Abstract: A closed center-load sensing system, capable of varying a pump discharge volume easily and with a high degree of accuracy, includes a power source having an indicator for indicating a rotational speed, a variable volume hydraulic pump driven by the power source, actuators driven by pressure oil discharged from the variable volume hydraulic pump, change-over valves for controlling the flow of the pressure oil, an indicator for setting the rotational speed of the power source in a load sensing system in which the pressure difference between the pump pressure and the actuator load pressure is maintained at a predetermined pressure and the rate of flow of a discharge from the variable capacity hydraulic pump is varied when the pressure difference between a pump pressure and an actuator load pressure varies, a controller for computing and outputting a command signal for the rotational speed of the power source in response to a command signal from the indicator, and an electronic proportional control governor for c

Abstract: A device for the improvement of the running conditions in a hydraulic installation or in a so-called hydraulic system. The device contains a central circulating circuit separated from the influence of the atmosphere. To the circulating circuit are connected an outlet and an inlet for the connection of the hydraulic fluid to the other part of the hydraulic system. The circulating circuit is divided into at least two chambers separated by respective pressure generating and pressure reducing units. The first chamber is to a certain extent an expansion room for the hydraulic fluid in the system which is separated from the atmosphere and it forms a low-pressure part in the circuit. The second chamber forms a high-pressure part which is directly connected to the outlet. The circulating circuit holds a medium for the cooling and filtering of the hydraulic fluid.

Abstract: A swash-plate plunger-type hydraulic device has a cylinder block with a plurality of plungers slidably fitted in cylinder bores, a swash plate confronting one end of the cylinder block, and a distribution valve plate slidably held against the other end of the cylinder block. The cylinder block has an even number of circularly arrayed connecting ports communicating with the cylinder bores and opening at the other end thereof. The distribution valve plate has inlet and outlet ports. The cylinder block is rotatable through an angular displacement .theta.1 in which the hydraulic pressure in one connecting port between the inlet and outlet ports increases from a lower pressure to a higher pressure, through an angular displacement .theta.2 in which the hydraulic pressure in one connecting port between the inlet and output ports decreases from the higher pressure to the lower pressure, and through an angular displacement .theta.

Abstract: The seal bellows of a Stirling cycle device is connected between the bottom of a reciprocating piston and a cylinder wall to form a buffer space between the cycle working space and the lubricated crankcase. The piston and cylinder wall form a noncontact clearance seal between the buffer space and the working space in which an expander piston has a vented clearance seal to reduce the thermal loss due to cold gas leaking along the clearance seal.

Abstract: In a first preferred embodiment of a thermal rotary actuator constructed according to the present invention, an actuator body includes first and second spaced, parallel linear actuator elements each linear actuator element having a respective predetermined coefficient of thermal expansion (CTE) and respective first and second ends defining the linear actuator element length. The linear actuator elements, in response to a selected temperature differential therebetween, are thereby subject to a predetermined length differential. Means are provided for effecting the selected temperature differential in the first and second linear actuator elements to thereby effect the predetermined length differential. First yoke means, attached to the first ends of the first and second linear actuator elements, include fixing means for fixing the first ends in a predetermined spatial relationship, and means for flexibly attaching said fixing means to the reaction structure.

Abstract: An energy converter for converting a sound energy into a kinetic energy is comprised of a source device for radiating the sound energy, and a body having a cover member for absorbing the sound energy and a reflecting member mounted thereon with the cover member in such a manner that the sound energy after passing through the cover member reaches the reflecting member so as to be tangential thereto.

Abstract: A gas turbine engine having a compressor and an air-cooled turbine is provided with a cooling system for decreasing the temperature of the turbine cooling air. A heat exchanger, mounted on the compressor casing, receives a portion of the pressurized air which is bled from the compressor. A heat sink medium is pumped through the heat exchanger into heat exchange relationship with the pressurized air, thereby cooling the air. The cooled air is then further pressurized and routed to and circulated through the turbine rotor blades to provide improved cooling thereof. The intercooling of the compressor bleed air permits a reduction in the quantity of compressor air required for turbine rotor blade cooling or allows an increase in turbine entry temperature and thus provides an improvement in engine power and performance. In the case where the heat sink medium is engine fuel, the heat extracted from the compressor bleed air is returned to the engine operating cycle in the form of heated engine fuel.

Abstract: The invention provides a controlled connection, or heat switch, between a source of cryogenic cooling and an item which is to be cooled, using control valve means which is not itself subjected to the cryogenic temperatures involved.

