Abstract: A retainer and spring with threaded end are machined from a single piece of material for threading to a piston in a closed cycle cryogenic cooler. Since the machined retainer and spring are a unitary part, they cannot rub against each other during operation of the piston which reduces debris generation. The spring is preferably formed as a double start helix which further increases axial stability and reduces side loading. The spring extends into an integrally formed, threaded end at the end thereof opposite the retainer.

Abstract: A unitary pulse tube expander for removable attachment to a SADA II coldfinger and insertion within a Dewar assembly. The regenerator of the pulse tube expander is encased in a regenerator sleeve and a cold cap to create a unitary pulse tube expander that may function as a drop-in replacement for a Stirling type expander in a SADA II coldfinger cryocooler.

Abstract: A unitary pulse tube expander for removable attachment to a SADA II coldfinger and insertion within a Dewar assembly. The regenerator of the pulse tube expander is encased in a regenerator sleeve and a cold cap to create a unitary pulse tube expander that may function as a drop-in replacement for a Stirling type expander in a SADA II coldfinger cryocooler.

Abstract: A retainer and spring with threaded end are machined from a single piece of material for threading to a piston in a closed cycle cryogenic cooler. Since the machined retainer and spring are a unitary part, they cannot rub against each other during operation of the piston which reduces debris generation. The spring is preferably formed as a double start helix which further increases axial stability and reduces side loading. The spring extends into an integrally formed, threaded end at the end thereof opposite the retainer. The spring is therefore solidly connected to its adjoining parts which greatly reduces tilting and off-axis movements inherent in the prior art, wound spring designs.

Abstract: The present invention relates to a saturable nonwoven material comprising fluoropolymer floc and aramid floc, which can be used as a substrate for a liner for self-lubricating bearings and for other applications.

Abstract: The present invention relates to a saturable nonwoven material comprising fluoropolymer floc and aramid floc, which can be used as a substrate for a liner for self-lubricating bearings and for other applications.

Abstract: The present invention relates to a saturable nonwoven material comprising fluoropolymer floc and aramid floc, which can be used as a substrate for a liner for self-lubricating bearings and for other applications.

Abstract: This invention provides a low friction linear clearance seal for use in closed cycle cryogenic coolers. The clearance seal comprises a cylinder, a piston mounted within the cylinder for reciprocating movement and a self lubricating polymer liner bonded to the piston which forms an effective seal around the piston. The clearance seal improves the sealing capability between the piston and the cylinder and reduces heat generated by the motion of the piston along the cylinder wall. The clearance seal also improves the performance and reliability of the cryogenic cooler.

Abstract: This invention pertains to cargo transportation, and more particularly to an apparatus that facilitates loading and unloading of cargo from a vehicle. In accordance with the present invention, a retractable bed for vehicles is provided that is simple in design, can be adapted to different vehicle applications and has greater safety and cargo carrying capacity than prior devices. In addition, the invention can be installed or removed by a single user because of it's light weight and efficient design. The apparatus comprises a load carrying transport system having improved structural properties and arrangements for rollably supporting the cargo. The cargo is supported on a rolling deck that is rollably attached to a frame assemble by roller bearings. The frame assemble is mounted to the truck bed. The rolling deck moves along the roller bearings on the frame assembly to move the load.

Abstract: An integrated-optic waveguide apparatus uses a photoelastic substrate for sensing temperature changes. Optical channels are formed in a photoelastic crystal substrate by depositing film stripes thereon to cause stress-induced changes in the relative refractive index responsive to changes in the substrate temperature. Absorption and coupling or switching of light waves between the channels provides a variable light intensity as a function of temperature. A single-mode temperature sensor of the interferometer type provides high sensitivity without requiring a secondary reference light source. Multimode temperature sensors are also described which exhibit a wide dynamic range useful up to several hundred degrees C. at a slight compromise in sensitivity.

Abstract: A wide bandwidth, high sensitivity optical accelerometer having a lever arm to amplify the mechanical displacement of the accelerometer mass element. The optical accelerometer includes a high resonant-frequency spring-mass system, wherein the acceleration forces up to several hundred Hz cause a linear displacement of the mass with force, which, through the lever arm, modulates the intensity of a beam of light with a large gain. The modulated light beam is in turn converted to an electrical signal which corresponds to the applied accelerating force. The accelerometer of the present invention may be largely fabricated from a single piece of material such as silicon, wherein the lever, mass, spring and supporting structure are etched from a single substrate according to known photolithographic processes. Alternatively, the accelerometer components may be molded from a sheet plastic or other material.

