An emitter follower circuit applies to an input terminal of a second amplifying device a voltage according to a reference voltage applied to a reference terminal. First and second resistors are connected in series between the reference terminal and an input terminal of a first amplifying device. The collector of a first transistor is connected to the reference terminal and a control voltage is applied to the base of the first transistor. A third resistor is connected between the emitter of the first transistor and a grounding point. A current mirror circuit draws a current proportional to a current input from the collector of the first transistor from a connection point of the first and second resistors.

1. Field of the Invention
The present invention relates to a power amplifier having improved idle current controllability, reduced susceptibility to device variations and stable temperature characteristics.
2. Background Art
Power amplifiers using GaAs heterojunction bipolar transistors (GaAs-HBT) are presently used widely as power amplifiers for use in portable telephone in CDMA and other systems. FIG. 13 is a circuit diagram showing a conventional GaAs-HBT power amplifier. The area in the dotted frame in FIG. 13 corresponds to a GaAs chip. Circuit elements in the other area are formed of chip parts and conductor lines on a module substrate.
In FIG. 13, reference characters Tr1 and Tr2 denote a preceding-stage amplifying device and a following-stage amplifying device, respectively. Bias1 denotes a preceding-stage bias circuit for driving the preceding-stage amplifying device, and Bias2 denotes a following-stage bias circuit for driving the following-stage amplifying device.
Vc1 and Vc2 respectively denote collector power supply terminals of the preceding-stage and following-stage amplifying devices. Vcb denotes a power supply terminal for the bias circuits Bias1 and Bias2. Vref denotes a terminal through which a control voltage is applied to the bias circuits Bias1 and Bias2. IN denotes an RF signal input terminal. OUT denotes an RF signal output terminal. R1 to R4 denote resistors; C1 to C10, capacitors; L1 and L2, inductors; and L3 to L8, lines having particular electrical lengths and functioning as inductors. Recently, in ordinary cases, C1, C2, and L1 forming an input matching circuit and C3, C4 and L2 forming an interstage matching circuit are integrated on the GaAs chip for the purpose of reducing the module size.
FIG. 14 is a circuit diagram showing a conventional bias circuit. This bias circuit corresponds to the above-described preceding-stage bias circuit Bias1 or following-stage bias circuit Bias2. In FIG. 14, Vref denotes a terminal to which a control voltage is externally applied; Trb1 to Trb3, Trb7 and Trb8 denote GaAs-HBTs; Tr denotes an amplifying device; and Rb1 to Rb3 and Rb5 to Rb8 denote resistors.
An emitter follower circuit including Trb1 applies voltage to the base (input terminal) of the corresponding amplifying device Tr according to the control voltage. An RF signal input from a terminal RFin is input to the base of the amplifying device Tr via a capacitor C in an input matching circuit. The amplified RF signal is output from the collector of the amplifying device Tr to a terminal RFout.
This bias circuit operates so as to constantly maintain the idle current through the preceding-stage amplifying device and the following-stage amplifying device of the power amplifier with respect to changes in temperature (see, for example, Japanese Patent Laid-Open No. 2004-343244). The idle current is a bias current in the power amplifier when there is no RF input power.
FIG. 15 is a diagram showing input/output characteristics of a conventional CDMA HBT power amplifier. When the input power Pin is increased, the idle current Ictq is constant but the output power Pout increases and the total operating current Ict increases.
FIG. 16 is a diagram showing a distortion characteristic of the conventional CDMA HBT power amplifier. The distortion characteristic is expressed by the adjacent channel leakage ratio (ACLR). The ACLR increases with increase in the output power Pout. The output power Pout, power gain Gp and efficiency PAE when the output power increases determine whether the characteristic of the power amplifier is good or bad.
FIG. 17 is a diagram showing a probability distribution with respect to the output power of the power amplifier in a CDMA terminal in a suburb. The probability of low output about 0 dBm is the highest while the probability of the maximum output about 27 dBm is low (see, for example, B. Sahu and G. A. Rincon-Mora, "A high-efficiency linear RF power amplifier with a power-tracking dynamically adaptive buck-boost supply," IEEE Trans. MTT vol. 52, No. 1, pp. 112-120, January 2004). It is, therefore, desirable to enable easily obtaining the desired distortion characteristic by limiting the idle current to a small value when the output power is low and increasing the idle current when the output power is high. For example, as shown in FIG. 18, the idle current Icq of the power amplifier can be limited to the least necessary value by changing the idle current Icq according to the desired output power Pout. However, this method requires a complicated control circuit.
For this reason, a method for making selection between a high idle current and a low idle current in an analog manner according to the output power has been adapted in many cases. This method can be easily implemented if a current mirror circuit or the like is used with enhancement-mode field-effect transistors. However, there are only a small number of documents disclosing a GaAs-HBT power amplifier in which the idle current is controlling in an analog manner.
FIG. 19 is a circuit diagram showing a conventional GaAs-HBT power amplifier in which the idle current is controlled in an analog manner (see, for example, Y.-W. Kim, K.-C. Han, S.-Y. Hong, J.-H. Shin, "A 45% PAE/18 mA quiescent current CDMA/PAM with a dynamic bias control circuit," 2004 IEEE Radio Frequency Interated Circuit (RFIC) Symposium, 2004 Digest of Technical Papers, PP. 365-368). In FIG. 19, Tr denotes an amplifying device; Vc, a collector power supply terminal of the amplification stage constituted by the amplifying device Tr; Vcb, a collector power supply terminal of a bias circuit; Vref, a reference terminal to which a reference voltage is externally applied; and Vmod, a control terminal to which a control voltage is externally applied. Trb11 to Trb17 denote GaAs-HBTs. Rb11 to Rb17 denote resistors. L denotes a transmission line. C denotes a capacitor. An RF signal input from a terminal RFin is input to the base of the amplifying device Tr via the capacitor C in an input matching circuit. The amplifying device Tr amplifies the RF signal and outputs the amplified RF signal from the collector to a terminal RFout. A base circuit formed by Trb11 to Trb17 and Rb11 to Rb17 applies a voltage to the base of the amplifying device Tr according to the control voltage applied to the terminal Vmod.
The power amplifier shown in FIG. 19 has a problem that the control voltage and the idle current are in a nonlinear relationship with each other and, therefore, the controllability of the idle current is low. The amplifier also has a problem that since the idle current control function and the biasing function are incorporated in one circuit, its susceptibility to device variations is high and it is difficult to make constant the temperature characteristic of the idle current (variation in idle current with temperature with respect to the same control voltage).


a movable blade cartridge including a platform member having a blade seat and a guard member. The guard member is located of forward and parallel to the blade seat so as to form a longitudinal slot between the blade seat and the guard member. A primary blade which is disposed on the blade seat such that the cutting edge of the blade is located rearwardly of the guard member. A substantial portion of the primary blade extends into the slot formed between the guard member and the blade seat such that the blade is flexible into the slot. A spacer is located on the upper surface of the primary blade. The spacer comprises a rear portion which functions to separate the primary blade and a secondary blade, as well as a forward portion which extends from the rear portion and functions to prevent upward movement of the primary blade, and create an opening beneath the forward portion of the spacer and the lower surface of the secondary blade. Both the primary and secondary blade are manufactured and mounted so as to be flexible in response to forces encountered during the shaving operation. The blade cartridge also includes a cap member disposed on the secondary blade which prevents upward movement of the second blade.