Abstract: A flexible heat transfer assembly between a cryogenic refrigerator cold head sleeve and magnetic resonance imager thermal shields includes a plurality of rope-lay stranded copper ropes, each containing a large number of section.

Abstract: An apparatus to control the air as it passes a tractor trailer combination as they travel along a road. This device will allow for variable redirection of the air flow to allow various desired effects to be met. The flow of air is streamlined to minimize the effects of cross winds. Air pressure responsive plates are provided at the ends of laterally extending gates mounted on tractor trailer combinations to minimize the effects of sudden drafts of air that sweep across roadways. A method of redirecting the air flow for ventilation and cooling purposes for both refrigeration units and brake components is provided. Air ducts are provided for the transport of the redirected air for the ventilation and cooling of the brake components. Additionally the air flow can be directed to impact with the exterior vertical front face of the trailer section to create an air drag which will create resistance to forward travel.

Abstract: In order to cool food in a display compartment, a cold air stream is generated by refrigeration means, preferably a fan, an evaporator and a condenser, and is passed through the display compartment from its inlet to its outlet. The air temperatures at the inlet and outlet may be sensed by sensors in which case control means are responsive to a signal from the output of both the sensors and control the operation of the refrigeration means to maintain the air temperature in the display compartment within a narrow predetermined range.

Abstract: A water vapor vacuum refrigeration chilled water system with a compressor that allows flash cooling refrigeration system to be practical size and weight. The system utilizes only water vapor. Innovative features include a unique plenum condenser system which allows the refrigeration system to be totally enclosed with little or no effect of ambient temperatures on system performances. The plenum type spray condenser does not need fins or tubes as common refrigeration condensers. The compressor allows the large volume of water vapor to be compressed at high pressure ratios. The compressor is much smaller and lighter than state of the art positive or centrifugal type compressor for the required compression requirements. The compressor sections are made with two dissimilar type compressor rotating sections to obtain the required pressure ratios and flows.

Abstract: This invention relates to an apparatus and method for increasing the cooling rate of an item and its contents within a refrigeration system. The item is supported in a housing that also includes a motor driven fan. The apparatus containing the item to be cooled is placed in a refrigeration system and the motor driven fan moves cold air from the refrigeration system through the housing, thereby quickly and favorably cooling the item. An important use of the apparatus and method is for quickly cooling scientific and medical specimens and substances.

Abstract: A refrigerant precooler device, connecting into the Freon line of an existing air conditioning unit, and directing this freon through a finned cooling coil, and having a downdraft fan blowing air downward onto a supply of water in the bottom of the precooler device, and the fan blades being surrounded at a strategic location by a venturi shroud, which tends to disperse some of the air from the fan outward, and over the fins of the cooling coil, thereby causing an accelerated evaporation effect, with the added cooling of the Freon. A controlled supply of water in a reservoir at the bottom of the device is pumped upwards through a tubing device and into a pipe which is located onto the top of the cooling coil, and the pipe has a slot cut lengthwise of its bottom longitudinal dimension, and the pumped water drips out of the slot in the pipe, and drains downward over the fins of the cooling coil.

Abstract: The present invention pertains to a circular knitting machine with a pair of cutting devices (15) in opposite positions for longitudinally cutting, on two sides, the tubular fabric component and for forming two individual even pieces (13a, 13b) and with two winding units (11, 12) for separately winding the two pieces onto rolls, the pieces being led in opposite directions by central return rollers (16, 17).

Abstract: Flexible abrasive means having an underlay, which comprises a knitted fabric, which consists of a base knitted fabric (1) and at least one layer of warp threads (6) and at least one layer, separated from the latter, of weft threads (5) and includes a strengthening size. In each case a plurality of warp threads (6) per needle space (3) are held next to one another by different binding into the pattern in such a way that they run partly under and partly over the cross threads (4) of the base knitted fabric (1). All of the warp threads of a group of warp threads can be separated from one another by cross threads of this base knitted fabric alternating from the upper side to the underside of this warp thread group. A high dimensional stability of the abrasive means in the directions other than the directions of the warp and weft threads is obtained.

Abstract: In a bobbin treating system connected to a fine spinning frame and an automatic winder, a steam setter is installed inside of the automatic winder for steaming bobbins coming from the fine spinning frame.

