Abstract: A rotary thumbwheel switch assembly has a switch module including a translucent light ring for indicating positions of the rotary thumbwheel. The ring is illuminated from within by a light emitting diode which can be snap-mounted in place in the center of the translucent ring. The switch module comprises a thumbwheel to which contact brush sets can be easily secured by a spring biased tab. The switch module can be combined with a separable bezel. The switch module can be mounted from either side of a front panel, and can be connected to circuit assemblies housed by the panel prior to the insertion of the bezel. The bezel secures the switch modules to each other and to the panel. A kit comprising the separable elements of the illuminating diode, the bezel and the switch modules is described. A method for installing the separable elements includes the steps of inserting the modules from the front of the housing panel for testing each module's connection with circuit assemblies prior to installing the bezel.

Abstract: In multiple position rotary switch a pair of printed circuit boards are arranged adjacent opposite sides of a single brush bearing rotatable element. Brush blocks have a plurality of contacting extensions which may be selectively deleted in accordance with circuit design. The rotatable element includes an integral wheel having peripheral means in association with a detent in the housing for particularly positioning the wheel relative to the circuit boards for selectively connecting circuits thereon to establish desired switch connections.

Abstract: The invention is concerned with a pressure diaphragm that is composed of a nonmetallic material that has been sculptured by etching a plate to form thick motes, or islands, and a thick rim interconnected by thin sheet material. The thick portions are separated by thin flexures in which the deflection of the diaphragm is concentrated, whereby the deflection yields a high value of electric output per unit pressure.

Abstract: In a capacitive key for use in a keyboard, an operator depresses a plunger which alters the separation between the plates of a capacitor, thereby altering its capacitance. It is desirable to provide plunger overtravel which permits further depression of the plunger after the capacitor has been altered. In the present invention a portion of the movable capacitor plate is formed into a spring which elastically deforms after the capacitor has been altered, to permit overtravel of the plunger.

Abstract: A diaphragm for a miniature pressure transducer has its surface sculptured by anisotropic etching to provide gauge areas in the form of narrow thin flexure areas between thick areas in the form of islands or motes. The thick areas act to constrain or stiffen the flexure areas from bending along their lengths while facilitating the bending thereof about axes parallel to their lengths when the diaphragm deflects in response to a pressure change. Linear piezoresistive gauges diffused into the gauge areas are responsive to the bending of said flexure areas to change resistance by an amount corresponding to the pressure change.

Abstract: An electromechanical transducer is provided which employs a piezoresistive substrate support body of semiconductive material of which a first type N or P and a lineal resistor composed of material of a second type (P or N) formed on one surface thereof. The support body has a reduced neck intermediate two pads. The lineal resistor extends between the pads and across the neck on one side of the support body. The lineal resistor is formed by diffusing semiconductive material of the second type of conductivity into the substrate material. Strain is detected by measuring the change in resistance of the lineal resistor. When the transducer is subjected to strain, the resistance changes by an amount depending on the strain. While the electrical current flows through the resistor, heat developed in the resistors flows into the neck and then is conducted through the flaring portions of the neck to the pads and then to an object under test.

Abstract: The electromechanical acoustic emission detector of this invention comprises a plurality of sensor elements secured in an areal array on a base plate. The spacing and arrangement of the sensor elements are such that the transducer is "tuned" to acoustic emission waves that travel along the surface of the vessel to which the transducer is attached. Because of the non-linear character of the array the transducer detects waves arriving from different directions with substantially equal sensitivity.

Abstract: An electrical switch is provided with a switch wheel having indicia appearing around the periphery of the switch wheel adapted to be presented to view through an aperture in a switch case as the switch wheel is rotated by a lever that projects through the wall of the switch case. The switch wheel rotates in accordance with the rotation of a lever-actuated switch plate with which the switch wheel is interconnected. Gears are provided interconnecting the switch wheel and the switch plate thereby allowing the switch wheel to be rotated through about 360.degree. when the switch plate is rotated through a much smaller angle, such as about 90.degree..

Abstract: The transducer of this invention utilizes an annular lithium niobate crystal operated in the compression mode with the sensitive axis of the crystal arranged at an angle of about -51.4.degree. to the Z, or optical, axis of the crystal in the first and third quadrants of the Y-Z plane of the crystal. This accelerometer has high efficiency and operates effectively over a wide range of temperatures, including high temperatures above 1000.degree. F.