An anode for a ring laser gyroscope which provides improved current stability in the glow discharge path is disclosed. The anode of this invention permits operation at lower currents thereby allowing a reduction of heat dissipation in the ring laser gyroscope. The anode of one embodiment of this invention is characterized by a thumbtack appearance with a spherical end where the normal sharp end of the thumbtack would be located. The stem of the anode extends from the outside of the gyroscope structure to the interior of the structure such that the spherical end is substantially adjacent to the laser beam.

This invention relates to ring laser gyroscope in general and more particularly to a novel anode that permits operation at substantially lower currents, which in turn allows operation of the ring laser gyroscope with a considerable reduction in the heat dissipation.
As is inherent in its name, the ring laser gyroscope uses a laser beam which travels in a closed path. Regardless of whether the closed path is triangular, rectangular, pentagonal, etc., the closed path is commonly referred to as a ring. Such a ring laser gyroscope is used to detect rotation about the axis of the path around which the laser beam travels. Typical ring laser gyroscopes are disclosed in U.S. Pat. Nos. 3,373,650 and 3,467,472. According to the ring laser gyroscopes described in these patents, there is included a triangular block which forms a triangular-shaped ring laser cavity defined by mirrors at the three corners.
As is understood by those skilled in the art, and as will be further discussed with respect to prior art FIG. 1 hereinafter, a ring laser gyroscope is typically made of a glass ceramic material which forms an optical cavity. The selected lasing gas is used to fill this optical cavity. Mirrors are positioned around the optical cavity at appropriate locations such that the laser beam is reflected in a triangular shape through the optical cavity. A glow discharge is created in the gas filled optical cavity by means of anodes and cathodes which are in communication with the gas filled optical cavity. In the prior art ring laser gyroscopes, the paths by which the anodes and cathodes communicated with the gas filled optical cavity were capillaries leading to that portion of the gyroscope at which anodes and cathodes were mounted. Thus, because of the very high dielectric index usually associated with the ceramic material from which the cavity was made, stray capacitance existed between the anodes and the glow discharge in the capillaries. Furthermore, stray capacitance also existed between the anodes and surrounding areas and portions of the gyroscope and mounting structures. This stray capacitance between the anode and other structures is believed to be the chief reason for current instabilities in the glow discharge. Therefore, it is an object of this invention to provide a ring laser gyroscope which reduces the stray capacitance between the anodes and other structures as well as between the anode and the capillary path containing the glow discharge.
In addition, presently available ring laser gyroscopes necessarily must use a low gas pressure in the gas filled cavity which results in considerable sputtering of the cathode. Even a small increase of the gas pressure in the ring laser gyroscope would result in a substantial reduction in the sputtering of the cathode. Therefore, it is another object of this invention to provide a ring laser gyroscope which operates at a higher gas pressure without simultaneously having a plasma oscillation condition.
It is also understood by those skilled in the art that if a lower anode current can be used without a drop out of the glow discharge, there will be a considerable reduction of power consumption and consequently heat dissipation in the gyroscope due to the lower currents. Therefore, it is still another object of this invention to provide a ring laser gyroscope having reduced power consumption and heat dissipation.
Since temperature variations or gradients in the plane of the triangular structure of the ring laser gyroscope, causes gas currents to flow, it is not unusual that a false input rate may be indicated because of such gas currents. Thus, since increasing the fill pressure of the gas cavity reduces the sensitivity to temperature variation, it will be appreciated that a reduction in power consumption and consequently in heat dissipation will increase the stability of the ring laser gyroscope itself. Thus, it is another object of this invention to increase the stability of a ring laser gyroscope.


The invention is an improved partially jacketed projectile intended for small arms use. The projectile includes a central stem integral with a rear wall of the projectile, the rear wall in turn being integral with the partial jacket. A core surrounding the stem and encased by the jacket is softer than the material forming the stem, rear wall and jacket. The jacket retards core petalling during initial projectile impact whereas the rear wall configuration enhances petalling when the projectile achieves subsequent target penetration.

Our invention falls within the art of petalling small arms projectiles that are sometimes considered desirable for close range antipersonnel applications. We believe that initial delay of petalling relative to the rate of target penetration will increase the lethality of antipersonnel projectiles. Consequently, we have designed projectiles whose structure controllingly retards initial petalling rate.
Our improved projectile design includes an integral structure of an axial stem, a rear wall at the base of the stem and a jacket joined to the rear wall. A core surrounding the stem and partly encased by the jacket is made of softer material than the stem, rear wall and jacket. The jacket causes petalling retardation during initial stages of projectile impact wherein the core begins to break into elongate sectors. However, the rear wall is specially configured to enhance petalling motion of core sectors as a function of forward stem movement relative to these sectors, most of which movement occurs after the initial stages of projectile impact. Thus, at least some projectiles designed according to our disclosure will exhibit initial petalling retardation and subsequent petalling acceleration relative to projectile penetration rate. The cores of such projectiles will quickly widen or disperse after penetrating to relatively deeper, more vulnerable zones of the target, whereby projectile lethality is enhanced.


A device having a resistor and a heater disposed proximate to the resistor and capable of raising the temperature of the resistor. The device further includes a dieletric disposed between the heater and the resistor and a tuner electrically coupled to the resistor. The heater adjusts the resistance of the resistor in response to the tuner.

1. Technical Field
The technical field is resistors.
2. Related Art
Resistors are typically specified as having a nominal resistance, a room temperature resistance variation, and temperature coefficient of resistance. The temperature coefficient of resistance describes the variation in resistance of a resistor as a function of temperature change.
Integrated circuit performance depends upon the electrical characteristics of semiconductor devices in the circuit. One method for adjusting the electrical characteristics of a semiconductor device is by "trimming" one or more resistors in the device. Trimming of resistors can be done by chemical, mechanical, and electrical means. Conventional trimming methods involve heating a resistor to change electrical and physical properties of the resistor. Once a conventional resistor has been trimmed, however, its properties are fixed and cannot be changed once the semiconductor wafer carrying the circuit has been diced and packaged.

International Business Machines Corporation


The present invention finds applicability in barrel assemblies defining a ring shaped cavity that is to be fluidly sealed from a central bore. Current barrel assemblies, such as those used in hydraulic pumps, are made from castings. This can be undesirable due to long production time and difficulty in producing consistent components. The present invention is directed to overcoming one or more of these problems by disclosing a barrel assembly and a method for making the same wherein the barrel and the plug are manufactured from the same material, or from materials having similar coefficients of thermal expansion. Thus, upon pump operation and optional heat treatment of the assembled barrel assembly, both the barrel and the plug will expand in a similar manner. The present invention finds application in axial piston pumps, especially for high pressure hydraulic systems, and other two piece components having a cavity requiring a seal.

The present invention relates generally to a barrel assembly for an axial piston pump, and more particularly to a barrel having a ring shaped cavity closed to a central bore at least in part by a collar and a method of forming the same.
Currently, barrels for axial piston pumps are usually made from castings. Such a casting is illustrated in U.S. Pat. No. 6,035,828, entitled Hydraulically-Actuated System Having A Variable Delivery Fixed Displacement Pump, which issued to Anderson et al. on Mar. 14, 2000. However, this method of production, while adequate, can be undesirable for a number of reasons. For instance, this method of producing pump barrels can result in long production times and difficulty in producing accurate parts. First, forming the casting can be difficult because the core that creates a ring shaped accumulator cavity defined by the barrel can shift position during pouring of the casting. This can cause positional tolerances of the barrel to be exceeded. In addition, when the cast material is not homogenous in content, it will contain relatively hard granules that are separated by relatively soft material. As the relative hardness of the casting granules approaches the hardness of the machining tool, the machining tool can be worn excessively fast.
The present invention is directed to overcome a one or more of the problems as set forth above.
According to one aspect of the present invention, a barrel assembly for an axial piston pump includes a barrel that defines a ring shaped cavity which opens to a central bore, and a plurality of parallel piston bores that surround the central bore and open to the ring shaped cavity. A collar is attached to the barrel and closes the ring shaped cavity to the central bore.
According to another aspect of the present invention, a pump includes a housing. A barrel assembly is mounted in the housing and provides a collar that is attached to the barrel to define a ring shaped cavity which surrounds, but is closed to, a central bore. The barrel defines a plurality of parallel piston bores that open to the ring shaped cavity. A piston is slideably received in each of the piston bores. A drive plate which has a slanted drive surface is rotateably mounted in the housing and is operably coupled to each piston.
According to yet another aspect of the present invention, a method of making a barrel assembly for a pump includes forming a barrel to provide a ring shaped cavity that opens to a central bore. The ring shaped cavity is closed to the central bore at least in part by attaching a plug into the barrel.

Two piece barrel design for a hydraulic oil pump


A log skidder including a vehicle having a frame with front and rear ends, ground engaging devices on the frame so that the vehicle may traverse the underlying terrain, an elongated boom on the frame and mounted thereto for pivotal movement about a generally horizontal axis between an upright position at least adjacent the rear end and a lower position intermediate the ends, a log engaging device, a lever mounting at one end the log engaging device and horizontally pivoted at a location remote from the lever one end to the boom at a location spaced from the horizontal axis, the lever one end extending rearwardly with relation to the frame, a motor on the frame for moving the boom between the positions thereof, and a linkage for maintaining the lever one end directed generally rearwardly for all positions of the boom on the frame.