Abstract: A device for attachment to a bed frame for the receipt of articles therein having a receptacle with a closed end and an open end, a door fastened to said open end, a lock attached to the door so as to fix a position of the door with respect to the receptacle, a clamp attached to a forward end of the receptacle so as to affix the receptacle to the bed frame, and a support connected to a back end of the receptacle so as to support the receptacle above a surface. The clamp is a mounting bracket affixed by a bolt to the receptacle. An area between the receptacle and the mounting bracket engages corresponding surfaces of the bed frame. The receptacle has a top surface, a base, a pair of sides, and a pair of ends extending upwardly relative to the base. The support is an extendible leg fastened to a rear end of the receptacle so as to support the receptacle in a generally level condition.

Abstract: A door lockset 20 includes a front loaded cylinder lock 75 which is assembled with an insert 64 within a knob 62. Cylinder lock 75 includes a locking bar 104 which is biased toward a central opening 83 formed through a body 76 of the lock. A plug 80 is located within opening 83 and is rotatable therein. A removal key 108 is formed with a slot 240 which is alignable with a plug slot 109 when the key is inserted into a key slot 113 of the plug. Plug 80 is thereafter rotated within opening 83 to align locking bar 104 with plug slot 109 and key slot 240 whereby the bar moves into the slots under the biasing action of a spring 106. Cylinder lock 75 can then be removed from the front of insert 64 and knob 62. A reverse process is followed to load cylinder lock 75 into opening 238 and to retain the lock with insert 64.

Abstract: A latch assembly for door locks. The latch assembly has (A) a box-shaped frame having two parallel plates each having a rectilinear slot, a curved slot with a middle section, (B) a first terminal section, (C) a second terminal section having a first shoulder and a second shoulder and (D) a hole for receiving a lock core. A dead bolt has (E) a first portion which is pressed by a finger extending from the core for retracting the dead bolt into the box-shaped frame, (F) a second portion which is pressed by the finger for moving the dead bolt out of the box-shaped frame, (G) a connection coupling the first portion with the second portion, (H) a recess extending in the connection, and (I) a passage transversely extending through the connection. A pin extends through the passage formed in the detent and its two ends are slidably received in the rectilinear slots.

Abstract: A free standing rotary tower assembly for applying a force to a damaged part of a vehicle, the assembly including a tower, a support plate mounted on the bottom of the tower, a cylindrical member mounted on the bottom of the plate and a floor mount for supporting the tower assembly, the floor mount including a center plate having a tubular member for matingly engaging the cylindrical member and a number of caster assemblies mounted in the centering plate in a position to engage the support plate when the cylindrical member is aligned with the tubular member.

Abstract: Contactless coupling of magnetic fields of a movable proximity detector when positioned juxtaposed to a fixedly mounted proximity detector permits transfer of signals from a remote proximity detector indicative of sensing the presence of a workpiece positioned at a work station of an automatic metal forming machine.

Abstract: Four lever units are linked to the arrangement of connecting rods via a common bolt. Each lever unit drives one ram of the punch press. The rams are arranged in configuration of a square. This allows a much higher loading by off-center forces and the punch press can be designed for a given punch press output with considerably smaller dimensions.

Abstract: The quick change insert system of the present invention utilizes a removable locking pin and an insert sleeve to permit easy replacement of an insert pin within a sleeve. Insert pin replacement occurs by removing the locking pin. After removing the locking pin, the insert sleeve is removed together with the insert pin. The insert pin is separated from the insert sleeve, and a replacement insert pin is put in its place. The new insert pin and the insert sleeve slide back into the sleeve, and the locking pin secures the insert pin and the insert sleeve to the sleeve. The present invention does not require the removing or re-adjusting of the sleeve during insert pin replacement. Furthermore, the present invention permits easy replacement of other sleeve assembly parts during part to part changeover and eliminates costly inventory of sleeve assemblies.

Abstract: A flowmeter proving apparatus for obtaining a reliable flow meter factor in a short time, using a flow-meter having a non-uniform pulse output with a small volume power. The flowmeter to be proved is connected in series with a small volume prover, using a by-pass valve. A CPU calculates irregularities of meter pulse spacing, determines the repeatability for a proving run from the number of counted meter pulses and a function given by the meter pulse number and the meter pulse space irregularity. The CPU then computes the proving pass number N.sub.p necessary for obtaining the required repeatability by substituting the repeatability value into another predetermined function.

