Abstract: My invention is of simple construction. It is easy to mount in place and efficiently holds the pad 43 to close the port 14. Because of the vertical slot 18 the bar 17 may be adjusted vertically so that the upper end 25 may be properly positioned even though the threaded opening 20 may be at a different elevational position.

Abstract: An accelerometer has two proof masses each constrained from movement by a beam resonant force transducer. The proof mass-force transducer systems are mounted with the sensitive axes of the proof masses aligned and the force transducers arranged so that their resonant frequencies f.sub.1 and f.sub.2 vary oppositely with a change in acceleration. The acceleration is determined in accordance with the relationa=A.sub.1 f.sub.1 -A.sub.2 f.sub.3 +A.sub.0ora=A.sub.1 f.sub.1.sup.2 -A.sub.2 f.sub.2.sup.2 +A.sub.0where a is the acceleration and A.sub.1, A.sub.2 and A.sub.0 are calibration coefficients.

Abstract: A cooling system pressure tester is provided which allows consumers to determine the approximate vent pressure of their automotive cooling system, as well as to check for leaks in the system. The device includes a connecting and restriction element for introducing water into the system and an adjustable pressure relief valve for limiting the maximum pressure.

Abstract: An oil seal test unit tests for leakage of oil seals in a rack and pinion steering unit having (a) a pinion housing with a main supply pressure inlet and outlet, and left and right turn fluid pressure connections; (b) a rack housing with left turn and a right turn fluid pressure fittings; and (c) right and left tie rod ends. The test unit includes a pump for supplying hydraulic fluid under pressure through a main supply line connected to the inlet of the pinion housing. A return line connected to an outlet from the pinion housing returns fluid to the pump reservoir. Steering pressure is simulated by a reciprocating bar secured to the tie rod ends of the steering unit. A hydraulic cylinder has a piston with an actuating rod connected to the reciprocating bar. Right or left turning movement of the steering unit moves the tie rods which, in turn, applies pressure against hydraulic fluid in the cylinder.

Abstract: An improved integrating accelerometer having a plurality of proof masses adapted to move relative to a casing in response to accelerations of the casing, a temperature compensated damping mechanism, and fluid resistors for extending the temperature operating range and for calibrating.

Abstract: A piezoresistive acceleration sensing transducer is disclosed which enables low cost microcircuit construction of accelerometers. A silicon wafer is etched to form individual acceleration sensing elements each of which includes a mass ring suspended from a diaphragm and mounted to a center pedestal support portion. A plurality of piezoresistive strain gauges are located on the diaphragm about the periphery of the pedestal portion and are positioned to form a circuit for sensing strain produced in the diaphragm by movement of the mass ring in response to acceleration. A pair of temperature sensors are located in a zero-stress area of the diaphragm to compensate for temperature effects. In one embodiment, the gauges are coupled in a bridge circuit to provide a measure of acceleration in one axis only. In another embodiment, the mass ring is modified to locate its center of mass above the plane of the diaphragm so that the mass ring responds to acceleration in three axes.

Abstract: A testing arrangement for testing injection nozzles in a nozzle holder combination, has a first testing circuit provided with a first pump for a hydraulic pressure medium and arranged for testing nozzles as to the throughflow, and a second circuit provided with a second pump for the hydraulic pressure medium and arranged for testing the nozzles as to the opening pressure, buzzing condition, tightness of nozzle holder combination and if necessary seat tightness and needle play of a nozzle, wherein the circuits are arranged so as to perform testing during operation of the nozzles.

Abstract: A proof mass for an accelerometer is electromagnetically constrained in three orthogonal directions. An array of filaments forms an elastic suspension for the proof mass to constrain it in the remaining degrees of freedom. The resulting instrument has the potential for low cost and high-accuracy operation over a wide temperature range without the use of temperature controls.