The present invention relates to wet shaving systems of the blade type and more particularly to a shaving system having a movable blade positioned within a blade cartridge or the like.
During the shaving process, shavers have long sought a wet shaving system which provides a smooth and comfortable shave without having annoying cuts and abrasions caused by the blade being at the wrong blade exposure or shaving angle in response to shaving forces.
The terms "blade exposure" and "shaving angle" represent geometrical relationships between the blade and the shaving surface. These terms as well as another term commonly used in the art are defined as follows. First, the term "shaving plane" means the plane tangent to skin engaging surfaces, referred to as a guard and a cap, which are disposed on both sides of the blade so as to engage the shaving surface before and after engagement by the blade. Second, the term "blade exposure" means the distance by which the blade edge projects forwardly of the shaving plane. Third, the term "shaving angle" means the acute angle between a plane tangent to the cutting edge of the blade and the shaving plane.
Various approaches have been used to enable the shaving blade to move relative to the blade cartridge or razor body in response to shaving forces encountered during the shaving process in an effort to present the correct blade exposure and shaving angle.
One approach disclosed in prior art patents illustrates a blade cartridge comprising two blades separated by a spacer with the blades and the spacer attached to a cap to form a unitary assembly. The blade assembly is movable between various blade exposures and shaving angles within various degrees of control and direction in response to forces encountered during shaving. For example, Ciaffone et al., U.S. Pat. No. 4,461,079, discloses a razor cartridge comprising a body portion 10 which includes a guard bar 12 (FIGS. 1-5). The guard bar 12 defines a leading skin-engaging surface fixed to the body portion. A rear beam 17 spans end walls 14 and 16 of the body portion 10 and a medial support member 13 to join the front of the cartridge 12 to the end thereof. A plurality of generally flat coplanar segments 18,19,21,22, each having an opening 23, are hinged to the rear beam 17 by mating webs 24,26,27,28 (col. 2, lines 50-52). Collectively, the segments 18,19,21,22 define a blade seat which is operable to pivot about the beam 17, thereby changing the attitude of blade edge relative to guard bar 12 (col. 2, lines 53-57). A cap 33 is apparently placed above an assembly of two skin-engaging blades 34,36, straddling a spacer 37 (FIG. 3). The two blades and the spacer are secured to one coplanar segment 21 of the blade support or blade seat by a conventional rivet 38 to form a rigid unit. A hinge 27 connects the coplanar segment 21 to the rear-beam 17 (col. 3, lines 1-8). As compared to the position of the blade edges relative to the guard bar at the normal or free position set in accordance with a predetermined blade geometry (FIG. 3), a change in blade geometry occurs during the course of shaving when a shaving force F causes the blade package to rotate or pivot about rear-beam 17 in the direction of arrow R where the blade edges are rendered less "aggressive" (FIG. 4, col. 3, lines 13-23). Upon relaxation of shaving forces, the elastic memory of hinges 24,26,27,28 forces the blade seat, and therefore the blade edges, to return to their normal position (FIG. 3., col. 3, lines 24-26).
In an alternative embodiment, Ciaffone et al. shows the blade seat is hinged to a front beam 175 by webs 240,260,270,280 (FIGS. 6-10, col. 3, lines 46-48). Upon exertion of a shaving force F' (FIG. 9) onto the cap 330, the coplanar segments 180,190,210 and 220, move in the direction of the arrow R (FIG. 9) to provide a more aggressive edge exposure (col. 4, lines 1-9). As in the embodiment of FIGS. 1-5, the elastic memory of the hinges 240,260,270,280 forces the blade edges to return to the free position when shaving forces are released (col. 4, lines 11-13).
Oldroyd et al., U.S. Pat. No. 4,063,354, discloses a shaving unit wherein a blade unit comprises two blades separated by a spacer 5 (FIGS. 13-16). A resiliently flexible metallic or plastic guard 3 is secured to the blade unit by spot welding or other means (col. 3, lines 26-28). The blade unit, which is illustrated in its normal forward position of maximum blade exposure in FIG. 13, can bow rearwardly under pressure applied during shaving to carry the blade unit along a plane to the rear, relative to the platform 1 and cap 4. This reduces blade exposure but increases the shaving angle, as indicated by dotted lines 3' in FIGS. 13 and 15 (col. 3, lines 26-37).
Althauset et al., U.S. Pat. No. 5,074,042, discloses a shaver head comprising two staggered blades 7 embedded in a blade block 6 (FIG. 3). A cover cap portion 9 covers the top side of the blade block 6 (col. 3, lines 12-15). A spring 14 is placed between the blade block 6 and a body 2. The blade block 6, together with the two staggered blades 7, can swivel about an axis A (col. 3, lines 17-43). During shaving, pressure is applied to the razor blade unit, thereby causing the blade block 6 to swivel and alter shaving geometry of the blades (col. 3, lines 46-60).
Jacobson U.S. Pat. Nos. 4,442,598, 4,378,634 and 4,270,268 disclose a razor blade assembly including a body member 2 having blade means 36,36' being independently movable in response to spring finger biasing means 18,18' integral with the body member. In the Jacobson patents, the spring fingers 18,18' move the blade means 36,36' along planes defined by slots 16 in end portions 4,6 of the body member 2.
In all of the aforementioned patents, the blade members either engage movable spring fingers formed integral with the blade cartridge, or are mounted permanently to a platform which is movably connected to the blade cartridge. These methods of providing a movable blade necessitate an elaborate and expensive molding procedure to create a blade cartridge having either integral spring fingers or a movable blade platform. While it has been noted that blades movable relative to the shaving surface during the shaving process are advantageous, it is desirable to eliminate the need for the elaborate molding process required by the movable blade assemblies of the prior art.

Movable blade shaving cartridge or the like


The invention relates to apparatus for braking a set of aircraft wheels, the apparatus comprising a normal hydraulic circuit and an emergency hydraulic circuit, both circuits leading to each of the various brakes via associated brake valves. According to the invention, the brake valves of the normal circuit and/or of the emergency circuit are constituted by direct drive valves that are electrically controlled by an associated electronic control unit.

There already exist numerous brake apparatuses fitted with a first hydraulic circuit powered by an associated hydraulic source and used for braking under normal conditions, and with an emergency hydraulic circuit powered by a different source of hydraulic pressure and used only in the event of a breakdown.
Traditionally, each of the two hydraulic circuits (normal and emergency) is connected to each of the various brakes via a brake valve which is a servo-valve that is electrically controlled by a cockpit unit which measures information corresponding to brake pedal depression, and in general also to the speed of the wheel in question. For the state of the art, reference can be made to the following documents: EP-A-0 443 213, U.S. Pat. Nos. 4,834,465, 5,050,940, 5,024,491, 3,926,479, FR-A-2 038 001, and DE-B-1 118 020. Another example of a particularly elaborate electro-hydraulic brake apparatus for a set of aircraft wheels is described in the Applicant's document U.S. Pat. No. 5,397,173.
The various brake apparatuses described in the above-mentioned documents thus comprise electrically controlled servo-valves of structure that always has two hydraulic stages interconnected by a hydraulic link and respectively associated with control and with distribution, the control stage acting on the slider of the distribution stage. The hydraulic control stage is electrically controlled, and the feed pressure input to the servo-valve is modulated in the distribution stage by through sections (nozzles) operating on the principle of hydraulic leakage that is generally at a rate of about one liter per minute. Such hydraulic leakage is always required in that kind of design, and the magnitude thereof makes it difficult to use such servo-valves when the hydraulic source is constituted by a hydraulic accumulator, as may be the case for an emergency circuit. The volume of fluid consumed by the permanent leakage of such servo-valves is no longer available for powering the brakes, thereby considerably diminishing the duration and number of times the brakes can be applied before the accumulator has been emptied.
Although the structure of presently-used braking servo-valves is generally well understood, specialists are fully aware of the drawbacks and operating constraints on brake valves of those types.
The operating pressure recovered at the outlet from a servo-valve, which pressure is a function of the magnitude of the reference current, is, in fact, obtained with relatively poor accuracy. Firstly, the mechanical adjustment of the servo-valve nozzles cannot achieve dispersion on utilization pressure of less than a few bars, or indeed of about ten bars at some points, given the non-linearity and hysteresis phenomena specific to any type of hydraulic equipment. Furthermore, the servo-valve is sensitive to fluctuations in the feed pressure and in the temperature of the hydraulic fluid, which can give rise to operating pressure variations of several bars, even in normal operation. Finally, mechanical wear of the nozzles inevitably gives rise to drift over time.

Apparatus for braking a set of aircraft wheels


A 3-D visual simulating system stores image data sets in a predetermined viewing space for right and left visual field and selects a portion of the stored image data corresponding to the current visual field for displaying it to an observer. The 3-D image stimulus changes according to the current visual field of the observer and the location of the observer in a predetermined visual space in a manner that undesirable perceptional effects are substantially eliminated. The image data sets are stored in a reduced space in an efficient manner for retrieval.

To have an observer experience three-dimensional (3D) vision, a number of prior art technologies has attempted to simulate a stereo vision based upon a pair of two-dimensional (2D) images from a right visual field and a left visual field. These two images are slightly different from each other since they are taken at two closely located points which are substantially identical to a distance between human eyes. Based upon the above pair of images such as disclosed in Japanese Patent Publication Hei 7-182533, one can experience stereographic vision in a limited visual space in a predetermined direction. In other words, as an observer changes his or her visual field, additional pairs of images must be provided. For example, in order to accommodate 360 degrees of visual space, approximately fifteen pairs or thirty images are necessary. Although a plurality of pairs of the above described images can simulate 3-D vision in wide visual space, one may not necessarily experience natural or smooth 3-D vision as his or her visual field changes from one direction to another. In other words, an observer of the plural images may experience an undesirable jump in the 3-D vision as his or her visual field changes.
In other prior art attempts, wide-angle images from the right and left visual fields have been provided to reduce the above described undesirable jumping effects. For example, superimposed wide-angle images are projected onto a wide screen to simulate 3-D vision for audience with 3-D glasses. Although an observer of such wide-angle images may experience the 3-D vision without the jumping effect, the 3-D experience is still limited within a predetermined wide angle which is generally less than 180 degrees. At the same time, since an observer sees a portion of the wide-angle vision, the images outside a visual field of the observer are unused at any given time. Without the 3-D glasses, a viewing angle is generally limited (A Handbook for TV, Image-Information Engineering, Nov. 30, 1990).
There remain certain improvements in the area of simulating stereographic vision from 2-D images, and the improvements include efficient storage of image data, efficient use of the image data and smooth transitions in a display process. The current invention addresses these improvements.

Method and system for simulating stereographic vision


Earth-boring drill bits include a bit body, an element having an attachment feature bonded to the bit body, and a shank assembly. Methods for assembling an earth-boring rotary drill bit include bonding a threaded element to the bit body of a drill bit and engaging the shank assembly to the threaded element. A nozzle assembly for an earth-boring rotary drill bit may include a cylindrical sleeve having a threaded surface and a threaded nozzle disposed at least partially in the cylindrical sleeve and engaged therewith. Methods of forming an earth-boring drill bit include providing a nozzle assembly including a tubular sleeve and nozzle at least partially within a nozzle port of a bit body.

