US3793885A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Diaphrgam construction for differential pressure transducer
Assignee: Rosemount Inc
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Filing: 1972-09-05
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Granted: 1974-02-26
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Expires: 1992-09-05
Abstract
Abstract A diaphragm construction for a differential pressure transducer wherein the diaphragm is deflected under pressure, and which has means around the periphery thereof to isolate the diaphragm stresses from the mounting portion of the diaphragm.
Inventors
- 👤 R Frick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 00:25
CPC Classifications
G; G01; G01L; G01L9/00; G01L9/0041; G01L9/0072; G01L13/00; G01L13/02; G01L13/025
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
179 words
A pressure transducer of the capacitance type having a housing including a surface defining a first capacitor plate, and a diaphragm mounted to be deflected under pressure with respect to said first capacitor plate; said diaphragm comprising a central sensing portion comprising a disc member having a sensing surface and a bisecting reference plane generally parallel to the sensing surface, a peripheral mounting ring symmetrically located with respect to said bisecting plane and fixedly, rigidly mounted on said housing, and an annular web portion extending radially to join said ring and said central portion; said web being substantially thinner than the central portion at the junction of the web and central portion, said web portion extending symmetrically in direction of said bisecting plane and being defined by generally flat surfaces on opposite sides of said bisecting plane, said flat surfaces being of length in direction between the ring and the central portion in relation to the size of the central portion so that the central portion deflection under pressure substantially corresponds to the deflection of a free edge diaphragm.
Claim 2
Dependent Claim
179 words
A pressure transducer of the capacitance type having a housing including a surface defining a first capacitor plate, and a diaphragm mounted to be deflected under pressure with respect to said first capacitor plate; said diaphragm comprising a central sensing portion comprising a disc member having a sensing surface and a bisecting reference plane generally parallel to the sensing surface, a peripheral mounting ring symmetrically located with respect to said bisecting plane and fixedly, rigidly mounted on said housing, and an annular web portion extending radially to join said ring and said central portion; said web being substantially thinner than the central portion at the junction of the web and central portion, said web portion extending symmetrically in direction of said bisecting plane and being defined by generally flat surfaces on opposite sides of said bisecting plane, said flat surfaces being of length in direction between the ring and the central portion in relation to the size of the central portion so that the central portion deflection under pressure substantially corresponds to the deflection of a free edge diaphragm.
Claim 3
Dependent Claim
38 words
THe pressure transducer of claim 1 wherein said housing comprises a metal structure, and wherein the ring is welded to the housing to prevent movement of the ring relative to the housing during deflection of said central portion.
Claim 4
Dependent Claim
53 words
The pressure transducer of claim 1 wherein the central portion has a peripheral edge surface, and the major portion of the edge surface of the central portion is substantially perpendicular to the sensing surface of the diaphragm and said edge surface is joined to the flat surfaces of said web with small fillets.
Claim 5
Dependent Claim
73 words
The pressure transducer of claim 1 wherein said surface defining said first capacitor plate is configured to substantially conform to the shape of said diaphragm as said diaphragm is deflected toward said first capacitor plate, said first capacitor plate being spaced from the diaphragm a distance whereby said central portion is supported substantially across its entire sensing surface by said first capacitor plate when said diaphragm is subjected to a preselected maximum pressure.
Claim 6
Dependent Claim
69 words
The pressure transducer of claim 1 wherein said housing is constructed in two sections, said first capacitor plate being positioned on a first housing section, and a second surface of a second housing section defining a second capacitor plate, said diaphragm being mounted to said housing between said first and second capacitor plates, and means to permit subjecting said diaphragm to differentials in pressure on its opposite side surfaces.
Claim 7
Dependent Claim
44 words
The pressure transducer of claim 1 wherein said central portion is circular, and has a diameter D, and said web extends in radial direction between the central portion and said ring a distance L, and wherein the ratio D/L ranges between 6 and 60.
Claim 8
Dependent Claim
48 words
The pressure transducer of claim 6 wherein said web extends in radial direction a distance L, and said web is of a substantially uniform thickness t, and wherein the web is constructed to a proportion whereby the ratio L/T is greater than 0.5 and is less than 5.0.
Claim 9
Dependent Claim
71 words
The pressure transducer of claim 6 wherein the web extends annularly around the central portion and increases in thickness in radially outward direction from a thickness t adjacent the edge of said central portion to a thickness T adjacent said ring and the ratio of T/t is equal to or greater than 1 and is no greater than 4, with T being no greater than the thickness of the central portion.
Claim 10
Dependent Claim
146 words
A pressure transducer having a housing, a diaphragm mounted to be deflected under pressure, means to sense deflection of said diaphragm under pressure; said diaphragm comprising a disc shaped central sensing portion, a peripheral mounting ring fixedly, rigidly mounted on said housing and surrounding said disc shaped central portion, and a web portion extending radially from the central portion and joining said ring and said central portion; said web portion being substantially thinner than the central portion where the web and central portion join and being of length in radial direction between the ring and the central portion in relation to the size of the central portion so that the central portion deflection under pressure substantially corresponds to the deflection of a free edge diaphragm, said web portion being not substantially thinner throughout its radial outward length than it is where it joins said central portion.
Claim 11
Dependent Claim
146 words
A pressure transducer having a housing, a diaphragm mounted to be deflected under pressure, means to sense deflection of said diaphragm under pressure; said diaphragm comprising a disc shaped central sensing portion, a peripheral mounting ring fixedly, rigidly mounted on said housing and surrounding said disc shaped central portion, and a web portion extending radially from the central portion and joining said ring and said central portion; said web portion being substantially thinner than the central portion where the web and central portion join and being of length in radial direction between the ring and the central portion in relation to the size of the central portion so that the central portion deflection under pressure substantially corresponds to the deflection of a free edge diaphragm, said web portion being not substantially thinner throughout its radial outward length than it is where it joins said central portion.
Claim 12
Dependent Claim
24 words
The pressure transducer of claim 9 wherein said web portion increases in thickness in direction radially outwardly from the central portion to the ring.
Claim 13
Dependent Claim
62 words
The combination as specified in claim 9 wherein said disc shaped central sensing portion has a sensing surface, and an annular edge surface substantially perpendicular to said sensing surface, surrounding said disc shaped central portion, and said web portion being defined by substantially planar surfaces, at least one of which joins said edge surface of said central portion with a small fillet.
Claim 14
Dependent Claim
71 words
The combination as specified in claim 9 wherein said disc shaped central sensing portion has at least one sensing surface, and a reference plane parallel to said sensing surface and passing through at least portions of said central portion, said web being defined by a pair of generally radially extending flat surfaces positioned symmetrically with respect to said plane, and extending between said peripheral mounting ring and said central sensing portion.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-25 | 1977-08-27 | 1978-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-25 | 1981-08-27 | 1982-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-25 | 1985-08-27 | 1986-02-26 | $7700.00 | Window Closed / Lapsed |