Abstract: A heating wire is wound around a casing within which a sensor body is placed. Thermo-sensitive switch means is connected to the heating wire, which is responsive to the temperature within the casing to control the rate at which electric current is supplied to the heating wire so as to keep the temperature at a constant value. The casing may be placed within an airtight housing which is made of an insulating material. A further heating wire may be arranged on the inner wall of the airtight housing, which is controlled by further thermo-sensitive switch means so as to keep the temperature within the housing at a constant value.

Abstract: A proof mass for an accelerometer is electromagnetically constrained in three orthogonal directions. An array of filaments forms an elastic suspension for the proof mass to constrain it in the remaining degrees of freedom. The resulting instrument has the potential for low cost and high-accuracy operation over a wide temperature range without the use of temperature controls. The array of filaments becomes relatively compliant in all six degrees of freedom when loading exceeds a selected design load. This provides overload protection since the proof mass can be brought to a practical mechanical stop for support before excessive stress can fracture a filament.

Abstract: A compensated measurement system utilizing dual sensing elements (10, 12) and a single variable frequency oscillator (14). A common operative association between the sensing elements (10, 12) and the oscillator (14) is achieved by multiplexing. Temperature and supply voltage variations are compensated by generating an output (f.sub.0) which is proportional to the ratio of the two generated frequencies (f.sub.1, F.sub.2).

Abstract: A method of testing an engine aftercooler without removing it from the engine, the method including the steps of exposing the air inlet of the aftercooler, applying a gas under a superatmospheric pressure to the air chamber of the aftercooler, maintaining the gas pressure at a predetermined level, monitoring the liquid in the liquid chamber of the aftercooler, whereby the presence of leaks in the aftercooler can be determined by observing the evolution of bubbles from the liquid in the aftercooler.

Abstract: A universal clamp for use in sealing the surface ports of an engine part possessing a fluid circulating jacket such as a cylinder head so that the part may be subjected to fluid pressure testing, which includes, a mounting member adapted to be positioned in an engine cylinder head bolt hole, consisting of an actuation element which extends through a fixed sleeve portion and is threadedly interconnected with a wedging sleeve portion for axial movement with respect to the fixed sleeve so as to engage the wedging and fixed portions and force them into wedging engagement with a portion of the wall of the bolt hole, thereby securing the clamp. Slotted arms are slidably and rotatably mounted on the mounting member so as to be radially adjustable to allow sealing of ports positioned at varying distances from the mounting member. Screw members threadedly interconnected with the arm members secure plug or other sealing structures thereby sealing the ports.

Abstract: A pendulous type of oil filled accelerometer is disclosed herein, specifically one which is sensitive to temperature changes sufficient to introduce a temperature related error into its output signal, if left uncorrected. A technique which compensates for these temperature changes in order to reduce the resultant error to an acceptable level is also disclosed herein. This technique uses the oil itself, specifically its sensitivity to changes in temperature resulting in changes in its density, in combination with an expandable/contractible bellows.

Abstract: An accelerometer utilizes a pair of SC-cut crystals which respond differentially to acceleration inputs. Each crystal exhibits a highly temperature sensitive resonant mode and a relatively temperature insensitive resonant mode. Both modes are excited simultaneously by an oscillator. The difference frequency data between respective modes of each crystal, as well as the difference frequency data between the two modes of one of the crystals, is processed to obtain a temperature compensated value of acceleration.

Abstract: A comprehensive automotive cooling system testing apparatus allows for the separate testing of the radiator and the engine block cooling passageways, in addition to the testing of the radiator cap and the complete cooling system. The testing apparatus includes a master pressurizing test unit, and adaptors to attach the unit to the various portions of the cooling system. The master pressurization test unit includes a gauge for visually observing the level of pressure, an air inlet for connecting the device to an external source of pressurized air, a manual pressure relief valve for releasing pressure when the testing is finished, and an automatic pressure relief valve for releasing pressure from the portion of the cooling system under test whenever the pressure reaches a predetermined level. The various portions of the master test unit are mounted to an air conduit which is attached to a cap similar to a radiator cap.

