US4860587A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stress gauge
Assignee: Individual
•
Filing: 1988-05-31
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Granted: 1989-08-29
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Expires: 2008-05-31
Abstract
Abstract This invention is a stress gauge whose components include a piezoresistive sensor embedded in epoxy, a flatjack, and a housing for the sensor and flatjack. The preferred piezoresistive sensor is ytterbium because of its sensitivity to pressures in the range of interest. This arrangement allows the gauge sensing element to be calibrated at the place of measurement. That calibration is provided by a well controlled uniaxial load applied to the gauge to test the gauge response. Upon removal of the applied load, the gauge can continue to measure the stress history of the surrounding medium.
Inventors
- 👤 Carl E. Keller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:34
CPC Classifications
G; G01; G01L; G01L25/00
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
93 words
An electrical stress gauge comprising: a. a stress sensor material which generates a voltage proportional to applied stress; b. electrical insulating means surrounding said sensor; c. a closed housing surrounding said sensor and insulating means; d. a flat jack positioned with said housing and overlying said sensor in closely spaced parallel relation, thereto, e. conduit means extending through said housing and affording connection of a source of pressurized fluid to said flat jack for uniaxial loading of said sensor; and f. conductive means extending through said housing affording electrical connection to said sensor.
Claim 2
Dependent Claim
93 words
An electrical stress gauge comprising: a. a stress sensor material which generates a voltage proportional to applied stress; b. electrical insulating means surrounding said sensor; c. a closed housing surrounding said sensor and insulating means; d. a flat jack positioned with said housing and overlying said sensor in closely spaced parallel relation, thereto, e. conduit means extending through said housing and affording connection of a source of pressurized fluid to said flat jack for uniaxial loading of said sensor; and f. conductive means extending through said housing affording electrical connection to said sensor.
Claim 3
Dependent Claim
20 words
A stress gauge as defined by claim 1 in which said housing permits only a uniaxial load on said sensor.
References Cited (Backward Citations)
US4377185A
Cited
US4542655A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-08-28 | 1993-02-27 | 1993-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-08-28 | 1997-02-27 | 1997-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-08-28 | 2001-02-27 | 2001-08-29 | $7700.00 | Window Closed / Lapsed |