves as an alarm signal in times of emergency, or a signal to enhance driving safety during nighttime, or a decorative article.

Water jet mechanism with composite control light-emitting modules


A tension roller assembly includes a tension roller, a pivotable support arm, a tension arm, a compression spring, a rod, first and second spring stops, a mounting plate, and an overcenter assembly connected to an end of the tension arm. The overcenter assembly connects the tension arm to the mounting plate. The overcenter assembly is configured to make a pivoting movement over a pivot trajectory between engaged and disengaged positions. The overcenter assembly further has a center position located between the engaged and disengaged positions. The pivot trajectory between the center position and the disengaged position is divided into a tensioned section in which the end stop does not engage the stop surface and the spring exerts a force on the overcenter assembly, and a free-moving section in which the end stop engages the stop surface and the spring does not exert any force on the overcenter assembly.

Belt drives comprising tension rollers for providing tension to the belt have been known for a long time and the application of such belt drives in combine harvesters has also been known for a long time. These belt drives are used to drive the threshing drum of a combine harvester. The threshing drum beats the cut crops to break the crop, and subsequently shakes the grains away from their stalks.
GB1480566, U.S. Pat. No. 3,550,463 and U.S. Pat. No. 4,324,552 disclose earlier concepts of such belt drives including tension rollers.
Apart from the tension roller assemblies disclosed in GB1480566, U.S. Pat. No. 3,550,463 and U.S. Pat. No. 4,324,552, the present applicant currently manufactures a further version of a tension roller assembly. The tension roller assembly is in particular used for a combine harvester having twin rotors, and a dynamic feed roll. The dynamic feed roll is a drum which removes stones and accelerates the crop into the twin rotors. This tension roller assembly is further elucidated in the figures and the description of the present document.
The belt drive of the currently manufactured system has two gear ratios, one for low speed operation and one for high speed operation of the rotating drum. This is required because a combine harvester should be able to harvest different crops having different characteristics. To this end, the rotating drum should be able to rotate at two different speeds.
The currently manufactured system has two gear ratios which are formed by two different driven pulleys of the belt drive, i.e. a driven pulley with a small diameter for the high gear ratio and a driven pulley with a large diameter for the low gear ratio. This allows the belt drive to be operated at two different speeds having two different maximal torques. Because the driven pulleys have different diameters, each gear ratio requires its own belt of a required length. When switching gear ratios, the user also has to exchange one belt for the other belt.
In order to switch gear ratios, it is a requirement to be able to remove the tension from the belt by disengaging the tension roller from the belt. This is also necessary in case of replacement of a damaged or worn-out belt. To this end, the tension roller is incorporated in a tension roller assembly which allows for a movement of the tension roller between an engaged position and a disengaged position from the belt. A spring, generally a compression spring, provides the tension of the roller onto the belt.
The currently manufactured system is equipped with a tension roller assembly having an overcenter assembly which allows the tension roller to be moved between the engaged position and the disengaged position. The current tension roller assembly comprises a support arm which supports the tension roller. The tension roller assembly further comprises a tension arm which is connected to the support arm at one end. The tension arm is connected to a frame at the other end via an overcenter assembly. The overcenter assembly is pivotably mounted to the frame.
When the tension roller is moved from the engaged position to the disengaged position, it has to move beyond the center position of the overcenter assembly. During the movement from the engaged position to the center position, the spring is further compressed, and the movement is therefore carried out against the compression force of the spring. When the overcenter assembly passes the center position, the spring starts to extend and during a further movement from the center position to the disengaged position, the pulley is retracted from the belt, thereby relieving the belt from its tension.
The system which is currently manufactured has a number of drawbacks.
First, the system is relatively unpractical for a user who wishes to switch the tension roller assembly between the engaged position and the disengaged position. The rotation of the overcenter assembly between the engaged position and the disengaged position is carried out under the force of the spring, and the spring force may be rather high. This results in a strong force on the user. The rotation is generally carried out with a wrench. Because of the high spring force, the hand of the user may get stuck between the wrench and the machine. In extreme cases, this may even lead to an injury of the user.
Further, the present assembly has relatively little room for the belt to be removed from the belt drive when the tension roller is in the disengaged position. This is a result of the specific configuration of the present assembly. The limited space makes it difficult for a user to exchange one belt for the other belt.
Further, during operation the belt generally stretches somewhat as a result of pulling forces. The stretching results in an extension of the spring which pushes the tension roller against the belt. The stretching may become particularly large when large, unevenly distributed packages enter the combine, causing high torque peaks on the belt drive.
The stretching in turn results further inward position of the tension roller, caused by an extension of the spring. The extension of the spring results in a lower spring force and a lower force exerted by the tension roller and thus, in a lower tension of the belt. This lowers the torque which can be applied by the belt drive and results in earlier slipping of the belt and, eventually, blockage of the dynamic feed roller.

