Other

Mark Telephone Products, Inc.

The United States of America As Represented by the United States

The United States of America As Represented by the Administrator of the

United States of America As Represented by the Administrator of Nasa

Varian Associates, Inc.

John Dimeff

Clyde R Stewart

William J Kerwin

Lowell J Fox

An air flow measurement device includes a connector conduit for the air flow having a transverse restrictor plate located therein with a plurality of uniform and uniformly spaced apertures extending therethrough. The restrictor plate is maintained in the connector conduit by a pair of sleeves each of which includes on its interior diameter a plurality of angularly spaced passages and on its outer diameter a circumferential groove communicating with the passages. A pair of valves are mounted through the wall of the connector conduit for communication with the circumferential grooves so that a differential pressure meter may be connected to the valves to measure the difference in pressure upstream and downstream of the restrictor plate to thereby determine the flow rate. The sleeves may be made in two identical pieces to form the passages and grooves, and additional smoothing screens may be positioned upstream and downstream of the restrictor plate by further identical sleeve pieces.

Air flow measurement device

A circuit for generating a linear current proportional to the displacement of the movable member of a transducer receives an undetermined supply voltage from a monitoring circuit which has a relatively high internal resistance. The circuit is provided with two parallel current paths with one path including a resistive potentiometer strip and other path including a transistor and resistor connected in series. The movable member of the transducer has an electrical contact member attached thereto with the contact member having one end making contact with the resistive potentiometer strip and with the other end thereof making contact with a conductive strip which is connected to the gate of the transistor so that the current drawn by the circuit will be linearly related to the movement of the movable member.

Circuit for generating a current linearly proportional to displacement

A gas flow meter includes a cylinder closed at its upper end and slidably supported within a bearing ring. The cylinder side wall is provided with openings. A gas flow is directed into the interior of the cylinder which causes it to rise with respect to the bearing ring and permitting the gas to flow out of the area of the openings exposed above the bearing. During a constant flow of gas through the cylinder the flow rate can be measured by the distance which the cylinder has moved upwardly as indicated on a fixed marker positioned adjacent to the cylinder. An electrical signal is also provided by means of an electrical sensor positioned axially within the cylinder.

Gas flow meter

An improvement in the test for air leaks of an air pressurized telephone cable is disclosed. The cable is of the type wherein a number of individually insulated conducting electrical strands are surrounded by a protective plastic tubing impermeable to water and maintained dry under air pressure. The cable is typically buried. The improvement comprises a capillary flow controller for the introduction of trace gas, such as helium into the cable. The trace gas is introduced into the system at a pressure exceeding twice and preferably 10 times the ambient dry air pressure within the cable. The capillary introduces the high pressure trace gas to the interior of the cable by leaking a relatively constant volume flow rate to a discharge chamber. The discharge chamber includes a pressure relief valve--to guard against cable sheath rupture in the case of local occlusion, a pressure gauge--to measure the pressure of the line at the point of helium introduction, and a discharge aperture--which is the point of introduction of the trace gas into the air pressurized cable. Trace gas enters into the system through the capillary at a constant rate which can from time to time be monitored with conventional flow rate equipment.

Capillary flow controller for air pressurized telephone cable trace gas

A calorimetric load for very high microwave power at very high frequencies is formed by a metallic, cylindrical chamber into which the wave-guide carrying the power opens. Inside the metallic cylinder is a coaxial dielectric cylinder, with a space between full of circulating wave-absorbing fluid such as water. The incoming wave may be in a higher-order mode. To make it disperse rapidly into the absorbing fluid, a conical reflector is located inside the dielectric cylinder to reflect the wave outward.

Waveguide load having reflecting structure for diverting microwaves into

Apparatus for processing a composite noise signal containing sonic and ultrasonic components generally in a frequency range of about 20 Hz-100 KHz to make audible both components of the signal includes a heterodyne circuit operable in response to a rectangular wave local oscillator signal to produce output signals which are within the frequency range of human hearing.

Signal processor

A transducer unit comprised of a pair of transducers coupled together in a manner such that the offsets, drifts and the like of the circuit elements of one transducer are opposed by and cancelled out by the circuit elements of the other transducer. The transducers can be in the form of Wheatstone bridges and each of the branches of the bridge contains a circuit element of each transducer, respectively, the circuit elements of the branches of the transducer unit being in opposition to each other so as to cancel out the effects due to temperature, acceleration, aging and the like.

Method and apparatus for transducer error cancellation

An improved flow meter has a vertical chamber of relatively constant cross-section. In this chamber a float resides having a corss-section only slightly less than the cross-section of the chamber. Fluid is introduced at the bottom of the chamber and flows to the top of the chamber. The chamber top is provided with relief port outletting through a chamber throttle value. Similarly, a passage through the float has a float throttle valve. The chamber throttle valve controls the back pressure on the float and provides adjustability to the lifting of the float at various pressure levels. The throttle valve provides adjustability to the range of flow to which positioning of the float responds. A series of apertures configured along the sides of the chamber open as the float moves upwardly in response to increasing fluid pressure in the chamber below the float. The flow meter is digitally sensitive on an analog basis to changes in flow. One of the chamber walls can be formed from a printed circuit board which includes apparatus for sensing the position of the float as well as the flow meter apertures. Calibration of the float sensors to float position is obviated by this arrangement.