This invention relates to log skidders or the like for dragging heavy loads such as logs through rough terrain.
In many operations, such as timber harvesting operations, it is often necessary to move, by dragging, loads such as logs over rough terrain. In a timber harvesting operation, for example, the point at which trees are felled may be quite remote from a loading point or the like. Consequently, skidding vehicles, such as log skidders, have been utilized to drag such loads across rough terrain from one point to another.
Many conventional log skidders in use today have fixed arch assemblies, that is, the boom-like assembly on the vehicle frame to which one end of the log to be skidded is attached as, for example, by a grapple or a fairlead and choker assembly. Because the end of the logs to be secured to the vehicle must be elevated to facilitate skidding, the arch assemblies extend a fair distance above the underlying terrain and, because the logs are to be dragged, the arch assembly is typically located near the rear of the vehicle. As a consequence, abrupt forces caused by the logs dragging over uneven terrain are directed to the vehicle at a relatively high location which produces rearward pitching of the vehicle and poor ground pressure distribution of the ground engaging means of the vehicle which produces ground disturbance and reduces traction. Obviously, rearward pitching is undesirable as an impediment to good handling qualities of the vehicle. Poor traction is undesirable due to its deleterious effect on vehicle handling qualities as well as promoting the possibility that the vehicle may become mired in a particular location. A high degree of ground disturbance is likewise undesirable, particularly where a vehicle must traverse substantially the same path several times since, as the ground progressively becomes more and more disturbed with each passing vehicle, traversing the path becomes increasingly difficult.
In an attempt to at least partially overcome one or more of the above difficulties, the prior art has resorted to pivoted arch assemblies and at least one log skidder having a pivoted arch assembly is commercially available today. In that vehicle, the arch extends rearwardly of the vehicle when logs are to be loaded and is pivoted forwardly on the vehicle to hoist the logs into a skidding condition. A choker type load carrying device is utilized and, as a consequence, the point of attachment of the fairlead when the arch is in a skidding position is relativey high on the vehicle and intermediate the ends of the vehicle frame. The latter factor improves weight distribution on the vehicle which includes traction and tends to reduce ground disturbance. However, because of the high location of the point of attachment of the fairlead, forces conveyed to the vehicle are applied thereto well above its center of gravity so that rearward pitching movements and any ground disturbances caused by such movement remain as problems accompanying the use of such vehicles.


A tong assembly includes a power tong, a backup tong, and a carriage assembly operatively connecting the power tong and the backup tong. The carriage assembly includes a movable trolley assembly. The movable trolley assembly is axially located between the power tong and the backup tong. The movable trolley assembly is supported by the power tong. The movable trolley assembly is configured to axially move the power tong and backup tong relative to each other.

Field of the Disclosure
Embodiments of the present disclosure generally relate to an apparatus for making up and breaking out tubular connections. More particularly, embodiments of the present disclosure relate to a tong assembly for use in making up and breaking out tubular connections within a tubular string of an oil or gas well.
Description of the Related Art
Construction of oil or gas wells usually requires making long tubular strings that make up casing, risers, drill pipe, or other tubing. Due to the length of these strings, sections or joints of tubulars are progressively added to or removed from the tubular strings as they are lowered or raised from a drilling platform. A tong assembly including a power tong and a backup tong is commonly used to make up or break out joints in the tubular strings.
The power tong and the backup tong are typically vertically spaced from each other by a fixed distance. In some situations, however, it is desirable to be able to adjust the vertical spacing between the power tong and the backup tong. Therefore, there is a need for a movable tong assembly in which the vertical spacing between the power tong and the backup tong is adjustable.


To simplify coupling of a video recording transducer to a recording network, and to improve the fidelity of the signals as actually recorded with respect to the signals applied to the recording network, an amplifier, preferably a current amplifier including emitter-coupled transistors, is connected between a current-supplied compensating network and the transducer, the connection being through a short cable, preferably a coaxial cable which has a length substantially less than the wave length of the signals to be recorded, so that the overall response of the compensating network-amplifier-cable-transducer will be essentially linear with respect to the signals to be recorded.

It has previously been proposed to compensate for distortion due to the characteristics of video transducers by connecting signals to be recorded by the transducer thereto over a compensating network including an amplifier. When recording high-frequency signals by means of an electromagnetic transducer, for example when recording video signals, it is necessary to so modify the current in the transducer head that the recorded signals will correspond to the desired signals to as close a degree as possible. An undulating current is necessary when recording video signals which are frequency-modulated. The quality of recording also substantially depends on the faithful reproduction of the wave shape of the signal to be recorded--which is particularly important when recording digital or pulse-type, square wave signals. The winding of the magnetic transducer head of video transducers has a highly inductive component which, upon connection to an amplifier which provides a square wave output voltage, requires compensation so that the actual signal to be recorded will have a wave shape which closely approximates that of the output signal. The referenced U.S. Pat. No. 3,524,017, Pezirtzoglou, of Aug. 11, 1970, describes a circuit arrangement in which a compensation network is connected in advance of the winding of the transducer head, typically a magnetic tape recording head. This transducer is connected to the output of an amplifier by means of a coaxial cable, as customary, and when developing the compensation network, it was primarily considered to so design the network that the input thereof, and hence the input of the combination of the transducer-network, has a real or positive resistance which corresponds essentially to the impedance of the coaxial cable. It is intended that the current through the winding of the transducer should, thereby, have the same square wave shape as the voltage supplied by the output amplifier.
It has been found that the aim of faithful reproduction of the wave shape of the current to the output voltage cannot be obtained at all times, and usually only very approximately so. The power output requirements placed on the amplifier are high.

Inductive signal transducer supply circuit particularly for video recording use


A thermoplastic elastomer resin composition for a moisture-permeable waterproof film includes a thermoplastic elastomer resin composed of a hard segment containing polybutylene terephthalate and a soft segment containing polyethylene glycol and polytetramethylene glycol, wherein the polyethylene glycol is contained in an amount of 30 to 70 wt % and the polytetramethylene glycol is contained in an amount of 1 to 10 wt %, based on the total weight of the thermoplastic elastomer resin. A moisture-permeable waterproof film formed of the elastomer composition and a moisture-permeable waterproof fabric in which the moisture-permeable waterproof film is stacked on at least one surface of a substrate fiber are also provided.

A moisture-permeable waterproof material is a highly functional material in which two contradictory properties, namely moisture permeability for allowing air or water vapor to pass and waterproofness for preventing the penetration of liquid such as raindrops, are balanced well, and has become popular due to application not only to ski wear or rainwear but also to many types of sportswear for climbing, golf, marine sports, etc. Techniques for realizing such a moisture-permeable waterproof material have been steadily developed since the 1960s and then accelerated owing to the development of Gore-Tex in the mid and late 1970s, and various developments are still being made to improve the performance thereof.
A moisture-permeable waterproof material may be classified according to the processing method thereof into a coated type in which a film is formed and a laminated type in which a thin film is bonded, and the coated type may be divided into (i) a wet-coated type in which a polyurethane coating layer having fine pores is formed on a fabric in water and (ii) a dry-coated type in which a uniform polyurethane film layer is formed on a fabric by applying a resin composition including an organic solvent having high volatility to a predetermined thickness on the fabric and then performing thermal treatment to volatilize the organic solvent. Furthermore, depending on the principle whereby the moisture-permeable waterproof function is exhibited, it may be classified into a microporous type comprising fine pores, a nonporous hydrophilic type, a nanoweb type, and a shape-memory type.
With regard to the moisture-permeable waterproof material, patent techniques using a laminating process include Japanese Patent Application Publication No. Hei. 5-124144, which discloses a moisture-permeable waterproof sheet manufactured by laminating a polyethylene porous film and a nonwoven fabric comprising a heat-bondable fiber using heat and pressure, and Japanese Patent Application Publication No. Hei. 3-213581, which discloses a moisture-permeable waterproof fabric having high wear resistance obtained by laminating, on a fabric, a moisture-permeable film comprising poly-amino-acid-based polyurethane containing 0.1% or more of a powder composed of L-lysine and an organic acid, and additionally, a variety of dry/wet coating processes are disclosed in Japanese Patent Application Publication Nos. Hei. 4-249142, 4-146275, 7-258971, 5-78984, and 8-13352.
The manufacturing methods disclosed in the above conventional techniques are very complicated, and the resulting moisture-permeable waterproof film or membrane has non-uniform pores, making it impossible to solve the problem of low moisture permeability. Furthermore, in the case where the organic solvent is used during the manufacturing process, the dye of the fabric is released due to the organic solvent, undesirably causing contamination.
Meanwhile, polytetrafluoroethylene (PTFE), which is commonly known to be a material for Gore-Tex, has high moisture permeability, chemical resistance and lightfastness because of the uniform formation of fine pores in the film, and is thus very favorably used despite the high price thereof. However, PTFE is poor in mechanical fatigue strength and washing durability and involves the risk of releasing environmentally harmful materials such as PFCs (perfluorinated and polyfluorinated compounds), FTOHs (fluorotelomer alcohols), PFCAs (perfluorinated carboxylic acids), PFOS (perfluorinated sulfonate), PFOA (perfluorooctanoic acid), etc.
Although polyurethane, which has high moisture permeability and may be subjected to various processing methods, has been mainly used to date as the moisture-permeable waterproof material, polyurethane suffers from poor washing durability when applied to clothes, thereby decreasing hydrostatic pressure. In particular, when the pore size of the film is increased in order to ensure air permeability as high as that of PTFE, the mechanical strength of the material may be drastically decreased. Moreover, in the case where polyurethane is directly applied on a fabric through a wet or dry process, the resin solution may penetrate into the fabric, and thus the tactile sensation of products may become hard, and furthermore, limitations are imposed on exhibiting functionality such as moisture permeability, water resistance, etc.