Rotary drill bits are commonly used for drilling wellbores in earth formations. One type of rotary drill bit is the fixed-cutter bit (often referred to as a "drag bit"), which typically includes a plurality of cutting elements secured to a face region of a bit body. The bit body of a rotary drill bit may be formed from steel. Alternatively, a bit body may be fabricated to comprise a composite material. A so-called "infiltration" bit includes a bit body comprising a particle-matrix composite material and is fabricated in a mold using an infiltration process. Recently, pressing and sintering processes have been used to form bit bodies of drill bits and other tools comprising particle-matrix composite materials. Such pressed and sintered bit bodies may be fabricated by pressing (e.g., compacting) and sintering a powder mixture that includes hard particles (e.g., tungsten carbide) and particles of a metal matrix material (e.g., a cobalt-based alloy, an iron-based alloy, or a nickel-based alloy).
A conventional earth-boring rotary drill bit 10 is shown in FIG. 1 that includes a bit body 12 comprising a particle-matrix composite material 15. The bit body 12 is secured to a steel shank 20 having a threaded connection portion 28 (e.g., an American Petroleum Institute (API) threaded connection portion) for attaching the drill bit 10 to a drill string (not shown). The bit body 12 includes a crown 14 and a steel blank 16. The steel blank 16 is partially embedded in the crown 14. The crown 14 includes a particle-matrix composite material 15, such as, for example, particles of tungsten carbide embedded in a copper alloy matrix material. The bit body 12 is secured to the steel shank 20 by way of a threaded connection 22 and a weld 24 extending around the drill bit 10 on an exterior surface thereof along an interface between the bit body 12 and the steel shank 20.
The bit body 12 further includes wings or blades 30 that are separated by junk slots 32. Internal fluid passageways (not shown) extend between the face 18 of the bit body 12 and a longitudinal bore 40, which extends through the steel shank 20 and partially through the bit body 12. Nozzle assemblies 42 also may be provided at the face 18 of the bit body 12 within the internal fluid passageways.
A plurality of cutting elements 34 is attached to the face 18 of the bit body 12. Generally, the cutting elements 34 of a fixed-cutter type drill bit have either a disk shape or a substantially cylindrical shape. A cutting surface 35 comprising a hard, super-abrasive material, such as polycrystalline diamond, may be provided on a substantially circular end surface of each cutting element 34. Such cutting elements 34 are often referred to as "polycrystalline diamond compact" (PDC) cutting elements 34. The PDC cutting elements 34 may be provided along the blades 30 within pockets 36 formed in the face 18 of the bit body 12, and may be supported from behind by buttresses 38, which may be integrally formed with the crown 14 of the bit body 12. Typically, the cutting elements 34 are fabricated separately from the bit body 12 and secured within the pockets 36 formed in the outer surface of the bit body 12. A bonding material such as an adhesive or, more typically, a metal alloy braze material may be used to secure the cutting elements 34 to the bit body 12.
During drilling operations, the drill bit 10 is secured to the end of a drill string, which includes tubular pipe and equipment segments coupled end-to-end between the drill bit 10 and other drilling equipment at the surface. The drill bit 10 is positioned at the bottom of a wellbore such that the cutting elements 34 are adjacent the earth formation to be drilled. Equipment such as a rotary table or top drive may be used for rotating the drill string and the drill bit 10 within the borehole. Alternatively, the shank 20 of the drill bit 10 may be coupled directly to a drive shaft of a downhole motor, which then may be used to rotate the drill bit 10. As the drill bit 10 is rotated, drilling fluid is pumped to the face 18 of the bit body 12 through the longitudinal bore 40 and the internal fluid passageways (not shown). Rotation of the drill bit 10 under weight applied through the drill string causes the cutting elements 34 to scrape across and shear away the surface of the underlying formation. The formation cuttings mix with and are suspended within the drilling fluid and pass through the junk slots 32 and the annular space between the wellbore and the drill string to the surface of the earth formation.
Conventionally, bit bodies that include a particle-matrix composite material 15, such as the previously described bit body 12, have been fabricated in graphite molds using the so-called "infiltration" process. The cavities of the graphite molds are conventionally machined with a multi-axis machine tool. Fine features are then added to the cavity of the graphite mold using hand-held tools. Additional clay work also may be required to obtain the desired configuration of some features of the bit body. Where necessary, preform elements or displacements (which may comprise ceramic components, graphite components, or resin-coated sand compact components) may be positioned within the mold and used to define the internal passages, cutting element pockets 36, junk slots 32, and other external topographic features of the bit body 12. The cavity of the graphite mold is filled with hard particulate carbide material (such as tungsten carbide, titanium carbide, tantalum carbide, etc.). The preformed steel blank 16 may then be positioned in the mold at the appropriate location and orientation. The steel blank 16 typically is at least partially submerged in the particulate carbide material within the mold.
The mold then may be vibrated or the particles otherwise packed to decrease the amount of space between adjacent particles of the particulate carbide material. A matrix material (often referred to as a "binder" material), such as a copper-based alloy, may be melted, and caused or allowed to infiltrate the particulate carbide material within the mold cavity. The mold and bit body 12 are allowed to cool to solidify the matrix material. The steel blank 16 is bonded to the particle-matrix composite material 15 forming the crown 14 upon cooling of the bit body 12 and solidification of the matrix material. Once the bit body 12 has cooled, the bit body 12 is removed from the mold and any displacements are removed from the bit body 12. Destruction of the graphite mold typically is required to remove the bit body 12 therefrom.
After the bit body 12 has been formed, PDC cutting elements 34 may be bonded to the face 18 of the bit body 12 by, for example, brazing, mechanical, or adhesive affixation. Alternatively, the cutting elements 34 may be bonded to the face 18 of the bit body 12 during furnacing of the bit body if thermally stable synthetic diamonds, or natural diamonds, are employed in the cutting elements 34. Of course, more than one type of cutting element may be employed, as is known to those of ordinary skill in the art.
The bit body 12 may be secured to the steel shank 20. As the particle-matrix composite materials 15 typically used to form the crown 14 are relatively hard and not easily machined, the steel blank 16 is used to secure the bit body 12 to the shank 20. Complementary threads may be machined on exposed surfaces of the steel blank 16 and the shank 20 to provide the threaded connection 22 therebetween. The steel shank 20 may be threaded onto the bit body 12, and the weld 24 then may be provided along the interface between the steel blank 16 and the steel shank 20.
As discussed above, nozzle assemblies 42 also may be provided at the face 18 of the bit body 12. Nozzle assemblies 42 allow fluid flow areas to be specified or selected to obtain various flow rates and patterns. During drilling, drilling fluid is discharged through nozzle assemblies 42 located in nozzle ports in fluid communication with the face 18 of bit body 12 for cooling the cutting surface 35 of cutting elements 34 and removing formation cuttings from the face 18 of drill bit 10 into passages such as junk slots 32. As shown in FIG. 2 of the drawings, a conventional earth-boring rotary drill bit 10 for use in subterranean drilling may include a plurality of nozzle assemblies, exemplified by illustrated nozzle assembly 42. While many conventional drill bits use a single piece nozzle, the nozzle assembly 42 is a two piece replaceable nozzle assembly, the first piece being a tubular tungsten carbide inlet tube 50 that fits into a port or passage 54 formed in the body 12 of the drill bit 10, and is seated upon an annular shoulder 56 of passage 54. The second piece is a tungsten carbide nozzle 52 that may have a restricted bore 64 that is secured within passage 54 of the drill bit 10 by threads that engage mating threads 58 on the wall of passage 54. The inlet tube 50 is retained in passage 54 by abutment between the annular shoulder 56 and the interior end of the nozzle 52. The inlet tube 50 and the nozzle 52 are used to provide protection to the material of the drill bit 10 through which passage 54 extends against erosive drilling fluid effects by providing a hard, abrasion- and erosion-resistant pathway from a fluid passageway 68 within the bit body to a nozzle exit 60 located proximate to an exterior surface of the bit body. The inlet tube 50 and nozzle 52 are replaceable should the drilling fluid erode or wear the parts within internal passage 62 extending through these components, or when a nozzle 52 having a different orifice size is desired. The outer surface or wall of the nozzle 52 is in sealing contact with a compressed O-ring 66 disposed in an annular groove formed in the wall of passage 54 to provide a fluid seal between the bit body 12 and the nozzle 52.

Earth-boring tools and components thereof and related methods


Methods and systems for correlating cross-feed of audio and video. One system includes a display and an electronic processor connected to the display. The electronic processor is configured to receive a plurality of videos and a plurality of audio feeds, present an initial arrangement including one or more of the plurality of videos on the display, and generate a soundscape based on the initial arrangement, the soundscape including one or more of the plurality of audio feeds. The electronic processor is further configured to determine which of the videos of the plurality of videos contains a predetermined item of interest, determine which of the audio feeds of the plurality of audio feeds contains audio associated with the predetermined item of interest, and adjust the initial arrangement and the soundscape to highlight the predetermined item of interest.

A public safety emergency operator, call-taker, dispatcher, and the like responding to an incident may be tasked with reviewing multiple videos and audio recordings from numerous sources. The multiple videos may be reviewed during or subsequent to the incident.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.

Correlated cross-feed of audio and video


A light emitting package structure and a method of manufacturing the light emitting package structure are provided. The method includes: a preparation process: mounting a light emitting unit on a substrate; a dispensing process: coating a sealant on a first joint area of the substrate; a cover-enclosing process: disposing a cover element having a second joint area on the substrate, the first joint area and the second joint area joined to each other by the sealant; a vacuum process: reducing an ambient pressure to a first pressure lower than the original ambient pressure; a pressure-adjusting process: adjusting the ambient pressure around the package structure to a second pressure higher than the first pressure; and a curing process: curing the sealant.

