US3729829A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Double cantilever split-pin displacement gage
Assignee: United States Department of the Navy
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Filing: 1971-10-22
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Granted: 1973-05-01
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Expires: 1991-10-22
Abstract
Abstract This disclosure is directed to a double cantilever split-pin displacement gage for measuring small displacements such as the opening of a crack in a test specimen. The device is provided with two legs of a particular shape to which strain gages and a half section of a split-pin have been secured. The split-pin halves are formed with cylindrical end probes which are inserted into a hole drilled into a test specimen and as the test specimen separates the strain gages will produce an appropriate electrical signal to indicate the displacement of the separation due to movement of the split-pins in the hole.
Inventors
- 👤 E Lange
- 👤 R Bryner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 10:28
CPC Classifications
G; G01; G01B; G01B7/00; G01B7/16; G01B7/18; G01L; G01L5/00; G01L5/0057; Y; Y10; Y10S; Y10S33/00; Y10S33/13
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
159 words
An improved device for measuring a small displacement between opposite surfaces; which comprises: a pair of resilient arms secured together at one end and separated by a spacer, each of said arms having upper and lower end portions bent in opposite directions at an angle with respect to a central portion, a pair of strain gages secured on opposing faces directly opposite each other on each of said pair of arms and centered on the bend in the upper end of said arms near the end portions which are secured together, a probe secured to each of the arms at the unsecured ends of the arms, said probes including a small end portion for minimum contact of the surfaces whose displacement are to be measured, whereby said probes are substantially in parallel when said arms are forced together under tension and said strain gages are flexed by bending movement of said arms at the upper bend in said arms.
Claim 2
Dependent Claim
159 words
An improved device for measuring a small displacement between opposite surfaces; which comprises: a pair of resilient arms secured together at one end and separated by a spacer, each of said arms having upper and lower end portions bent in opposite directions at an angle with respect to a central portion, a pair of strain gages secured on opposing faces directly opposite each other on each of said pair of arms and centered on the bend in the upper end of said arms near the end portions which are secured together, a probe secured to each of the arms at the unsecured ends of the arms, said probes including a small end portion for minimum contact of the surfaces whose displacement are to be measured, whereby said probes are substantially in parallel when said arms are forced together under tension and said strain gages are flexed by bending movement of said arms at the upper bend in said arms.
Claim 3
Dependent Claim
31 words
A device as claimed in claim 1; wherein: said smaller end portion of each of said probes have rounded surfaces which engage the opposite surfaces whose displacement are to be measured.
Claim 4
Dependent Claim
23 words
A device as claimed in claim 2; wherein: said small end portions of said probes have a combined diameter of about one-eighth inch.
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) | 1976-04-30 | 1976-10-30 | 1977-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-30 | 1980-10-30 | 1981-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-30 | 1984-10-30 | 1985-05-01 | $7700.00 | Window Closed / Lapsed |