Patent US4774466A successfully refreshed from Google Patents.
Patent US4251918A successfully refreshed from Google Patents.
US4251918A
Expired / Lapsed
US
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Extensometer
Assignee: Individual
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Filing: 1979-12-03
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Granted: 1981-02-24
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Expires: 1999-12-03
Abstract
Abstract A strain gage extensometer used for measuring uniaxial and biaxial strains in material test specimens. The extensometer is composed of two independent axial strain measuring sensors joined together by a resilient member which is instrumented to provide transverse strain data. All compliant, instrumented members are coupled to the deformations of the specimen, which thus causes strain in the instrumented members which is sensed by suitable strain gages and instruments. A special attachment mechanism is provided by the thin, parallel elements machined into one of the sensors.
Inventors
- 👤 Michael F. Duggan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:32
CPC Classifications
G; G01; G01B; G01B7/00; G01B7/16; G01B7/18
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
249 words
An extensometer for axial and transverse strain measurement of a test specimen comprising, a pair of U-shaped sensor elements each having a pair of parallel arms and a connecting base portion, said elements being secured by said base portions to one side of a single, flat, resilient leaf spring in spaced parallel relation, the free ends of each said arms having cone pointed screw means mounted thereon for contact with a test specimen positioned between the sensor elements, a pair of handle sections secured to the other side of the leaf spring adjacent said base portions, said handle sections and leaf spring acting to provide a clamping force of sufficient energy to cause the pointed screws to contact the specimen with pressure great enough to support the extensometer thereon, one arm of each sensor element comprising a long thin resilient blade having strain gages mounted thereon and adapted for flexing in an axial direction for indicating a deformation of the test specimen in the axial direction, one other arm of one of said sensor elements being rigid in the axial direction and a direction transverse thereto while the other arm of the other sensor element is rigid in the axial direction but compliant in the direction transverse thereto, said last mentioned arm being in the shape of two thin parallel blades, said flat spring having strain gages mounted thereon between the base portions for indicating a deformation of the test specimen in a direction transverse to said axial deformation.
Claim 2
Dependent Claim
249 words
An extensometer for axial and transverse strain measurement of a test specimen comprising, a pair of U-shaped sensor elements each having a pair of parallel arms and a connecting base portion, said elements being secured by said base portions to one side of a single, flat, resilient leaf spring in spaced parallel relation, the free ends of each said arms having cone pointed screw means mounted thereon for contact with a test specimen positioned between the sensor elements, a pair of handle sections secured to the other side of the leaf spring adjacent said base portions, said handle sections and leaf spring acting to provide a clamping force of sufficient energy to cause the pointed screws to contact the specimen with pressure great enough to support the extensometer thereon, one arm of each sensor element comprising a long thin resilient blade having strain gages mounted thereon and adapted for flexing in an axial direction for indicating a deformation of the test specimen in the axial direction, one other arm of one of said sensor elements being rigid in the axial direction and a direction transverse thereto while the other arm of the other sensor element is rigid in the axial direction but compliant in the direction transverse thereto, said last mentioned arm being in the shape of two thin parallel blades, said flat spring having strain gages mounted thereon between the base portions for indicating a deformation of the test specimen in a direction transverse to said axial deformation.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-02-24 | 1984-08-25 | 1985-02-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-24 | 1988-08-25 | 1989-02-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-24 | 1992-08-25 | 1993-02-24 | $7700.00 | Window Closed / Lapsed |