FIG. 13A and FIG. 13B illustrate a conventional light emitting package structure 100. The package structure 100 includes a substrate 101, a cover element 102 and a light emitting chip 103. The package structure 100 packages the light emitting chip 103 in an accommodation space 105 through the cover element 102. The cover element 102 is usually fixed to an opening of the accommodation space 105 through a sealant 104. However, during the curing of the sealant 104 under the normal pressure, the cover element 102 often has undesirable conditions such as skewing, which leads to an increase in the defect rate of the package structure 100.

Light emitting package structure and method of manufacturing the same

LITE-ON OPTO TECHNOLOGY (CHANGZHOU) CO., LTD.


An escapement for a timepiece, comprising: —an escapement wheel pivotally mounted around a corresponding axis of rotation and intended to be driven by a drive source, said escapement wheel comprising a plurality of teeth; —a pallet fork pivotably mounted around a corresponding axis of rotation, said pallet fork comprising an entry pallet and an exit pallet, each pallet comprising a rest face arranged to block the escapement wheel, as well as a pulse face arranged to interact with the escapement wheel in order to transmit the pulses received from the latter to a regulating member arranged to perform oscillations, said pallet fork being arranged to free the escapement wheel periodically under the control of the regulating member, characterized in that at least one of the pulse faces is shaped in such a way that, on at least one portion of the pulse face, and considered at each point of contact (C′) between the escapement wheel and the pulse face, the tangent of the pulse face intersects the center-to-center distance between the escapement wheel and the pallet fork according to an angle (αorientation) that observes a particular relation.

A traditional escapement, such as a Swiss anchor escapement, an English anchor escapement, a Daniels escapement or similar, includes an anchor which blocks an escapement wheel in an intermittent manner and transmits energy from the going train to the regulating member when the wheel is released. Oscillations of the regulating member, such as a balance wheel and hairspring, actuate the anchor lever in order to perform this periodic release of the escapement wheel and to supply an impulsion once more to the regulating member in order to maintain its oscillations.
To this end, the anchor includes at least two pallets, one of which—the entry pallet—being situated upstream in relation to the direction of rotation of the escapement wheel, and the other—the exit pallet—being situated downstream. On each half-oscillation of the regulating member, the pallet which is engaged with the escapement wheel is raised, releasing the escapement wheel and transmitting an impulsion to the regulating member by means of an impulsion surface that each pallet includes. At the same time, the other pallet is displaced in the trajectory of the teeth of the escapement wheel and blocks it. Then, the cycle recommences for the other pallet.
Typically, the impulsion surfaces are constituted by planes. Although these simple forms are easy to manufacture, the transmission of torque varies throughout the impulsion phase, which is detrimental to the performance of the escapement.
Furthermore, such plane impulsion surfaces often give rise to a lifting-off of the pallet, in particular when it performs the transition from the impulsion phase on the pallet to the impulsion phase on the tooth, which similarly compromises the performance of the escapement.
Document CH702689 describes an escapement in which the exit pallet and/or the entry pallet presents an impulsion surface which is curved in such a way that, during an entire part of the impulsion phase, the angle defined by the impulsion surfaces of the tooth and of the pallet at the point of contact between these surfaces is at most equal to 7°. Although this certainly represents an improvement in relation to planar impulsion surfaces, the form chosen does not eliminate the variations in the transmission of torque. A modeling study has shown that the derivative of the torque ratio between that of the anchor and that of the escapement wheel in relation to the angle of the escapement wheel changes sign several times, and that said torque ratio varies in the order of 25% to 35% along the concave part of the pallet. In addition, the convex part at the start of the impulsion surface exhibits an entirely conventional radius of curvature, which results from the current manufacturing processes, and has not been optimized at all.
The object of the present invention is thus, at least partially, to overcome the disadvantages mentioned above.

Escapement for a timepiece with optimized torque transmission


An electrolyte composition for a dye-sensitized solar cell (DSSC) is provided, which includes a redox couple solution and inorganic nanoparticles. The surface of the inorganic nanoparticle may have a substituted or unsubstituted silane group, an ether group, a substituted amino group, a carbonyl group, an ester group, an amide group or a combination thereof.

1. Technical Field
The present disclosure relates to an electrolyte composition for a dye-sensitized solar cell (DSSC).
2. Description of Related Art
A dye-sensitized solar cell (DSSC) is recognized as one of the new generation solar cells for advantages like simple processing, easy mass production and low cost. Generally, the DSSC includes an anode, a semiconductor layer (e.g., a titanium dioxide layer), dye, a counter electrode and electrolyte. The electrolyte is used to transfer holes to the counter electrode, such that the ion conductivity of the redox couple would have critical influence on the photoelectric conversion efficiency of the DSSC. In addition, the electrolyte ideally requires the features of low volatility, less leakage and easy packaging.
In order to meet the requirement of the electrolyte on low volatility and less leakage, researchers developed a wide range of electrolyte compositions. Taiwan (R.O.C) Patent Publication No. 201043662 provided a polymer-containing gel electrolyte, which may further include nanoparticles to increase the ion conductivity. Since the gel electrolyte has a certain viscosity, the sedimentation rate of the inorganic particles from the gravity can be slowed down. Nevertheless, the ion conductivity is thus decreased due to the viscosity of the gel electrolyte. Therefore, the transfer rate of the hole cannot be effectively increased so as not to increase the photoelectric conversion efficiency of the solar cell, even though the nanoparticles are added into the gel electrolyte. Concerning the type of liquid electrolyte, although liquid electrolyte exhibits high ion conductivity and electrode permeability, it is not suitable for adding nanoparticles therein to increase the ion conductivity for its high fluidity.
Accordingly, there is a need for an electrolyte composition having inorganic nanoparticles hard to subside, so as to increase the photoelectric conversion efficiency of the DSSC.

Electrolyte composition for dye-sensitized solar cell


A golf ball comprising a cover and a core, and optionally at least one intermediate layer interposed between the cover and the core, wherein the cover, the intermediate layer or both are formed from a blend comprising a thermoplastic silicone-urethane copolymer.