Thermoplastic elastomer resin composition for moisture-permeable waterproof film, film and fabric using same


A water source (12, FIG. 1) is provided for mounting on a toilet housing (32) rearward of the toilet bowl (18), which has a small rearward-to-forward depth (D) and low height (H), and which enables close control of the flow of water and any vacuum to the toilet bowl and its outlet. The source includes a frame (40) for mounting on the rearward portion of the toilet housing, the frame having two wide holes (50, 52) and a diaphragm device (54, 56) extending across each hole to separate water regions (60, 62) from air regions (64, 66) that lie on opposite sides of the diaphragm. The holes and diaphragms form two horizontally spaced water supply units 42, 44 that lie on opposite sides of the toilet bowl outlet 24 to efficiently use space. A spring or weight biases each diaphragm to compress the water region. The two water regions are connected together and to a flush valve (14) for supplying water to the toilet bowl. Where a vacuum assisted toilet is used, at least one of the air region is connected to the toilet bowl outlet (24) to apply a vacuum thereto when water flows out of the water regions.

The amount of water required in each effective flushing of a toilet, can be reduced by flowing water rapidly into the toilet bowl at the beginning of a flushing. This is conventionally accomplished by storing water in a water closet of substantial height such as fifteen inches (37.5 cm) above the level of the top of the toilet bowl. However, toilets of "low profile" require that the water closet area be of low height to enhance the overall appearance of the toilet. Such "low profile" toilets often must have only a small rearward extension behind the toilet bowl, such as one that is no more than about seven inches (17 cm) behind the location where the toilet bowl cover is mounted. Even low water usage toilets require perhaps 1.5 gallons (6 liters) of water, which is difficult to accommodate in a reliable pressure source in the small depth available. A water source which could supply water at a moderate pressure such as at least twelve inches (30 cm) of water pressure and preferably more than that, and which could be accommodated in a small volume of a depth such as seven inches (17 cm) behind the toilet bowl while providing room for the toilet outlet, would be of considerable value.
One type of water saver toilet applies a vacuum to the toilet bowl outlet to help draw water and debris out of the bowl. A water source which could supply pressured water to the toilet bowl during a flushing, and which could apply a vacuum in a controlled manner, would be of considerable value.


If the sequence of a traffic of a first communication link from a communication apparatus to another communication apparatus includes a traffic of a second communication link from that another communication apparatus to a communication apparatus, latency is reduced, thereby saving processing time.

Currently, in 3GPP (Third Generation Partnership Project), the standardization of a LTE (Long Term Evolution) system is in progress as a next-generation mobile communication system. With this LTE system, transmitting data from a communication terminal to the base station equipment by uplink requires the acquisition of a channel in advance. Hence, the communication terminal transmits a scheduling request (SR) to the base station equipment. Receiving the scheduling request, the base station equipment executes scheduling of which channel to assign to the communication terminal, thereby notifying the communication terminal of the channel source assignment information. The communication terminal transmits data to the base station equipment on the basis of this assignment information. Such a scheduling scheme for channel resource assignment is called dynamic scheduling (refer to PTL 1 below, for example).
The dynamic scheduling as described above may sometimes be required for not only transmitting data by uplink but also for a sequence of transmitting data from the base station equipment to a communication terminal by downlink (refer to PTL 2 below, for example). For example, as with the transmitting, by uplink, of a successful reception (ACK) message for TCP data by downlink, the above-mentioned necessity applies to the case in which uplink traffic is included in the sequence of downlink traffic.

Base station equipment, communication terminal, communication system, program, frame transmitting method, and data structure

Abstract: If, after data is transmitted from a communication apparatus to another communication apparatus by the upper layer, a data receive response signal is required from that another communication apparatus to the communication apparatus, a predetermined frame including transmission grant information for that another communication apparatus to transmit the receive response signal and data is generated in the communication apparatus. The communication apparatus transmits this generated frame to that another communication apparatus. That is, data and transmission grant information are transmitted from the communication apparatus to that another communication apparatus as a predetermined frame.


A location of a wireless device relative to a vehicle is determined using received data. Data may be received from the vehicle sensors. Data may also be received from the wireless device sensors of a wireless device. The presence of one or more persons may be determined using received data. A user-to-wireless device association may be detected based, at least in part, upon the presence of one or more persons in the vehicle and the location of the wireless device relative to the vehicle.

The prolific nature of wireless devices permits users to make calls, surf the Internet, or send SMS messages without being tied to a particular location. People may operate such wireless devices, such as smartphones, while driving a vehicle. However, the use of wireless devices while driving increases the chances of being involved in an automobile accident, which may result in serious injury or even death. People who operate wireless devices while driving are often distracted by the wireless device and/or are not concentrating on the task of driving the vehicle. Even with the use of hands-free devices, studies have indicated the risk of an accident related to inattentiveness caused by the user of the wireless device is not completely eliminated.
Certain implementations will now be described more fully below with reference to the accompanying drawings, in which various implementations and/or aspects are shown. However, various aspects may be implemented in many different forms and should not be construed as limited to the implementations set forth herein; rather, these implementations are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Like numbers refer to like elements throughout.

Detecting a user-to-wireless device association in a vehicle


The present application includes wind turbine condition monitoring method and system. The method includes: acquiring historical SCADA data, and wind turbine reports corresponding to the historical SCADA data; training an overall model for overall diagnosing the wind turbine, and training different individual models for analyzing different components of the wind turbine based on the historical SCADA data and the corresponding wind turbine report, by establishing relationship between the historical SCADA data and the wind turbine report; acquiring real time SCADA data, inputting the real time SCADA data to the trained overall model, obtaining the health condition of the wind turbine from the trained overall model, and performing individual diagnosing step if the trained overall model determines wind turbine as defective status; inputting the real time SCADA data to the trained individual model corresponding to the defective component, and obtaining the fault details of the defective component from the trained individual model corresponding to the defective component.

Wind power has become the most popular renewable energy promising to displace traditional pollutive thermal power generation due to rich resources, mature technology, and zero emission. Global wind turbine installation had reached 318 GW by end of 2013. With rapid installation increase of wind farms, expensive O&M (operation and maintenance) cost and downtime electricity sale loss develop to be more and more pressing issues. Taking a 2 MW wind turbine as example, as evaluated by master thesis of KTH, about 248.4 kUSD annual cost arises, incl. 242.7 kUSD O&M cost and 5.7 kUSD electricity sale loss.
Under such environment, it's desired by the market to develop a kind of condition monitoring system (CMS) product which is able to real time detect the defects of wind turbine, analyze the fault type, and position the defective part, before the wind turbine evolves to real failure. Now the available products in market with such functionality are all based on additional sensors, e.g. vibration, acoustic, etc. These intrusive sensors not only largely increase the capital cost, but also cause recertification of wind turbines, both of which are undesirable for wind farm operators.

Wind turbine condition monitoring method and system


A device for inserting a substantially square sheet of flexible material through a laparoscopic cannula into an abdominal cavity. The device is an elongate, generally cylindrical member having a proximal end and a distal end and a body portion therebetween. A pair of tines is rigidly affixed to the distal end of the body portion with a slot separating the tines. A handle is affixed to the proximal end of the body portion. The slot defined between the pair of tines is dimensioned to accommodate the sheet thickness therewithin. In a preferred use, the sheet of material is inserted between the tines with diagonal corners of the sheet within the slot. The free corners of the sheet are drawn together with one hand and the handle of the device is rotated to wrap the sheet around the exterior surface of the two tines. The distal end of the body portion is then inserted into a laparoscopic cannula and advanced therethrough with a twisting motion until the distal end of the device emerges from the cannula positioned within the abdominal cavity. At this point, the device is slightly withdrawn to dislodge the film from the receptacle at the base of the tines and the sheet unwinds from around the tines, effectively unfolding the sheet within the target cavity. The sheet is finally released from the slot between the tines when the device is withdrawn from the cannula; the sheet remaining within the abdominal cavity.

1. Field of the Invention
The present invention related to a device for inserting a film or sheet of bioabsorbable material into the abdominal cavity of a patient during laparoscopic surgery.
2. Prior Art
Laparoscopic surgery involves the transcutaneous placement of at least one, and usually two, three or four laparoscopic cannulas through the abdominal wall to provide a conduit into the abdomen. The cannula(s) are inserted by means of a trocar placed against the skin which, in response to pressure, provides a open pathway into abdominal cavity through which the cannula(s) may pass. One of such cannulas is employed to inflate the abdominal cavity with carbon dioxide gas to improve the field of view and accessibility to organs within the abdomen. Others are used for the insertion of specialized surgical instruments. All such cannulas are fitted with a leak-proof valve to prevent gas under pressure from leaking from within the abdominal cavity. Instruments used in laparoscopic surgery are passed through the cannulas and manipulated within the abdominal cavity. One of the cannulas houses a camera which, together with a light source, provides a means for a physician or surgeon to view the field of operation and perform a surgical procedure within the abdominal cavity.
It has been difficult in the art to insert sheets of flexible material through such cannulas for deployment within the abdominal cavity. Films or sheets of material which are particularly desirable for such insertion include adhesion barriers, bioabsorbable and biodegradable drug releasing films and the like.
The prior art has dealt with the problem of inserting sheets of material through a cannula into the abdomen in a variety of ways, some of which are set forth in U.S. Pat. No. 5,503,623 by Tilton, Jr. In particular, the Tilton Jr. patent ('623) discloses a laparoscopic device which is operable through a cannula and which employs a set of jaws to grasp a sheet, wind said sheet around said jaws, retract said jaws and sheet into a sheath, and inserting the sheath through the cannula into the abdomen then advancing the jaws and sheet through the sheath and, when the jaws and sheet are clear of the cannula, releasing the sheet. Such devices are expensive and difficult to clean. It is, therefore, desirable to provide a device which can be used in laparoscopic surgery to insert and deploy a sheet or film of flexible material into an abdominal cavity which obviates some or all of the problems associated with prior art devices.

