Abstract: A pressure transducer for measuring high differential pressure media in a harsh environment where a diaphragm assembly is mounted to an intermediate support number which is mounted to a main support member where the high pressure media impinges on the diaphragm to create a force opposing that provided by the diaphragm support structure thereby loading the diaphragm in compression. The strain sensitive piezoresistive elements are protected and sealed from the low pressure media by a passivation layer and electrical signal leads are attached to bonding pads formed on the diaphragm assembly which are sealed to the intermediate support member by a sealing cap.

Abstract: A biomedical pressure sensor having a pressure sensing diaphragm is provided with a distensible membrane overlying the diaphragm, and the diaphragm is provided with one or more holes. During normal operation, externally applied pressure forces the membrane against the diaphragm so that the membrane and diaphragm deform under pressure as a unit and transmit pressure-applied forces to a force transducer within the probe housing. When a reference pressure exceeding the externally applied pressure is supplied within the probe housing, such reference pressure passes through the hole in the diaphragm and forces the membrane away from the diaphragm, thereby isolating the diaphragm from the externally applied pressure and bringing the diaphragm to a zero-differential pressure condition. Use of a hole in the diaphragm permits an extremely compact construction.

Abstract: A signaling gauge may utilize a magnetically actuated variable resistor made up of a plurality of noncaptivating, magnetically actuated switch elements, each of which is mounted in an influence zone of a path of a magnet carried on an arm of a condition sensor such as a gauge movement. The arm may be an indicating pointer of the gauge. The gauge may alternatively utilize a magnetically-sensitive, variable-resistance element in a contactless arrangement with a magnet. The variable resistance element may include a plurality of noncaptivating, magnetically actuated switch elements and associated resistors mounted in an influence zone of a path of a magnet. The contactless arrangement eliminates the need for electromechanical contacts.

Abstract: A pressure sensor comprising a pressure sensing assembly 24 and a pressrue transmitting medium 26 disposed within a main body 20 a seal assembly 34,35,36 disposed between the pressure sensing assembly and the main body for sealing between them against said pressure transmitting medium while allowing an easy attachment and detachment of the pressure sensing assembly relative to the main body. The pressure sensing assembly may comprise a sensing element 27 for detecting pressure, a base plate 25 for sealingly supporting the pressure sensing element within the main body and a pressure transmitting pipe 26 for transmitting the pressure to be detected to the element, and an O-ring in contact with the pressure transmitting pipe. A filling passage 15 which may be closed by a plug screw 16 may be disposed in the main body for filling the detection cavity with the pressure transmitting medium.

Abstract: A pressure sensor, such as the type of sensor used in screw-type refrigeration compressors, permits sensing of positive as well as negative pressures and provides an indication of the direction in which the compressor is rotating. Negative pressure leads to system shut-down, while positive pressure verification will allow compressor operation to continue. The pressure sensor includes a pair of adjustable tension springs, on opposite sides of the diaphragm, to vary the position of the diaphragm within its mechanical stroke. By establishing a pressure range of interest, and by employing an electrical sensor, such as a Hall effect sensor, the direction of movement of the diaphragm and sensor can be monitored immediately upon compressor start-up.

Abstract: A pressure sensor for determination of pressure in a combustion chamber of an internal combustion engine, particularly for motor vehicles has a housing, a membrane associated with the housing, a sensor element, a plunger supplying a pressure to be determined to the sensor element and located in the housing. The housing has at least one housing opening and a shaft and the membrane closing the opening of the housing and is connected with the shaft of the housing in the region of a side wall so that a bottom of the membrane is flexible and a pressure to be determined is transferable to the plunger, a counter bearing for the plunger. A support is provided for a hybrid and composed of ceramic material and located on the counter bearing for the plunger. The sensor element is a piezoresistive measuring element and located on the hybrid so as to produce an electrical signal corresponding to the pressure.

Abstract: A pressure sensor including a semiconductor strain gauge and resistors for compensating temperature, a zero point or the like and made of the same material as that of said semiconductor strain gauge are formed on a metal diaphragm thereof. The resistors for the compensating circuit and the strain gauge are simultaneously formed by patterning a polycrystalline silicone thin film or the like laminated on the diaphragm. As a result, the number of the elements and the manufacturing processes such as a soldering process are reduced for the purpose of improving manufacturing yield. In order to widen the zero point compensating range, a plurality of zero-point compensating resistors, if formed, are disposed on a circumference relative to the center of the diaphragm so as to reduced the scattering in the level of the resistance of each of the resistors.

