Abstract: A fluid actuator system disposed for internally increasing fluid pressure therein. The system includes a first fluid actuator including a cylinder provided with a first axial bore having a first piston and piston rod reciprocally mounted therein. The first cylinder is provided with first and second inlet and outlet fluid passages communicating into the first axial bore for directing fluid in and out of the first axial bore. A second fluid actuator is provided which has a cylinder provided with a second axial bore having a second piston and piston rod reciprocally mounted therein. The second cylinder is provided with third and fourth inlet and outlet fluid passages communicating into the second axial bore for directing fluid in and out of the second axial. An end closure assembly common to the first and second cylinders for sealing one end of each of the cylinder is provided. The end closure assembly includes structure therein for internally increasing fluid pressure of the fluid actuator system.

Abstract: A master cylinder for a vehicle hydraulic brake system, in which the master cylinder includes a body having a stepped bore formed therethrough and at least one piston disposed within the stepped bore. A plug is preferably permanently fixed to one end of the bore providing for a leak tight seal at the end of the bore. The master cylinder preferably includes a spring assembly having a pin with a longitudinally regular end portion which is retained in a bore of the piston.

Abstract: A method for controlling an engine turbocharger having a wastegate control valve is provided where the turbocharger is controlled by an electronic controller which is capable of delivering a wastegate control signal to the wastegate control valve. A determination is made as to whether an engine speed falls within a predetermined speed range defined by a first predetermined speed and a second predetermined speed, where the second predetermined speed is higher than the first predetermined speed. A predetermined initializing wastegate control signal may be delivered to the wastegate control valve in response to the engine speed falling within the predetermined speed range. A determination is made as to whether an engine speed exceeds the second predetermined speed, and a determination is made as to whether an engine load falls within a predetermined load range defined by a first predetermined load and a second predetermined load, where the second predetermined load is greater than the first predetermined load.

Abstract: A large electrical power plant includes two operating units, one of which is more efficient and is run as a base load unit. The less efficient operating unit is run only during periods of peak demand or when the more efficient unit is down. Hot condensate from the more efficient unit is cooled in the condenser of the less efficient unit and then sprayed into the turbine outlet of the more efficient unit. This condenses steam more efficiently, at a lower pressure, and allows the more efficient unit to produce more electricity because there is a greater pressure differential across the turbine. In addition, cool condensate is sprayed into the duct connecting the turbine and the condenser to reduce choking flow, when it is prone to occur. In addition, cool make up water is sprayed into the condenser of the operating unit.

Abstract: A temperature control device of an optical semiconductor device is provided for keeping the optical semiconductor device constant. An optical semiconductor device is fixed to a thermal conductor. One thermistor is arranged on the thermal conductor at the portion where it is susceptible stronger to an ambient temperature rather than the optical semiconductor device is susceptible to the ambient temperature while another thermistor is arranged on the thermal conductor at the portion where it is susceptible weaker to the ambient temperature rather than the optical semiconductor device is susceptible to the ambient temperature.

Abstract: A system and a method for transferring cryogenic fluids; e.g. transferring liquefied natural gas (LNG) between an offshore receiving/loading station and an onshore facility. The flowline system which can be submerged in water is comprised of a main transfer conduit which is positioned within an outer jacket and a return conduit which is positioned within the main transfer conduit. The annulus between the jacket and the main conduit is insulated. Both the main conduit and the return conduit include means which allow the respective conduits to expand/contract with temperature changes.

Abstract: The present invention relates to a method and an apparatus for freezing of material into fully or partially frozen blocks. The apparatus includes a refrigeration panel and a sheet or belt which is passed along the refrigeration panel. The apparatus includes at least one flexible, material receiving mold having at least one open compartment, where the sheet or belt provides a base for the compartment. The compartment is conveyed along the refrigerating panel to freeze the material, and then is subject to bending and/or twisting forces release the block(s) from the compartment.

Abstract: In a heat pump type air conditioner, a refrigerant ejection port of a compressor in a refrigerating cycle thereof is connected to a refrigerant inflow port of an outdoor heat exchanger via a bypass pipe with a shut-off valve, and temperature sensors detect the temperatures of the refrigerant inflow and runoff port sides of an outdoor heat exchanger. In a heating operation mode, when the temperature of the refrigerant inflow or runoff port side reaches a certain value or lower that requires defrosting, the shut-off valve of the bypass pipe is "opened" to start defrosting using the hot gas bypass defrosting method.