Tension roller assembly for a belt drive


In a fast response time pipelined data processor, an interrupt control device stores the interrupt service routine address or the target address of a branch instruction, as applicable, in a register. If an interrupt occurs while the pipelined data processor is processing a branch instruction, the branch instruction target address stored in the register is used as the return address, and is stored in a working space, so that the interrupt can be processed immediately. Similarly, if an interrupt occurs while the pipelined data processor is processing a prior interrupt or exception, and the first instruction of the interrupt service routine of the previous interrupt has not yet reached the memory access stage, the interrupt service routine as address of the previous interrupt stored in the register is used as the return address, and is stored in the working space, so that the next interrupt can be processed immediately.

An interrupt is an important channel of communication between a data processor and its associated external devices. In many data processing systems, the data input and output is achieved through interrupts. In a real time and embedded system, there is a critical need for very fast response times to incoming interrupts. In industrial applications such as aviation, automation control, and biomedical monitoring systems, the central processing unit (CPU) must have a very fast response time control mechanism, in order to process any type of emergency interrupt in a timely fashion, so as to avoid tragic consequences.
For example, in the general prior art, the pipelined data processor can be divided into five stages:
1) instruction fetch (IF), PA1 2) instruction decode and operand fetch (DI), PA1 3) instruction execution (EX), PA1 4) memory access (MA) PA1 5) write back (WB). PA1 otherwise, storing a first return address of a first interrupt or exception at the first part of the working space, PA1 b) fetching a service routine starting address of the first interrupt/exception and executing a first instruction of the service routine at the starting address, PA1 c) completing the execution of the first interrupt/exception service routine, and PA1 d) returning to either the target address of the branch instruction or the first interrupt/exception starting address, whichever address having been previously stored in the first part of the working space. PA1 a) storing the fetched first interrupt/exception service routine starting address in temporary storage in the pipelined processor, PA1 b) if a second interrupt/exception occurs with a higher priority than the first interrupt/exception, and the first instruction of the first interrupt/exception service routine has not reached the instruction boundary, fetching the first instruction of the first interrupt/exception service routine from temporary storage and storing it in a second part of the working space, or PA1 c) when the first instruction of the first interrupt/exception service routine has reached the instruction boundary, storing the return address of the second interrupt/exception service routine at the second part of the working space, PA1 d) fetching a starting address of the second interrupt/exception service routine and executing the second interrupt/exception service routine, and PA1 e) returning to either the first interrupt/exception starting address or the second interrupt/exception starting address, whichever address having been previously stored in the second part of the working space, after completing execution of the second interrupt/exception service routine.
The pipelined data processor usually has to meet the requirement of "precise interrupt" in processing interrupt requests. That is, when there is an interrupt, the save state and the state of normal execution of the processor must be the same. To meet this requirement, a prior art processor will process an interrupt only at the boundary of an instruction, so that the instruction is either completely executed, or not executed at all. To simplify this type of processor design, those exceptions which are generated by memory access (stage 4) are not processed, so that the time for processing interrupt requests is after the execution stage (stage 3), and before the write back stage (stage 5). Nevertheless, it is also possible to process interrupt requests at different stages, depending on the designer's choice and the processor type.
The pipeline stages of a typical prior art processor are discussed herein to show the disadvantages of this kind of interrupt processing design. The instruction fetch (stage 1) is assumed to require one clock cycle. Also, the method of processing interrupts is assumed to be similar to that of the trap type exception, which requires that the trap instruction be retired before the processor state is stored. Or, if the method of processing interrupts is assumed to be similar to that of the fault type exception, where the fault instruction is discarded before the processor state is stored, there will be further disadvantages, as discussed below.
FIG. 1 shows a program fragment sample, and FIG. 2 depicts the timing relationship of the program fragment sample during a pipelined execution. If I.sub.1 in FIGS. 1 and 2 is assumed to be a branch instruction, the processor will know whether or not a branch is taken, immediately after the stage of instruction execution (T.sub.4). If a branch is taken, the processor will clear the pipeline after the instruction execution stage, and start to execute the branch instruction with the branch target address (T.sub.5) However, if an interrupt occurs between T.sub.4 and T.sub.7, the processor must wait until T.sub.8 to process the interrupt, since that is the time when the target address instruction (D.sub.1) of the branch instruction (I.sub.1) reaches the memory access (MA) stage.
In addition to this undesirable delay, there is yet another disadvantage to the design selection stated above. This is illustrated in FIG. 3, which shows an example of delayed response and processing time, as caused by a second interrupt that occurs after the first interrupt or exception. As shown in FIG. 3, ISR1.sub.i represents the i.sup.th instruction of the interrupt service routine for the first interrupt (or exception), while ISR2i represents the i.sup.th instruction of the interrupt service routine for the second interrupt. If an interrupt or exception occurs at instruction I.sub.1 during the time T.sub.1, the processor will save the processor state 1 (such as program counter, register, and memory content) in the memory access (MA) stage, at T.sub.2 in FIG. 3. At the same time, the processor will fetch the starting address of the interrupt service routine (ISR1.sub.1) from an external memory unit, and send it to Instruction Fetch, to be executed anew by the interrupt service routine, at T.sub.3. If a second interrupt occurs between T.sub.2 and T.sub.5, the processor must wait until the ISR.sub.1, reaches the memory access (MA) stage at T.sub.6 before it can process the interrupt.
Thus, if an interrupt occurs when an instruction in the MA stage is a branch instruction, or when an interrupt occurs at the time the processor is processing another interrupt or exception, no interrupt will be accepted until the branch address instruction or the first instruction of the interrupt service routine reaches the memory access stage. If the processor does not have a cache, or there is a cache miss, the time will be prolonged for fetching either the branch target address instruction or the first instruction of the interrupt service routine. Thus, the time that the processor takes to process an interrupt would be increased. As such, the processor could not satisfy a requirement for real time control.
It is therefore an object of the present invention to improve the interrupt response time performance of a pipelined data processor by overcoming the disadvantages of the prior art.

