Diaphragm for pressure sensors

• US 4,237,775 A
• Filed: 08/21/1978
• Issued: 12/09/1980
• Est. Priority Date: 08/21/1978
• Status: Expired due to Term

• Current Assignee: Gould, Inc. (Transdigm Group Incorporated)
• Original Assignee: Gould, Inc. (Transdigm Group Incorporated)
• Inventors: Eisele, Walter H.
• Primary Examiner(s): Cohen, Irwin C.
• Application Number:
  US05/935,180
• Time in Patent Office: 841 Days
• Field of Search: 92/104, 92/99, 92/103 M, 92/34, 92/45, 73/715, 73/716, 73/729
• US Class Current: 92/99
• CPC Class Codes: F16J 3/02 Diaphragms
• CPC Class Codes: G01L 7/082 construction or mounting of diaphragms of semiconductive diaphragms G01L9/0042
• CPC Class Codes: G01L 7/102 construction or mounting of capsules

Abstract

A diaphragm consisting of multiple arches configured such that radial compliance is increased and pressure responsive radial compression loading will approximate radial tension loading resulting from deflection of an associated pressure sensor mechanism. On the pressure receiving side of the diaphragm, a broad shallow convex section extends between two concave sections of tighter curvature. The portions of the concave sections remote from the convex section each extend to a substantially cylindrical configuration. A sharp convex bend extending to a flat radial flange provides an attachment edge with minimum attachment stress. A method of forming such a diaphragm to insure uniform wall thickness by allowing maximum lateral migration of the diaphragm sheet is also disclosed.

Claims

1. An annular diaphragm element for a pressure sensor, comprising

a first sheetlike diaphragm member having a pressure receiving side, said pressure receiving side having a first annular concave section which extends inwardly to form a first substantially cylindrical portion, a first annular convex section radially outwardly of said first annular concave section and extending directly therefrom and a second annular concave section radially outwardly of said first annular convex section and extending directly therefrom which extends outwardly to form a second substantially cylindrical portion, said first annular convex section having a sufficiently shallower curvature and a sufficiently wider span than each of said first and second annular concave sections such that radial compression loading from flattening of said first annular convex section is substantially equal to radial tension loading from pressure responsive deflection of the pressure sensor when said diaphragm member is subjected to pressure loading of said pressure receiving side.

2. The annular diaphragm element of any one of claims 1, or 7 wherein said pressure receiving side further has a first annular, sharply convex section radially inwardly of said first annular concave section and a second annular, sharply convex section radially outwardly of said second annular concave section.

3. The annular diaphragm element of claim 2 further comprising at least a second sheet like diaphragm member being identical and smaller than said first sheet like diaphragm member, being radially inwardly thereof and being integral therewith.

4. The annular diaphragm element of claim 2 wherein said first annular, sharply convex section extends inwardly to form a first flat sensor attachment flange and said second annular sharply convex section extends outwardly to form a second flat transducer flange.

5. The annular diaphragm element of claim 1 wherein the radius of curvature of said first annular convex section is about eight times the radius of curvature of each of said first and second annular concave sections.

6. The annular diaphragm element of claim 1 wherein the distance between said first and second substantially cylindrical portions is about the same as the radius of curvature of said first annular convex section.

7. An annular diaphragm element for a pressure sensor, comprising

a first sheet like diaphragm member having a pressure receiving side, said pressure receiving side having a first annular concave section, a first annular convex section radially outwardly of said first annular concave section and a second annular concave section radially outwardly of said first annular convex section, said first annular convex section having a shallower curvature and a wider span than each of said first and second annular concave sections, the radius of curvature of said first annular convex section being about eight times the radius of curvature of each of said first and said second annular concave sections and the distance between the inner extremity of said first annular concave section and the outer extremity of said second annular concave section being about equal to the radius of curvature of said first annular convex section such that radial compression loading from flattening of said first annular convex section is substantially equal to radial tension loading from pressure responsive deflection of the pressure sensor when said diaphragm member is subjected to pressure loading of said pressure receiving side.

8. An annular diaphragm assembly of a pressure sensor, comprising

a circular support rim, a concentric disc and a first sheet like diaphragm member having a pressure receiving side, said pressure receiving side having a first annular concave section extending inwardly to form a first substantially cylindrical portion, a second annular concave section radially outwardly and spaced from said first annular concave section extending outwardly to form a second substantially cylindrical portion, an intermedite section extending between said first and said second annular concave sections, said intermediate section defining a first annular convex section directly connected to said first and second annular concave sections, said first annular convex section having a sufficiently shallower curvature and a sufficiently wider span than each of said first and second annular concave sections, a first annular, sharply convex section radially inwardly of said first annular concave section at said first substantially cylindrical portion thereof, a second annular, sharply convex section radially outwardly of said second annular concave section at said second substantially cylindrical portion thereof, a first flat sensor attachment flange extending inwardly from said first annular, sharply convex section, said first flat sensor attachment flange being attached to said disc immediately adjacent the peripheral edge thereof, a second flat sensor attachment flange extending outwardly from said second annular, sharply convex section, said second flat sensor attachment flange being attached to said rim immediately adjacent the inner end thereof.