Abstract: An apparatus for fluid pressure testing of engine cylinder heads and similar parts by sealing the fluid circulating jacket ports and subjecting the head to a fluid pressure comprising, a lockable pivoting frame structure on which the head is positioned and secured by clamp bars, individual port closure members secured to the cylinder head by clamps and bolts so as to seal the cylinder head ports and a modified port closure member when connected to a pressurized fluid supply conduit allows a pressurized fluid to be introduced into the fluid circulating jacket.

Abstract: An eddy-current speedometer having a rotatably driven permanent magnetic element and a cooperating eddy-current rotary element provided with an indicating device and mounted to rotate coaxially therewith and be set rotating by alternating magnetic fields generated by the magnetic element at spaced points therearound and penetrating the rotary element in directions radially thereof, has its magnetic element made of a magnetic material of low permeability and provided with at least eight sets of magnetic poles of alternating polarity equally spaced apart in a concentric path around the rotatable magnetic element with the poles of each set being of opposite polarity and spaced apart radially of the rotatable magnetic element to define an air gap therebetween.

Abstract: In order to reduce bias errors resulting from mounting of a force restoring coil assembly element of a force balancing transducer, the force coil assembly is suspended by means of one or more hinges from a force sensing movable member, which includes position pick-off means, that in turn is connected by hinging means to a support member. The effects of strain may further be reduced by locating the first hinges essentially along the axis of the centroid of the pick-off means.

Abstract: Testing apparatus which permits precise determination of the existence and location of possible fractures and cracks in the cylinder head of an engine. In a preferred embodiment, the apparatus comprises a plurality of individual test plates which are specially designed for the particular engine desired to be tested. The plates include at least one planar surface having one or a plurality of generally circular recesses formed therein for holding and retaining O-ring seals. The position of the recesses on the plate corresponds to the position of water conduit outlets in the cylinder head. The preferably transparent plates, along with the O-ring seals, are bolted onto the cylinder head, and water under pressure is then applied. The reverse side of the plates may conveniently include a different arrangement of recesses to accommodate a different engine cylinder head design.

Abstract: A transducer for mechanical measured variables, especially a pressure transducer, having a heat pipe system within the housing, the heat pipe system is connected on one side to the thermally high stressed parts of the transducer, and on the other side to parts not exposed to heat or cold. The sensor element of the transducer is cooled through heat transport by means of an alternatively vaporizing and condensating working fluid within the heat pipe system.

Abstract: A portable universal apparatus for use in pressure testing engine cylinder heads and blocks. Sealing members are placed over all surface openings of an engine cylinder head or block leading to the cooling jacket. Retaining bars are placed over the sealing members and extend longitudinally of the engine part. A plurality of clamping units are attached directly to the engine part and apply pressure to the clamping bars in a direction to effect airtight engagement of the sealing members with the surface openings of the cooling jacket.

Abstract: A temperature compensation mechanism for a vibrating beam accelerometer comprising first and second bridge circuits. A quadrature signal is applied to the first bridge circuit containing the quartz crystal which pulls the resonant frequency of the quartz oscillator up or down depending upon the frequency shift caused by temperature variations.

Abstract: A method for pressure testing a rocket motor case by inserting a movable ton in the nozzle end of the rocket motor case, sealing the piston relative to the throat of the rocket motor case and then applying pressure to the rocket motor case to pressure test the rocket motor case to a predetermined pressure or to failure.

Abstract: A signal compensator is combined with a second order system, for example, a fluid damped rate gyroscope, which produces a signal in response to the movements of a damped member for providing an output signal which is indicative of the input to the second order system and is unresponsive to variations of the (selected) damping (ratio) of the movable member.