Abstract: An optical waveguide apparatus provides for single-mode and multimode switching or modulation of light wave energy with reduced bias voltages. Optical channels are formed in a crystal substrate by depositing film stripes thereon to cause stress-induced changes in the relative refractive index. Coupling or switching of light waves between the channels is provided by applying a bias which is of reversed polarity at adjacent film stripes, thereby augmenting or diminishing the stress in individual channels. By allowing operation with close spacing of the electrodes and using the enhancement in refractive index change of the stressed substrate in combination with the applied bias, the required control voltage is substantially reduced.

Abstract: A fiber optic sensor for sensing pressure, temperature, voltage and other environmental parameters. A fiber is terminated in a series of semiconductor layers, each absorbing light as a function of the sensed parameters at a different wavelength. Light is transmitted down the fiber with plural frequencies and reflected by the termination to provide in the reflected light an attenuation representative of the parameters sensed. The reflected light intensity is detected and electronically processed to provide an indication of the magnitude of the parameters being sensed. With each frequency differently attenuated, the sensed parameters are separately detected.

Abstract: An optical sensing system for detecting a physical parameter such as acceleration, temperature or pressure through parameter induced motion of an optical element in a fiber optic path. The motion of the optical element varies the light transmission through the path in which the optical element defines the relationship between motion and alteration in light transmission. In one embodiment the optical element includes a focusing system between an input and an output optical fiber to result in an increase in sensitivity by enhancement of the effect of motion of the optical element of the amount of light transmitted to the output fiber. The optical element may include or be attached to a mass to provide acceleration sensitivity for use in geophysical exploration. In addition, the optical element can be adapted to provide acceleration sensitivity in one direction in combination with insensitivity to acceleration in an orthogonal direction of particular use in such geophysical exploration.

Abstract: A system for monitoring the temperature of a plurality of bearings and motors, for example in a grain elevator, includes a plurality of sensors associated with the respective bearings and motors whose temperatures are to be monitored. A first circuit energizes a display for providing a readout of the temperature at each sensor location, and a second circuit compares the temperature at each sensor with a maximum desired temperature for its associated bearing or motor, and energizes an alarm when this desired maximum is exceeded. A third circuit drives a display indentifying the sensor being monitored by the first and second circuits. A malfunction detector circuit produces an observable indication in response to an open circuit condition at any of the sensors.

Abstract: An apparatus is described for multimode electro-optic switching with reduced switching voltages. A main optical channel is formed by providing a guiding electrode on an electro-optic substrate which is bounded on either side by barrier electrodes to which voltages are applied that possess polarities opposite to the polarity of the voltage applied to the guiding electrode. Quadratic behavior of Snell's law at glancing incidence is utilized to produce, via voltage excitation, a relatively large change in critical angle over a short section of barrier electrodes, which comprises a coupling region, to allow some portion of the guided light energy to couple from the main channel to a similar branch channel positioned in a coupling relationship thereto. Since the polarity of the barrier electrode is opposite to that of the guiding electrode, the guiding voltage is significantly reduced from that required by the prior art.

Abstract: An improved electrode structure is provided for electro-optical modulators applicable in multiple mode fiber light propagation systems. The electrodes form effective light guiding elements and, when appropriately excited, efficiently refract light away from the output port of the modulator. The improvement affords increased modulation depth, a lower driving power requirement, and an increased operating band width.

Abstract: A method and apparatus is described for multimode electro-optic multiplexing which provides high interchannel isolation. This isolation is achieved by utilizing voltage induced optical barriers to channelize optical signals and may be increased by positioning spoiler electrodes, which are energized with the channel barrier electrode, in each channel. These spoiler electrodes establish a varying refractive index in the median which deflects optical signals from the output port of the channel, thus providing the increased isolation. The spoiler electrode concept is also employed to provide a non-guided optical multiplexer/demultiplexer.

Abstract: A structure for electro-optic channeling of multimode light radiated from multimode fiber optic waveguides is disclosed. The light is channeled in a planar optic waveguide comprised of a high index electro-optic material to which the fiber optic waveguide is non-normal butt coupled to achieve higher in-plane collimation and greater confinement of divergent light beams with lower control voltages.