Abstract: An air conditioning system for vehicles includes a sensor for detecting opening and closing of a vehicle portal, such as a door or a window, and a control device for selectively opening ports through which temperature controlled air flows into an interior of a vehicle, in response to a signal generated by the opening and closing detecting sensor and a target air temperature. In the system, even if a door or a window of a cabin is opened, ports are opened according to a most suitable port mode depending on the target air temperature at a present time. Therefore, an improved air conditioning state for an operator, and an improved driving condition with reduced waste power and reduced loads to the respective equipment, may be achieved.

Abstract: A controller for climate controller system having a humidity and temperature sensor wherein the controller operates to insure that both temperature and humidity are within comfort levels. Wherein said controller further controls a reheat system which reheats chilled air in order to keep the dry bulb temperature of an enclosure near a specific set point.

Abstract: A vehicle air conditioning apparatus in which the larger the air conditioning cooling load in a vehicle compartment, for example, the larger the solar radiation amount, the lower the set temperature or the larger the temperature deviation between set temperature and inner air temperature, the narrower the swing ranges of swing louvers of respective center and side FACE blow outlets are set. Regardless of the swing range of the swing louvers, swing cycles of the swing louvers are set constant, and the narrower the swing ranges of the swing louvers, the slower the swing speeds of the swing louvers are set. Therefore, annoying feeling is reduced, and comfortable feeling for passengers is significantly improved.

Abstract: A method and system for delivering aqueous ice slurry is disclosed. In one embodiment, the ice slurry delivery system includes a storage tank having an inlet to receive an aqueous ice slurry from an ice generating unit. A circulation loop is connected to the storage tank. Ice slurry held in the storage tank flows through the circulation loop generally continuously at a first rate. Valved discharge points are located along the circulation loop at spaced locations and are operable to re-direct some of the ice slurry flowing though the circulation loop to deliver ice slurry for end use upon demand. The rate of flow of ice slurry through the discharge points is less than the first rate even when all of the discharge points are re-directing ice slurry for end use.

Abstract: A process for controlling a refrigeration system, as well as the refrigeration system and a new expansion valve for the refrigeration system. An electronic regulator is used to operate a sensor system having a device for applying heat power to the sensor system in direct dependence on sensed superheat of the refrigerant leaving the evaporator. By locating the sensing system in communication with liquid refrigerant upstream of the evaporator, heat transfer to the liquid refrigerant is utilized for operation of the sensor system rather than heat transfer to the superheat, resulting in a far more stable and efficient refrigeration control.

Abstract: A pressure control valve controlling the temperature and pressure at the outlet side of a heat emitter so as to enable efficient operation by a CO.sub.2 system operating at the super critical region, wherein CO.sub.2 is sealed in a closed space at one side of a diaphragm moving the valve element at a density of approximately 600 kg/m.sup.3, a through member made of a material with a high heat conductivity is provided extending between the inside and outside of the closed space, and step differences are eliminated at the contact surfaces to improve the durability of the diaphragm.

Abstract: A valve body of a thermal type expansion valve comprises of a fist path 32 and a second path 34 as the valve body 30, and a rod member 316 forming a heat sensing shaft 36f is a shaft having a small diameter, and according to the displacement of the diaphragm 361 of the power element member 36, the shaft is driven back and forth crossing the path 34. The rod member 316 has an overall length whose ratio is 17 to 28 against the outer diameter size, and is formed not to buckle against the stress added in the axial direction, which contributes to the miniaturization and lighter weight of the valve as a whole.

Abstract: A jewelry assembly having stones on the sidewalls of a setting is provided. The jewelry assembly includes a jewelry element, such as a ring, earring, bracelet or necklace. The assembly also includes at least one top stone having a table portion, girdle and a depending tapered portion. The top stone is attached to the jewelry element by means of a plurality of prongs depending from the element. Retaining elements are located alongside the tapered portion of the top stone and fixedly receive one or more side stones, creating an overall unique visual effect.

Abstract: The present invention provides for a method and articles produced from this method for eutectically bonding together single crystal elements, such as sapphire, to form a strong bond therebetween which can withstand high temperatures and chemical attack. The eutectic bonding mixture of the present invention can include a Group IIIA compound, such as yttria.