Abstract: A servo amplifier system for an accelerometer includes a torque coil. A torque coil is included in the output circuit of a first amplifier. A position sensor circuit develops a signal corresponding to the position of the coil which is applied to the input circuit of the first amplifier. An element, which may be a resistor, senses the current through to the coil and produces a voltage which is applied to a second amplifier having a low impedance output circuit. The output signal from the second amplifier is fed back to the input circuit of the first amplifier. Means are associated with the second amplifier to comply with the scaling and bandwidth requirements of the system.

Abstract: A temperature compensated accelerometer of the type having a permanent magnet, moving coil rebalance system is disclosed. A cylindrical permanent magnet and surrounding sleeve produce radial magnetic fields in annular regions in which are located rebalance coils on a suspended bobbin. A noninductive temperature sensing winding on the magnet is connected in a bridge input circuit to an amplifier which produces a current in an auxillary winding for augmenting the fields produced by the permanent magnet so as to maintain constant magnetic field strength in the annular regions.

Abstract: A test assembly for determining the acceptability of an engine driven lubrication oil pump without disassembling the pump from the engine. A conduit housing is provided for assembly on the engine in place of its oil filter. The housing fluidly communicates with a test valve assembly which carries the engine oil filter and is operative to direct or prevent fluid flow through the filter to the engine and includes means for measuring the pressure developed by the engine pump during flow prevented mode of operation and means for preventing operation in the flow prevented mode beyond a predetermined duration.

Abstract: Test apparatus for the oil cooler from a Volkswagen.RTM. automobile including a support having apertures and studs compatible with the mounting studs and apertures of a Volkswagen.RTM. oil cooler. The support has an air chamber with two ports communicating with the ambient atmosphere located to sealingly engage with the inlet and outlet ports of a Volkswagen.RTM. oil cooler when the oil cooler is mounted on the support. A pressure gauge is connected to the air chamber, and a one-way air entry conduit is also connected to the air chamber. When the oil cooler is installed on the support air under pressure is applied to the air entry conduit which fills the air chamber together with the oil cooler. When the pressure remains constant it indicates that there is no leak in the oil cooler. Conversely, a pressure drop indicates a leak in the oil cooler.

Abstract: A measurement of the quantity of gas entering or within the coolant of an internal combustion engine cooling system, is made with the engine running, preferably at high idle speed, and a test is performed to ensure that the thermostat is open, whereby it is known that coolant is circulating through the entire cooling system, by providing a radiator cap connected to an orifice of a known size that will allow gas to escape from the cooling system and measuring substantially the pressure differential across the orifice, such as by measuring the pressure on the radiator side of the orifice with respect to atmospheric pressure.

Abstract: The servo system has a fluid damped moving mass, a pickoff providing a signal indicative of the position of the moving mass, and a torquer disposed to move the mass. A single operational amplifier has a pair of inputs and an output. One input is connected to the pickoff signal and the other is connected to a reference signal. A feedback path extends between the operational amplifier input and output, and includes a temperature sensitive combination in series with a feedback resistor. A basic gain control resistance is connected between the node located intermediate of the temperature sensitive combination and feedback resistor and the reference signal. Basic gain and gain change over a temperature range are independent of interaction therebetween as each is set, and a selected servo system operational characteristic is maintained substantially constant over the temperature range.

Abstract: A vibrating quartz accelerometer of moving object under test, wherein both ends of at least two vibrating quartz resonators are rigidly coupled each other so as to confront their faces each other and to form gap between said resonators, one end of which is made as a fixed end to said moving object and another end thereof is made as a free end to said moving object, a weight is provided on said free end, and when said moving object is put into motion, inertia force, which acts on said weight in the direction for keeping original state of motion or state of standstill relative to said motion, is converted into beat frequency in resonant frequency of said two vibrating quartz resonators, which beat frequency is caught to detect acceleration of said moving object.

Abstract: Linear accelerometer mechanism having a housing and a pendulous member. Means is provided for pivotally mounting the pendulous member in the housing. A torque coil is carried by the pendulous member and first and second magnets are mounted in the torque coil for establishing a magnetic field in the vicinity of the torque coil. A conducting planar element is carried by the pendulous member and pick-off means is mounted within the housing in the vicinity of the pendulous member.