Abstract: A transducer having a plurality of sensing elements disposed in a single diaphragm wherein each of the sensing elements is spaced from every other of the sensing elements a predetermined distance so as to control interference among the sensing elements. Each of the sensing elements preferably comprises a plurality of piezoresistors each of which are coupled in a Wheatstone bridge configuration. This transducer achieves sensitive, accurate, high spatial resolution measurements of non-uniform pressures.

Abstract: A low cost piezoresistive pressure transducer utilizing premolded elastomeric seals in which at least one seal is electrically conductive. A piezoresistive stress sensitive element in the form of a diaphragm of semiconductor material having a thickened rim is held at its rim between a pair of premolded elastomeric seals in a two piece housing. Electrical connections with external circuitry are made by conductive paths through one of the elastomeric seals which makes contact with electrical leads which pass through the housing wall.

Abstract: Disclosed is a pressure gauge which is mainly composed of two parts, a pressure sensing element and an electronic processing and displaying unit. The pressure sensing element includes an elastic member and a variable resistor whose resistance value can be varied by the force of the pressure. An output electrical signal is occasioned by the electronic circuit, which is in proportions corresponding to the resistance value of the variable resistor. The electronic processing and displaying unit will further process the output electrical signal and display the value of the pressure in an indicator, preferably a liquid crystal display (LCD). The pressure goes through a calibration process every time when the power is just turned on to calibrate an initial output electrical signal occasioned by the variable resistor.

Abstract: A piezoresistive device, in which separation grooves having a cross section defined by four (111) planes and including side walls of a silicon oxide film are formed in a surface area of a semiconductor substrate having a surface of (100) plane, and at least one piezoresistor having an inversed triangular cross section defined by one (100) plane and two (111) planes is formed in the surface area of the semiconductor substrate and is surrounded by the separation grooves for separating the piezoresistor from the semiconductor substrate.

Abstract: A semiconductor pressure sensor having a diaphragm formed over the surface of a semiconductor substrate by thin film forming technique is provided.

Abstract: A pressure transducer having means for improving the linearity and sensitivity of an output signal from the pressure transducer. Ribs and bosses are introduced in the diaphragm region to collect the moments caused by a difference in pressure on the two sides of the diaphragm and thus improve device sensitivity. In addition, the ribs and bosses prevent stretching of the piezoresistors thus improving the linearity of the device. A constraint can also be included to improve the alignment of the piezoresistors thus improving the linearity of the device.

Abstract: A pressure sensor has a thin plate diaphragm having a strain detecting section thereon, and a support member for receiving and properly positioning the diaphragm within a stepped bore structure. The pressure sensor with which the strain detecting section is formed on the diaphragm surface is formed by the use of semiconductor manufacture technology by making the diaphragm of the pressure sensor in the form of a thin plate member. The diaphragm and the support member are joined together by diffusion bonding, and heat treatment for this diffusion bonding is also utilized to crystallize the semiconductor strain gauges.

Abstract: Pressure sensor having a silicon diaphragm chip. The diaphragm in the chip is less than 200 mils in diameter and has an ultrasonic resonant frequency that varies with pressure exerted on it. The chip has resistors with values that change with fluctuation of the chip. The changing resistor values are fed to a supporting electronics that detect the resonant frequency of the diaphragm and indicate measurement of the pressure exerted on the diaphragm. The supporting electronics feed back a signal corresponding to the detected resonant frequency for a sensed pressure to a piezoelectric device that drives the diaphragm to sustain its vibration.

Abstract: A silicon pressure chip operates in a two-wire resistive mode. A thin-film resistor located on a long silicon beam which is the thicker portion of a thin diaphragm is partially shorted out by a metallized deflection stop. The pressure response of the resistor is determined by the resistor layout.

Abstract: An improved pressure transducer having a switching device operated in response to changes in fluid pressure is disclosed which incorporates a terminal support member having electrical contacts which are designed to be electrically bonded to and mechanically interlocked with electrical contacts provided within the housing. The invention also includes an improvement in the piston contacts for preventing scratching of the resistor board. A method is provided for permanently connecting terminals of the housing with the mating metal connector terminals once they have been properly calibrated and connecting the housing ground strap with the terminal support member.

