US4972579A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressure sensor
Assignee: NGK Insulators Ltd
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Filing: 1989-06-21
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Granted: 1990-11-27
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Expires: 2009-06-21
Abstract
Abstract A pressure sensor including a ceramic diaphragm which is deformable in response to a pressure applied thereto, a ceramic base associated with a periphery of the ceramic diaphragm, for supporting the ceramic diaphragm, and at least one resistor formed on the ceramic diaphragm. Resistance values of the resistor are adapted to vary depending upon a magnitude of deformation of the ceramic diaphragm, and thereby represent the pressure applied to the ceramic diaphragm. The ceramic diaphragm and the ceramic base consist of a co-fired body obtained by co-firing an unfired diaphragm member and an unfired base member.
Inventors
- 👤 Yasuhito Yajima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:07
CPC Classifications
G; G01; G01L; G01L9/00; G01L9/0041; G01L9/0051; B; B28; B28B; B28B1/00; B28B1/002; B28B7/00; B28B7/34; B28B7/342; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49082; Y10T29/49103
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
215 words
A method of producing a ceramic pressure sensor, which pressure sensor comprises a ceramic diaphragm deformable in response to a pressure applied thereto, a ceramic base associated with a periphery of the ceramic diaphragm for supporting the ceramic diaphragm, and at least one resistor formed on the ceramic diaphragm, a resistance value of the resistor varying depending upon a magnitude of deformation of the ceramic diaphragm and thereby representing the pressure applied to the ceramic diaphragm, the method comprising the steps of: preparing an unfired ceramic diaphragm member; preparing an unfired ceramic base member; preparing an unfired laminar body by superposing said unfired ceramic diaphragm member on said unfired base member; forming an opening between said unfired diaphragm member and said unfired base member; inserting a sublimable insert into said opening, which insert sublimes during firing of said unfired laminar body; and co-firing said unfired ceramic diaphragm member and said unfired ceramic base member of said unfired laminar body together to form an integral body thereby, said co-fired integral body comprising the diaphragm formed from said unfired ceramic diaphragm member and the base formed from said unfired base member, the diaphragm and the base being integral with each other, wherein said opening defines an internal cavity formed in said co-fired integral body, adjacent the diaphragm.
Claim 2
Independent Claim
215 words
A method of producing a ceramic pressure sensor, which pressure sensor comprises a ceramic diaphragm deformable in response to a pressure applied thereto, a ceramic base associated with a periphery of the ceramic diaphragm for supporting the ceramic diaphragm, and at least one resistor formed on the ceramic diaphragm, a resistance value of the resistor varying depending upon a magnitude of deformation of the ceramic diaphragm and thereby representing the pressure applied to the ceramic diaphragm, the method comprising the steps of: preparing an unfired ceramic diaphragm member; preparing an unfired ceramic base member; preparing an unfired laminar body by superposing said unfired ceramic diaphragm member on said unfired base member; forming an opening between said unfired diaphragm member and said unfired base member; inserting a sublimable insert into said opening, which insert sublimes during firing of said unfired laminar body; and co-firing said unfired ceramic diaphragm member and said unfired ceramic base member of said unfired laminar body together to form an integral body thereby, said co-fired integral body comprising the diaphragm formed from said unfired ceramic diaphragm member and the base formed from said unfired base member, the diaphragm and the base being integral with each other, wherein said opening defines an internal cavity formed in said co-fired integral body, adjacent the diaphragm.
Claim 3
Dependent Claim
19 words
The method of claim 1, further comprising forming the at least one resistor on said unfired ceramic diaphragm member.
Claim 4
Dependent Claim
21 words
The method of claim 1, further comprising forming the at least one resistor on the diaphragm of said co-fired integral body.
Claim 5
Dependent Claim
54 words
The method of claim 1, further comprising: forming a through hole in said unfired base member; and inserting a sublimable insert into said through hole, which insert sublimes during firing of said unfired laminar body, said through hole defining a passage formed in said co-fired integral body, which passage communicates with said internal cavity.
Claim 6
Dependent Claim
43 words
The method of claim 4, further comprising: mixing a sublimable material selected from the group consisting of theobromine, indigo, 1,5-diaminoanthraquinone, hexabromobenzene and naphthacene, with additives including a binder and a plasticizer, to thereby form said insert of said opening and said through hole.
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) | 1993-11-26 | 1994-05-28 | 1994-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-11-26 | 1998-05-28 | 1998-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-11-26 | 2002-05-28 | 2002-11-27 | $7700.00 | Window Closed / Lapsed |