Abstract: A displacement detector yielding an electrical output signal that is linearly proportional to the extent of input motion. The input motion to be monitored is applied to the shiftable armature of a differential reluctance transducer constituted by a pair of transformers, each having a primary, a main secondary and an auxiliary secondary. Fed to the primaries is a high-frequency drive voltage generated by an oscillator whose amplitude is regulated by a feedback loop in which a feedback voltage taken from the auxiliary secondaries is compared with a reference voltage to provide a control voltage that so regulates the drive voltage oscillator as to cancel out the effect of temperature on the output signal derived from the main secondaries.

Abstract: In an accelerometer in which a proof mass is disposed in a damping fluid and acts against said fluid through a flow path controlled by the groove length of a helix disposed on a bellows, a low resistance flow path is provided connecting the areas above and below the helix to prevent movement of the proof mass due to fluid displacement caused by rapid temperature changes.

Abstract: The measurement bridge of a fluidic angular rate sensor in which a pair of temperature sensitive resistive elements are differentially cooled by a jet of fluid, the direction of which lags the position of the resistive elements when the rate sensor is rotated in the plane of sensitivity, is driven by a constant voltage source through resistances substantially equal to the rate sensing resistive elements so that as the resistive elements increase in resistance with temperature, the voltage also increases, so the power consumption and therefore the heat generated in the resistive elements remains constant, thereby tending to maintain a constant temperature differential of the resistive elements above the ambient, and in turn reducing changes in thermally-induced mechanical stress and resulting motion; further, lack of tracking between the two resistive sensing elements over wide temperature ranges is compensated by coupling some of the resultant temperature-dependent voltage to a bridge node to compensate for t

Abstract: Modal test method and apparatus is described for use in automotive engine plants, vehicle inspection stations, diagnostic centers, etc., for quickly, accurately and repeatably measuring the principal air contaminants; i.e., carbon monoxide (CO) and hydrocarbons (HC) in engine exhaust gas emissions. Quantitive measurement of oxides of nitrogen (NO.sub.x) and oxygen (O.sub.2) may also be measured if desired. While O.sub.2 is not an air contaminant, a measure of its concentration in the exhaust gas has diagnostic value. The engines are tested at prescribed modes of operation (usually three; high cruise, low cruise and idle) at which emission-related engine malfunctions, if they exist, are most likely to be exposed. CO and HC (NO.sub.x and O.sub.2 if desired) evaluations are made at each test mode and may be recorded on a "report card." The measured test values of the air contaminants are compared at each test mode with prescribed permissible values either automatically or manually.

Abstract: A toroidal accelerometer having a housing containing an electrolytic fluid at least partially immersing a plurality of electrodes disposed within said housing and an amplifier circuit coupled to the electrodes for providing an output signal indicative of the angle of tilt or rotation of the accelerometer about a reference axis. The accelerometer further includes a circuit connected across the amplifier to prevent polarization of the electrolytic fluid by detecting any d.c. voltage developed by the amplifier circuit and, in response thereto, coupling a compensating signal generated thereby to the amplifier until the d.c. voltage is substantially eliminated.

Abstract: A mathematical expression is converted and approximations applied to remove complex processes, simplifying the circuitry of system which controls compressor speed in dependence on ambient temperature.

Abstract: Apparatus for testing engine heads of internal combustion engines of various sizes for fluid tightness of internal cavities in a head which commmunicate with ports in the fire deck surface of the head. A universal mounting frame for a cylinder head is rotatable on a longitudinal pivot axis to position the head with its fire deck surface at any orientation relative to the axis. Longitudinal support rails are positioned above the water ports, and spring loaded stopper means and fluid supply and venting members which are longitudinally adjustable on the rails are aligned with the ports, and the support rails are then moved down to seal the stoppers and heads against the rims of the ports. Compressed air, and then hot water are introduced to the head cavities to check it for leaks.