Laparoscopic insertion and deployment device


A lubricating oil composition having a low P content of 0.01 to 0.1 wt. %, and a sulfated ash of 0.1 to 1 wt. %, which is composed of a) a major amount of mineral base oil having a low S content of at most 0.1 wt. %; b) an ashless alkenyl or alkyl-succinimide dispersant; c) a metal-containing detergent (non-sulfurized alkali metal or alkaline earth metal salt of an alkylsalicylic acid and/or non-sulfurized alkali metal or alkaline earth metal salt of an alkylphenol derivative having a Mannich base structure); d) Zn-DTP; e) an oxidation inhibitor (phenol compound and/or amine compound) and wherein the sulfur content is 0.01 to 0.3 wt %. The lubricating oil composition shows good high temperature detergency notwithstanding its low S, P, and sulfated ash content, and is favorably employable in diesel engines using fuel of an extremely low sulfur content.

This application claims priority from Japanese Patent Application Number 2000-166774, filed Jun. 2, 2000.
The present invention relates to a lubricating oil composition favorably employable for lubricating internal combustion engines such as diesel engines, gasoline engines, and gas engines. In particular, the invention relates to a lubricating oil composition having a low sulfated ash content, a low phosphorus content, and a low sulfur content, while showing good detergency at high temperatures.
Diesel internal combustion engines mounted on motor-driven vehicles, constructions machines and power generators are generally driven using gas oil or heavy oil (which is a fuel having a sulfur content of approximately 0.05 wt. % or more). Most lubricating oils for the diesel engines have a sulfated ash content of approx. 1.3 to 2 wt. %, a sulfur content of approx. 0.3 to 0.7 wt. %, a phosphorus content of approx. 0.1 to 0.13 wt. %, and a chlorine content of 50 to 100 ppm (wt.) or more.
As for internal combustion engine-mounted vehicles, particularly, diesel engine-mounted vehicles, it is required to find ways of meeting problems to obviate environmental pollution caused by the exhaust gas components such as particulate and nitrous oxides (NOx). For obviating such environmental pollution, it is proposed to mount exhaust gas-clearing devices containing a particulate filter and oxidizing catalysts and/or NOx reducing catalysts on the vehicles. The combination of the particulate filter and oxidizing catalysts can trap the soot produced and then oxidize and burn the trapped soot. However, metal oxides, sulfates and carboxylates produced by burning of conventional lubricating oil are apt to plug the filter.
Sulfur contained in the fuel is also converted to sulfuric acid and sulfates which emigrate into exhaust gas. Sulfuric acid and sulfate lower activity of the oxidizing catalysts and/or NOx reducing catalysts in the exhaust gas-cleaning device. In turn, the sulfur content of fuel should be decreased. Accordingly, it is expected that requirements for decreasing the sulfur content of diesel fuel from the present value of approx. 0.05 wt. % to 0.01 wt. % or lower, and perhaps even further to approx. 0.001 wt. % or lower may be required.
As the sulfur content of fuel is decreased, the content of metal-containing detergent (which functions to neutralize the produced sulfuric acid) in the lubricating oil will also be decreased. The lubricating oil is employed for lubricating the engine parts, but a portion of the lubricating oil is burnt and emigrates into the exhaust gas. Therefore, the decrease in content of the metal-containing detergent, which means decrease of a metal content and a sulfur content, is favorable for decreasing environmental pollution. Moreover, it is preferred to decrease the phosphorus content in the lubricating oil so as to keep the oxidizing catalyst from deterioration. The content of chlorine in the lubricating oil should also be as low as possible, so as to decrease production of dioxins.
Japanese Patent No. 2,922,675 describes an ashless lubricating oil composition favorably employable for diesel engines in combination with fuels of a low sulfur content, which contains specific amounts of an alkylester of (3,5-di-t-butyl-4-hydroxyphenol)carboxylic acid, an ashless succinimide type dispersant, and an ashless amine type or phenol type oxidation inhibitor.
U.S. Pat. No. 5,102,566 describes a low sulfated ash lubricating oil composition which comprises a base oil, at least about 2 wt. % of an ashless nitrogen- or ester-containing dispersant, an oil-soluble antioxidant material, and an oil soluble dihydrocarbyl dithiophosphate anti-wear material, and which has a total sulfated ash (SASH) level of 0.01 to 0.6 wt. % and a weight ratio of SASH to dispersant in the range of 0.01:1 to 0.2:2.
Japanese Patent Provisional Publication No. 8-48989 describes a lubricating oil composition which has a low sulfated ash content and does not disturb functions of particulate traps and oxidizing catalysts, but shows good stability at high temperatures so that it can meet the anticipated exhaust gas regulations. The disclosed lubricating oil composition comprises at least 5 wt. % of a boron-containing ashless dispersant, 0.05 to 0.15 wt. % (in terms of phosphorus content) of zinc thiophosphate, and optionally 0.01 to 2 wt. % of an ashless oxidation inhibitor, under such conditions that the boron content in the composition is at least 0.1 wt. %, the boron content/phosphorus content ratio is at least 0.8, and the sulfated ash content is at most 1.0 wt. %.
The present invention provides a lubricating oil composition which has a low sulfur content, a low phosphorus content and a low sulfated ash content, and does not disturb functions of particulate traps and oxidizing catalysts and/or NOx reducing catalysts, while having stability at high temperatures so that it can meet the anticipated exhaust gas regulations.
It is well known to those skilled in the art that decreases of the sulfur content, phosphorus content, and sulfated ash content in the lubricating oil composition result in lowering of high temperature stability of the lubricating oil composition.
It has now been discovered that the lowering of the high temperature stability of the lubricating oil composition by the decreases of the sulfur content, phosphorus content, and sulfated ash content can be compensated using a small amount of a metal-containing detergent having a certain amount of soap content, namely, a content of an organic acid metal salt component is contained, in combination with an ashless dispersant, zinc dialkyldithiophosphate, and an oxidation inhibitor.
In its broadest aspect, the present invention resides in a lubricating oil composition having a sulfur content of 0.01 to 0.3 wt. % and a phosphorus content of 0.01 to 0.1 wt. %, and giving a sulfated ash in the range of 0.1 to 1 wt. %, which comprises
a) a major amount of a mineral base oil having a sulfur content of at most 0.1 wt. %;
b) an ashless dispersant comprising an alkenyl- or alkyl-succinimide or a derivative thereof in an amount of 0.01 to 0.3 wt. % in terms of a nitrogen atom content;
c) a metal-containing detergent containing an organic acid metal salt which is selected from the group consisting of a non-sulfurized alkali metal or alkaline earth metal salt of an alkylsalicylic acid having a TBN of 10 to 350 mgxc2x7KOH/g and a non-sulfurized alkali metal or alkaline earth metal salt of an alkylphenol derivative having a Mannich base structure, in an amount of 0.1 to 1 wt. % in terms of a sulfated ash content;
d) a zinc dialkyldithiophosphate in an amount of 0.01 to 0.1 wt. % in terms of a phosphorus content; and
e) an oxidation inhibitor selected from the group consisting of a phenol compound and an amine compound in an amount of 0.01 to 5 wt. %.
The lubricating oil composition of the present invention preferably has a sulfur content of 0.01 to 0.15 wt. %, a phosphorus content of 0.01 to 0.06 wt. %, and a chlorine content of at most 40 ppm (more preferably at most 30 ppm).
The ashless dispersant employed in the lubricating oil composition of the present invention preferably is a succinimide or a derivative thereof which is obtained by the reaction of a polybutenylsuccinic anhydride and a polyamine, the polybutenylsuccinic anhydride being produced from polybutene and maleic anhydride by a thermal reaction method using neither chlorine or a chlorine atom-containing compound.
The metal-containing detergent in the lubricating oil composition of the present invention preferably is a non-sulfurized alkali metal or alkaline earth metal salt of an alkylsalicylic acid having a TBN of 30 to 300 mgxc2x7KOH/g, more preferably 30 to 100 mgxc2x7KOH/g. The metal-containing detergent is chosen and incorporated into the lubricating oil composition under the condition that the organic acid metal salt (i.e., soap content) originating from the metal-containing detergent is in an amount of 0.2 to 7 wt. %, more preferably 0.5 to 5 wt %, and most preferably 1 to 3 wt %.
The oxidation inhibitor preferably is a hindered phenol compound or a diarylamine compound, or a combination thereof.
The lubricating oil composition of the present invention preferably further contains a molybdenum-containing compound in an amount of 0.01 to 5 wt. %, an alkali metal borate hydrate in an amount of 0.01 to 5 wt. %, and, optionally, a viscosity index improver.
The mineral base oil preferably has an aromatic content of at most 5 wt. %, a nitrogen content of at most 0.005 wt. %, a sulfur content of at most 0.005 wt. %, and a viscosity index in the range of 100 to 150.
In another aspect, the present invention also resides in a method of lubricating a diesel engine with a lubricating oil composition of the present invention.
In still another aspect, the present invention also resides in a method of lubricating a diesel engine equipped with an exhaust gas after-treatment system comprising a particulate filter and an oxidizing catalyst composition and/or NOx reducing catalysts, using a lubricating oil composition of the present invention.
Among other things, it has now been discovered that the high temperature stability of a lubricating oil composition having a low sulfur content, a low phosphorus content, and a low sulfated ash content can be maintained by using a small amount of a metal-containing compound, namely a metal-containing detergent having a certain amount of soap content, in the lubricating oil composition. The lubricating composition of the present invention is useful in motor driven vehicles using low sulfur hydrocarbon fuels (0.01 wt. % or less), particularly diesel engine-mounted vehicles to which exhaust gas-cleaning devices containing particulate filters and oxidizing catalyst and/or NOx reducing catalyst are attached.
In the lubricating oil composition of the present invention, the base oil is a mineral oil having a sulfur content of at most 0.1 wt. %, preferably at most 0.03 wt. %, most preferably at most 0.005 wt. %, and generally having a kinematic viscosity of 2 to 50 mm2/s at 100xc2x0 C. The mineral base oil can be produced by processing a lubricating oil grade distillate by solvent refining and/or hydrotreating or hydrocracking.
A mineral base oil having a viscosity index of 100 to 150, an aromatic content of less than 5 wt. %, N- and S-content of less than 50 ppm, which can be obtained by hydrocracking is preferably employed for preparing the lubricating oil composition of the present invention.
The mineral base oil can be produced from slack wax or natural gas. The mineral base oil can be a known Shell XHVI (Extra High Viscosity Index) oil.
A portion (less than 50 wt. %) of the mineral base oil can be replaced with a synthetic oil. Examples of the synthetic oils include poly-xcex1-olefins (e.g., polymers of xcex1-olefins having 3 to 12 carbon atoms; dialkyl diesters which are di-(C4-C18)alkyl esters of sebacic acid, azelaic acid, or adipic acid (typically, dioctyl sebacate); polyol esters derived from 1-trimethylolpropane or pentaerythritol and monobasic acids having 3 to 18 carbon atoms; and alkylbenzenes containing an alkyl group of 9 to 40 carbon atoms.
The lubricating oil composition of the present invention further contains an ashless dispersant which comprises an alkenyl- or alkyl-succinimide or a derivative thereof in an amount of 0.01 to 0.3 wt. % in terms of the nitrogen atom content. A representative succinimide can be prepared by the reaction of a high molecular weight alkenyl- or alkyl-substituted succinic anhydride and a polyalkylene polyamine having 4 to 10 nitrogen atoms (average value), preferably 5 to 7 nitrogen atoms (average value) per mole. The alkenyl or alkyl group of the alkenyl or alkyl succinimide compound is preferably derived from a polybutene having a molecular weight (in this specification, this means a number average molecular weight) of 900 to 3,000.
