Capacitive pressure sensor
First Claim
1. A pressure sensor comprising, a housing, a flexible diaphragm received in said housing and having a generally flat face when in its unflexed state, a separate and rigid substrate received in said housing and having a generally flat face in spaced apart and generally opposed relation to the flat face of said diaphragm, at least one electrode on each of said generally flat opposed faces of said substrate and said diaphragm, a spacer disposed between said substrate and said diaphragm adjacent the periphery thereof and extending circumferentially at least substantially continuously and constructed and arranged to space apart said electrodes in substantially parallel and opposed relation when said diaphragm is unflexed, a seat carried by said housing for receiving one of said flexible diaphragm and rigid substrate thereon, a resilient clamp carried by said housing and yieldably biasing said substrate, spacer and diaphragm together at least substantially continuously around the electrodes on the substrate and diaphragm and yieldably urging onto said seat one of said flexible diaphragm and rigid substrate, whereby said electrodes are disposed in operative relationship in said housing to produce a signal varying with and responsive to the pressure of fluid acting on said diaphragm to flex it and displace the electrode thereon relative to the electrode on said rigid substrate.
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Accused Products
Abstract
A capacitive pressure sensor preferably for a vehicle fuel system with a flexible diaphragm, spacer and rigid substrate disposed in opposed face-to-face relation in a housing and yieldably urged together by a spring clamp. Electrodes disposed on the immediately adjacent opposed faces of the diaphragm and substrate produce a signal indicative of and varying with changes in the pressure of fluid acting on the diaphragm to displace its central portion relative to the substrate. In operation, through sensor and control circuitry, the speed of a fuel pump is varied to vary and control the pressure of fuel supplied to an engine in response to varying engine operating loads and conditions. To control the flow of fuel, a check valve, pressure relief valve and vent valve may be provided in the housing.
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Citations
31 Claims
- 1. A pressure sensor comprising, a housing, a flexible diaphragm received in said housing and having a generally flat face when in its unflexed state, a separate and rigid substrate received in said housing and having a generally flat face in spaced apart and generally opposed relation to the flat face of said diaphragm, at least one electrode on each of said generally flat opposed faces of said substrate and said diaphragm, a spacer disposed between said substrate and said diaphragm adjacent the periphery thereof and extending circumferentially at least substantially continuously and constructed and arranged to space apart said electrodes in substantially parallel and opposed relation when said diaphragm is unflexed, a seat carried by said housing for receiving one of said flexible diaphragm and rigid substrate thereon, a resilient clamp carried by said housing and yieldably biasing said substrate, spacer and diaphragm together at least substantially continuously around the electrodes on the substrate and diaphragm and yieldably urging onto said seat one of said flexible diaphragm and rigid substrate, whereby said electrodes are disposed in operative relationship in said housing to produce a signal varying with and responsive to the pressure of fluid acting on said diaphragm to flex it and displace the electrode thereon relative to the electrode on said rigid substrate.
- 20. A pressure sensor for a fuel system of an engine comprising, a housing, a fluid chamber in said housing, a seat carried by said housing, extending circumferentially at least substantially continuously, encircling said chamber and having an essentially planar surface constructed and arranged to receive a diaphragm thereon, a flexible diaphragm received in said housing on said planar surface of said seat with at least the central region of one face thereof opening onto said fluid chamber and the other face being generally planar when the diaphragm is in its unflexed state, a separate and rigid substrate received in said housing and having a generally planar face spaced apart in generally opposed relationship to the generally planar face of said diaphragm, at least one electrode on each of said generally planar opposed faces of said substrate and said diaphragm, a spacer disposed between said substrate and said diaphragm adjacent the periphery thereof, circumferentially extending at least substantially continuously around the periphery thereof and constructed and arranged to space apart said electrodes in essentially parallel opposed relationship when said diaphragm is unflexed, and a resilient clamp carried by said housing and yieldably biasing said diaphragm onto said seat and said substrate, spacer and diaphragm together at least substantially continuously around the periphery of said electrodes on said substrate and diaphragm, whereby said electrodes are disposed in operative relationship in said housing to produce a signal varying with and responsive to changes in pressure of fuel in said fluid chamber acting on said diaphragm to flex it and displace the electrode thereon relative to the electrode on said rigid substrate.
Specification