Abstract: A number of unique processes are disclosed for manufacture of sintered high-purity quartz glass products in which a shaped silica body or preform is made from an aqueous slurry of micronized silica particles by gel casting, slip casting or electrophoretic deposition. The silica particles may comprise a major portion by weight of crystalline silica. In one embodiment of the invention the sintered quartz glass is transparent, substantially bubble-free and suitable for scientific or optical uses. In another embodiment the porous silica preform is fired in steam to increase the hydroxyl content and then nitrided in a nitrogen-hydrogen reducing atmosphere. A minute amount of chemically-combined nitrogen in the high-purity quartz glass is sufficient to provide a tremendous improvement in physical properties and an incredible increase in the resistance to devitrification.

Abstract: An apparatus for producing an optical fiber porous glass preform using the VAD method which can stably produce a high quality optical fiber porous glass preform, wherein a target bar is only rotatably supported by a chuck and is not pulled upward, a lower tip of a soot body is detected by a laser and a photodetector, and a core burner and a cladding burner is lowered in response to the result detected. A tip position detecting drive and burners are synchronizingly lowered while the deposit of porous glass grows at the lower portion of the target bar.

Abstract: A combined laundry washing/drying machine wherein the washing and drying means are mounted within a pivoting subassembly. In the washing mode the laundry is washed within a basket oriented vertically. In the drying mode, the pivoting subassembly is moved so that the laundry is tumbled in the basket as it spins on a horizontal axis. The washing mode further employs a perforated washing plate which moves in a reciprocating vertical motion to provide the cleaning action.

Abstract: A dry-cleaning system operable for selectively controlling agitation of items during cleaning, rinsing, and draining cycles. The dry-cleaning system includes a pressure vessel for containing a liquid gas dry-cleaning solvent and a rotary basket disposed within the vessel for containing items to be cleaned. Controlled agitation is achieved by the combination of (1) driving the basket by a directional, variable speed motor and (2) a simultaneously selectively operable gas jet system having a plurality of nozzles rotatable with the basket for directing pressurized jet streams into the liquid wash bath.

Abstract: An apparatus for magnetically laundering garments with permanent ceramic magnets compiled in unique configuration with a flux density of at least 3,900 gauss at a pole face thereof, thick plastisol casing to protect magnets from water and washing machine agitation; the magnet configuration ionizes water, increasing the natural solvency to assist in releasing stains and odors in fabrics; design, size and the casing make it practical for use in washing machine, uses specially calibrated magnetism to alter the basic nature of water and increase its natural solvency by ionization for usage in a laundry machine, and a preferred embodiment includes the magnets as a rare earth magnet.

Abstract: A pad lock includes an outer casing, a lock main body, and a shackle. A stem is slidably mounted in the lock main body. Several number wheels are rotatably mounted around the stem. Also rotatably mounted around the stem are several retaining sleeves each being releasably engaged with an associated number wheel to rotate therewith. A lever member includes a first end for releasably engaging two pin members to retain the shackle in a locked status. The lever member includes a second end with a number of tongues for engaging with the retaining sleeves. A positioning member is formed on the second end of the lever member. A safety pin is mounted to the lever member to assure the positioning member in a position that prevents setting of a new code when any one of the number wheels is not in the correct position for unlocking.

Abstract: A motorized lock assembly includes a lock bolt mounted in a door and having a rotary core containing a first slot, an inside assembly having a casing attached to the inside of the door, and a transmission mechanism having a rectangular block rotated by a drive device, and an extension post containing a second slot aligning with the first slot, and an outside assembly attached to the outside of the door and having an elongate rotor in turn extending through the first slot and the second slot such that the rotary core rotates in conjunction with the extension post, whereby the rectangular block can be rotated so as to rotate the extension post and the rotary core, thereby extending a dead bolt outward from the lock bolt.

Abstract: A cylindrical "shell and plug" assembly has the plug rotatably received within the shell. The plug has a central rear shaft and an engagement portion thereon. The engagement portion has a pie-shaped stop member and a pie-shaped engagement member. A connecting member rotatably held within the shell has an inner engagement that can engage the pie-shaped engagement member and an operation key slot capable of receiving an end of an operation key. The plug can be rotated until the engagement member is positioned behind the flange to retain the plug with the connecting member, and the plus can be rotated so that the engagement member can be positioned away from the flange, thereby permitting the plug to become disengaged from the connecting member.

Abstract: A double blank detector apparatus and method of operation determines the condition of when one blank, no blanks or more than two blanks are about to be fed into a press. An indicator bar advances relative to the number of blank sheets of material being detected and interrupts an infra-red light beam when only blank of material has been detected. Under this preferred condition, a signal is produced which allows a press located adjacent to the double blank detector to continue its stamping operation. Alternatively, if either a no blank or a double blank condition is sensed, then the indicator bar advances accordingly, thus not interrupting the infra-red light beam. During this condition, a signal is produced indicative of the situation thus notifying the operator that there is a problem and stopping the press from cycling.