The reaction between polybutene and maleic anhydride for the preparation of polybutenyl succinic anhydride is generally performed by a chlorination process using chlorine. Accordingly, the resulting polybutenyl succinic anhydride as well as a polybutenyl succinimide produced from the polybutenyl succinic anhydride has a chlorine content in the range of approx. 2,000 to 3,000 ppm (wt). In contrast, a thermal process using no chlorine gives a polybutenyl succinic anhydride and a polybutenyl succinimide having a chlorine content in a range of such as less than 30 ppm (wt). Therefore, a succinimide derived from a succinic anhydride produced by the thermal process is preferred due to a smaller chlorine content in the lubricating oil composition.
The alkenyl- or alkyl-succinimide can be a modified alkenyl- or alkyl-succinimide which is obtained by after-treatment using a boric acid, an alcohol, an aldehyde, a ketone, an alkylphenol, a cyclic carbonate, an organic acid, or the like. Preferable modified succinimides are borated alkenyl- or alkyl-succinimides which are produced by after-treatment using boric acid or a boron-containing compound. The borated succinimides are preferred because of their high thermal and oxidation stability.
The lubricating oil composition of the present invention can further contain other ashless dispersants such as succinic acid ester dispersants and benzylamine dispersants.
The lubricating oil composition of the present invention further contains a metal-containing detergent which contains an organic acid metal salt component. Specifically, the metal-containing detergent may be one or a combination of a non-sulfurized alkali metal or alkaline earth metal salt of an alkylsalicylic acid having a TBN of 10 to 350 mgxc2x7KOH/g or a non-sulfurized alkali metal or alkaline earth metal salt of an alkylphenol derivative having a Mannich base structure. Preferably, the metal-containing detergent is a non-sulfurized alkali metal or alkaline earth metal salt of an alkylsalicylic acid having a TBN of 30 to 300 mgxc2x7KOH/g, more preferably 30 to 100 mgxc2x7KOH/g. The detergent is used in the lubricating oil composition in an amount of 0.1 to 1 wt. % in terms of the sulfated ash content.
The alkylsalicylate preferably employed in the present invention is an alkali metal salt or an alkaline earth metal salt of an alkylsalicylic acid which is prepared from an alkylphenol by Kolbe-Schmitt reaction. The alkylphenol is prepared by a reaction of xcex1-olefin having approx. 8 to 30 carbon atoms (mean number) with phenol.
The alkaline earth metal salts such as Ca salt and Mg salt can be produced from Na salt or K salt by double decomposition or decomposition using sulfuric acid. The double decomposition using calcium chloride (CaCl2) is not preferred, because chlorine is incorporated into the resulting salt.
Alternatively, calcium salicylate can be produced by direct neutralization of alkylphenol and subsequent carbonation. However, the conversion ratio is less than that of the Kolbe-Schmitt reaction.
Accordingly, a non-sulfurized alkylsalicylate having a TBN of 30 to 300 mgxc2x7KOH/g, preferably, 30 to 100 mgxc2x7KOH/g, which can be prepared by a series of Kolbe-Schmitt reactions and decomposition using sulfuric acid is most preferred for the use in the lubricating oil composition of the present invention.
In addition to the metal-containing detergent in the lubricating oil composition of the present invention, an alkali metal salt or an alkaline earth metal salt of an organic acid or phenol derivative having a carbon-nitrogen bonding is also preferred. Generally, a metal-containing detergent having been treated with an amine compound has a base number originating from the basic nitrogen component and hence it advantageously has a low ash but a high base number. For instance, there are exemplified various compounds such as metal salts of aminocarboxylic acids. Most preferred is a non-sulfurized alkylphenate (alkali metal salt or alkaline earth metal salt of alkylphenol derivative) having a Mannich base structure. This compound can be prepared by the following process: an alkylphenol, formaldehyde, and an amine or an amine compound are subjected to Mannich reaction; the phenol ring of the resulting compound is amino-methylated; and thus obtained product is neutralized with a base such as calcium hydroxide to give the desired metal salt. Particularly preferred is a compound of the following formula, in which R is an alkyl group having 8 to 30 carbon atoms, and n is 0 or a positive integer:
A representative compound of the above-mentioned formula can have 2.5 wt. % Ca, 1.6 wt. % N, and a TBN of 135 mgxc2x7KOH/g. This means that the base number originating from the nitrogen component amounts to approximately 50% of the total base number.
The non-sulfurized alkylsalicylate and the non-sulfurized alkylphenate having a Mannich base structure can be employed in combination.
Other metal-containing detergents such as sulfonate or phenate detergents can be employed in combination with the non-sulfurized alkylsalicylate and/or the non-sulfurized alkylphenate having a Mannich base structure.
The sulfonate detergents are alkali metal salts or alkaline earth metal salts of petroleum sulfonic acids or alkylbenzenesulfonic acids. Preferred is a sulfonate having a low TBN which has high stability at high temperatures but gives a relatively low sulfated ash content. A known phenate detergent such as alkali metal salts or alkaline earth metal salts of sulfurized alkylphenol would be employed within the limits of the sulfated ash or sulfur content of the lubricating oil composition of the present invention.
The metal-containing detergent in the lubricating oil composition of the present invention is generally available in the form of an oily dispersion which comprises a metal salt of an organic acid (generally referred to as xe2x80x9csoap componentxe2x80x9d) and particles of basic inorganic salts (e.g., calcium carbonate particles) gathering around the organic acid metal salt in a base oil. The high temperature detergency (that is, ability to keep the inside of engine clean at high temperatures) of a lubricating oil composition does not decrease when the content of the metal-containing detergent in the lubricating oil composition is decreased, provided that the organic acid metal salt (i.e., soap component) is contained in the lubricating oil composition at a certain level or more, i.e., 0.2 to 7 wt. %.
The lubricating oil composition of the present invention further contains a zinc dialkyldithiophosphate (i.e., Zn-DTP) in an amount of 0.01 to 0.1 wt. % in terms of the phosphorus content. More preferred is an amount of 0.01 to 0.06 wt. %.
The ZN-DTP preferably is zinc dihydrocarbyldithiophosphate containing an alkyl group of 3 to 18 carbon atoms or an alkylaryl group having an alkyl group of 3 to 18 carbon atoms. Particularly preferred is a Zn-DTP having an alkyl group derived from a secondary alcohol of 3 to 18 carbon atoms or a mixture of the secondary alcohol and a primary alcohol. The primary alcohol has a property of high heat resistance.
The lubricating oil composition of the present invention further contains an oxidation inhibitor selected from the group consisting of phenol compounds and amine compounds in an amount of 0.01 to 5 wt. %, more preferably 0.1 to 3 wt. %. Generally, a lubricating oil composition having a low sulfated ash content, a low phosphorus content, and a low sulfur content shows low detergency at high temperatures, low oxidation stability and low wear-resistance due to decreases of amounts of a metal-containing detergent and a zinc dithiophosphate. In order to compensate the decreased detergency, oxidation stability and wear-resistance, a hindered phenol oxidation inhibitor and/or a diarylamine oxidation inhibitor are favorably used. The diarylamine oxidation inhibitor advantageously gives a base number originating from the nitrogen component, while the hindered phenol oxidation inhibitor advantageously shows inhibition of oil deterioration caused by oxidation in the presence of NOx.
Examples of the hindered phenol compounds include 2,6-di-t-butyl-p-cresol, 4,4xe2x80x2-methylenebis(2,6-di-t-butylphenol), 4,4xe2x80x2-methylenebis(6-t-butyl-o-cresol), 4,4xe2x80x2-thiobis(2-methyl-6-t-butylphenol), 4,4xe2x80x2-isopropylidenebis(2,6-di-t-butylphenol), 4,4xe2x80x2-bis(2,6-di-t-butylphenol), 2,2xe2x80x2-methylenebis(4-methyl-6-t-butylphenol), 4,4xe2x80x2-thiobis(2-methyl-6-t-butylphenol), 2,2-thiodiethylenebis[3-(3,5-d 1-t-butyl-4-hydroxyphenyl)propionate], octyl 3-(3,5-d 1-t-butyl-4-hydroxyphenyl)propionate, and octadecyl 3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate.
Examples of the diarylamine compounds include an alkyldiphenylamine containing a mixture of alkyl groups having 4 to 9 carbon atoms, p,pxe2x80x2-dioctyidiphenylamine, phenyl-xcex1-naphthylamine, phenyl-xcex2-naphthylamine, alkylated xcex1-naphthylamine, and alkylated phenyl-xcex1-naphthylamine. Each of the hindered phenol compound and diarylamine compounds can be employed singly or in combination. Other oil soluble oxidation inhibitors can be employed in combination.
The lubricating oil composition of the present invention preferably further contains a molybdenum compound and/or a hydrated alkali metal borate in an amount of not more than 5 wt. %, particularly, 0.01 to 5.0 wt. %, for each compound. These compounds give sulfated ash and may have a sulfur content. Accordingly, the amounts of these compounds are controlled in view of the various component contents and the desired characteristics.
The molybdenum compound functions as a friction modifier, an oxidation inhibitor and/or an anti-wear agent in the lubricating oil composition of the present invention, and further imparts increased high temperature detergency to the lubricating oil composition. The content of the molybdenum compound in the lubricating oil composition preferably is in an amount of 10 to 2,500 ppm in terms of molybdenum element. Examples of the molybdenum compounds include a sulfur-containing oxymolybdenum succinicimide complex compound (described in Japanese Patent Publication No. 3-22438), an oxymolybdenum dithiocarbamate sulfide, oxymolybdenum dithiophosphate sulfide, amine-molybdenum complex compound, oxymolybdenum diethylate amide, and oxymolybdenum monoglyceride. Particularly, the sulfur-containing oxymolybdenum succinic imide complex compound is effective for increasing the high temperature detergency.
The addition of a hydrated alkali metal borate is also effective for imparting high temperature detergency and adding a base number to the lubricating oil composition. Preparation of typical hydrated alkali metal borates is described in U.S. Pat. Nos. 3,929,650 and 4,089,790. For instance, the hydrated alkali metal borate can be prepared by the steps of carbonation of neutral alkali metal or alkaline earth metal sulfonate in the presence of an alkali metal hydroxide to give over-based sulfonate; and causing thus obtained sulfonate to react with boric acid so as to produce micro-particles of an alkali metal borate dispersed in the resulting reaction mixture. For the carbonation reaction, an ashless dispersant such as succinimide is preferably present in the reaction mixture. The alkali metal preferably is potassium or sodium. Particularly preferred is a dispersion of micro-particles (particle size: less than approx. 0.3 xcexcm) of KB3O5.H2O in a succinimide-containing oil. The corresponding salt in which K is replaced with Na is also advantageously employed from the viewpoint of resistance to hydrolysis.
The lubricating oil composition of the present invention preferably further contains a viscosity index improver in an amount of not more than 20 wt. %, preferably 1 to 20 wt. %. Examples of the viscosity index improvers include polyalkyl methacrylate, ethylene-propylene copolymer, styrene-butadiene copolymer, and polyisoprene. The viscosity index improvers can be of a dispersant type or a multi-functional type. The viscosity index improvers can be employed singly or in combination.
The lubricating oil composition of the present invention may further contain other auxiliary additives. Examples of other auxiliary additives include zinc dithiocarbamate, methylenebis(dibutyldithiocarbamate), oil soluble copper compounds, sulfur-containing compounds (e.g., olefin sulfide, ester sulfide, and polysulfide), phosphoric acid esters, phosphorous acid esters, and organic amide compounds (e.g., oleylamide) which serve as oxidation inhibitors and anti-wear agents. The examples may further include metal-inactivating agents (e.g., benzotriazole compounds and thiadiazole compounds), anti-rust agents or anti-emulsifiers (e.g., nonionic polyoxyalkylene surfactants such as polyoxyethylene alkylphenyl ether, copolymer of ethylene oxide and propylene oxide), friction modifiers (e.g., amine compounds, amide compounds, amine salts, their derivatives, fatty acid esters of polyhydric alcohols, their derivatives), anti-foaming agents, and pour point depressants. Each of these auxiliary additives can be incorporated into the lubricating oil composition in an amount of not more than 3 wt. %, preferably 0.001 to 3 wt. %.


