Abstract: A trigger mechanism for an air gun with a cocking mechanism has a trigger and a trigger lever, actuated by the trigger, which retains a tensioned member of the air gun. The trigger lever is coupled with the cocking mechanism by intermediate members in such a manner that when the cocking mechanism is returned to its position of rest, it causes the overlap of the trigger lever over the member retained thereby to be reduced during the last portion of its path of travel.

Abstract: A surface acoustic wave device for use as an amplifier or convolver, or the like, and incorporating a plurality of parallel, spaced rails disposed between and separating a semiconductor slab and a surface acoustic wave propagating planar surface of a piezoelectric substrate a relatively small but finite distance apart, the rails having longitudinal axes aligned with the propagation beam path by and between a pair of spaced electro-acoustic transducers disposed on the substrate.

Abstract: Thermal compensation for frequency control of microwave resonators through utilization of bimetallic boundary motion type phenomena is described, the resonator being rectangular and preferably having composite broad walls of integral layers, one of which having a relatively lower thermal expansion coefficient than another of the layers and each having an initial deformation in a stabilized curvature condition to render these walls frequency sensitive.

Abstract: A device to be used in a darkened cockpit of an aircraft and the like in night flying or driving conditions for supporting in the device a chart treated with a fluorescent material, the device including an ultraviolet light source, means for directing the ultraviolet light energy from the source to the upper surface of the chart causing it to glow, and a filter disposed above the chart at the upper portion of the device which allows the fluorescent glow to be viewed therethrough while preventing glare-producing light rays from leaving the device.

Abstract: A surface acoustic wave device useful as a notch filter or a narrow-band transmission filter, the device including a periodic metallic grating disposed on a suitable surface acoustic wave supporting substrate in a beam path defined by an input transducer, the grating elements each exhibiting energy storage discontinuities at the extremities thereof.

Abstract: A rudder is pivotably mounted in an integral rudder-tiller support having a spring-loaded detent engageable by a lock on the rudder which may be adjusted to change rake and which may be released to free rudder to swing on its pivot by moving detent out of locking engagement with the lock.

Abstract: Surface acoustic wave devices having broadband characteristics with a desired transfer efficiency of less than unity at a desired center frequency are described, the devices incorporate a multistrip coupler array of a predetermined number N of conductive strips disposed on a piezoelectric substrate which is capable of supporting two tracks of approximately equal widths of propagating surface acoustic wave energy, the array having a tapping portion in one of the tracks and an approximately equal length launching portion in the other of the tracks for launching only a portion of the energy incident on the tapping portion, the strip periods p.sub.1 and p.sub.2 of the two portions being different and the ratio of p.sub.1 /p.sub.2, in conjunction with N, provides the desired characteristic.

Abstract: A microwave resonator operating in the TE.sub.11 circular mode with a pair of iris plates defining the resonator, each iris including an elliptical aperture centrally disposed therein, the resonator having a rotary joint midway between the irises at the location of a current null so that the two half portions of the resonator may be rotated with respect to each other in order to provide a desired relative iris axis alignment for an infinitely variable coupling value between a minimum value determined by the minor axis dimension of the elliptical apertures and a maximum value determined by the major axis dimension thereof.

Abstract: A coupled-cavity microwave filter including a plurality of relatively high Q cylindrical cavity filters, a relatively large non-adjustable iris aperture coupling adjacent ones of the cavities, a relatively smaller secondary tuning aperture located near the edge of the irises separating the cavities, each such secondary tuning aperture containing a tuning screw extending through the wall of the cavity in order to provide adjustment of the coupling between such adjacent cavities without degrading the cavity Q.

Abstract: A surface acoustic wave device including a synchronous reflection array disposed in a delay line between the input and output transducers, the synchronous reflection array having a synchronous reflection frequency that distorts the beam profile of propagating surface acoustic wave energy in the delay line so that when the beam profile is amplitude averaged at the output transducer, the transducer output signal has a relatively deep notch in amplitude at the synchronous reflection frequency.

Abstract: A bulk acoustic wave delay line including a body of acoustic wave supporting material and having at least one planar surface capable of reversably converting longitudinal wave mode acoustic energy to shear wave mode acoustic energy, the delay line also including at least one transducer for converting electromagnetic wave energy to acoustic wave energy and vice versa for propagating said acoustic wave energy along a path, a major portion of which supports shear wave mode energy and which path is at least partially defined by the mode converting planar surface, the planar surface being treated to increase the attenuation of propagating acoustic wave energy thereat by a predetermined amount, the attenuation provided at said planar surface being relatively frequency independent as compared to the attenuation per unit time of the propagating acoustic wave energy in the delay line body whereby triple transit signal suppression is significantly increased while still maintaining a relatively wide band frequency respo

Abstract: A bulk wave acoustic wave device with electrodes fabricated on a crystal in the form of arrays each having a plurality of closely spaced electrodes, one array being angularly disposed with respect to the other to provide at least one pair of matching electrodes notwithstanding uncontrolled beam wander within the crystal.

Abstract: Modular panels may be used as floor, exterior wall, interior wall and roof panels each including a honeycomb member sandwiched between skins to one of which a rectangular frame and insulation are affixed in a manner such that panels may be secured together in the same plane or in planes normal to each other using fasteners carried by the frames.

Abstract: A system wherein a plurality of thermoelectric modules are thermally connected by heat pipes forming a cascaded structure that is capable of operating effectively and reliably with large temperature gradients, the heat pipes providing relatively low temperature gradient interfaces between the thermoelectric modules and thereby act as stress isolation structures.

Abstract: A temperature stable surface acoustic wave device utilizing reflective gratings in a material such as Y-cut quartz having two propagation directions in which the temperature coefficients of delay are of opposite sign, the gratings reflecting the Rayleigh waves in the two propagation directions along suitable path lengths to provide a total linear zero temperature coefficient of delay. A temperature stable oscillator is formed by providing an amplifier in a feedback path from the output transducer to the input transducer of the surface acoustic wave device.