Patent US4289036A successfully refreshed from Google Patents.
US4289036A
Expired / Lapsed
US
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Gauge for measuring the mouth opening displacement of fracture toughness test specimens
Assignee: Terra Tek Inc
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Filing: 1980-03-24
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Granted: 1981-09-15
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Expires: 2000-03-24
Abstract
Abstract The gauge of the present invention consists of a three-pronged spring clip for arrangement between the grips of a conventional grip-loading fracture specimen loading machine, which grips are inserted into the mouth of a standard slotted fracture toughness test specimen, the gauge to monitor the specimen mouth opening displacement thereof during a test for fracture toughness. The spring clip preferably is formed from a single sheet of material that is bent appropriately to produce two aligned legs or prongs with a center leg or prong there between. In operation the outside prongs are essentially stationary while the center prong is arranged to flex with respect to grip movement apart, which center movement is sensed electrically by a strain gauge secured thereto at its point of bending.
Inventors
- 👤 Lynn M. Barker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 17:51
CPC Classifications
G; G01; G01N; G01N3/00; G01N3/02; G01L; G01L1/00; G01L1/20; G01L1/22; G01L1/2206; G01N2203/00; G01N2203/0058; G01N2203/006; G01N2203/0062; G01N2203/0066; G01N2203/02; G01N2203/026; G01N2203/0262; G01N2203/027; G01N2203/06; G01N2203/0617; G01N2203/067; G01N2203/0682
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
106 words
A gauge for measuring the mouth opening displacement of fracture toughness test specimens consisting of, a clip gauge formed from a single sheet of suitable material that is cut and bent appropriately to form a base wherefrom center and outside prongs extend in essentially parallel planes; means secured to the prong ends opposite to said base for directly engaging opposite slot faces across a test specimen mouth; strain gauge means secured to said center prong so as to sense flexure thereof as a change in electrical resistance; and means, connected to said strain gauge means, for translating changes in electrical resistance to specimen mouth opening displacement.
Claim 2
Dependent Claim
106 words
A gauge for measuring the mouth opening displacement of fracture toughness test specimens consisting of, a clip gauge formed from a single sheet of suitable material that is cut and bent appropriately to form a base wherefrom center and outside prongs extend in essentially parallel planes; means secured to the prong ends opposite to said base for directly engaging opposite slot faces across a test specimen mouth; strain gauge means secured to said center prong so as to sense flexure thereof as a change in electrical resistance; and means, connected to said strain gauge means, for translating changes in electrical resistance to specimen mouth opening displacement.
Claim 3
Dependent Claim
92 words
A gauge as recited in claim 1, wherein, the clip gauge is formed to include two outside prongs with a single center prong arranged to flex therebetween, which outside and center prongs are bent and twisted appropriately to present surfaces that resist bending thereacross such that movement at said prong ends causes bending in an area of said center prong proximate to its connection to said base; and the strain gauge means is secured to said center prong in said area of said center prong proximate to its connection to said base.
Claim 4
Dependent Claim
23 words
A gauge as recited in claim 1, wherein the means secured to the outside and center prong ends are oppositely facing barbed ends.
Claim 5
Dependent Claim
55 words
A gauge as recited in claim 1, wherein the means for translating changes in electrical resistance to specimen mouth opening displacement include means for conditioning said change in resistance to operate a movement of a meter; and a meter operated by said conditioned change in resistance to provide a display of said specimen mouth opening.
References Cited (Backward Citations)
US1557341A
Cited
US4003246A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-09-14 | 1985-03-16 | 1985-09-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-09-14 | 1989-03-16 | 1989-09-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-09-14 | 1993-03-16 | 1993-09-15 | $7700.00 | Window Closed / Lapsed |