The present invention relates to golf balls. More specifically, to the use of thermoplastic silicone-urethane copolymer materials in a golf ball cover, core and intermediate layers between the cover and the core for improving golf ball physical properties.
Conventional golf balls can be divided into two general types or groups: solid balls and wound balls. The difference in play characteristics resulting from these different types of constructions can be quite significant.
Balls having a solid construction are generally most popular with the average recreational golfer because they provide a very durable ball while also providing maximum distance. Solid balls are generally made with a single solid core, usually made of cross-linked rubber, which is encased by a cover material. Typically the solid core is made of polybutadiene which is chemically cross-linked with zinc diacrylate and/or similar cross-linking agents and is covered by a tough, cut-proof blended cover. The cover is generally a material such as SURLYN(copyright), which is a trademark for an ionomer resin produced by DuPont. The combining of the core and cover materials provides a ball that is virtually indestructible by golfers. Further, such a combination imparts a high initial velocity to the ball that results in improved distance. Because these materials are very rigid, two-piece balls have a hard xe2x80x9cfeelxe2x80x9d when struck with a club. Likewise, due to their hardness, these balls have a relatively low spin rate, which provides greater distance.
Wound balls typically have either a solid rubber or liquid center core around which many yards of a stretched elastic thread or yam are wound. The wound core is then covered with a durable cover material such as ionomer or polyurethane. Wound balls are generally softer and provide more spin, which enables a skilled golfer to have control over the ball""s flight and final position. Particularly, with approach shots into the green, the high spin rate of soft, wound balls enables the golfer to stop the ball very near its landing position.
The design and technology of golf balls has advanced to the point whereby the United States Golf Association has now instituted a rule that prohibits the use, in a USGA sanctioned event, of any golf ball which can achieve an initial velocity of 255 ft/s when struck by an implement having a velocity of 143 ft/s. (Herein referred to as the USGA test.)
Manufacturers place a great deal of emphasis on producing golf balls that consistently achieve the highest possible velocity in the USGA test without exceeding the limit, which are available with a range of different properties and characteristics, such as velocity spin and compression. Thus, a variety of different balls are available to meet the needs and desires of a wide range of golfers.
Regardless of the form of the ball, players generally seek a golf ball that delivers maximum distance, which requires a high initial velocity upon impact. Therefore, in an effort to meet the demands of the marketplace, manufacturers strive to produce golf balls with high initial velocities.
As a result, golf ball manufacturers are continually searching for new ways in which to provide golf balls that deliver the maximum performance for golfers at all skill levels, and seek to discover compositions that provide the performance of a high compression ball with lower compression.
The physical characteristics of a golf ball are determined by the combined properties of the core, any intermediate layers, and the cover. These, in turn, are determined by the chemical compositions of each. The composition of some balls will provide for increased distance. Other compositions provide for improved spin. Manufacturers are constantly looking to develop the ideal materials, silicone elastomers for example, have been examined for their innate ability to provide material having fairly high ultimate elongation, which is a very desired property in the make-up of a golf ball. However, they also have only low-moderate tensile strengths. One of the least attractive properties of silicone elastomers in the manufacture of golf balls is that the materials require covalent cross-linking to develop useful properties. This is because linear or branched silicone (polydimethylsiloxane)(PSX) homopolymers are viscous liquids or millable gums at room temperature. Fabrication of these materials must include, or be followed by, cross-linking to form chemical bonds among adjacent polymer chains. The infinite network thus formed gives the polymer its rubber elasticity and characteristic physical-mechanical properties. Cross-linking of extrudable and moldable silicone stock is usually done via peroxide-generated free radicals adding to vinyl groups incorporated along the polymer backbone, or increasingly, by the platinum-catalyzed addition of silane (xe2x80x94Sixe2x80x94H) terminal vinyl groups. Certain low-strength (RTV) silicone adhesives vulcanize at room temperature by condensation reactions, eliminating an acid or alcohol to generate xe2x80x94Sixe2x80x94OH or silanols, followed by the elimination of water as silanols condense to form xe2x80x94Sixe2x80x94Oxe2x80x94Sixe2x80x94 (siloxane) bonds and create a three-dimensional network.
Regardless of how the cross-linking or vulcanization is effected, the resulting thermoset silicone cannot be re-dissolved or re-melted. This severely reduces the number of post-fabrication operations that could be used in the fabrication process of golf balls. Thermal forming, radio frequency welding, heat sealing and solvent bonding are all essentially unavailable when working with conventional silicone elastomers. In contrast to cross-linked silicone rubbers, many polyurethane elastomers are thermoplastic in nature. That is, they can be processed by methods that involve melting or dissolving the polymer to reshape it. The molecular structure of a typical thermoplastic urethane (TPU) consists of alternating high-melting xe2x80x9chardxe2x80x9d urethane segments and liquid-like xe2x80x9csoftxe2x80x9d segments.
Hard segments are almost always the reaction product of an aromatic or aliphatic diisocyanate and a low molecular weight, chain-extending dialcohol or diol. The diisocyanates may be selected from the group consisting of alkyl diisocyanates, arylalkyl diisocyanates, cycloalkylalkyl diisocyanates, alkylaryl diisocyanates, cycoalkyl diisicyanates, arly diisocyanates, cycloalkylaryl diisocyanates, all of which may be further substituted with oxygen, and mixtures thereof. The chain extender of the hard segment used in the preparation of the copolymers may be an aliphatic polyol or an aliphatic or aromatic polyamine such as known for preparing polyurethanes and polyureas. The polyol for the hard segment may be preferably selected from the group consisting of alkylene, cycloalkylene, arylene diols, triols, tetraalcohols and pentaalcohols, and mixtures thereof. The polyamine of the hard segment may be selected from the group consisting of alkyl, cycloalkyl, and aryl amines that may be further substituted with nitrogen, oxygen, halogen, complexes thereof with alkali metal salts and mixtures thereof.
Soft segments may be built from polyols with terminal hydroxyl (xe2x80x94OH) groups. The hydroxyl creates a urethane group, while the reaction between isocyanates and existing urethane groups will form allophanate groups that can produce minor amounts of covalent cross-linking in TPUs. When a TPU is heated, the hydrogen-bonded hard segments and any allophanate cross-links, both of which hold the polymer together at its use temperature, dissociate to allow the polymer to melt and flow. Dissolution in a polar solvent can also disrupt the hydrogen bonds that hold together the hard segments on adjacent chains. Once these virtual cross-links are broken, the polymer can be fabricated into golf balls. Upon cooling or solvent evaporation, the hard segments de-mix from the soft segments to re-associate by hydrogen bonding. This restores the original mechanical properties of the polyurethane elastomer. Polyether and polycarbonate TPUs generally have excellent physical properties, combining high elongation and high tensile strength, albeit having fairly high-modulus. Varying the hard segment of a TPU during synthesis can produce a whole family of polymers of related chemistry but with a wide range of hardness, modulus, tensile-strength properties and elongation. In the fabrication of golf balls, the use of TPUs of different hardness values within a single family provides considerable versatility in manufacturing.
Therefore, there exists a need for a golf ball comprising a thermoplastic silicone-urethane having improved golf ball performance.
The invention is related to a use of a silicone-urethane material for forming golf balls. More particularly, the present invention is directed to the use of silicone-urethane copolymers and their blends in the formation of a golf ball core, cover or intermediate layer.
A first embodiment is a golf ball comprised of a core and a cover, one of which comprises an aromatic or aliphatic urethane hard segment with a silicone based soft segment to create a thermoplastic silicone-urethane copolymer. Preferably the core or cover is comprised of a thermoplastic silicone-polyether urethane copolymer.
A second embodiment of the invention combines the above hard and soft segments with a polycarbonate to form a thermoplastic silicone-polycarbonate urethane copolymer.
Another embodiment of the invention combines the above hard and soft segments with a polyethylene oxide to form a thermoplastic silicone-polyethyleneoxide urethane copolymer.
Other embodiments of the invention include blends of silicone-polyurethane with at least one thermoplastic or thermoset polymer including ionomers, including highly neutralized ionomers, non-ionomers, polyurea, epoxy, styrenic, olefinic homo and copolymers (including metallocenes and single-site), polyamides, polyester, polyimide, polydiene, block copolymers of polyether (or ester)-ester, polyether (or ester)-amide and suitable compatibilizers.
Examples of these may be found in U.S. Pat. Nos. 4,675,361, 5,428,123, 5,589,563, and 5,863,627 issued to Ward et al.; which are incorporated by reference herein in their entirety.
The invention is either a two-piece or a multi-layered golf ball having a coefficient of restitution greater than about 0.7 and an Atti compression of at least about 50. In a preferred use of the invention, the thermoplastic silicone-urethane is used for the ball cover and has a material tensile strength of greater than about 1,000 psi, and preferably between about 1000 to 50,000 psi; an ultimate elongation greater than about 40%, and preferably and greater than about 400%; and and an initial modulus from about 300 psi to 100,000 psi, preferably from about 300 psi to 10,000 psi.
In another preferred embodiment, the golf ball is comprised of an intermediate layer formed form a silicone-urethane copolymer. Preferably, the material has a tensile strength greater than about 3000 psi; an ultimate elongation greater than about 40% and more preferably greater than about 400% and/or an initial modulus greater than 300 psi.
In preferred embodiments of the present invention, the thermoplastic silicone-urethane copolymers have a silicone content from 0.1% to 60% of polymer by weight. More preferably, the thermoplastic silicone-urethane copolymers have a silicone content of between about 1% and 20%.
A preferred embodiment is a golf ball wherein one of the ball components is comprised of a thermoplastic silicone-urethane copolymer composition consisting of methane bis(4-phenylisocynate) (MDI), or hydrogenated MDI (H12-MDI), 3-hydroxypropyl terminated polydimethylsiloxane, and 1,4 butane-diol. A suitable catalyst would be used in the preparation.
A golf ball utilizing the compositions of the present invention will target the most favorable properties of both silicones and urethanes, wherein the strengths of each material can be maximized.

Golf balls with thermoplastic silicone-urethane copolymers


Lightweight structural component including at least one panel and at least one stiffening element oriented one of lengthwise and crosswise. The at least one stiffening element includes two side pieces. Each of the two side pieces is at least partially connected to the panel in a material-locking manner. The two side pieces are connected to the panel at two separate joint zones. A method of producing the lightweight structural component includes milling the at least one panel to form at least one thickened region and joining the two side pieces to the at least one panel at the two separate joint zones. This Abstract is not intended to define the invention disclosed in the specification, nor intended to limit the scope of the invention in any way.

