The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 31, 1983
Filed:
Sep. 18, 1981
James W Phillips, Michigan City, IN (US);
Gregory Dirks, La Porte, IN (US);
Dwyer Instruments, Inc., Michigan City, IN (US);
Abstract
A strain gauge pressure transducer comprising a housing having an internal pressure cavity across which is mounted a flexible elastomeric diaphragm that separates high and low pressure chambers in the gauge that the housing is arranged to separately connect the sources of high and low pressure, respectively. A range spring in the form of a leaf spring is anchored to the housing cantilever fashion in the high pressure chamber and to one side of the diaphragm to dispose the live length of same, as defined by a clamp device, in overlying relation to the diaphragm, to which the leaf spring live length is connected for deflecting movement thereof by the diaphragm. The leaf spring has fixed to its live length a strain gauge in the form of four square grid etched foil sensing elements of the self temperature compensated type connected in Wheatstone bridge fashion that forms an electro-mechanical transducer that is powered by an electronic circuit mounted inside the gauge on a printed circuit board that is in overlying relation to and spaced from the leaf spring, which when energized supplies a constant direct voltage, to the strain gauge. Deflection of the leaf spring live length under deflection of the diaphragm in response to fluid pressure applications to the high and low pressure chambers unbalances the strain gauge from a null relation and effects a corresponding change in the strain gauge signal which is amplified and converted by the electronic circuit to a low output that is supplied to instrumentation such as a controller or recorder. The electronic circuit has internal adjustments that provide for adjustment of the range or span of the transducer, and the zero operating point of the transducer.