Abstract: A stress sensor for detecting a stress, including a ceramic hollow member, a pair of support members for supporting the ceramic hollow member, and at least one resistor provided on the ceramic hollow member. The ceramic hollow member is deformable according to a stress applied thereto in a direction in which a hollow of the hollow member extends. The support members are disposed at opposite ends of the hollow member, so as to support the hollow member such that the stress is imparted to the hollow member through the pair of support members. The resistor or resistors is/are disposed on one of the inner and outer surfaces of the hollow member. The stress is detected based on a change in the electrical resistance value of the resistor or resistors which is caused by the deformation of the hollow member.

Abstract: A transducer having a plurality of sensing elements disposed in a single diaphragm wherein each of the sensing elements is spaced from every other of the sensing elements a predetermined distance so as to control interference among the sensing elements. Each of the sensing elements preferably comprises a plurality of piezoresistors each of which are coupled in a Wheatstone bridge configuration. This transducer achieves sensitive, accurate, high spatial resolution measurements of non-uniform pressures.

Abstract: A housing and a pressure seal structure for use with a thick film circuit having a pressure sensor and terminals includes a base plate below the thick film circuit, a top housing above the thick film circuit covering the pressure sensor and an intermediate rubber ring between the housing and the thick film circuit. A coupling force is applied between the base plate and the top housing to draw the two together and apply a sealing force to the rubber ring and establish a pressure seal at the rubber ring.

Abstract: A pressure sensor that utilizes an extension type conductive elastomer that will exhibit a decrease in its electrical resistance in response to an extension thereto. Like sheets of the conductive elastomer and an electrically insulative elastomer are overlaid and sandwiched between supporting members within a housing of the pressure sensor. The housing and each supporting member are preferably cylindrical or ring shaped, and which conductive elastomer has a pair of spaced electrodes electrically connected thereto at opposite points on its periphery. The periphery of the electrically insulative elastomer is squeezed continuously in a circle between the supporting members, while that of the conductive elastomer that includes recesses is squeezed therebetween discontinuously in the sections between the electrodes.

Abstract: A condition responsive sending and indicating unit for sensing a condition and transmitting a signal representative of the sensed condition to an indicator at a remote location. The sending unit includes indicia for giving an indication of the sensed condition at the site of the unit, and has a movable contact operatively associated with a variable resistor in circuit with the remote indicator, whereby a variable signal is produced in response to variation in the sensed condition. Calibration of the unit is accomplished by adjustment of the set point of the movable means, and by adjustment of the position of the resistor relative to the movable contact.

Abstract: A differential pressure transducer has a first pressure chamber, defined by a first chip having a reduced-thickness first pressure-sensitive diaphragm on one side of that pressure chamber, and a second chip having a reduced-thickness second pressure-sensitive diaphragm on another side of that pressure chamber. A first pressure port communicates with that first diaphragm on a side opposite the first pressure chamber and a second pressure port is coupled to the first pressure chamber. A second pressure chamber is on a side of the second diaphragm opposite the first pressure chamber. Sensors are at the first diaphragm for measuring differential pressure between said first and second ports and at the second diaphragm for measuring differential pressure between said first and second pressure chambers. An aperture may extend through one of the chips in a region spaced from its pressure-sensitive diaphragm, which may therethrough be coupled to the second pressure port.

Abstract: A piezoresistive pressure transducer employing a sapphire force collector diaphragm having piezoresistive films of silicon epitaxially formed on a major surface thereof, preferably in a Wheatstone bridge pattern. The silicon piezoresistive film is preferably of a thickness of from 1,000 to 60,000 angstroms and is doped with boron in the range of from 5.times.10.sup.17 to 9.times.10.sup.20 atoms/cc. Electrical lead traces and electrical contact pads are also formed on the major surface of the force collector diaphragm. The diaphragm is mounted on a pressure cell base having a cavity in the upper surface thereof, the diaphragm enclosing the cavity so as to form a chamber with the piezoresistive silicon films within said chamber. The diaphragm is hermetically bonded by a ceramic glass to the base in a vacuum such that the chamber provides a vacuum pressure reference.