1. Field of the Invention
The invention relates to the design and production of lightweight structural components. Objects in which its application is expedient and possible are all large-volume lightweight structures in which an essential part of the bearing pressure occurs as area load via skin sheets and which are provided with stiffening elements for load distribution, load diversion, reduction of deflection or prevention of denting or buckling. Typically such cases of stressing are particularly marked in many lightweight structures that are acted on by a pressure difference between the outside and the inside of the skin sheet in addition to the structural load. The invention can be used particularly advantageously for aircraft structures, in particular for fuselage structures, but also for wing structures, engine intakes, pressure bulkheads, landing gear shaft covers, etc. Other fields of application lie in liquid tanks or gas tanks, pressure tanks or vacuum tanks, components of rockets and rocket engines and fuselage structures of lightweight watercraft.
2. Discussion of Background Information
Without restricting the generality, the prior art and the background of the invention will be explained by way of example based on the construction of aircraft fuselage structures. Usually aircraft fuselages are produced from riveted panels that are reinforced by riveted stiffening elements—respectively stringers running lengthwise along the fuselage pipes and ribs running in the circumferential direction. Typically a stringer comprises a suitably formed stringer head, a stringer bar and a stringer base resting on a panel base at an angle of 90° relative to the stringer bar, which stringer base is riveted to the panel base.
The stress on the panel/stiffening element structure is very complex due to the different load originations and the static and cyclical loads dependent on many parameters. In the design of aircraft fuselages constructed in such a way, preset static strength demands must be met, fatigue strengths taken into account and safety guaranteed with regard to different preset critical failure scenarios. In the embodiment of the aircraft fuselage as a riveted structure, these demands are taken into account through the location-dependent and loading-dependent selection of the thickness of panel, stringers, ribs, the shape and the spacing of stringers or ribs, the dimensions of panel base and rivets and rivet spacing, etc. The fact that weight-saving potentials in terms of construction methods have been largely exhausted and that the production of this type of differential structure is too expensive because of the limited riveting speed and, in addition, can hardly be improved on in qualitative terms, have a negative impact on the design of the conventionally riveted structure.
It is known, for example, from P. Heider: Lasergerechte Konstruktion und lasergerechte Fertigungsmittel zum Schweiβen groβformatiger Aluminium-Strukturbauteile in: VDI-Fortschrittsberichte, series 2: Fertigungstechnik, no. 326, VDI-Verlag Düsseldorf (1994) to replace riveting by welding the stringer foot to the panel base from both sides simultaneously by means of two lasers. In order to realize this connection with a sufficiently well-developed root of the weld seam and in a manner low in pores, it is necessary for both laser beams to produce a common melting bath. This is achieved in that the two laser beams, placed opposite one another, are focused on identical positions with respect to the joint. Hot cracks are thereby avoided, through the use of suitable wire-shaped weld fillers, such as, e.g., wire of the alloy AlSi12. Through the very low linear energy of the process and the energy input symmetrical to the stringer, the deformation is limited.
In another embodiment of this principle the construction of completely welded shell components is possible, including stringers, ribs, clips, distribution belts and rib heads. See, for example, P. Brinck et al.: Schalenbauteil für ein Flugzeug und Verfahren zur Herstellung, PS DE 198 44 035 C1.
Despite better static strength and higher rigidity compared with a riveted connection, the disadvantage of a connection produced in this way lies in its lower damage tolerance which is manifested by, e.g., a higher rate of crack growth of a circumferential crack after crossing the stringer and a lower residual strength. The reason for this is that, on reaching a welded-on stiffening element, a crack spreads out into the latter. Whereas with a conventional differential construction, the crack growth in the fuselage planking is delayed through the riveted or adhered reinforcements, such as stringers or ribs, since the crack tip does not spread into the stiffening elements for a certain number of load cycles and, moreover, is held together through the intact reinforcement, in the welded-on stiffening elements the crack grows in the planking and the stiffening element simultaneously, without a noticeable crack-delaying effect occurring. The weight-saving use of laser beam-welded fuselage shells is thus only possible for fuselage regions for which the design criteria for damage tolerance do not need to be met, i.e., only for the lower shells of the fuselage.
The reason for this defect or disadvantage is that the known integral embodiments of the connection of the stiffening elements does not provide any adequate geometric, stress-related or microstructural possibilities for stopping a crack, a less damaging crack branching or an energy dissipation near the crack opening. The crack can thus spread unhindered into the stiffening elements.
Another defect or disadvantage is that the direct tensile strength of a stringer/panel connection laser beam-welded from both sides simultaneously decreases with increasing weld seam depth, i.e., with increasing stringer thickness.
The reason for this is, i.a., to produce greater weld seam depths the weld parameters have to be changed such that a greater linear energy and more unfavorable ratios of wire conveying speed of the weld filler to welding speed have to be selected. Together with solid state mechanical influences, both of these lead to a greater under-matching in the welding zone, a broader overaged region in the heat affected zone and to an increased risk of formation of micro-hot cracks.
To improve the crack growth behavior of shell components with welded-on stiffening elements, it has become known from, for example, F. Palm: Metallisches Schalenbauteil, PS DE 199 24 909 C1 to increase the thickness of the bar of the stiffening element near the welding zone without increasing the connection depth of the laser beam weld seam made from both sides simultaneously. In other embodiments of the invention a reduced weld seam depth is made or notches placed between the weld seam and the increased thickness. The object of all three measures is to make it more difficult for a crack to spread in the direction of the stringer head. The crack can possibly be deflected and can run for a certain distance in the weld seam or along the weld seam.
The disadvantage of this solution is that this embodiment is only geared to the two bay crack type of stress, i.e., the bearing of a longitudinal or circumferential crack over two rib sections or stringer divisions. Both for the "tension in the direction of the head of the stiffening element" type of stress, such as occurs in the lower fuselage region and for ribs, and for the combined "bending with bending deflection crosswise to the stiffening element" and "tension in the direction of the head of the stiffening element" types of stress, as occurs in the areas of the fuselage loaded by transverse stress, the proposed solution leads to a reduction of the bearable loads or to a premature stringer or rib rupture.
The reason for the defect is that the two disadvantages of an integrally welded structure—the lack of an effective mechanism for delaying cracks and the locally increased crack growth rate in the weld seam—are combated only with disadvantageous consequences regarding loading capacity for other types of stress, or cannot be combated at all.
An embodiment of a welded arrangement of panel and reinforcing elements that achieves an increase in residual strength and thus is also intended to render possible the use of welded fuselage shells for the side and upper shell area of the fuselage is known from H. J. Schmidt (PS DE 100 31 510 A1). To this end reinforcements are applied to the stiffening elements before the laser beam-welding. The reinforcements can thereby be arranged as doubler plates or as tension bands.
The doubler plates comprise high-strength Al alloys or fiber-reinforced metal laminates and are attached by riveting or an adhesive bond. The doubler plates must thereby be an adequate distance from the weld seam, which distance is determined by the temperature field of the welding process. The tension bands comprise high-strength steel alloys or titanium alloys or fiber composites and are inserted and twisted into through bores that are to be made beforehand. Cross section reinforcements are provided in the lower bar area of the stiffening element to contain the through bores. Another variant provides embodying the lower bar area in a slotted manner, inserting the tension band through a mounting opening in the slotted lower bar area and connecting the inserted tension band to the tension band in a form-locking manner by compressing the slotted bar area and subsequently connecting it to the skin sheet by laser beam welding in a known manner.
An increase in residual strength is achieved through the crack-delaying effect of the reinforcements. This occurs in that the number of the load cycles necessary for the complete severance of the stiffening element is increased and the reinforcing element does not fail until after the stiffening element. Through the latter effect the reinforcing element can reduce the crack opening angle and reduce the tensions at the crack tip for the period between the failure of the stiffening element and the failure of the reinforcing element.
The embodiment of the weld seam itself is not changed with respect to the previously known prior art. This means that the stringer or rib foot is attached to the skin sheet across its entire width by a single weld seam, whereby the weld seam is produced by laser beam welding from both sides simultaneously.
One defect of the arrangement is that it is not suitable for improving the prior art with regard to the two critical stress types "tension in the direction of the head of the stiffening element" and "bending in the direction crosswise to the stiffening element." The danger of static failure as a result of the separation of the stiffening element from the panel, in particular during transverse stress in the side shells, therefore remains.
The reason for this is-that the unchanged weld seam arrangement and weld seam vicinity cannot bear any greater direct tensile stress or bending stress crosswise to the longitudinal directions of the stiffening elements.
Moreover, it has a disadvantageous effect that the reinforcements of the stiffening elements do not reduce the local crack growth rate in the weld seam and its direct vicinity. This applies in particular to stress types such as, e.g., transverse stress in which there is a danger of a crack spreading along the weld seam.
The reason for this is that, for reasons determined by the process and the arrangement, they have to be installed at a distance from the weld seam at which their effect in terms of stress relief for the weld seam is very slight.
Another defect is that the reinforcing elements cannot be applied to or inserted in the stiffening elements in an economic manner.
The reason for this is that additional production steps, such as, e.g., riveting the doubler plates, adhering the doubler plates or drilling very long through bores are necessary to apply the reinforcements, which steps are in themselves very expensive or in part even more expensive than the riveting of the stiffening elements to the panel which is to be replaced.
Furthermore, the fact that the variant with inserted tension bands is not suitable for ribs has a disadvantageous effect. The reason for this lies in the impossibility of drilling a curved slot or of bending together the two side pieces of the slotted lower bar area after inserting the tension band in a plastic manner without damage to the materials or a permanent deformation of the entire stiffening element.

Lightweight structural component in particular for aircraft and method for its production

Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.


A paper punch apparatus comprising a flange-storing space for storing the flange portion in an elevating unit, an insertion/removal portion for insertably supporting a supporting axis of a bit reception plate in communication with the flange portion, and a bit-reception-plate engagement/disengagement portion for engagement/disengagement with respect to the flange portion of the bit reception plate in the flange-storing space, so that the bit reception plate can be parallelly and linearly inserted/detached with respect to the elevating unit, insertion/detachment can be steadily and securely performed at all times, whereby the apparatus is simple in structure, inexpensive, and excellent in, for example, paper punch functions, handling functions for a hole punch bit(s), bit reception plate(s), punched-paper-scrap discharge functions, and punch-position adjustment functions, and further the punch apparatus enables quality improvement, cost reduction, and the like to be implemented.