Abstract: A method is provided for detecting moisture in a sterilization chamber or other enclosure (including moisture present on the external or lumened surfaces of an instrument or other load placed in the enclosure). The method includes the steps of exhausting air from the enclosure under vacuum until the pressure in the enclosure is reduced from a starting pressure to a predetermined subatmospheric pressure which is above the saturation pressure of water, and then a second predetermined subatmospheric pressure which is below the saturation pressure of water or other liquid. The times taken to reach each pressure from the starting pressure are measured and their difference is calculated and compared to a reference time difference pre-established for a dry system (or, alternatively, in a known, leak-free system, only the pull-down time period to reach the second subatmospheric pressure is measured and compared to a pre-recorded reference pull-down time for a dry system).

Abstract: Apparatus for detecting the presence of a gas in an ambient atmosphere comprises a multiple quantum well structure; a thin mesh of a transition metal formed on the multiple quantum well structure; and an arrangement for monitoring transmission of electromagnetic radiation through the mesh and the multiple quantum well structure.

Abstract: The detection of thickness variations in sheet material, more specifically the presence or absence of labels on a moving web, is accomplished by providing two spaced apart nozzles, an entry for pressurized fluid, first and second conduits to connect the entry and the nozzles, and a differential pressure sensing element connected between the conduits so as to detect a mismatch between the fluid pressures in the two conduits.

Abstract: An improved method for detecting small leaks in underground pressurized piping systems is disclosed. In particular, the method comprises the steps of taking pressure measurements over identical time intervals from a product line at a pressure above the pump discharge pressure while the product pump is running. Thereafter, the absolute value of the difference between successive pressure decays is calculated and compared to an acceptable value. Next, the value of the latest pressure decay value is compared to acceptable and unacceptable values reflecting acceptable and unacceptable tightness of the product line.

Abstract: A leak detector for sensing a test gas leaking into a vacuum chamber in accordance with this invention comprises a vacuum chamber having an opening, and a momentum transfer pump connected to such opening and serving to compress the gases emanating from the vacuum chamber. An entrainment pump is connected to receive the gases exhausted from the momentum transfer pump, with the entrainment pump having means for entrapping the active exhaust gases coming from the vacuum chamber, but not the noble gases, which remain in a gaseous state and continually increase in pressure. A mass spectrometer is connected to receive the output from the entrainment pump, with the entrapment of the active exhaust gas by the entrainment pump reducing the total pressure at the mass spectrometer gas detector, thus making possible the detection and measurement by the mass detector of extremely small noble gas leaks.

Abstract: A method for determining whether surface connected, through thickness defects exist in a coated carbon-carbon composite article. The method involves the immersion of the coated article in a low viscosity liquid; if a stream of bubbles rises from the surface of the coating, such bubbles indicate the existence of at least one surface connected, through thickness defect in the coating.

Abstract: The apparatus for checking the volume of bottles (1) comprises a head (2) adapted to be moved sealingly onto the bottle mouth (21), with a metering piston (7) which is displaceable in relation to the head (2) to be inserted into the bottle (1) and compress the air contained therein, and a pressure sensor (9) for measuring the excess pressure produced in the bottle. The measured volume (11) in the bottle is linked to a compensating volume (12) through a duct (10). The compensating volume is determined on the one hand by the constant starting height of the metering piston (7) and on the other hand by the variable displacement path length of the head (2).

Abstract: An apparatus and method for controlling the charging of refrigerant into a refrigerant system is disclosed. The apparatus determines the mass amount of refrigerant charged by determining the volume of refrigerant charged, the density of the refrigerant based on its pressure as it is charged, and determines the mass amount charged from the determined density and pressure. The apparatus has a pressure compensated flow valve and determines the volume of refrigerant charged based on the amount of time refrigerant has flowed through the constant flow valve. The type of refrigerant being charged can be selected from a plurality of refrigerant types and the apparatus has a memory in which data related to density and flow characteristics of each refrigerant type is stored. The apparatus uses the data for the selected refrigerant to determine the mass amount of refrigerant charged. The apparatus further determines that the refrigerant supply tank is empty when its pressure decay exceeds a predetermined amount.

Abstract: Air is conditioned by compressing air at a first location during a first interval of time and storing the compressed air at the first location. Compressed air stored at the first location is transported by pipeline to a second location remote from the first location during a second interval of time different from the first interval of time and expanded at the second location. The expanded air is delivered to enclosures at the second location. The first interval of time is preferably during the night when the power required to compress the air is relatively inexpensive.

Abstract: A refrigeration system where the refrigerant starts out as a liquid at ambient temperatures and pressures and is expanded to a very low pressure and temperature through the use of a special design ejector and pump assembly. The preferred design uses a new type of centrifugal pump which is designed to produce a high velocity discharge rather than pressure. The refrigerant in expanding to a gas extracts BTU's from its surroundings.

