US 4,052,903 AGranted

Pressure sensor

AssigneeThor Instrument Company, Inc.

InventorPetur Thordarson

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Abstract

A cup-shaped elastomeric diaphragm is snugly fitted onto an end portion of a support member which includes internal gas delivery and return passageways. A plurality of ports extend both radially and axially from the gas delivery passageway towards the diaphragm. A like number of identical gas return ports extend from another region of the diaphragm inwardly to the gas return passageway. A gas tight seal is provided between the diaphragm and the support member above the ports. In use the outer surface of the diaphragm is subjected to a pressure to be measured, e.g. subsurface hydrostatic pressure. A gas is delivered into the delivery passageway and through the sensor at a constant flow rate. The gas pressure expands the diaphragm in the regions of the ports to complete gas flow paths from the gas delivery ports to the gas return ports. The magnitude of the pressure to be measured acting on the diaphragm determines the gas pressure that is necessary to drive the gas through the sensor at a constant flow rate. The driving pressure of the gas is measured and is used to determine the magnitude of the pressure that is being measured.

Claims10

Dependent claims

A pressure sensor, comprising:

a support member having an axially elongated cylindrical end portion;
a cup-shaped elastomeric diaphragm mounted onto said support member and including an inboard portion and an outboard portion which is snugly fitted over the cylindrical end portion of said support member, said outboard portion having an outer surface which during use is subjected to a pressure to be measured;
means establishing a fluid seal between the inboard portion of said diaphragm and said support member, with the outboard portion of said diaphragm being free of attachment to the cylindrical end portion of said support member;
said support member including a gas delivery passageway therein and gas delivery port means extending outwardly from said gas delivery passageway through the end portion thereof towards a wall part of the outboard portion of said diaphragm;
said support member also including a gas return passageway therein and gas return port means extending inwardly through the end portion thereof from another wall part of the outboard portion of said diaphragm to said gas return pasageway;
with the outboard portion of said diaphragm normally overlying and substantially closing both the delivery port means and the return port means but being free to bulge outwardly during use in response to gas pressure within said passageway, an amount sufficient to open both of said port means and allow flow between the gas delivery port means and the gas return port means;
wherein said gas delivery port means comprises at least one axial gas delivery port extending outwardly from the gas delivery passageway to an end wall part of the outboard portion of said diaphragm, and further including at least one axially extending gas return port extending from another end wall part of the outboard portion of said diaphgragm inwardly into said gas return passageway;
wherein said gas delivery port means includes a plurality of radial ports extending from the gas delivery passageway to a cylindrical side wall part of the outboard portion of said diaphragm, and wherein the gas return port means also includes a plurality of radial ports extending from the gas return passageway to a cylindrical side wall part of the outboard portion of said diaphragm;
and
wherein the gas delivery ports and the gas return ports are substantially identical.

7 more elements

Pressure sensing apparatus comprising:

a pressure sensor comprising:
a support member having an axially elongated cylindrical end portion;
a cup-shaped elastomeric diaphragm mounted onto said support member and including an inboard portion and an outboard portion which is snugly fitted over the cylindrical end portion of said support member, said outboard portion having an outer surface which during use is subjected to a pressure to be measured;
means establishing a fluid seal between the inboard portion of said diaphragm and said support member, with the outboard portion of said diaphragm being free of attachment to the crylindrical end portion of said support member;
said support member including a gas delivery passageway therein and gas delivery port means extending outwardly from said gas delivery passageway through the end portion thereof towards a wall part of the outboard portion of said diaphragm;
said support member also including a gas return passageway therein and gas return port means extending inwardly through the end portion thereof from another wall part to the outward portion of said diaphragm to said gas return passageway;
and
with the outboard portion of said diaphragm normally overlying and substantially closing both delivery port means and the return port means, but being free to bulge outwardly during use in response to gas pressure within said passageways, an amount sufficient to open both of said port means and complete a flow path between the gas delivery port means and the gas return port means;
means for delivering a gas into said delivery passageway and through said sensor at substantially a constant flow rate;
means for measuring the pressure of said gas to in that manner determine the magnitude of the pressure acting on the outer surface of said diaphragm;
wherein said gas delivery port means includes a plurality of radial ports extending from the gas delivery passageway to a cylindrical side wall part of the outboard portion of said diaphragm, and wherein the gas return port means also includes a plurality of radial ports extending from the gas return passageway to a cylindrical side wall part of the outboard portion of said diaphragm;
wherein said gas delivery ports comprise a plurality of radial ports which are at least axially spaced apart;
and
wherein the gas return ports comprise a substantially identical pattern of ports diametrically opposite the gas delivery ports, whereby during use gas flowing between the support member and the diaphragm from the gas delivery ports to the gas return ports divides and flows circumferentially about the support member in both directions from the delivery ports.

11 more elements

Dependencies are inferred from the claim text.