Abstract: Process for creation and adjustment, from one moment to the next, of the external force to apply by the feed assembly to the preformed forging in cold rolling mills of the "pilgrim process" type with rollers and mandrel for producing seamless tubes by means of a computer, in accordance with the geometric parameters of the contours of the rollers and of the mandrel and in accordance with the reaction generated during rolling in the roller supports, for lessening the risk of breaking the tube, reducing unit loads and raising productivity.

Abstract: The invention resides in a module used in conjunction with other such modules in an apparatus for rapidly producing an article having a three-dimensional design comprising a base, a plurality of pins mounted on said base and said plurality of pins movable relative thereto, a plurality of drive motors corresponding in number to the number of said plurality of pins and means interconnecting each of said plurality of pins with said base, each said means being connected independently between said base and a corresponding one of said pins. A control means interconnects each of said drive means and a controller with one another to effect selective energization of said drive means.

Abstract: In order to manufacture a pipe having a plurality of flow channels, by minimizing die jigs and steps, and thus to permit facilitation of manufacture, reduction of cost, and improvement of accuracy, the method of manufacturing a pipe comprises the steps of holding a sheet material at a center portion in the width direction thereof from both surfaces thereof by core members composing a split structure, folding both sides in the width direction of the sheet material in opposite directions and causing the thus folded both sides of the sheet material to follow the shapes of the outer surfaces of the core members, thereby forming a substantially an S-shaped cross-section.

Abstract: With a view to increasing the lifespan of metallic dental components as regards fatigue fractures, compressive stresses are introduced into the surface layer of these components, such as by means of shot-peening.

Abstract: An arrangement for the internal high-pressure forming of hollow profiles has an internal high-pressure forming tool, into whose die sinking the hollow profile can be inserted. At least one axial die has a sealing head which can be inserted with play by a section into the hollow profile. This sealing head has a support part which is provided with a pressure fluid duct and on which a sealing arrangement is held and which is rigidly connected with the axial die, and has a stop surface, which in the operative position of the sealing head rests on the face side against the end of the hollow profile. The sealing arrangement contains at least one sealing element which can be radially spread open for an allaround sealing contact on the interior side of the hollow profile.

Abstract: The present invention relates to a method of producing a sheet metal pulley for a V belt without cutting which may impair the environment of a factory. A sheet metal pulley for a V belt which is obtained by the production method of the present invention has plural valley portions around which V belts are to be wound. In the production method, an annular first valley portion which is opened in a V-like shape is formed by slitting a root portion of a cylindrical portion of a sheet metal cylindrical member and an outer periphery of a base plate portion continuous to the root portion.

Abstract: A rolling mill is provided with a pair of work rolls 2, a pair of intermediate rolls 3 and a pair of backup rolls 4 in a mill stand 5, wherein the pair of backup rolls are arranged so that their axial lines cross perpendicularly a plate travelling direction and do not incline to the direction in a horizontal plane, the intermediate rolls and work rolls are arranged so that the axial lines of the intermediate rolls and the axial line of the work rolls incline to (cross) the axes of the backup rolls in a counter direction to each other in a horizontal plane, and a lubricant supplying apparatus 6 is provided for supplying a lubricant to the roll surfaces.

Abstract: Disclosed is a preferred embodiment of straightening apparatus (100) featuring a pair of adjacent rotary block members (8) and (8') having channels (30) and (30') respectively disposed therein for receiving spaced-apart legs (6) and (6') of a heated leaf springs folded into a substantially flat "U" shaped configuration as block members (8) and (8') are caused to rotate in unison in opposite directions, inner walls (12) and (12') of channels (30) and (30') respectively engage and urge legs (6) and (6') away from each other whilst outer walls (10) and (10') of channels (30) and (30') respectively are operative to engage and provide support for substantially the entire length of a convex side (26) of a curved section (24) of the folded leg spring effective to prevent warpage thereof during the straightening process.