Abstract: System and process are disclosed for selecting a range or configuration of refrigerants that may thereafter be used by a refrigerant recovery system in the recovery of one or more of the refrigerants. The recovery of refrigerants may occur at anytime after a range has been selected including a time during which the refrigerant recovery system has been switched off and back on again.

Abstract: In an air conditioning apparatus, the refrigerant discharged from a compressor of an outdoor unit is passed through an outdoor heat exchanger, the refrigerant having passed through the outdoor heat exchanger is passed through an indoor heat exchanger of an ambient air-conditioning unit and the refrigerant having passed through the indoor heat exchanger is returned to the compressor to cool the whole space in the room. At the same time, the refrigerant discharged from the compressor is passed through the outdoor heat exchanger, the refrigerant having passed through the outdoor heat exchanger is passed through indoor heat exchangers of a plurality of personal air-conditioning units and the refrigerant having passed through the indoor heat exchangers is returned to the compressor to separately cool the discrete spaces in the room.

Abstract: A transducer for inline process control of highly viscous fluids at high pressure and high temperature having a torsionally oscillating sensor tip supported by a pressure resistant threaded body portion. The sensor tip, which includes a thermocouple to measure fluid temperature, is driven by a crossarm which oscillates with a constant angular amplitude, the power required to maintain that amplitude despite the viscous resistance offered by the fluid being a measure of the viscosity-density product of the fluid. The crossarm driver and detector electromagnetic coils are oriented at right angles to each other to reduce crosstalk and transducer housing diameter. The associated electronic control unit includes means to compensate for the effects of fluid flow rate and fluid pressure which were found to be encountered with the vibratory viscometer method of measurement when inline measurements are made on high viscosity fluids.

Abstract: An apparatus for detecting an abnormality of a fuel transpiration prevention system which includes a canister with an absorbing device and a control valve provided in a passage between a fuel tank and an intake pipe of an internal combustion engine so that a fuel gas generated within the fuel tank is absorbed by the absorbing device of the canister and introduced into the intake pipe by opening and closing the control valve in accordance with an operating state of said internal combustion engine. The apparatus includes a pressure detecting device for detecting a pressure within the fuel tank and a deviation calculating unit responsive to the output of the pressure detecting device for calculating a deviation between the pressure detected when the control valve opens the passage and the pressure detected when the control valve closes the passage. The apparatus decides an abnormality of the fuel gas supply system on the basis of the deviation calculated by the deviation calculating unit.

Abstract: A process for determining the flow rate of a fluid, in particular of an air flow of an internal combustion engine, a temperature dependent resistor through which a heating current flows being arranged in the flow path of the fluid, the size of the heating current being a measure of the flow rate of the fluid, the temperature of the resistor being determined by a temperature sensor and being set to a constant value by means of a circuit arrangement which influences the heating current, and the fluid flow rate determined immediately after the start of the fluid flow being corrected by means of a correction value (k, k') in order to compensate for a measurement error which occurs when the heating current is switched on but when fluid is not yet flowing due to temperature deviation of the resistor.

Abstract: A diesel fuel injector fixture is disclosed for torquing a solenoid valve within a diesel fuel injector body. The fixture includes a hydraulic ram for partially clamping the solenoid valve to the injector body and a nesting fixture for locating the fuel injector relative to the hydraulic ram. An adjustable stop assembly on the torquing fixture adjusts to the orientation of a torque wrench engaged with the solenoid valve and locks in place to provide stops for the torque wrench. The torque wrench rotates between the stops to apply a predetermined final torque to the solenoid valve, wherein the combination of the hydraulic clamp load and the predetermined final torque properly seat the solenoid valve in the injector body.

Abstract: A system for changing the chucks of a tire uniformity machine includes a control which inactivates the main machine hydraulic and electrical system. The control also activates the chuck changing system which includes a small hydraulic power unit and a low set pressure relief valve for raising and lowering the lower chuck assembly and a small gearmotor for rotating the upper chuck assembly to facilitate removal of the upper chuck. The small hydraulic power unit and gearmotor, while mounted on the tire uniformity machine, operate entirely independently thereof for safety purposes.

Abstract: This invention refers to an apparatus for determining the sag of a running web of material transversely to its longitudinal direction. For this purpose according to the invention a carrier of a web sensing roller is guided in a housing to be movable against spring force transversely to its rotational axis and apparatus is provided for measuring the displacement distance of the roller. The roller is replicated in triplicate across the width of the web. In other embodiments web sag is measured by roller rotation and by web force respectively on the three rollers.