Abstract: An improved pressure transducer to measure and indicate fluid pressure levels including a housing in which a piston assembly is movable in response to pressure changes, the housing being of a composite material of metal and plastic and having grooves therein, the piston having bosses formed thereon to be engaged within the grooves of the housing to prevent rotation of the piston. The transducer is also designed to facilitate grounding of an electrical contact assembly located within the housing. The external portion of the housing may be formed in a hexagonl shape to facilitate installation and removal of the unit.

Abstract: A fluid pressure transducer with an electrical switch structure therein including a conductor which is movable relative to fixed contacts as influenced by the force of internal spring forces whereas the relative positioning of a spring's end in the housing is adjustable after the transducer's assembly thereby effectively calibrating the switch's opening and closing characteristics relative to a predetermined fluid test pressure.

Abstract: A pressure sender is provided with a variable electrical resistance corresponding to a sensed pressure, to be placed in series with a voltage source and a pressure gauge. The pressure sender is diaphragm-actuated, which diaphragm controls the positioning of an electrical contact against a ceramic thick film rheostat. An electrically conductive metal clip secures the rheostat in position as well as completes the electrical connection between the rheostat and the electrical circuit of which the pressure sender is a part. The electrical contact is rockingly mounted so that deflection of the diaphragm displaces the electrical contact through an arcuate travel path along various resistance positions of the thick film ceramic rheostat. Current from the electrical circuit will flow through the metal clip to input contacts of the rheostat, and then to the resistance positions.

Abstract: A wet-to-wet pressure sensor package (10) having a housing (12) with a pressure sensitive semiconductor die (34) supported within a resilient mounting (44) including continuous beads (46, 48) of elastomeric adhesive on the same portion of the housing to provide a protective seal with less stress so that improved sensitivity and repeatability of the wet-to-wet pressure sensor is achieved.

Abstract: The pressure sensor has a housing, a sensing body mounted inside an internal space of the housing and having a cavity, one end thereof being open and other end thereof being closed, to form a pressure introducing portion therein, the closed end thereof having a thin thickness forming a diaphragm for receiving a pressure, and a semiconductor chip mounted on one surface of the closed end opposite to the diaphragm for receiving a pressure. The pressure sensor is characterized in that the sensing body is attenuated at a portion including at least the closed end thereof and has a diameter smaller than that of the remaining portion thereof, and a shoulder is provided therebetween, whereby the sensing body is fixedly connected to the internal space of said housing by abutting the shoulder thereof against a stopper portion provided in the internal space of the housing and the external surface thereof is placed in contact with the inner surface of the internal space of the housing.

Abstract: A sensor chip subassembly for use in a transducer assembly includes a support member to which a pressure sensitive chip is elastically bonded at predetermined but spaced points to separate the chip from direct contact with the support member. The separation minimizes vibration and stress from being transmitted from the support member to the chip.

Abstract: A pressure sensor having a ceramic pressure sensing element including a bottom wall serving as a diaphragm, and a tubular wall which extends from a periphery of the bottom wall and cooperates with the bottom wall to define a cavity. The diaphragm has resistors formed thereon. The resistors are electrically connected to an external electric device by electrically conductive members. The sensing element is held in a housing by a retainer member such that one end of the retainer member is aligned with an end face of the tubular wall remote from the bottom wall. A biasing member is provided for biasing the retainer member toward the ceramic pressure sensing element, to exert a retaining force to the sensing element.

Abstract: A pressure sensor including a cylindrical metallic housing having an open end having an opening, a ceramic pressure sensing element having a ceramic diaphragm and fixedly accommodated within an open end portion of the metallic housing, and a strain detector associated with the ceramic diaphragm. The ceramic diaphragm is exposed at one of opposite major surfaces thereof to an external space through the opening of the metallic housing and is deformable in response to a pressure of a measurement fluid in the external space. An electrical output of the strain detector varies with an amount of deformation of the ceramic diaphragm, thereby representing the pressure of the fluid.

Abstract: A facedown-type semiconductor pressure sensor has a Si sensing element including a diaphragm, a spacer, and a piezoresistive device embedded in the diaphragm, and a pedestal. The spacer, which is positioned between the semiconductor substrate and the pedestal, has a photolitho-graphically etched hole such that the sensing element, the hole and the pedestal define a sealed chamber. The sealed pressure chamber is substantially aligned with the diaphragm.

