US3577883A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Capacitive strain sensor
Assignee: Emerson Process Management Ltd
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Filing: 1969-06-26
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Granted: 1971-05-11
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Expires: 1989-06-26
Abstract
Abstract A method of measuring strain wherein a metal rod is mounted transversely within a cylindrical test hole in a metal structure. A spaced relation is maintained between the rod ends and hole surface and changes in electrical capacitance between the rod and the structure are indicative of strains in the test structure.
Inventors
- 👤 Frank D Werner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:15
CPC Classifications
G; G01; G01L; G01L1/00; G01L1/14
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
93 words
A method of measuring strain along a first predetermined axis in a test structure comprising the steps of making a hole defined by a metallic surface in the structure, said hole extending along a second axis transverse to the first axis, mounting capacitive sensing rod means to position its axis transverse to said second axis within the hole in position with the rod ends closely spaced from the metallic surface, and measuring the capacitive change between the ends of said rod means and the metallic surface when said structure is subjected to strain.
Claim 2
Independent Claim
93 words
A method of measuring strain along a first predetermined axis in a test structure comprising the steps of making a hole defined by a metallic surface in the structure, said hole extending along a second axis transverse to the first axis, mounting capacitive sensing rod means to position its axis transverse to said second axis within the hole in position with the rod ends closely spaced from the metallic surface, and measuring the capacitive change between the ends of said rod means and the metallic surface when said structure is subjected to strain.
Claim 3
Independent Claim
101 words
A method of determining strains in an operating structure having a wall that is subjected to strains in use comprising the steps of making a hole directly in the wall of said structure, said hole being defined by a metallic side surface defined about an axis, placing a rodlike electrical capacitance sensing element in said hole transverse to said axis and having end portions closely spaced from the side surface at spaced locations along said side surface, and measuring capacitive changes between the side surface defining said hole and the end portions of said element when said structure is in use.
Claim 4
Independent Claim
101 words
A method of determining strains in an operating structure having a wall that is subjected to strains in use comprising the steps of making a hole directly in the wall of said structure, said hole being defined by a metallic side surface defined about an axis, placing a rodlike electrical capacitance sensing element in said hole transverse to said axis and having end portions closely spaced from the side surface at spaced locations along said side surface, and measuring capacitive changes between the side surface defining said hole and the end portions of said element when said structure is in use.
Claim 5
Independent Claim
138 words
The method of determining the strain in a structure in which the strain is to be measured comprising the steps of forming a hole within the structure opening to an outer surface of said structure, said hole being defined by a metal side surface generated about an axis and having a bottom wall opposite from the opening of said hole, positioning a rodlike conductive element within the confines of said hole with end-sensing surfaces of said element closely spaced from the side surface of said hole at spaced locations along said side surface, and substantially spaced from the bottom wall of said hole, and measuring the capacitive changes between the end surfaces of said element and the side surface of said opening when said structure is subjected to strain in direction transverse to the axis of said hole.
Claim 6
Independent Claim
138 words
The method of determining the strain in a structure in which the strain is to be measured comprising the steps of forming a hole within the structure opening to an outer surface of said structure, said hole being defined by a metal side surface generated about an axis and having a bottom wall opposite from the opening of said hole, positioning a rodlike conductive element within the confines of said hole with end-sensing surfaces of said element closely spaced from the side surface of said hole at spaced locations along said side surface, and substantially spaced from the bottom wall of said hole, and measuring the capacitive changes between the end surfaces of said element and the side surface of said opening when said structure is subjected to strain in direction transverse to the axis of said 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) | 1974-05-10 | 1974-11-09 | 1975-05-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-10 | 1978-11-09 | 1979-05-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-10 | 1982-11-09 | 1983-05-11 | $7700.00 | Window Closed / Lapsed |