Abstract: A driving device for a pressing machine, particularly effective on a turret punch press, whereby both high speed processing at times of low load and high load processing at low speeds can be carried out even with a low output motor. A driving device for a press machine that transmits the rotation of a motor 12 to a press system 11 via a rotation transmission system 29 having a speed reduction gear 30, wherein a speed change gear 31 intervenes on the rotation transmission system 29. The speed change gear 31 is arranged on the input side of the speed reduction gear 30. The press system 11 is a system for exchanging a rotation movement to a linear movement, reciprocally driving the punch tool 4 and comprises the toggle system 8 and the crank system 13 or the like. With regard to control, a method 36 for exchanging the rotation transmission ratio of the speed change system 31 corresponding to the type of process is arranged.

Abstract: A slide-driving device for knuckle presses employs a side link affixed at a base end to the knuckle press, and pivoted at its outer end to a junction between links that drive the slide. The side link maintains a very small slope angle for the lower link, which raises and lowers the slide. The small slope angle prevents thrust force from being generated on the slide, and enables performing high-precision molding of products even with extrusion operations, where the molding is started from a position high above the bottom dead center of the slide. In one embodiment of the invention, the base end of the side link is rigidly affixed to the frame of the knuckle press. In a second embodiment of the invention, a bottom dead center compensation device adjusts the position of the outer end of the side link at bottom dead center to compensate for changes in the linkage.

Abstract: A method for providing an automatic calibration check of a measuring device in which particles to be measured are subjected to tangential acceleration in a whirling impeller, and torque exerted on the vanes of the impeller in reaction to the Coriolis force of accelerated particles is measured as an indication of a mass flow rate, and wherein the flow of material is fed to the central part of the impeller and thereafter is by centrifugal force thrown towards the circumference of the impeller. Flow is measured by an electronic device which includes a microcomputer. When the flow is absent or constant the rotational speed of the impeller is varied, the moment change thereof is measured and an integrated value of the kinetic energy is used to verify the operation of the instrument.

Abstract: The invention relates to a method for measuring gas content in a fluid, such as papermaking pulp or coating paste, and to a gas content measuring device. Pressure variations generated by a pump, for instance, are to occur in the fluid. Travel time, phase and/or attenuation of the microwave signal (20) are measured with the gas content measuring device while the signal (20) penetrates through the fluid (13), and the gas content is determined on the basis of changes in travel time, phase and/or attenuation of the microwave signal (20) caused by pressure variations of the fluid (13).

Abstract: A method and apparatus for measuring metallic impurities within a fluid by X-ray fluorescence in which a sample stream flowing at a constant flow rate is passed through a microporous filter. The microporous filter contains substantially no metallic impurities and is configured to adsorb the particulate solid phase and vapor phase of the compounds. Excitation of the metallic compounds by X-ray produces an X-ray florescence having an intensity that can be measured. The change in intensity is compared with that produced by a calibrated inflow of a standard gas sample to derive the impurity concentration. In a preferred embodiment, the filter is housed within a chamber having a window that is preferably fabricated from Beryllium so as not to appreciably attenuate the X-rays.

Abstract: An apparatus for detecting the presence of volatile substances in a gaseous medium, including apparatus for producing within a sensor chamber a localised electric field the energy density of which is sufficient to excite the gaseous medium to a plasma condition, and apparatus for detecting changes in a parameter of the plasma due to the presence of the volatile substances in the gaseous medium.

Abstract: A gas sensor and method for manufacturing a gas sensor is provided. In order to increase the selectivity and the sensitivity to a gas to be measured, a gas-sensitive gallium oxide layer of a gas sensor is coated with a filter layer that comprises silicon dioxide. In an alternative embodiment, the gallium oxide layer can be coated with a gas-sensitive metal oxide layer made of titanium oxide, aluminum vanadate, tungsten oxide or tantalum oxide.

Abstract: In a method for determining depth when putting in place supporting elements into a waterbed, a pressure sensor fastenable to a supporting element or a device connected to the supporting element measures a water pressure, the reading is supplied by the pressure sensor and transmitted via signal lead to an evaluating unit which determines the penetration depth of the supporting element from the reading differences which occur during the sinking of the pressure sensor on penetration of the supporting element into the waterbed.

Abstract: In the tire examination method before and after an alteration in the tire pressure a respective interferogram is produced of the tire surface using coherent radiation and the interferogram is converted into a modulo 2 .pi. image, which for its part is processed to obtain a gray value image and in the case of which from a comparison of the gray value images information concerning any defects present in the tire is obtained. For testing a tire the wheel, which bears such tire to be tested, is arranged on a driven roller set by driving the vehicle with the wheel, a test head is moved toward the tire to be at a predetermined test distance therefrom for producing such interferograms, at a first test segment of the tire examination for defects is performed, the wheel is incrementally rotated by the roller set by an amount equal to the size of a test segment and so many test segments are examined that the complete tire is tested.

