Abstract: A method and apparatus for balancing of a motor armature and fan coupled thereto is disclosed. The apparatus includes a pair of spaced end brackets for supporting an armature of the motor and the fan for rotary movement. At least one motor bracket is coupled between the end brackets and includes means for detachably mounting a set of field coils for the motor thereon. The motor bracket further includes a recess therein which, when the set of field coils is detached from the motor bracket, exposes the armature to permit the armature and fan to be rotated as a unit so that the balance of the unit can be determined. The method and apparatus are particularly adavantageous for balancing a motor-fan system in which the motor is of the split-field coil type.

Abstract: A method and device which measures the velocity of ultrasonic waves in a moving web is disclosed. The excitation source is a laser or other device which produces short intense light pulses and the detection system is either a piezoelectric transducer or a microphone. The latter obviates any need for physical contact with the web in order to carry out tests for strength parameters as the web is manufactured.

Abstract: A navigation sensor, including a gyroscopic element, which has a spin axis, and which has flexure hinge for resiliently mounting the element on a base, and a torque sensing assembly, which has a first piezoelectric beam that is mounted in coaxial relation to the spin axis, and which has a first beam restraining member that mounts a first edge portion of the first piezoelectric beam, and which has a second beam restraining member that mounts an opposite edge portion of the first piezoelectric beam. The first piezoelectric beam is adapted to generate an electrical signal proportional to the angular velocity of the navigation sensor about an axis perpendicular to the spin axis.

Abstract: A differential surface acoustic wave (SAW) accelerometer comprises a resilient beam 1 one end of which is clamped in a support 2. Opposite faces of the beam are provided with SAW transducers 3, 4 and 6, 7 which respectively form delay lines driven by oscillator 5. Means are introduced for setting the beam into a low frequency mechanical flexural oscillation. The two outputs are connected in antiphase so that under conditions of no acceleration null points in the output waveform will be equally spaced. During acceleration the time intervals between successive nulls will become unequal.

Abstract: A G-force acceleration measuring instrument for use in an aircraft, spacecraft, submarine, or other vehicle, and employing electronic sensing and display transducers for increased reliability, small size, and small mass. The instrument includes a bar graph display, preferably incorporating liquid crystal transducer elements, uses a solid state or limited motion acceleration transducer, and provides graphic and numeric indication of the present G-force value together with numeric indication of historic maximum and minimum G-force values. The instrument also includes gain adjustment arrangements for accommodating different instrument panel slopes mounting in different types of vehicles with different G force capability, and a signal output tap for recording or slave indicating or telemetry or feedback use.

Abstract: The invention involves the design of a piezoelectric pressure transducer d for measuring pressure-time characteristics in gun tubes during the propellent ignition and burning process. The transducer utilizes one or two Z-cut tourmaline crystals as the piezoelectric pressure sensing element which produces a finite amount of electrical charge for a given change in pressure. The tourmaline crystals are incapsulated in a mechanical fixture which provides means for mounting in the gun tube, electrical terminals for connecting to signal conditioning and recording instrumentation, and insulators for electrically insulating the transducer from the weapon ground. A needle valve is also incorporated in the transducer which provides means for replenishing the thermal protecting material around the crystal assembly without removing the transducer from the weapon.

Abstract: A portable acoustic intensity measuring device comprising a pair of electroacoustic transducers at a positioned predetermined distance from one another. The measuring device utilizes analog summing, subtraction, integration and multiplier means for measuring an acoustic intensity vector midway between the two electroacoustic transducers. The acoustic intensity measuring device further comprises error correction means connected in circuit with a preamplifier means and a meter means. The error correction means includes switching means comprising a first switch connected in circuit with the preamplifier and summing means and subtraction means and a second switch connected in circuit with the multiplier and the meter for simultaneously switching the first and second preamplified analog signals at the summing input and subtraction input and for simultaneously switching the polarity of the acoustic intensity signal at the meter.

Abstract: An improved cylinder pressure transmitter provides an electrical signal corresponding to pressure in a cylinder of an automotive internal combustion engine during engine operation and furnishes the signal to computer control means for use in regulating spark advance to improve engine efficiency and performance and reduce engine knocking. The pressure transmitter includes means for mounting piezoelectric means in sealed relation to an engine cylinder to be responsive to variations in cylinder pressure during engine operation to provide initial electrical signals representative of pressure variations in the cylinder and includes high temperature electronic means carried by the mounting means and electromagnetically shielded with the piezoelectric means within the mounting means for amplifying those initial signals to provide low impedance signals for transmission to computer control means at a location remote from the cylinder.

Abstract: A digital accelerometer comprising a linear analog accelerometer and a digitizer. The analog accelerometer includes a housing and conductor means extending outside the housing, and is adapted to produce on the conductor means an analog signal representing linear acceleration along one axis. A casing is positioned against the housing so as to form a substantially enclosed space between the housing and the casing. The digitizer is located within such enclosed space and receives the analog signal and produces a corresponding digital signal. An interface circuit is positioned within the enclosed space for receiving the analog signal and producing a second analog signal that is input to the digitizer. The digital signal produced by the digitizer may be conveyed to a location outside the enclosed space and housing by a flexible strip of insulating material having a plurality of conductive strips embedded therein.

Abstract: In an acceleration sensor for use in an automobile seatbelt system comprising a rolling body which moves when subjected to an acceleration, a cup-like receptacle member for supporting the rolling body on a sloping surface rising towards an outer periphery of the receptacle member, and a pivotally mounted actuator over the rolling body for triggering a web halting mechanism, wherein the sloping surface is formed with a plurality of radially disposed ribs, so that the rolling body is prevented from rolling around the sloping surface even when subjected to vibration from rough roads. The invention prevents the web belting mechanism from being triggered spuriously without diminishing the sensitivity of the acceleration sensor in a bona fide vehicular emergency situation.