Flow meter

A sensor for use on the front end of a flexible, resilient probe for use in an underground duct of the type which contains one or more current-carrying cables. The sensor is provided with a signal generating device for detecting a particular operating condition of a cable in the duct when the sensor moves through the duct adjacent to the cable. In one embodiment of the sensor, acoustical signals are sensed by a crystal when such acoustical signals originate from a leak in the pressurized sheath surrounding the cable. In another embodiment of the sensor, a coil senses the magnetic field surrounding the cable so that electrical shorts occurring in the cable can be monitored. In a third embodiment of the sensor, a heat detector is provided so that the sensor can detect hot spots in a duct.

Sensor for underground duct probe

A circuit having a transducer which normally provides a non-linear output as a function of a stimulus to which the transducer is responsive. The circuit is provided with a feedback resistor from at least one of a pair of output terminals coupled to the transducer, and the feedback resistor is coupled to the power input of the transducer. Any change in the output voltage will cause a current change through the transducer, and this current change has a linearizing effect on the output voltage. The circuit is especially adapted for use with a Wheatstone bridge having a power amplifier coupled to the input thereof and a differential amplifier coupled to the output thereof. In such a case, a pair of feedback resistors couple the output terminals of the differential amplifier with the input terminals of the power amplifier.

Circuit for linearization of transducer

A differential amplifier suitable for use with a transducer network, such as a Wheatstone bridge, for measuring small signal voltages while eliminating common mode voltage contributions applied to the input of the amplifier. A potentiometer is connected across the output terminals of a pair of amplifiers whose positive input terminals receive the common mode voltage components and induced signal voltages from the transducer network. The shiftable terminal of the potentiometer is connected to the negative input terminals of one of the two amplifiers and adjusted to control the gain of the amplifier pair. The output signals of the differential amplifier are proportional to the induced signal voltages and devoid of the common mode voltage.

Differential amplifier with common mode rejection means

A duct probe having a coaxial cable is provided to advance a microphone through an underground or other duct containing a cable in a pressurized sheath for sensing fluid leaks in the sheath. The coaxial cable is embedded in a resilient fiberglass rod of one-piece construction. The rod is sufficiently flexible so that it can be wound onto and unwound from a reel having a cage-like configuration. A stationary base is provided to rotatably mount the reel, and the base is provided with a length measuring device responsive to the movement of the duct probe as it is unwound from the reel so that the distance by which the duct probe penetrates a duct can be determined. At the outer end of the rod, a microphone is mounted for sensing the sounds caused by a fluid leak in the pressurized sheath in the duct. The coaxial cable in the rod couples the microphone to a telephone jack at the reel, one part of the jack being stationary and the other part of the jack being coupled to the reel so that the reel can rotate relative to the base, yet a signal can be taken from the coaxial cable and directed to a electronic signal processor unit for showing an indication of the leak. The rod can be repaired quickly and easily by an improved technique if the rod cracks as a result of being misused.

Duct probe and dispensing apparatus therefor

Multi-component motions between two parts are sensed by this apparatus which comprises a first conductive element and a plurality of second conductive elements with a frame connected to the first and second elements to hold them closely spaced from each other but not in electrical contact. An electric oscillator is connected between the first element and the second elements to apply an oscillating signal between the first element and each of the second elements. A sensing circuit is connected to each of the second elements to separately detect changes in the protential between the first element and each of the second elements as the two parts are moved relative to each other and to produce a first set of separate electrical signals representative of such changes in the potential. These signals are then algebraicly combined in a plurality of predetermined combinations to thereby generate a second set of electrical signals which are each representative of the separate linear and rotative orthogonal components of the relative motion between the two parts.

Non-contacting device for sensing multi-component motion

A remote volume flow meter is disclosed in which a variable density optical filter attached to a moving diaphragm indicates flow by filter position. The diaphragm has a hole, which hole travels along a needle. The needle is mounted to the housing via a needle stem. Excursion of the diaphragm at the hole occurs against a spring force. Upon movement against this spring force the diaphragm hole sees a changing area defined by the needle. Typically, the needle is of overall cylindrical configuration with one or more linearly tapering grooves extending from one end of the needle to another end of the needle. These grooves taper from a small interruption of the cylindrical cross-section at the low mass flow rate end of the needle to a large interruption of the cylindrical cross-section of the needle at the high mass flow rate end of the needle. Centrally of the needle and protruding to the high flow rate end of the needle there is provided a threaded adjustment needle. This adjustment needle is for advancement into the deepest portion of the tapering grooves.

Flow measuring needle and orifice for flow meter

A pair of spaced apart grooves are machined in a plate in correspondence with the movement of a patient's left and right condyles relative to the sockets in which they move. A third groove is also machined in the same plate, equally spaced and remote from the pair of grooves, in correspondence with the minimal separation of the patient's mandibular and maxillary teeth at various lateral and anterior positions. The plate is then attached to a cast of the patient's maxillary teeth and is mounted in an articulator frame on rigid posts which slide in the machined grooves of the plate as the plate is manually moved, thereby reproducing movements corresponding to the patient's closure pathway and condylar topography.

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San Jose, CA, United States of America

John Dimeff