1. Field of the Invention
The invention relates to a paper punch apparatus capable of securely and steadily punching a paper-binding hole(s) into one or more paper sheets between a bit reception plate and a tubular hole punch bit.
2. Description of the Related Art
Conventionally, various types of paper punch apparatuses that are capable of punching binding holes into, for example, one or more paper sheets by sandwiching the document paper sheets between a resin-discoidal bit reception plate and a hole punch bit formed in a metallic-tubular shape. As paper punch apparatuses of this type, high power paper punch apparatuses have been proposed.
For example, Japanese Patent Application Laid-Open No. 9-109098 (hereafter referred to as "Patent Reference 1") discloses a high power paper punch apparatus in which an elevating unit is supported on a base unit to be vertically movable via an operating handle, and a hole punch bit is fixed and supported immobilizably on the elevating unit. In a paper-stacking base fixedly mounted immobilizably on the base unit, an insertion concave portion is formed. A bit reception plate is inserted and supported rotatably in the insertion concave portion in a deflected state with respect to the vertical line of the hole punch bit. A bit tip portion of the hole punch bit has a positional relationship with the bit reception plate to perform approaching/detaching operation with respect to the bit reception plate.
Ratchet teeth are formed around a periphery of the bit reception plate. When the elevating unit descends with the operation of the operating handle, operation pawls engaging the ratchet teeth advance in the direction opposite the rotational direction of the ratchet teeth via an interlocking mechanism connectively operating with the operating handle. In contrast, when the elevating unit ascends with the operation of the operating handle, the operation pawls engage the ratchet teeth via the interlocking mechanism whereby to cause the bit reception plate to rotate by one pitch.
In the paper punch apparatus, a contact position between the bit reception plate and the hole punch bit can be changed each time the operating handle is manipulated. As such, the construction prevents such an event that the hole punch bit constantly abuts a same portion whereby causing a ringular extracting groove on the bit reception plate. The consequence enables overcoming such shortcomings that when punching paper holes into a plurality of paper sheets, the lowest paper sheet engages the ringular extracting groove caused by a bit tip portion of the hole punch bit whereby making it impossible to take out the lowest paper sheet.
By way of another example paper punch apparatus, a paper punch apparatus disclosed in Japanese Patent Application Laid-Open No. 2000-233398 (hereafter referred to as "Patent Reference 2") will be discussed. The apparatus is constructed such that an elevating unit is supported on a base to be vertically movable by using an operating handle, and a hole punch bit is insertable and detachable with respect to the elevating unit. In the paper punch apparatus disclosed in the publication, an insertion/detachment opening is formed in the horizontal direction perpendicular to the elevational direction in a lower portion of the elevating unit, and a hole-punch-bit support unit for fittably supporting the hole punch bit is inserted and supported in the insertion/detachment opening to be insertable and detachable.
The hole-punch-bit support unit has an engagement/disengagement member resiliently vertically moving toward an inner upper surface of the insertion/detachment opening. The engagement/disengagement member has an engagement/disengagement detent for performing engagement/disengagement with respect to an engagement/disengagement concave portion formed on an inner upper surface of the insertion/detachment opening, and manipulation piece extending on a side opposite the engagement/disengagement detent. When the engagement/disengagement member is engageably inserted into the insertion/detachment opening in resistance with spring forces, the engagement/disengagement member resiliently returns upwardly at an engageable insertion limit position of the hole-punch-bit support unit. Then, push-up force of the engagement/disengagement detent is received in the engagement/disengagement concave portion, whereby the engagement/disengagement concave portion and the engagement/disengagement detent are engaged with each other.
By way of another example paper punch apparatus, a paper punch apparatus disclosed in the Japanese Patent Application Laid-Open No. 6-190794 (hereafter referred to as "Patent Reference 3") will be discussed. The paper punch apparatus is capable of preventing fall of paper perforation scraps being discharged from the inside of an upper-side cylinder of a tubular hole punch bit approachable and detachable with respect to a bit reception plate disposed on a paper stacking base. The paper punch apparatus disclosed in the publication is constructed such that an elevating unit is supported on a base unit to be vertically movable with an operating handle, a scrap collection receptacle is attachably and removably tightened and fixed to the elevating unit, and a proximal end portion of the hole punch bit is attachably and removably tightened and fixed to a bottom portion of the scrap collection receptacle. A proximal-end-side opening of the hole punch bit communicates with the inside of the scrap collection receptacle.
In the paper punch apparatus disclosed in Patent Reference 1, the bit reception plate formed into a discoidal shape disposed away downwardly from the operating handle is inserted and supported in an automatically rotatable fashion inside the insertion concave portion of the paper-stacking base. In addition, the hole punch bit fixedly supported in immobile manner on the elevating unit is disposed in a relatively movable fashion with respect to the bit reception plate. As such, structurally, an intricate interlocking mechanism should be provided that causes connective operation of the operating handle and the bit reception plate to automatically rotate at a predetermined angle in association with rotational movement.
For the provision of the interlocking mechanism causing the connective operation of the operating handle and bit reception plate, high level relative-position setting, positioning, and the like should be adjusted for the operating handle, bit reception plate, interlocking mechanism, and the like. When required accuracies of setting dimensions, assembly adjustment, and the like cannot be obtained, it is impossible to bring an actuating force to act on the bit reception plate away from the operating handle. As a result, it becomes difficult to operate the operating handle, the bit reception plate, or the interlocking mechanism in a synchronous, smooth, and steady manner. In addition, the intricate interlocking mechanism for causing the connective operation of the operating handle and bit reception plate is required to be provided. This arises a problem in that the number of components is increased, leading to the cause of associated problems of significantly increasing, for example, assembly costs and manufacturing costs.
The conventional paper punch apparatus disclosed in Patent Reference 2 is now viewed. As described above, in this apparatus, the engagement/disengagement detent of the engagement/disengagement member resiliently vertically moving toward the inner upper surface of the insertion/detachment opening is engaged with the engagement/disengagement concave portion formed on the inner upper surface of the insertion/detachment opening. As such, an engagement surface of the engagement/disengagement detent and an engagement surface of the engagement/disengagement concave portion are therefore positioned perpendicular to the insertion direction of the hole-punch-bit support unit. As such is the structure, when releasing the engagement state between the elevating unit and the hole-punch-bit support unit, while the engagement surface is being moved down by a distance necessary to climb over the top end of the engagement/disengagement detect in resistance with the elastic force, an excessively high force necessary to cause the engagement surface of the engagement/disengagement concave portion to directly act on the manipulation piece, which extends to the opposite side of the engagement/disengagement detent.
At this event, of course the force acting on the manipulation piece to release the engagement with the engagement surface of the engagement/disengagement concave portion should be maintained. Concurrently, however, the hole-punch-bit support unit should be withdrawn along a withdrawal direction perpendicular to depression force of the manipulation piece. That is, when withdrawing the hole-punch-bit support unit, the unit should perform stepwise operations bidirectionally along the depression direction of the manipulation piece and the withdrawal direction thereof perpendicular to the withdrawal direction. This significantly impairs the mountability and operability of the hole-punch-bit support unit.
Further, the withdrawal of the hole-punch-bit support unit with respect to the elevating unit requires considerably high force. Thereby, not only the mountability and operability of the hole-punch-bit support unit are deteriorated, but also drawbacks such as entanglements, damage, and deflection are promoted. Regarding the discoidal bit reception plate, it is ordinarily inserted and supported in the insertion concave portion of the paper-stacking base, as in the conventional techniques disclosed in Patent Reference 1. As such, the bit reception plate cannot therefore easily be removed to the outside from the inside of the insertion concave portion with hands and fingers in such an event of replacing the bit reception plate. Here arises another problem of making the removal operation thereof to be complex, making it impossible to quickly perform punch operation.
In general, conventional paper punch apparatuses form punch holes in such a manner that in association with the pivotal operation of the operating handle, a top-end bit tip portion(s) of the tubular hole punch bit(s) is pushed at one time to a number of paper sheets (paper set) placed on the paper stacking base. As described above, in the conventional paper punch apparatus disclosed in Patent Reference 3, the proximal end portion of the hole punch bit is attachably and removably tightened and fixed to the bottom portion of the scrap collection receptacle fixed to the elevating unit. As such is the structure, sufficient high post-mounting strengths of these components should be secured, thereby significantly increasing the number of components. This arises the problems of significantly increasing costs such as assembly costs, manufacturing costs, and component costs in association with the increase in the number of components.
In addition, the proximal-end-side opening of the hole punch bit communicates with the inside of the scrap collection receptacle through the bottom of the scrap collection receptacle. As such, paper perforation scraps discharged from the inside of the upper-side cylinder of the hole punch bit can be directly stored into the scrap collection receptacle. However, as a large amount of paper perforation scraps are stored in the scrap collection receptacle, paper perforation scraps are nonuniformly piled in peripheral portions of the tubular hole punch bit.
For the above reason, paper perforation scraps block an upper-end-side opening before filling the inside of the scrap collection receptacle, whereby causing punched paper scraps to jam. Consequently, not only does such the troublesome event disable effectively using the inside of the scrap collection receptacle, but also it can easily lead to deflection, damage, and the like of the hole punch bit due to jammed paper perforation scraps, whereby leading to the cause of significantly impairing the functionality of the hole punch bit.
Further, as in the prior art disclosed in Patent Reference 1, a paper abutment member is fixed and supported in an erect state perpendicular to extending end portions of a pair of side gauge racks disposed extendible in both-side end portions of the base unit. In this construction, hole-punching operation can be performed by positioning the paper center. However, punch holes cannot be formed in such a manner that, regardless of the paper size, same punch positions are chosen in accordance with the paper upper or lower ends being used as a reference. As such, it is difficult to bind papers into files by arranging the papers in desired arrangement patterns.
Thus, the individual prior arts disclosed in Patent References 1 to 3 have various problems. They are, for example, problems of impairing the mountabilities and operabilities of the components such as the hole punch bit and bit reception plate; problems of causing the functionality of the tubular hole punch bit to be impaired due to paper perforation scraps accumulated in the scrap collection receptacle; and problems of disabling accurate setting of same punch positions in the upper or lower ends of paper sheets of different sizes.
Accordingly, what is strongly demanded is that while the structure is simple, improvements can be implemented for punching function, handling function of the hole punch bit and bit reception plate, the punched-paper-scrap discharge function and the punch-position adjustment function, for example. If the demand is satisfied, quality improvement and cost reduction for the paper punch apparatus can be implemented.