Systems for measuring a distance include a lens positioned a distance above a target surface. A camera is configured to measure a first interference pattern between the lens and the target surface using a light source at a first wavelength and to measure a second interference pattern between the lens and the target surface using a light source at a second wavelength. A processor is configured to determine an absolute measurement of the distance between the lens and the target surface based on the first interference pattern and the second interference pattern.

Technical Field
The present invention relates to height measurement at small distances and, in particular, to the use of optical interference to determine absolute vertical position above a surface.
Description of the Related Art
Optical interference can provide a precise measurement of a change in distance between a lens surface and a target surface. However, interference patterns (e.g., Newton's rings) are typically periodic, repeating their pattern with height changes on the order of the wavelength of the light used. Measuring absolute distances between the lens and the target surface is therefore difficult.

Height measurement using optical interference

INTERNATIONAL BUSINESS MACHINES CORPORATION


In a semiconductor device including a super junction structure that p-type columns and n-type columns are periodically arranged, a depth of a p-type column region in a cell region that a semiconductor element is formed is made shallower than a depth of a p-type column region in an intermediate region which surrounds the cell region. Thereby, a breakdown voltage of the cell region becomes lower than a breakdown voltage of the intermediate region. An avalanche breakdown phenomenon is caused to occur preferentially in the cell region in which even when an avalanche current is generated, the current is dispersed and smoothly flows. Thereby, it is possible to avoid local current constriction and breakage incidental thereto and consequently it becomes possible to improve avalanche resistance (an avalanche current amount with which a semiconductor device comes to be broken).

The present invention relates to a semiconductor device and a manufacturing method for the semiconductor device and is favorably utilized in, for example, a power semiconductor device and a manufacturing method for the power semiconductor device.
In the field of vertical-type power MOSFETs, that is, the power semiconductor devices, adoption of a super junction structure is now being examined in order to suppress on-resistance while maintaining a breakdown voltage.
For example, in Japanese Unexamined Patent Application Publication No, 2007-335844, there is disclosed a semiconductor device which has adopted the super junction structure in a cell region and a peripheral region. Then, semiconductor pillar regions having the super junction structure are formed such that the closer to the termination of each of the cell and intermediate regions the semiconductor pillar region is located, the more the depth thereof is reduced stepwise.

Semiconductor device and manufacturing method for the semiconductor device


Phosphor compositions are disclosed comprised of a BaGd.sub.2 O.sub.4 host which is activated by at least one of Tb and Sm. These phosphors are useful as storage phosphors. An imaging plate utilizing these phosphors is also disclosed.

Phosphor materials have been used in the past, in a variety of forms, to help in alleviating the exposure of patients to X-rays during X-radiation diagnoses.
Storage phosphors, or photostimulable phosphors, have the ability to store some of the X-ray energy and emit longer wavelength radiation when exposed to (excited by) visible light, infrared rays, heat, etc. The secondary excitation needed to cause the emission of longer wavelength radiation in storage phosphors is commonly referred to as stimulation radiation. Storage phosphors are typically used in imaging plates to acquire images in a digital format and to produce images which may be electronically displayed on a CRT, or printed to a suitable hardcopy medium such as photographic film. Typically, in such imaging plates, the storage phosphors are incorporated into a binder which is applied to a suitable support, such as polyethylene terephthalate (PET), and a protective overcoat material is applied over the phosphor containing binder layer.
When ionizing radiations such as X-rays or Gamma rays are used for imaging human bodies it is desirable that the photostimulable phosphors employed in imaging plates emit light at as high a luminescence intensity as possible due to exposure to stimulating radiation after exposure to ionizing radiation so that the dose of ionizing radiations to which the body must be exposed can be reduced. Of the many different and photostimulable phosphor compositions known, many fail to satisfy the practical demands of medical imaging applications by failing to generate sufficient or photostimulated emission intensity for the desired radiation dose. It is therefore desirable to identify storage phosphors which are capable of producing high photostimulated emission intensities.
It would also be desirable to identify useful phosphor hosts having relatively high densities, since, theoretically, for phosphors which have higher densities, thinner phosphor layers could be utilized, resulting in increased resolution. One very popular storage phosphor, BaFBr, has a relatively low density of about 4.96 g/cc.
Phosphors typically consist of a host compound, which is often combined with a small amount of an activator element to change the hue and/or improve the efficiency of fluorescence.
U.S. Pat. Nos. 4,959,174; 4,829,188; and 4,857,741 disclose phosphors in which gadolinium may be combined with at least one divalent metal selected from the group consisting of Be, Mg, Ca, Sr, Ba, Zn and Cd. However, these phosphors also include either or both of Ta and Nb.
Two articles, "On the Eu.sup.3+ Fluorescence of Mixed Metal Oxides," by G. Blasse, J. Chem. Phys., Vol. 47, No. 7, pp. 2356-2360 (October 1966); and "On the Eu.sup.3+ Fluorescence in Mixed metal Oxides," by G. Blasse and A. Bril, Philips Res. Depts. 21, pp. 368-378 (1966), deal with the fluorescence of several gadolinium-containing phosphors, including BaGd.sub.2 O.sub.4 activated by europium. However, there is no mention of photostimulated luminescence or whether other activating elements result in photostimulable properties for this host compound, nor is there any mention that these phosphors are suitable as storage phosphors.
There continues to be a need for materials which are suitable as storage phosphors, particularly those having higher densities and higher photostimulated emission intensity.

Barium gadolinate phosphor activated by terbium and/or samarium


The installation for microscopic observation of a semiconductor electronic circuit includes, in a vacuum, a reflection particle interaction microscope and parts for supporting the circuit facing the reflection particle interaction microscope. The installation further includes a reflection optical microscope including optical observation part and elements for illuminating the circuit to be observed, with the illumination elements and the optical observation part on the same side of the circuit and the reflection optical microscope and the reflection particle interaction microscope disposed face-to-face on a common observation axis on respective opposite sides of the circuit.

