US4435986A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressure transducer of the vibrating element type
Assignee: Centre Electronique Horloger SA
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Filing: 1981-11-09
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Granted: 1984-03-13
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Expires: 2001-11-09
Abstract
Abstract 44A pressure transducer which uses the principle of a variation in the resonance frequency of a membrane when it is subjected to a variable pressure. The transducer comprises a vibrating membrane which is fixed on a support member forming a cavity, and a cover member forming a second cavity. Excitation of the membrane is facilitated since it is made of a piezoelectric material and is provided with electrodes. An object of the invention is to provide a digital output pressure transducer which can be minaturized and which has low power consumption.
Inventors
- 👤 Hubert Choffat
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:36
CPC Classifications
G; G01; G01L; G01L9/00; G01L9/0001; G01L9/0008; G01L9/0016; G01L9/0022
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
74 words
A pressure transducer comprising a vibrating membrane which comprises a reduced-thickness bottom of a cavity in a first member which is fixed on and closed by a support member forming a first cavity, the vibrating membrane at least partially comprising a piezoelectric material and having a curvature therein, and means for exciting the membrane and maintaining oscillations of the membrane at its resonance frequency and for producing an electrical signal at that resonance frequency.
Claim 2
Dependent Claim
74 words
A pressure transducer comprising a vibrating membrane which comprises a reduced-thickness bottom of a cavity in a first member which is fixed on and closed by a support member forming a first cavity, the vibrating membrane at least partially comprising a piezoelectric material and having a curvature therein, and means for exciting the membrane and maintaining oscillations of the membrane at its resonance frequency and for producing an electrical signal at that resonance frequency.
Claim 3
Dependent Claim
26 words
A pressure transducer according to claim 1, which the curvature in the membrane is produced by different pressures on the two respective sides of the membrane.
Claim 4
Dependent Claim
20 words
A transducer according to claim 1, further comprising a cover member which, with the vibrating membrane, forms a second cavity.
Claim 5
Dependent Claim
24 words
A pressure transducer according to claim 3, wherein the cover member comprises means for absorbing acoustic waves produced by oscillation of the vibrating membrane.
Claim 6
Dependent Claim
36 words
A pressure transducer according to claim 1, wherein the vibrating membrane is integrally formed by a piezoelectric material and on its faces carries electrodes capable of permitting oscillations of the membrane outside the normal plane thereof.
Claim 7
Dependent Claim
22 words
A pressure transducer according to claim 5, wherein the support member is made of the same piezoelectric material as the vibrating membrane.
Claim 8
Dependent Claim
38 words
A pressure transducer according to claim 5 or 6, further comprising a cover member which with the vibrating membrane forms a second cavity, wherein the cover member is made of the same piezoelectric material as the vibrating membrane.
Claim 9
Dependent Claim
42 words
A pressure transducer according to any of the claims 1 to 4, wherein the membrane is formed by an elastic substrate and by a portion comprising piezoelectric material, carrying at least one electrode, with another electrode being integral with the elastic substrate.
Claim 10
Dependent Claim
20 words
A pressure transducer according to claim 8, wherein the portion comprising piezoelectric material is vapor deposited on the elastic substrate.
Claim 11
Dependent Claim
24 words
A pressure transducer according to claim 8, wherein the portion comprising piezoelectric material is a pellet of piezoelectric material secured to the elastic substrate.
Claim 12
Dependent Claim
22 words
A pressure transducer according to claim 10, wherein the pellet of piezoelectric material is of substantially smaller area than the elastic substrate.
Claim 13
Dependent Claim
32 words
A pressure transducer according to any of the claims 1 to 6, wherein the vibrating membrane is fixed on the support member in such a way as normally to have a curvature.
Claim 14
Dependent Claim
24 words
A pressure transducer according to any of claims 1 to 6, wherein the membrane per se has a curvature in its normal, unexcited state.
Claim 15
Dependent Claim
29 words
A pressure transducer according to any one of claims 1 to 6, wherein the first cavity is filled by a gas at a given pressure and is hermetically closed.
References Cited (Backward Citations)
US3745384A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-03-13 | 1987-09-12 | 1988-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-13 | 1991-09-12 | 1992-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-13 | 1995-09-12 | 1996-03-13 | $7700.00 | Window Closed / Lapsed |