Other

Teledyne Industries, Inc.

David C Jacobs

Gerald M Masson

John L Driscoll

William J Alvesteffer

Edward K Law

Giorgio L Coraluppi

Joseph A Hochadel

A miniaturized silicon based thermally controlled vacuum sensor uses thin film resistors on a membrane in a minute measuring chamber to accurately detect vacuum pressures in the range of 760 Torr to 1.times.10.sup.-5 Torr. The configurations of the measuring chamber and gas diffusion port of the sensor structure insure that heat transfer from the membrane is predominately conductive over the pressure detection range to provide linear output up to 0.1 Torr. A microprocessor is used to control and measure power required to maintain a predetermined temperature differential between a sensing resistive element on the membrane and an ambient temperature sensing element of the sensor base from analog voltage and current values. Pressure detection errors introduced by ambient temperature variations are minimized by measuring power dissipated into the gas. Analog and digital converters for both current and voltage signals use a .SIGMA.-.DELTA. conversion method to reject electrical noise by an averaging technique to produce stable signal detection of pressure down to 1.times.10.sup.-5 Torr. The sensor is thermally stable over an ambient temperature range of 0.degree.-50.degree. C. at pressures between 10.sup.-4 to 760 Torr.

Miniature silicon based thermal vacuum sensor and method of measuring

A piezoceramic valve includes a valve actuator sandwich assembly including a piezoceramic bending element flexibly bonded between two metal sheets. Flexible elastomeric sheets are bonded to outer surfaces of the metal sheets, respectively, to form the sandwich assembly. The valve includes a first supporting member which sealingly engages an outer surface of the first elastomeric sheet and a second supporting member which sealingly engages an outer surface of the second elastomeric sheet to flexibly support the valve actuator sandwich assembly between the two supporting members. The valve actuator is engageable with a valve seat to prevent flow through the valve and is deflectable away from the valve seat to allow flow through the valve. The piezoceramic bending element is isolated in the valve actuator sandwich assembly from the flow stream to prevent diffusion of low molecular weight gases through the porous ceramic and to isolate electrically active elements of the bending element from the flow stream.

Piezoceramic valve actuator sandwich assembly and valve incorporating

A rearrangeable fully available multistage switching network having N.sub.T inputs and M.sub.T outputs, preferably where N.sub.T =M.sub.T, comprising a plurality of switching elements arranged in an array of .theta. stages, where .theta..gtoreq.3. The inner groups of stages define a plurality of nested modules where each of the switches in an outer stage is connected to associated subordinate inner modules such that at least one set, f.sub.i, of said connections between stages is redundant, that is, greater than 1.

Rearrangeable full availability multistage switching network with

A lightweight, hand-held portable tool for opening a smokeless tobacco container uses a rotatable cutting wheel to slit an adhesive coated paper wrapper extending around the rim of the lid and cylindrical body of the container. The tool has a top member which rests on the circular lid to fix the position of the cutting wheel at a distance therebelow. The cutting wheel is recessed in a body member perpendicularly disposed to the top member to restrict the cutting depth to the combined thickness of the rim and wrapper. The tool includes grasping surfaces for the user and a guide member shaped to conform to the side surface of the container so that the opening operation can be accomplished by revolving the tool about the body of the container as the top member rests on the lid.

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Hampton, VA, United States of America

David C Jacobs