The present invention relates to an installation for microscopic observation of a semiconductor electronic circuit, of the type which includes, in an evacuated observation enclosure (12):
a reflection particle interaction microscope;
means for supporting the circuit facing the reflection particle interaction microscope, and
means for causing relative movement between the circuit and the reflection particle interaction microscope.
It is essential to verify the quality of a semiconductor circuit, also commonly referred to as an integrated circuit, and that it is operating correctly, during or after its fabrication.
Integrated circuits are therefore observed while they are still joined together in a wafer of silicon or some other substance in which they have been etched side-by-side.
An initial observation is carried out using a reflection optical microscope to detect large defects, such as particles fouling the surface of the circuits.
The increasing complexity of the circuits and the decreasing size of their components make it necessary to use a scanning electron microscope or some other type of reflection particle interaction microscope to show up defects that cannot be detected by an optical microscope.
Because of its very high resolution, the scanning electron microscope is satisfactory for detecting small defects or impurities.
In addition to using a scanning electron microscope to detect defects, it is possible to stimulate the integrated circuit electrically, either directly or by induction, and to observe a localized area of the integrated circuit to detect and therefore measure variations in the signal with time.
In the case of an optical microscope, it is possible to observe and to measure the operation of the circuits by analyzing the signal reflected through the substrate (which is made of silicon, for example) from the bottom of the circuit or through the oxide from the top of the circuit.
In the case of a reflection particle interaction microscope, the reflected signal gives information on the electric signals flowing in the metal tracks that cover the surface of the circuit.
The scanning electron microscope has a very narrow field of view. Positioning it relative to the extremely large surface of the electronic circuit is therefore difficult. Similarly, the exact location of the observed area of the circuit relative to the circuit as a whole is difficult to determine because of the narrow field of view.
An object of the invention is to facilitate determining the location of the observation area, verifying a circuit in a microscopic observation installation which can detect small defects and analysing circuits made up of very small components.
To this end, the invention provides an installation for microscopic observation of a semiconductor electronic circuit, of the aforementioned type, characterized in that it includes, in said enclosure, a reflection optical microscope including optical observation means and means for illuminating the circuit, with the illumination means and the optical observation means on the same side of the circuit and the reflection optical microscope and the reflection particle interaction microscope disposed face-to-face on a common observation axis on respective opposite sides of the circuit carried by the support means, and in that it includes means for causing relative movement between the circuit and the reflection optical microscope identical to the relative movement between the circuit and the reflection particle interaction microscope so that the two microscopes are kept facing each other along the same observation axis and observe the same region of the circuit.
In one particular embodiment, the installation includes one or more of the following features:
the illumination means include a source of near infrared or ultraviolet radiation;
the reflection particle interaction microscope is at least one of the following: a scanning electron microscope, an ion beam microscope, an electron beam tester and a focussed ion beam system;
the reflection optical microscope is equipped with a laser beam measurement and observation system;
the means for supporting the object to be observed include a frame adapted to position the semiconductor circuit with its etched face towards the reflection particle interaction microscope and its face consisting of non-etched substrate towards the reflection optical microscope;
the means for producing relative movement between the circuit and each of the two microscopes include means for moving the circuit relative to the enclosure in a plane perpendicular to the common observation axis of the two microscopes;
the means for supporting the circuit are fixed relative to said enclosure and the means for causing relative movement between the circuit and each of the two microscopes include, for each microscope, means for moving the microscope relative to said enclosure in a plane perpendicular to the common observation axis of the microscopes, and in that it further includes laser interferometer means for aligning the two microscopes disposed between them.
The invention also provides method of microscopic observation of a semiconductor electronic circuit placed in an evacuated observation enclosure, the method including the steps of:
observing a first face of the circuit using a reflection particle interaction microscope; and
causing relative movement between the circuit and the reflection particle interaction microscope; characterized in that it further includes the steps of:
observing the face of the circuit opposite said first face using a reflection optical microscope which is disposed face-to-face with the reflection particle interaction microscope on a common observation axis and on the other side of the circuit by illuminating the opposite face of the circuit with illuminating means facing the opposite face of the circuit; and
causing relative movement between the circuit and the reflection optical microscope identical to the relative movement between the circuit and the reflection particle interaction microscope so that the two microscopes are kept facing each other along the same observation axis and observe the same region of the circuit.

Installation and method for microscopic observation of a semiconductor electronic circuit


A thin-film magnetic head has a first ferrite block on which a plurality of transducing elements are aligned on a predetermined surface, and a second ferrite block bonded to the first ferrite block, and has multi-track capabilities in accordance with the transducing elements. Eithr bonding surface of the first and second ferrite block is formed with an insulating film layer, the entire bonding surface is coated with an adhesive or formed with a plurality of recesses to be externally filled with the adhesive, and the adhesive is filled in gaps defined by the recesses and the surface of the opposed ferrite block. Thus, since the bonding portions of the first and second ferrite blocks are distributed over a wide region, the bonding strength can be largely increased, the transducing gap lengths are uniformly maintained, and the transducing element characteristic is not affected by the aging of the adhesive thereby improving the reliability of the magnetic head.

1. Field of the Invention
The present invention relates to a method for manufacturing thin-film magnetic heads having a plurality of conversion elements for use in a magnetic tape transport and a thin-film magnetic head manufactured thereby and, more particularly, to a method for manufacturing thin-film magnetic heads in which the length of transducing gaps of tracks are formed equally with high reliability.
2. Description of the Relevant Art
A thin-film magnetic head having a plurality of transducing elements is formed by forming a plurality of conversion elements by a known thin-film processing technique, such as sputtering, depositing or photoetching on one ferrite block, and fastening another ferrite block, having a surface opposed to the elements to be extremely smoothly finished to one ferrite block, by an adhesive.
In such a thin-film magnetic head manufactured by such a process, the steps of form a plurality of tracks on one magnetic head, and not solely forming transducing gaps corresponding to the tracks but merely bonding two ferrite blocks with an adhesive to simultaneously forming the respective transducing gaps are employed. Thus, the gap lengths of the transducing gaps corresponding to the respective tracks might become irregular after bonding. It is understood that such irregularity of the transducing gaps adversely influences the electromagnetic transducing characteristics of not only the thin-film magnetic head but all the magnetic heads.
For example, a process for making a read-while-write tape head and the magnetic head made thereby are disclosed in U.S. Pat. No. 4,044,392. The magnetic head disclosed in this U.S. Patent is constructed such that a plurality of write elements and a plurality of read elements are aligned on two opposed ferrite blocks and two magnetic layers and a center section sandwiched between the two magnetic layers are disposed between the blocks. Insulating pads made of aluminum oxide are disposed in the vicinity of the right and left ends of the ferrite blocks having the plurality of write elements and at the center of the elements, an insulative gap spacer formed slightly thicker than the elements is disposed on the top of the ferrite block, and the thickness of the spacer determines the write gap dimension, i.e., the transducing gap length. Slots are cut at the sides of the center section opposed to the ferrite blocks having the write elements, filled with glass therein to define write tracks. Such a magnetic head structure is clamped integrally by two bolts through a left end piece and a right end piece. A resulting structure is filled by capillary action with a low viscosity epoxy cement applied to the gap to seal and stabilize the structure. In the method disclosed in this U.S. Patent, when the two ferrite blocks and the center section are assembled, the control of clamping with the two bolts is difficult. If the ferrite blocks and the center section are clamped by a force of certain magnitude so that the insulating gap spacer is uniformly clamped, the transducing gap lengths of the tracks can be theoretically substantially uniformly set. But, since the gaps between the insulative pads and the center section become very short by clamping, the control of raising the bonding strength by supplying sufficient quantity of adhesive into the gaps by the capillary action is difficult. If sufficient quantity of adhesive cannot be fed to the very small gaps between the insulative pads and the center section, the adhesive overflows to the outer region of the surface to be originally bonded, with the result being that the bonding strength is remarkably decreased. The ferrite blocks or the center section are lifted to the medium feeding surface by a stress generated due to the overflowed adhesive aged to be thermally swelled, shrunk or to absorb the moisture in the environment to be swelled, with the result that stepwise differences of micron order might be formed partly on the medium feeding surfaces of the ferrite blocks or the center section. It is apparent that such stepwise differences cause serious defects in case of operating the magnetic head, i.e., recording and reproducing data. For example, if the center section is lifted to the ferrite block on this the elements are formed, the spacing between the medium and the transducing gap is directly affected to remarkably reduce the electromagnetic conversion characteristic. If the center section is pressed down to the ferrite block, the elements formed on the ferrite block are exposed in the vicinity of the medium feeding surface, with the result being that the elements are worn by feeding the recording medium so that the original characteristics cannot be maintained and there is a loss in reliability.

Thin-film magnetic head with a plurality of transducers


MOS structures with remote contacts and methods for fabricating such MOS structures are provided. In one embodiment, a method for fabricating an MOS structure comprises providing a semiconductor layer that is at least partially surrounded by an isolation region and that has an impurity-doped first portion. First and second MOS transistors are formed on and within the first portion. The transistors are substantially parallel and define a space therebetween. An insulating material is deposited overlying the first portion of the semiconductor layer and at least a portion of the isolation region. A contact is formed through the insulating material outside the space such that the contact is in electrical communication with the transistors.

