US4903164A
Expired / Lapsed
US
⏱️ 0.0 years remaining
O-ring/back-up ring seal for high pressure transducers
Assignee: Sensata Technologies Inc
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Filing: 1989-06-13
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Granted: 1990-02-20
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Expires: 2009-06-13
Abstract
Abstract A pressure transducer having a pressure sensing surface spaced from an interior surface of the transducer housing by a relatively rigid back-up ring which contacts each of the pressure sensing surface, the interior surface of the housing and an interior side wall of the housing. A relatively less rigid O-ring is disposed between the pressure sensing surface and the interior surface of the housing and contacts the back-up ring, the back-up ring and the O-ring providing sealing of the pressure cavity. The O-ring communicates with the fluid entering the housing via an inlet in the housing. Because the output of the pressure sensing element is affected by the loading of the O-ring and back-up ring, and because this loading changes over time, mainly due to cold flow, compression set, etc.), several special procedures are provided during manufacture and before calibration of the transducers to minimize this problem to avoid calibration change (drift) over time, these being conditioning or burning in prior to calibration. This is accomplished by an extended high temperature soak through a series of pressure cycles or overpressure cycles or a combination thereof and permits the back-up ring and the O-ring to be relieved of stresses so that they will be stable over time.
Inventors
- 👤 Robert P. Bishop
- 👤 Herman Purut
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 22:17
CPC Classifications
G; G01; G01L; G01L19/00; G01L19/14; G01L19/142; G01L19/143; G01L19/0007; G01L19/0038; G01L9/00; G01L9/0041; G01L9/0072; G01L9/0075; Y; Y10; Y10T; Y10T29/00; Y10T29/43; Y10T29/435
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
138 words
A pressure transducer which comprises, in combination: (a) a housing having a high pressure fluid inlet; (b) a pressure sensing element having a pressure responsive surface communicating with said fluid inlet and disposed within said housing to form a pressure cavity with said housing within said housing; (c) a relatively rigid member disposed within said pressure cavity and contacting said housing and said pressure responsive surface; and (d) a relatively less rigid O-ring contacting said relatively rigid member, said housing and said pressure responsive surface, disposed within said housing and communicating with said fluid inlet to define a surface of said pressure cavity and provide a seal among said rigid member, said housing and said pressure responsive surface; (e) said relatively rigid member minimizing extrusion of said seal into gaps caused by the tolerances on the transducer parts.
Claim 2
Dependent Claim
138 words
A pressure transducer which comprises, in combination: (a) a housing having a high pressure fluid inlet; (b) a pressure sensing element having a pressure responsive surface communicating with said fluid inlet and disposed within said housing to form a pressure cavity with said housing within said housing; (c) a relatively rigid member disposed within said pressure cavity and contacting said housing and said pressure responsive surface; and (d) a relatively less rigid O-ring contacting said relatively rigid member, said housing and said pressure responsive surface, disposed within said housing and communicating with said fluid inlet to define a surface of said pressure cavity and provide a seal among said rigid member, said housing and said pressure responsive surface; (e) said relatively rigid member minimizing extrusion of said seal into gaps caused by the tolerances on the transducer parts.
Claim 3
Dependent Claim
47 words
A pressure transducer as set forth in claim 1 wherein said housing further includes an interior surface defining a surface of said pressure cavity, spaced from said pressure responsive surface and communicating with said fluid inlet, said relatively rigid member and said O-ring contacting said interior surface.
Claim 4
Dependent Claim
21 words
A pressure transducer as set forth in claim 2 wherein said interior surface is substantially parallel to said pressure responsive surface.
Claim 5
Dependent Claim
37 words
A pressure transducer as set forth in claim 3 wherein said rigid member is formed from a material taken from the class consisting of polytetrafluoroethylene and nylon and said O-ring is formed from a relatively softer material.
Claim 6
Dependent Claim
37 words
A pressure transducer as set forth in claim 2 wherein said rigid member is formed from a material taken from the class consisting of polytetrafluoroethylene and nylon and said O-ring is formed from a relatively softer material.