Method and apparatus for fast response time interrupt control in a pipelined data processor

Industrial Technology Research Institute


A spectrometer has a multi-input aperture for admitting an input wavefront and an array of multiple waveguide structures terminating at the multi-input aperture. The input wavefront is incident on each of the waveguide structures, which provide a dispersive function for the input wavefront. Interferometers are formed by elements of the waveguide structures. The interferometers have different optical path length differences (OPDs). The interferometers provide a wavelength responsive output for spatially extended light sources. The output of the interferometers is detected with a detector array. The spectrometer has an improved etendue, and in some embodiments very high resolution.

Waveguide-based spectrometers capable of separating light signals at different wavelengths have already been established as one of the key technologies in wavelength division multiplexed telecommunications networks (wavelength multiplexers and demultiplexers, add-drop filters, channel monitors, etc.). High-resolution spectroscopic devices are also required for the development of new detection platforms for genomics and health related applications, and environmental monitoring, including space-born sensing.
In grating spectrometers, high resolution is achieved by reducing the input slit width, or the input waveguide width in planar waveguide based devices. However, a reduction in the input aperture invariably results in a reduced light throughput (étendue) because of a degraded light coupling efficiency between the delivery system (typically an optical fiber) and the spectrometer. The problem is even more obvious when using optical fibers with large core area (multimode fibers). Such fibers are typically used for efficient harvesting of light at the input end of the delivery fiber.
In addition to these étendue concerns, it is known that the input waveguide width cannot be reduced below the point at which the confinement of the mode is compromised and mode delocalization occurs. This sets an ultimate limit to a grating-based waveguide spectrometer resolution. One solution to overcome this fundamental resolution limit is to abandon altogether the slit imaging microspectrometer concept.
Diffraction gratings or arrayed waveguide gratings are commonly used to disperse the spectrum of optical radiation into different wavelength components in the focal plane of a spectroscopic instrument. Several grating-based microspectrometers have been demonstrated as shown by the following references: S. H. Kong et al., IEEE Instrument. & Measurement Mag. Vol. 4, pp. 34-38 (2001); P. Krippner et al., SPIE Vol. 2783, pp. 277-282 (1996); J. H. Correia et al., IEEE Trans. on Electron. Devices, Vol. 47, pp. 553-559 (2000); R. V. Kruzelecky et al., SPIE Proc. Vol. 4205, pp. 25-34 (2001); S. H. Kong et al., Sensors and Actuators, Vol. A92, pp. 88-95 (2001); Z. M. Qi et al., Optics Letters Vol. 27, pp. 2001-2003 (2002); D. Sander et al., Sensors and Actuators, Vol. A88, pp. 1-9 (2001); J. M. Harlander, Appl. Optics Vol. 41, No. 7, 1343-1352 (2002); and P. Cheben et al., Opt. Lett., Vol. 30, No. 14, 1824-1826.
However, virtually all of these spectrometers suffer from a limited resolution (typically >1 nm) which is not suitable for high resolution spectroscopies. Even to achieve a moderate performance, including resolution and light gathering capability (étendue), serious fabrication difficulties have to be resolved. For example, microspectrometers fabricated by LIGA process (deep X-ray lithography and micro-electro plating require exceptional high structuring resolution of <0.25 μm across the entire waveguide thickness of about 100 μm. Waveguide inhomogeneities during embossing induce a significant stray light level compromising resolution and crosstalk, and reducing detection accuracy particularly in spectral ranges of low sensitivity. In another reported example of an on-chip microspectrometer, bulk micromachining of silicon is used to create an array of Fabry-Pérot interferometers, yielding a limited number of available spectral bands (<20) and modest resolution (˜2 nm). The latter is due to difficulties with fabrication of micro-mirror surfaces with high surface quality, parallelism and reflectivity.
Commercial portable micro-spectrometer systems exist, such as the Ocean Optics S1000 and S2000 series, the microParts LIGA serie, the Carl Zeiss MMS1, IOSPEC by MPB Technologies, and the Elargen micro-lightguide spectrometer, but their use is again limited to spectroscopic application with low resolution. Increasing the resolution in these devices is inevitably accompanied by degrading light throughput rendering these devices useless for high-sensitivity high-resolution applications.
It is known that Fourier transform (FT) spectrometers outperform by several orders of magnitude the light gathering capability (étendue) of grating spectrometers at a comparable spectral resolution. Unfortunately, typical FT spectrometers require moving parts, which is very difficult to realize in an integrated optics version, although recently, a new FT spatial heterodyne spectrometer with no need for moving part has been demonstrated both in bulk optics and planar waveguide form.
Miniature spectrometers are typically bulk optic devices composed of lenses, mirrors and other large optical components. As such they are large and require careful assembly for each device. The actual physical layout of the device is somewhat complex and involves making compromises in resolving power, etendue and size to get a working device. In echelle waveguide grating devices, some complex fabrication steps are required to create waveguide vertical trenches with smooth vertical sidewalls. In an arrayed waveguide grating device, the waveguide lengths need to be fabricated within very tight tolerances. In these devices, the etendue is limited and single input aperture is used.