The majority of present day integrated circuits (ICs) are implemented by using a plurality of interconnected field effect transistors (FETs), also called metal oxide semiconductor field effect transistors (MOSFETs or MOS transistors). An MOS transistor includes a gate electrode as a control electrode that is formed overlying a semiconductor substrate and spaced-apart source and drain regions that are formed within the semiconductor substrate and between which a current can flow. A control voltage applied to the gate electrode controls the flow of current through a channel in the semiconductor substrate between the source and drain regions and beneath the gate electrode.
The MOS transistor is accessed via a conductive contact typically formed on the source/drain regions between the gate electrodes of two MOS transistors. The conductive contact is usually formed by depositing an insulating layer over a metal silicide on the source/drain regions and etching a contact opening in the insulating layer. A thin barrier layer, typically of titanium and/or titanium nitride, is deposited in the contact opening and the opening then is filled by a chemical vapor deposited layer of tungsten.
However, present-day contact manufacturing techniques create challenges to advanced MOS technology. For example, there is a continuing trend to incorporate more and more circuitry on a single IC chip. To incorporate the increasing amount of circuitry, the size of each individual device in the circuit and the size and spacing between device elements must decrease. However, one of the limiting factors in the continued shrinking of integrated semiconductor devices is the resistance of contacts to doped regions such as the source and drain regions of an MOS transistor. As the width of the contact decreases, the resistance of the contact becomes increasingly larger. In turn, as the resistance of the contact increases, the drive current of the device decreases, thus adversely affecting device performance.
In addition, conventional contacts raise challenges with respect to isolation of the contacts from the gate electrodes. To overcome an increase in resistance, designers often do not scale a contact to the degree that other features in a device are scaled. A larger contact formed between a smaller space between gate electrodes results in a thinner dielectric between the contact and at least one of the gate electrodes. In addition, as the overall device is decreased in size, it becomes more difficult to etch a contact opening within the smaller space between the gate electrodes. Often, the contact openings are not etched vertically but are etched inadvertently at a slight angle. In addition, misaligned mask overlays cause an overlay shift that may result in the etching of the contact opening closer to one of the gate electrodes. These deviations from the etching specifications can result in a thinner dielectric layer between the contact and the gate electrode. The thinner dielectric layer between the contact and a gate electrode can result in current leakage between the contact and the gate electrode. The smaller distance between the contact and a gate electrode also can result in a larger capacitance therebetween.
Still further, conventional contacts adversely affect the benefits of stress layers often formed on MOS transistors. MOS transistors, in contrast to bipolar transistor, are majority carrier devices. The mobility of holes, the majority carrier in a P-channel MOS transistor, can be increased by applying a compressive longitudinal stress to the channel. Alternatively, the mobility of electrons, the majority carrier in an N-channel MOS transistor, can be increased by applying a tensile longitudinal stress to the channel. These stresses are typically applied to the channels by forming a stressed layer over the MOS transistor device, including the source and drain regions and the gate electrode. However, the contact usually is formed through the stress layer, thus requiring a hole to be etched through the stress layer. The hole reduces the effect of the stress layer, thus compromising device performance.
Accordingly, it is desirable to provide MOS structures with contacts formed remote from gate electrodes. It is also desirable to provide methods for fabricating such MOS structures. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.

MOS structures with remote contacts and methods for fabricating the same


A vacuum chuck (10) holds a semiconductor wafer (56) securely in place during manufacturing processes. An external chuck (12) has a hollow center portion receiving a spindle support (14) and shaft (16). A positive pressure is applied through the shaft to a nozzle assembly (26) that rests on the spindle support. The nozzle assembly is further housed within a cavity in an internal chuck (28) that rests within a cup in the external chuck. The nozzle assembly use a venturi jet (44) to convert the positive pressure to a vacuum. A plurality of vacuum ports (34 and 36) from the cavity of the internal chuck transfer the vacuum to an upper surface (40) of the internal chuck to hold the semiconductor wafer in place. A plurality of exhaust ports (30 and 32) from the cavity of the internal chuck exhaust gases radially across the upper surface (13) of the external chuck toward its perimeter to prevent undesired chemicals from reaching the underside of the semiconductor wafer.

The present invention relates in general to semiconductor device fabrication and, more particularly, to a vacuum chuck with a venturi jet for converting a positive pressure into a vacuum that securely holds a semiconductor wafer during manufacturing processes.
A common process in semiconductor device fabrication is chemical etching where material is removed from specific areas of the semiconductor wafer by a chemical process. Areas on one surface the semiconductor wafer not intended to be etched are first masked. A liquid etchant, for example hydrochloric acid, is applied to the reactive surface of the semiconductor wafer. The etchant chemically removes material from the unmasked areas. The wafer is typically spun at a high rate to evenly distribute the etchant during the process. Etching is also used for bulk removal of material in thinning processes to achieve specific electrical characteristics.
The semiconductor wafers are commonly processed one at a time to maintain strict processing standards. One technique involves holding the semiconductor wafer in place by grasping the edges of the wafer with pins during the etching process. It is undesirable to allow the etchant to reach the bottom unreactive surface of the semiconductor wafer. A nitrogen gas is blown onto the bottom of the semiconductor wafer to remove any etchant. As the etching process proceeds, the diameter of the semiconductor wafer reduces as material at the edge etches away. The grasping of the semiconductor wafer by the edge pins becomes less secure allowing movement of the wafer and possible damage.
To solve the pin grasping problems, vacuum chucks have been used to securely hold the semiconductor wafer in place. The semiconductor wafer is positioned on the vacuum chuck and a negative pressure (vacuum) is drawn through the vacuum chuck to create a suction that secures the wafer in place. Unfortunately, the negative pressure also tends to draw liquid etchant around the edge to the bottom side of the semiconductor wafer. The liquid etchant removes semiconductor material on the bottom side of the wafer which is undesirable. Attempts have been made to block the migration of etchant from the upper surface to the bottom side of the semiconductor wafer including polymer coating and taping, but most if not all techniques involve additional processing steps and complexity that add to the overall cost of manufacture.
Hence, a need exists for an apparatus that holds the wafer securely throughout the etching process and further prevent the etchant from reaching the bottom side of the semiconductor wafer.

Vacuum chuck with venturi jet for converting positive pressure to a vacuum


In some embodiments, the present invention is directed to a computer-implemented method which includes at least the following steps of requesting a consent to obtain an individual social media profile data; based on the consent, electronically obtaining the individual social media profile data from a social media electronic data source; determining individual specific parameters based on the individual social media profile data; matching the individual specific parameters to at least one segment identifier generated based on a predetermined segmentation of a target population of individuals; based on the matching, associating the at least one segment identifier with the individual social media profile data; and outputting an advertisement to the individual based on the at least one segment identifier associated with the individual social media profile data of such individual.

Target audience matching techniques are generally known. For example, U.S. Patent Application Publication No. 2012041792 is generally directed to a method of segmenting a population. U.S. Pat. No. 8,131,271 is directed to categorization of a mobile user profile based upon browsing behavior. Similarly, U.S. Patent Application Publication No. 2010203876 describes a method of inferring user profile properties based upon mobile device usage.

Content targeting to particular individuals based on demographic and psychographic segmentations, utilizing the computer-implemented methods and specifically programmed computer systems for performing thereof


A control system for a load-handling clamp includes first and second load-engaging surfaces for selectively gripping and releasing a load disposed between said surfaces. At least one of said surfaces is selectively movable toward the other by a hydraulic actuator. At least one fluid valve assembly variably regulates a maximum hydraulic clamping pressure capable of causing the actuator to move one of the surfaces toward the other in a load clamping movement. Preferably, a load geometry sensor produces an electrical effect that varies as a function of the geometric profile of the load. A data receiver preferably also obtains load identification information related to at least one characteristic of the load, other than the load's geometry. A controller, in response to the data receiver and load geometry sensor, operates to control the valve assembly's regulation of the maximum hydraulic clamping pressure. In order to prepare for the load clamping movement, the controller is preferably also capable of enabling the actuator to move one of said surfaces toward the other in an initial clamp closing movement at a maximum hydraulic closing pressure greater than the maximum hydraulic clamping pressure. Thereafter the controller enables the load clamping movement at a pressure level substantially no greater than the maximum hydraulic clamping pressure.

The present invention relates to improvements in fluid power load-clamping systems with automatically variable maximum clamping force control, for optimizing the versatility and speed by which a wide variety of different load types in a warehouse or other storage facility can be properly clamped in a manner automatically adaptive to each load type and configuration.
Load handling clamps typically operate in a storage or shipping facility such as a warehouse or distribution center and must often be capable of handling more than one type, or variety, of load. The clamps in some of these facilities encounter a relatively small number of distinct load types. For example, a load handling clamp being used in a distribution center for a large consumer appliance manufacturer may encounter dishwashers, washing machines, clothes dryers and refrigerators almost exclusively. In other facilities, load handling clamps will encounter a much wider variety of load types. The appliances from the previous example may, for instance, be shipped to a warehouse for a large retail store. The warehouse may also contain computers, furniture, televisions, etc. A clamp may thus encounter cartons having similar outward appearances and dimensions but containing products having differing optimal maximum clamping force requirements due to different load characteristics such as weight, fragility, packaging, etc. A clamp may also not always be required to grip the same number of cartons. For instance a clamp may be utilized to simultaneously move four refrigerator cartons, then to move a single dishwasher carton, and finally a single additional refrigerator carton, presenting different load geometries also having differing optimal maximum clamping force requirements, separate from those arising from the foregoing load characteristics.
Fluid power clamping systems with automatically variable limitations on clamping force usually impose such limitations in a way which limits the speed with which the load-engaging surfaces can be closed into initial contact with the load, thereby limiting the productivity of the load-clamping system. This problem has been reduced in the past by allowing higher maximum fluid closing pressures than optimal maximum fluid pressure during initial closure and then, when the load is about to be contacted by the load-engaging surfaces, decreasing the maximum fluid pressure limit to a limit at or below the optimal limit to clamp the load. However this latter approach, although faster, has not previously been usable compatibly with complex inputs involving both load geometries and load characteristics as described above.

Control system for a load handling clamp