Claim 7
Dependent Claim
37 words
A pressure transducer as set forth in claim 1 wherein said rigid member is formed from a material taken from the class consisting of polytetrafluoroethylene and nylon and said O-ring is formed from a relatively softer material.
Claim 8
Independent Claim
103 words
A method of making a pressure transducer which comprises the steps of: (a) providing a housing having a high pressure fluid inlet; (b) providing a pressure sensing element having a pressure responsive surface communicating with said fluid inlet and disposed within said housing; (c) providing a relatively rigid member disposed within said housing and contacting said housing and said pressure responsive surface; (d) providing a relatively less rigid O-ring contacting said relatively rigid member, said housing and said pressure responsive surface, disposed within said housing and communicating with said fluid inlet; and (e) relieving stresses in said rigid member and in said O-ring.
Claim 9
Independent Claim
103 words
A method of making a pressure transducer which comprises the steps of: (a) providing a housing having a high pressure fluid inlet; (b) providing a pressure sensing element having a pressure responsive surface communicating with said fluid inlet and disposed within said housing; (c) providing a relatively rigid member disposed within said housing and contacting said housing and said pressure responsive surface; (d) providing a relatively less rigid O-ring contacting said relatively rigid member, said housing and said pressure responsive surface, disposed within said housing and communicating with said fluid inlet; and (e) relieving stresses in said rigid member and in said O-ring.
Claim 10
Dependent Claim
25 words
The method of claim 7 wherein step (e) includes the step of subjecting said rigid member and said O-ring to an extended high temperature soak.
Claim 11
Dependent Claim
25 words
The method of claim 8 wherein step (e) includes the step of subjecting said rigid member and said O-ring to a plurality of pressure cycles.
Claim 12
Dependent Claim
35 words
The method of claim 9 wherein said housing includes an interior surface spaced from said pressure responsive surface and communicating with said fluid inlet, said relatively rigid member and said O-ring contacting said interior surface.
Claim 13
Dependent Claim
17 words
The method of claim 10 wherein said interior surface is substantially parallel to said pressure responsive surface.
Claim 14
Dependent Claim
55 words
The method of claim 9 wherein said soak is at a temperature of from about 135 to about 150° C. for from about 24 to about 48 hours and said pressure cycles are from about zero to about 2500 to about 3500 psi for about forty thousand cycles at a frequency of about two Hertz.
Claim 15
Dependent Claim
35 words
The method of claim 8 wherein said housing includes an interior surface spaced from said pressure responsive surface and communicating with said fluid inlet, said relatively rigid member and said O-ring contacting said interior surface.
Claim 16
Dependent Claim
17 words
The method of claim 13 wherein said interior surface is substantially parallel to said pressure responsive surface.
Claim 17
Dependent Claim
28 words
The method of claim 8 wherein said soak is at a temperature of from about 135 to about 150° C. for from about 24 to about 48 hours.
Claim 18
Dependent Claim
25 words
The method of claim 7 wherein step (e) includes the step of subjecting said rigid member and said O-ring to a plurality of pressure cycles.
Claim 19
Dependent Claim
35 words
The method of claim 16 wherein said housing includes an interior surface spaced from said pressure responsive surface and communicating with said fluid inlet, said relatively rigid member and said O-ring contacting said interior surface.
Claim 20
Dependent Claim
17 words
The method of claim 17 wherein said interior surface is substantially parallel to said pressure responsive surface.
Claim 21
Dependent Claim
32 words
The method of claim 16 wherein said pressure cycles are from about zero to about 2500 to about 3500 psi for about forty thousand cycles at a frequency of about two Hertz.
Claim 22
Dependent Claim
35 words
The method of claim 7 wherein said housing includes an interior surface spaced from said pressure responsive surface and communicating with said fluid inlet, said relatively rigid member and said O-ring contacting said interior surface.
Claim 23
Dependent Claim
17 words
The method of claim 20 wherein said interior surface is substantially parallel to said pressure responsive surface.
References Cited (Backward Citations)
US4716492A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-02-19 | 1993-08-21 | 1994-02-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-02-19 | 1997-08-21 | 1998-02-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-02-19 | 2001-08-21 | 2002-02-20 | $7700.00 | Window Closed / Lapsed |