Abstract: A method and apparatus is described whereby lightning within thunderheads and other cloud formations may be triggered in such a way as to minimize damage to surrounding structures and persons. The system consists of a high-pressure pump, accumulator, electrically actuated fast-valve and triggering system. In operation, through manual or automatic control, a high-pressure jet of water, which is rendered electrically conductive by traces of a solute such as salt or acid, is directed upward toward a threatening cloud. The high-conductivity swath of the water jet will act as a path for the discharge of lightning to the jet nozzle. In this method, lightning strikes may be diverted from sensitive areas to the apparatus.

Abstract: Improved multifunction probe designs include circumferentially separated pairs of sensing ports which may respectively be dedicated to angle of attack functionality and air data pressure sensing functionality. In one preferred embodiment, a multifunction aircraft probe is provided with a rotatable probe element which is adapted to project outwardly from an aircraft with which it is operatively mated. The probe element is provided with a centrally located (i.e., in substantial alignment with the probe's stagnation line) dynamic pressure sensing port, and outer and inner pairs of pneumatic sensing ports which are symmetrically circumferentially separated from one another and from the dynamic pressure sensing port. Most preferably, each of the outer pneumatic sensing ports is circumferentially spaced from the central dynamic pressure sensing port by a first angle (e.g., substantially 90.degree.

Abstract: An ultrasonic measuring apparatus (FIG. 2) and method (FIG. 5) to accurately determine the depth of an overlaying backfat (14-20) on an animal (8) without incurring any damage to the animal. The apparatus employs a reverse time analysis approach in which a pulse generator (28) sends a preselected ultrasonic input signal by way of a piezoelectric transducer (16) through the outer skin (12) and successively through each one of the animal's fat layer interfaces (15, 17, 20) to a preselected distance within the loin portion (22) of the animal. This reverse time approach then analyzes the resulting echo signal produced by the input signal sequentially in a direction from this loin portion toward the outer fat layers (14, 16, 18). The first strong signal within a specified range, which depends on the species, breed, age or weight of the animal to be measured, is taken as the bottom-most fat/loin transition.

Abstract: The vibration control device comprises an electromechanical transducer module adapted to be attached to an outer surface of a rotating object, and a control circuit for electrically controlling an internal stress of the electromechanical transducer module so that the internal stress counteracts a stress of the rotating object resulting from a vibration of the object that is desired to be controlled. Thus, the stress produced from the vibration of the rotating object is transmitted to the electromechanical transducer module, and is converted into an electric energy. The electric energy thus produced by the vibration of the rotating object is applied to the electromechanical transducer module, and is thereby converted into an internal stress of the electromechanical transducer module which counteracts the vibration of the rotating object.

Abstract: A vibration wave detector, having a receiver for receiving vibration waves such as sound waves and so on to be propagated in a medium, a resonant unit having a plurality of cantilever resonators each having such a length as to resonate at an individual predetermined frequency, a retaining rod for retaining the resonant unit, a vibration intensity detector for detecting the vibration intensity, for each predetermined frequency, of each of the resonators, by the vibration waves received by the receiver and propagated to the resonant unit by way of the retaining rod.

Abstract: A method of making a pressure sensor or acoustic transducer having high sensitivity and reduced size. A thin sensing diaphragm is produced by growing a single crystal, highly doped silicon layer on a substrate using a chemical vapor deposition process. The diaphragm is incorporated into a pressure sensor or acoustic transducer which detects pressure variations by a change in the capacitance of a capacitor which includes the diaphragm as a movable member. The thin diaphragm produces a highly sensitive device which can be fabricated in a smaller size than sensors or transducers having thicker diaphragms.

Abstract: A microelectromechanical (MEM) capacitance pressure sensor integrated with electronic circuitry on a common substrate and a method for forming such a device are disclosed. The MEM capacitance pressure sensor includes a capacitance pressure sensor formed at least partially in a cavity etched below the surface of a silicon substrate and adjacent circuitry (CMOS, BiCMOS, or bipolar circuitry) formed on the substrate. By forming the capacitance pressure sensor in the cavity, the substrate can be planarized (e.g. by chemical-mechanical polishing) so that a standard set of integrated circuit processing steps can be used to form the electronic circuitry (e.g. using an aluminum or aluminum-alloy interconnect metallization).