A reference electrode including an outside wall which acts as a boundary between electrolyte and sample solution, which outside wall includes a resin which is ionically conducting, non-porous and salt-loaded, and a barrier through which no electrochemical communication between the electrolyte and sample solution is possible. A window is present in the barrier, allowing electrochemical communication between the electrolyte and the sample solution through the resin at the window. The reference electrode can be suitable for use with a separate measuring electrode, or can be combined with a measuring electrode in a single unit electrode assembly.

The present invention relates to a reference electrode and to a combined electrode comprising a reference electrode and a measuring electrode.
A combined electrode contains both a reference electrode and a measuring electrode in one unitary measuring member. Many applications utilize the reference electrode and the measuring electrode in one unit because this is compact and convenient. Nevertheless a separate reference and measuring electrode can be used, and the present invention relates to improvements in a reference electrode regardless of whether this is separate or part of a combined electrode.
Reference electrodes are used together with measuring electrodes in electrochemical systems to determine the concentration of ions in a sample, e.g. the pH or pX where X represents an ion. The electrochemical potential of the reference electrode should remain as constant as possible throughout the measuring process while the potential of the measuring electrode, which can be ion-selective, is a function of the concentration of the ion being tested in the sample. The potential of the reference electrode is kept substantially constant due to the presence of a saturated electrolyte salt bridge within the cell. The potential difference between the reference electrode and the measuring electrode is indicative of the concentration of the ion and may be displayed on a millivolt instrument such as a potentiometer.
The potential of the complete electrochemical cell made up of the measuring electrode and the reference electrode can be represented by the following equation:ECell=Emeas+Eref+Ej where Emeas is the potential of the measuring electrode, Eref is the potential of the reference electrode and Ej is a junction potential.
The junction potential arises from the different rates of mobility of anions and cations at the interface between two electrolytic solutions. Ideally, the junction potential of the reference electrode should have a negligible variation between solutions as otherwise the change in the junction potential will appear as an error in the overall potential calculated for the sample and hence the concentration determined.
Thus, where pH is being measured, a reference electrode ideally produces a constant millivolt potential in all aqueous liquids regardless of whether this be pure water, oily water, contaminated water or otherwise. A measuring electrode produces a different potential depending on the pH of the solution. Thus, using both electrodes together allows an accurate determination of the pH of a solution, taking into account a baseline measurement.
Well-known reference electrodes include the Ag/AgCl type and the calomel type amongst others; any convenient half-cell of electrode and electrolyte can be used in reference systems.
Some conventional reference electrodes require the electrolyte to leak slowly through an opening in the reference electrode, for example at a porous plug (e.g. made from wood or teflon or other porous materials), to form a liquid junction between the salt bridge and the sample solution being tested. In certain applications, a precipitate can form at the junction of the reference electrode and the sample solution where the electrolyte of the reference electrode flows into the sample. This precipitate can clog the opening and therefore interfere with the liquid junction potential and give rise to measuring errors. Furthermore, porous electrodes are prone to fouling, poisoning or back-diffusion of medium, and also lack robustness in the presence of temperature and pressure variations.
The problems associated with porous reference electrodes have previously been addressed by using a salt-loaded resin to surround the electrode chamber so as to provide a barrier to liquid movement whilst ensuring electrochemical communication. Such a system is described in for example WO 93/15393 of Amagruss Limited and Russell. Thus, the problems of porous reference electrodes can in part be avoided by using said salt-loaded resins instead of porous members. Such ionically-conducting salt-loaded resins cannot be poisoned because there is no liquid contact and furthermore the materials are steam sterilizable at 130 degrees C. and able to withstand pressures above 30 bar.
Nevertheless, further improvements of measurement accuracy and reliability are desirable.

Reference electrode and combined electrode


In a brake apparatus for a hydraulic two-circuit brake installation of a road vehicle with static brake circuits, an outlet pressure space is provided for one of these brake circuits in which the brake pressure that is coupled into a static brake circuit of the vehicle, is adapted to be built up by the displacement in the same direction of a master cylinder piston which is also displaceable by the pedal force alone, and of a servo piston which is displaceable only when the brake force servo unit is intact. The servo piston displaceable only with an intact brake force servo unit includes an annular piston which by pressure actuation of its actuating surface with the outlet pressure of a brake valve of the brake force servo unit, is urged into unilateral abutment with an entrainment flange of a plunger piston extending through the annular piston in the axial direction, which plunger piston, in its turn, is coupled for movement with a force-transmitting element, by way of which also the component of the actuating force resulting from the pedal actuation and acting on the master cylinder piston in the sense of a brake pressure build up displacement is introduced into the same.

1. Field of the Invention
The present invention relates to a brake apparatus for the pressure supply of the brakes of a hydraulic two-circuit brake installation of a road vehicle, in which at least one brake circuit is constructed as static brake circuit which is connected to an outlet pressure space, in which the brake pressure build up takes place by unidirectional displacement of the servo piston and of a master cylinder piston, whereby the servo piston experiences a pressure build-up displacement only when the brake servo unit operates properly and whereby the master cylinder piston experiences a pressure build-up displacement when the brake force servo unit is intact, as also when the brake force servo unit has failed, whereby in that case, in relation to a predetermined amount of the residual actuating force engaging at the master cylinder piston, an increase of the piston displacement travel and therewith a correlated pressure translation occurs.
2. Description of the Prior Art
Such a brake apparatus is known from the DE 34 44 828 A1.
In the known brake apparatus, a tandem master cylinder is coordinated to the static brake circuit of the primary outlet pressure space, along the central axis of which a linear hydrocylinder is arranged separated from the primary outlet pressure space by a partition wall, whose piston is provided on the side of the master cylinder with a plunger which passes through a central bore of the partition wall, sealed off with respect to the same, and is axially supported at the primary piston of the master cylinder.
The actuating cylinder piston has a piston rod on the side of the pedal which passes through an end wall of the cylinder housing also displaceably sealed pressure-tight with respect to the same. The pedal plunger is supported at this piston rod, by way of which the force exerted by the driver is introduced into the piston of the actuating cylinder. A brake valve is integrated into this piston which, depending on the actuating direction, couples a pressure proportional to the pedal force exerted by the driver, which pressure is derived from the high outlet pressure of an auxiliary pressure source, either into the actuating pressure space delimited axially in a fixed manner by the end wall of the cylinder housing and movably by the piston or--in case of a retraction movement of the brake pedal--into the space which is delimited axially movably by the piston of the actuating cylinder and fixedly by the partition wall which delimits the primary outlet pressure space of the master cylinder against this space of the actuating cylinder.
This actuating piston and together with the same the primary piston of the master cylinder is displaceable in the sense of a brake pressure build-up both when the brake servo unit is intact as also when the brake servo unit fails. The high pressure inlet chamber of the actuating cylinder is thereby constructed as annular space which is delimited in the axial direction by flanges of the actuating piston which are arranged at a distance from one another and which are sealed off with respect to the cylinder bore by O-rings.
A second housing bore is arranged adjacent the master cylinder and the actuating cylinder, having an arrangement parallel to the common longitudinal axis thereof, whereby a stepped piston is displaceably guided pressure-tight in the second housing bore, whose smaller piston step axially movably delimits an outlet pressure space in communicating connection with the primary outlet pressure space of the master cylinder, and whose larger piston step, together with a partition wall of the cylinder housing delimits a further actuating pressure space which is operatively connected by way of a function-control valve with the one actuating pressure space of the actuating cylinder which is fixedly delimited by the end wall of the cylinder housing on the pedal side. This second servo piston is displaceable in the sense of a brake pressure build-up within the outlet pressure space delimited by its smaller piston step and communicating with the primary outlet pressure space, only when the brake force servo unit is intact. This second booster or servo piston is provided with an L-shaped lug which axially engages also at the actuating piston containing the brake valve but is not securely connected with the same. As a result thereof, the actuating piston containing the brake valve is "taken along" by the second servo piston, so to speak of, when the brake force servo unit is operable; however, the second actuating piston remains stationary in its base position, into which it is urged by a return spring, when the brake force servo unit is not operable.
The considerable disadvantage of the known brake apparatus resides in that in case of a failure of the brake force booster or servo unit, disproportionately high pedal-actuating forces become necessary in order to cause the brake installation to respond, whereby the driver must actuate the brake pedal with about 50 to 60% of the maximum force to be applied by the driver until the brake pressure build-up starts. This is the consequence, on the one hand, of the fact that owing to the additional annular seals, by means of which the actuating piston of the actuating piston of the brake force servo unit containing the brake valve has to be displaceably sealed off with respect to the housing by means of altogether four additional annular seals, each of which contributes a friction to the friction resistance that is equivalent to several bar, and that--by reason of these friction losses--also relatively strong return springs are required urging the master cylinder pistons into the base positions thereof, which also provide a contribution to the forces equivalent to a pressure of several bar, against which the pistons have to be moved and which in case of a failure of the brake force booster or servo unit act in the sense of the pedal "becoming harder", i.e., a brake pressure can then be built up with an inoperative brake force servo unit only when the driver applies an actuating force corresponding to a minimum brake pressure of about 20 to 30 bar. As the actuating force necessary therefor is quite considerable, the driver, if he has to brake with an inoperative brake force servo unit, may receive the impression that the entire brake installation is inoperative which the driver will sense at least as a threatening situation. However, it may also lead in non-too-rare cases to a panic-like reaction which may become dangerous in a situation which requires a braking.