Abstract: A specific measured volume of a molding compound is placed within a cavity having a certain geometry and a compacting pressure is applied thereto until a predetermined measured pressure is reached on a side of said molding compound opposite the side where the pressure is applied in order to produce a test piece, with the volume of the test piece at the point at whcih the predetermined pressure is reached being determined so that the test piece may be subsequently used for determining other mechanical properties of the compound.

Abstract: In a knocking detection system for an internal combustion engine, a knocking is detected by a vibration sensor the output level of which is changed by controlling the sensor excitation current. The excitation current is controlled in dependence upon the output of the sensor, engine speed or load conditions or the like so that the output noise level of the sensor is maintained substantially constant regardless of engine operating conditions.

Abstract: A leak locating, mapping and measuring system (10) comprising an image recording medium (32), a laser (18), optical components (22) which cooperate with the laser to produce and superimpose successive holographic images of the test subject (12) upon the recording medium, a video camera (34) trained upon the medium and a real-time monitor (35) and recorder (36) for processing the output of the camera to assist analysis. The device is operated to create a first, reference hologram of the test subject while it is in an unpressurized state. A second holographic image is then taken while the test subject is pressurized with fluid from tank (38), which image is superimposed over the reference image. The resultant lines of interference between the superimposed images are then analyzed for distortions (66), which distortions indicate the location and magnitude of leakage flows at or about the test subject.

Abstract: A circuit for the recognition of knocking of an Otto engine includes a spark plug in the combustion chamber of a cylinder which also serves as an ionic current probe. Both an excitation voltage generator and, an evaluation circuit for the measuring voltage are coupled to the high-voltage ignition circuit. The excitation voltage generator is provided by a high-frequency oscillator. The input coupling of the excitation voltage is effected non-galvanically. The evaluating circuit comprises an amplitude demodulator for the high-frequency oscillations. The benefits of the present invention resulting from a knock recognition circuit of such a configuration that critical electrical components and galvanic coupling are avoided.

Abstract: A rotor blade test apparatus having a striking solenoid to strike a rotor blade to generate an audio signal. A microphone receives the audio signal and applies it to a spectrum analyzer wherein the predominant natural frequencies of the rotor blade are determined.

Abstract: A sample from a bath of killed molten steel which contains aluminum is removed with a vessel having a cover which undergoes at least partial disintegration on contact with molten metal and allows molten metal to fill the vessel as soon as the latter is lowered to a preselected level. The internal space of the vessel contains a strip of magnesium and a strip of zirconium. Magnesium evaporates with an explosion as soon as it is contacted by molten metal and thereby enters into a chemical reaction with oxygen in the vessel while also expelling the remaining air through the partially disintegrated cover to further reduce the likelihood of reaction between aluminum and air which is entrained with the immersed vessel. Zirconium dissolves in the metal which fills the vessel and bonds oxygen close to the surface surrounding the internal space of the vessel.

Abstract: A continuous gravimetry survey is carried out with a gravity logging tool having a column of fluid within the tool. First and second pressure sensors are located at spaced-apart axial positions within an upper portion of the fluid column. Third and fourth pressure sensors are located at spaced-apart axial positions within a lower portion of the fluid column. The outputs from the first and second pressure sensors are differenced to produce a first pressure difference signal. The outputs of the third and fourth pressure sensors are also differenced to produce a second pressure difference signal. The difference between these first and second pressure difference signals is related to the gravity gradient along the earth formation adjacent the fluid column. Such a gravity gradient is a continuously moving gradient that is insensitive to acceleration effects from unsteady motions of the logging tool as it traverses the earth formation during the gravimetry survey.

Abstract: An engine mounted combustion chamber pressure sensor is arranged with a body mounted in an external wall, such as of the cylinder head, and a probe engaging a combustion chamber defining wall to provide direct indication of combustion pressure caused movements of the chamber defining wall with respect to the external wall, thus providing direct combustion pressure signals usable for indicating or control purposes.

Abstract: A device for monitoring torsional vibrations in a rotary shaft comprises a laser source, a 50% transmission-reflection beamsplitter and a mirror arranged to provide two spaced parallel laser beams and which strike the surface of the shaft at points A and B respectively. Since the shaft surface is moving, light backscattered at the surface is Doppler shifted and since the velocity of the surface at points A and B differs, the frequency of light backscattered at the two points is shifted by different amounts. Light backscattered along the axes of the incident beams is mixed and directed into a detector where it heterodynes. The frequency at which the detected light intensity is modulated is directly proportional to the speed of rotation of the shaft. The device, and the method it embodies, can be used to measure the difference in velocity at two points on any surface undergoing non-uniform, motion and can, therefore, be used generally to characterize vibrational motion.

Abstract: A measuring circuit for the ionic current measurement in the combustion chamber of an Otto engine is disclosed. The circuit has an ignition transformer the secondary coil of which supplies an ignition circuit. On the side carrying the positive voltage of the ignition pulse, the coil is connected to ground and, on the side carrying the negative voltage of the ignition pulse, it is connected to the ignition spark gaps via a distributor. The circuit has, inserted into the ignition circuit, a parallel circuit of a high-voltage Zener diode connected in the non-conducting direction related to the ignition current, and a capacitor as the measuring voltage source. The present invention supplies the measuring voltage to the ignition spark gap without circuit elements influencing its sensitivity. A parallel circuit is connected between the side carrying the positive voltage of the secondary coil and ground.