Abstract: The hardened data acquisition system (HDAS) of the present invention is a mpact system built to fit within a canister container, which may be inserted in a moving projectile, such as an artillery shell. Any shock level, air pressure or acceleration/deceleration experienced by the HDAS is measured by a transducer as an analog signal. The analog signal, after proper amplification and filtering, is fed to an analog-to-digital converter and converted into a digital signal. The digital signal is in turn fed to a memory where a predetermined amount of the data is recorded. The thus recorded data can be downloaded to the external environment by an interface section. To provide integrity, the different electronic circuit components of the HDAS are encased in plastic instead of ceramic. Moreover, the different electronic components are encapsulated with an epoxy resin, before being inserted into a canister container.

Abstract: An apparatus for the detection of the icing-up of an aircraft rotor. The apparatus has a sensor (10) for the tractive force and a sensor (11) for torque; for measuring respectively the axial force and the torque exerted on the shaft of the rotor. A device (12) calculates the ratio between these two quantities. A determination is also made, as a function of the flying conditions, of what should be the nominal value of this ratio in the absence of icing-up. Finally a device (12) compares the calculated ratio with the nominal ratio.

Abstract: A digit grip sensor for measuring the grip strength of the human hand. The digit grip sensor comprises a post support having a first and a second sensor therein. A first post extends through the first sensor and a second post extends through the second sensor. A crossbar spaced from the post support extends between the first post and the second post. Each sensor has a plurality of strain gages mounted thereon for measuring the deflection of the sensor. The crossbar can have a plurality of individual digit sensors mounted thereon for measuring the contributions of each finger to the grip force. The crossbar and the individual digit sensors can be adjusted for various hand and finger sizes.

Abstract: A resonant pressure transducer, having a deformable diaphragm or membrane exposed to an ambient environment wherein a pressure force to be measured exists, is provided. A transducer according to the present invention comprises a converter for transmitting the pressure force experienced by the diaphragm to a resonator vibrated by an exciter whose resonant frequency is a function of the intensity of the ambient pressure force to be determined. The converter and resonator are mounted in a rigid frame. The converter has flexible bending means able to absorb the bending moments resulting from the deformation of the diaphragm, so as to transmit to the resonator a tension or a compression force free from bending moments that generate stresses at the entrance of the resonator.

Abstract: A pressure sensor comprises a pair of pressure compartments with deflective end walls and an elongated displaceable member with two extremities respectively anchored to the deflective end walls of the two pressure compartments, and a capacitor with first series of capacitor plates affixed to the elongated displaceable member and a second series of capacitor plates disposed in an alternating arrangement with the first series of the capacitor plates and affixed to a stationary member, wherein the pressure difference between the two pressure compartments displaces the elongated displaceable member in axial directions thereof and changes the capacitance value between the first and second series of capacitor plates and, consequently, the numerical value of the differential pressure is determined as a function of the measured value of the capacitance.

Abstract: A precision, low cost, capacitor sensor comprised of two parallel plates, with an air dielectric, with preferably both substrates comprised of vitreous materials and electrically conductive coating, but with at least one of the substrates and coating being transparent. The coatings are preferably of identical material, thickness and pattern to offset stress distortion of the sensor plates from thermal expansion and contraction. Uniform spacing between the plates is provided by means of glass fibers of uniform diameter, dispersed in a matrix of adhesive and bonded under pressure, deposited between the plates as two thin semicircular seal rings surrounding the dielectric and separated by a diametrical gap, allowing entrance or escape of air dielectric. A novel feature, provided by at least one plate and coating being transparent, is use of optical measuring techniques during fabrication to verify acceptability of the manufacturing process and uniformity of the sensor product.

Abstract: A resistive strain gauge pressure sensor including upper and lower housings coacting to define a pressure chamber within the housing. A board member is clamped between the housings and defines a diaphragm portion which extends across the pressure chamber to divide the pressure chamber into upper and lower chamber portions. All of the circuitry of the sensor is screen printed onto the lower planar face of the board member including the various resistor elements of the strain gauge assembly, the various elements of the conditioning circuit receiving the output of the strain gauge assembly, and the various further leads required to connect the circuitry elements to the terminals of the sensor. The sensor terminals are provided by a plurality of connector pins extending downwardly through the board member for connection at their respective lower ends to the circuitry provided on the lower face of the board member.