Abstract: In order to improve the stabilization and the heat-resistance of a strain gauge, the strain gauge is made of an amorphous alloy including Ni (nickel), Cr (Chromium) and Si (silicon). The amorphous alloy including Ni, Cr and Si has a high crystallization point, its temperature co-efficient of resistance is almost zero obtained by annealing. The amorphous alloy is stabilized from low to high temperatures and thus can be used from low to high temperatures without compensation. The amorphous alloy is a non-magnetic substance and the strain gauge thus is not substantially affected by external electromagnetic noise.

Abstract: A pressure transducer for in particular the measurement of relatively high pressures in the range of 10,000-50,000 psi and including an elongated frame having a capillary tube extending therethrough and employing a coupler at one end of the frame for sensing input pressure. A sensing member is provided disposed about the capillary tube at the other end of the frame and has, defined with the capillary tube, a sensing chamber in communication with the capillary tube. A recess is provided in the sensing member defining a relatively thin wall adjacent the annular sensing chamber. This wall has a pressure responsive sensing surface that extends substantially parallel to the capillary tube length and upon which strain gages are secured. A method is described for securing the capillary tube with the sensing member in a liquid tight manner.

Abstract: Sealed cavity structures suitable for use as pressure transducers are formed on a single surface of a semiconductor substrate (20) by, for example, deposit of a polycrystalline silicon layer (32) from silane gas over a relatively large silicon dioxide post (22) and smaller silicon dioxide ridges (27) leading outwardly from the post. The polysilicon layer is masked and etched to expose the outer edges of the ridges and the entire structure is then immersed in an etchant which etches the silicon dioxide forming the ridges and the post but not the substrate (20) or the deposited polysilicon layer (32). A cavity structure results in which channels (35) are left in place of the ridges and extend from communication with the atmosphere to the cavity (36) left in place of the post.

Abstract: A liquid fluid level sensor responds to differential pressure forces exerted on a diaphragm as produced by exposure of liquid fluid to one side and of atmosphere to the other side. An arched resistance card is movable with the diaphragm to engage the mid-portion of a metal spring which progressively overlies greater portions of the card as the diaphragm moves thereby changing the resistance of a circuit including the card and the spring.

Abstract: A pressure transmitter assembly includes a laminated ceramic structure for providing fluid passages as well as a support for a pressure sensor, electronic circuitry, fluid barrier diaphragms and input process fluid connections. The laminated structure is comprised of a plurality of co-fired ceramic layers having the fluid passages molded therein to enable fill fluids within the assembly to apply input pressures as a differential pressure across the pressure sensor. In one embodiment of the invention, three ceramic layers are used while a second embodiment uses four layers with an overload diaphragm captured between two of the layers. The laminated ceramic structure can be extended in either embodiment to include an outer ceramic circuit board which is bonded with a fluid-tight interface with an adjacent one of the other ceramic layers.

Abstract: A pressure sensor in which a Ni-Si-B amorphous alloy strain gauge is covered and protected from the external impact and dust in the air by a protective film.

Abstract: A pressure sensor has a metal housing. The housing has a closed-off and fluid-filled pressure space. A diaphragm partitions the pressure space off from the environment and transmits pressures derived therefrom to the fluid. A pressure-sensitive chip of semiconducting material is exposed to the pressure of the fluid and has a piezoresistant and anisotropic effect. Connectors, metal rods for instance, extend pressure-tight and electrically insulated from the metal housing into the pressure space. The connectors can be connected to an electric processing circuit. The pressure-sensitive chip is connected by bonds. To provide a pressure sensor that will be cheaper to manufacture, less sensitive to malfunction, and more precise, the pressure sensor is provided with a base plate of aluminum nitride. At least some areas of its surface are metallized. The pressure-sensitive chip is soldered to the base plate within a metallized area.

Abstract: A fluid pressure transducer with an efficient mechanism to transform linear movements of a diaphragm mid portion, for example, into rotative movements of an electrical contact assembly which is slidably interactive with a resistive circuit board means.

