US3894435A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressure sensor
Assignee: Hitachi Ltd
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Filing: 1973-10-25
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Granted: 1975-07-15
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Expires: 1993-10-25
Abstract
Abstract A semiconductor strain gauge is mounted on a cantilever whose free end is moved by a diaphragm or bellows adapted to be displaced by a pressure in a pressure chamber which varies, whereby the semiconductor strain gauge can produce an electric signal in accordance with the pressure. The diaphragm and bellows are constructed such that they produce a counter balancing force which increases in coefficient in accordance with an increase in the amount of its displacement.
Inventors
- 👤 Satoshi Shimada
- 👤 Ichiro Kimura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 16:18
CPC Classifications
G; G01; G01L; G01L13/00; G01L13/02; G01L13/025; F; F02; F02D; F02D3/00; G01L9/00; G01L9/0041; G01L9/0051; G01L9/0052
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
98 words
A pressure sensor comprising two diaphragms differing from each other in effective diameter, a bellows interposed between said two diaphragms, a vacuum chamber defined by said bellows and the smaller diameter diaphragm, a cantilever disposed in said vacuum chamber and adapted to be moved by said two diaphragms, a semiconductor strain gauge producing an electric signal consistent with the strain produced in the surface of the cantilever, an atmospheric pressure chamber exposing one side of the larger diameter diaphRagm to atmosphere, and a chamber exposing the other side of each of said two diaphragms to an engine manifold.
Claim 2
Dependent Claim
98 words
A pressure sensor comprising two diaphragms differing from each other in effective diameter, a bellows interposed between said two diaphragms, a vacuum chamber defined by said bellows and the smaller diameter diaphragm, a cantilever disposed in said vacuum chamber and adapted to be moved by said two diaphragms, a semiconductor strain gauge producing an electric signal consistent with the strain produced in the surface of the cantilever, an atmospheric pressure chamber exposing one side of the larger diameter diaphRagm to atmosphere, and a chamber exposing the other side of each of said two diaphragms to an engine manifold.
Claim 3
Dependent Claim
57 words
A pressure sensor according to claim 1 wherein the diaphragm exposed to atmosphere is adapted to be brought into engagement with a diaphragm stopper when it is displaced, the former being brought into engagement with the latter first at their outer peripheral portions and the area of contact between them gradually extending into their inner peripheral portions.
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) | 1978-07-14 | 1979-01-13 | 1979-07-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-14 | 1983-01-13 | 1983-07-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-14 | 1987-01-13 | 1987-07-15 | $7700.00 | Window Closed / Lapsed |