Planar waveguide wavelength dispersive devices with multiple waveguide input aperture


A chair with a seating surface and a link with two ends connected to the seating surface. A frame with two supporting portions connected to the link and the frame can displace against a bias to allow one of the two supporting portions to move, allowing the seating surface to tilt. A flexible front is attached to a front member on the frame, the flexible front bends when the seating surface tilts. The link rotates when the supporting portions displace. The supporting portions are round and pass through round holes in the link, allowing the supporting portions to rotate within the link when the seating surface tilts. A stop connected to the seating surface and a stop connected to the frame limits the maximum tilt angle of the seating surface.

It is often desired for comfort reasons that chairs can recline, and there are a number of known mechanisms for accomplishing this purpose. Some require a user input from a handle or lever to allow reclining and others use a number moving parts that result in an increased cost of manufacture, thus not all applications for chairs will provide a reclining action because of the increased cost of doing so. For example, stackable auditorium or event chairs may commonly be produced at a minimum price that results in an unsatisfactory comfort level.
The price of chairs can vary drastically based on the functionality and options provided, but a reclining option is often desirable. When cost is an issue as is usually the case with auditorium chairs, a reclining feature is often eliminated to reduce cost of the chair. A disadvantage to many known mechanisms is that they are generally complicated and require a number of moving parts and fasteners. It is therefore desirable to have a chair with a simple reclining action and mechanism that can be produced in a cost effective manner while providing increased comfort in relation to other available chairs.
It is further desired to provide a reclining swivel chair using a simplified and cost effective mechanism with enhanced tilting capabilities.
European Patent No. 0130229 to Chadwick discloses a one piece shell chair having a seat and a pivot frame. A support base and a frame member pivot with respect to a torsion bar, allowing the chair to recline.
European Patent No. 2039268 to Saez discloses a stackable chair having a frame, seat and a back, where the back has selectively located slot patterns or springs that allow for reclining.
U.S. Pat. No. 4,498,702 to Raftery discloses a seat element and a thigh support element flexibly connected by leaf springs, offering thigh support.
U.S. Pat. No. 6,050,642 to Erb discloses an adjustable chair having an arcuate contact support structure with two rollers spaced between the arcuate support structures. The rollers contact various support platforms, but are not affixed to the chair back or seat.
U.S. Pat. No. 6,168,233 to Markus discloses a reclinable seat using a torsion bar connected to the seat to allow for a reclining action.
U.S. Pat. No. 7,073,864 to Olsen discloses a stackable chair of substantially X shaped configuration having two bars capable of flexing movement relative to one another.
U.S. Pat. No. 7,722,119 to Delmestri discloses a chair with a tiltable seat.
It is therefore an object of the present invention to provide an improved mechanism for chairs that allows the seat to tilt or recline that overcomes the disadvantages of the prior art. Another object of the present invention is to provide an improved mechanism that allows stackable chairs to recline. It is yet another object of the invention to provide a cost effective mechanism that allows event chairs to be more comfortable. A further object of the present invention is to provide an improved swivel chair with a simplified tilting mechanism and enhanced tilting capabilities.

Reclining loop frame stacking / swivel chair