Abstract: A device for transmitting linear motion into rotary motion, particularly as applied to an oil pressure transducer for a vehicle I.C.E. Specifically, the linear movement is produced by action of pressure against a diaphragm as opposed by a yieldable spring. The spring is a wire curved into a helix shape and with the ends attached to a rotary table. The midportion of the spring is operably attached to the central portion of the diaphragm so that linear movement thereof toward the rotary table causes the spring's end portions to progressively engage the table in overlying relation and, accordingly, to produce rotation of the table.

Abstract: A pressure transducer to measure and indicate fluid pressure levels including a housing in which a diaphragm and piston assembly is movable in response to pressure changes, the piston having a portion extending therefrom to engage a switch contact thereby disengaging the switch when the fluid pressure falls below a desired level.

Abstract: A pressure transducer has a stress isolator layer which permits the sensor to be non-resiliently mounted (hard mounted) to a mounting surface that in turn is subjected to strain. The strain of the mounting surface tends to induce undesired stress in the sensing diaphragm, and the present stress isolator layer minimizes the amount of stress that is transferred to the measuring diaphragm, to thereby reduce error. The spring preferably comprises a silicon leaf0type spring, with or without isolating slots, and is used in various combinations of diaphragms that are sensitive to pressure. The deflection of the diaphragm in response to pressure can be measured in any desired known manner such as with strain gage resistors, or through capacitive sensing.

Abstract: A microbridge air flow sensor having a silicon nitride diaphragm formed on the surface of a single crystal silicon wafer. A rectangular 500 angstrom thick sacrificial layer was deposited on the silicon surface before the silicon nitride to define the exact position of the diaphragm. A series of etches from the backside of the wafer is performed to fabricate the device. A first silicon anisotropic etch from the backside is stopped at the sacrificial layer. A sacrificial layer selective etch is applied from the backside first pit to the sacrificial layer to remove all of the rectangular sacrificial layer. Anisotropic etch is again applied into the space created by the removed sacrificial layer whereby the second etch attacks the silicon exposed by the removal of the sacrificial layer and etches downward forming a second anisotropic etch pit. Thus all the etches are from the backside of the silicon wafer.

Abstract: The sensor includes a rigid support and a diaphragm having a peripheral portion fixed by a layer of glue to the support. The central portion of the diaphragm is spaced from the support and, on its surface facing the support, carries at least one thick-film resistor acting as a piezo-resistive transducer. The diaphragm can deform resiliently towards the support when a pressure is exerted on its other surface. The surface of the support which is connected to the diaphragm is flat, and the layer of glue has a calibrated thickness such that the distance between the diaphragm and the surface of the support at rest is substantially equal to the deflection of the diaphragm corresponding to a predetermined maximum pressure measured.

Abstract: An innput/output terminal assembly for pressure transducers of the flexure type. The transducer includes a flexure member which senses an applied pressure by means of strain gauges mounted thereon. A known problem with such an arrangement concerns the electrical connections to the strain gauges wherein there is conflict between the flexible connections required to accommodate flexure displacement and the rigid connections required to lead away from the gauges since a pressure chamber must be spanned. Previously this conflict has been resolved by bonding an insulative terminal plate proximate the flexure to provide a junction between flexible and rigid conductors. Such an arrangement gives rise to problems of construction rigidity and performance if excess bonding resin contacts the flexure. The invention provides a welded terminal plate, which is insulative by virtue of a thick film layer of glass, on which electrical connection may be made to areas of thick film gold.

Abstract: A switching device with a normally open electrical condition which engages contacts in response to a rise in fluid pressure for the purpose of activating an associated electric powered device such as a fuel pump in an automobile when pressures are much greater than zero.

Abstract: A semiconductor pressure sensor composed of a substrate formed adopting a thin-film forming technique and a diaphragm which is formed on the surface of the substrate. The sensor includes an insulating diaphragm film which is formed of an etching-resistant material on the main surface of the semiconductor substrate such as to coat it, at least one etching hole provided such as to penetrate the diaphragm film and reach the substrate, a reference pressure chamber which is formed by etching to remove a part of the semiconductor substrate and a disappearing film through the etching hole, and at least one strain gage which is provided at a predetermined position in the pressure receiving region of the diaphragm film.

Abstract: A switching device operated in response to changes in fluid pressure, including a housing supporting a switch conductor and including a movable terminal support which is insertably attached to the housing, the terminal having a contact surface thereon in sliding engagement with an exposed surface of the conductor to maintain electrical continuity even while there is relative insertive movement between the housing and support member.