US3675474A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Strain gauges
Assignee: Taylor Woodrow Construction Ltd
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Filing: 1969-03-07
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Granted: 1972-07-11
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Expires: 1989-03-07
Abstract
Abstract A strain gauge incorporating a length of wire maintained under a predetermined tension and an electric magnetic device for plucking the wire at substantially the mid point of its length, the wire being disposed in a hollow spacer tube assembly comprising an outer tube formed of a material such as ebonite which while being longitudinally compressible nevertheless has a lateral stiffness sufficient to withstand forces which may normally be expected to be applied thereto when in use, and an inner tube or liner of brass or other equivalent material made up of at least two axially aligned lengths of tube so arranged that at least one gap or space will be present in the overall length of said inner tube or liner.
Inventors
- 👤 Roger Drury Browne
- 👤 Laurence Henry Mccurrich
- 👤 John David Parkinson
- 👤 Edward Charles Heffer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:42
CPC Classifications
G; G01; G01M; G01M5/00; G01M5/0033; G01L; G01L1/00; G01L1/10; G01M5/0041; G01M5/0066; G01M5/0091
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
159 words
A strain gauge for insertion into a mass of generally low elasticity to measure strain in such mass, comprising; an outer tube formed of a compressible material having a modulus of elasticity comparable to that exhibited by the mass displaced by said tube; a second tube forming a liner disposed within said outer tube, said liner comprising at least two axially aligned tube segments dimensioned to define at least one space along the overall length of the liner, said liner being formed of a metallic material having a generally high modulus of elasticity and degree of compressive strength relative to said outer tube so as to impart a flexural rigidity to the latter; a wire extending coaxially through said assembled outer tube and liner; means for maintaining a predetermined tension on said wire; and an electromagnetic plucking device disposed substantially centrally of said assembled outer tube and liner and adapted upon energization to set up vibrations in said wire.
Claim 2
Dependent Claim
159 words
A strain gauge for insertion into a mass of generally low elasticity to measure strain in such mass, comprising; an outer tube formed of a compressible material having a modulus of elasticity comparable to that exhibited by the mass displaced by said tube; a second tube forming a liner disposed within said outer tube, said liner comprising at least two axially aligned tube segments dimensioned to define at least one space along the overall length of the liner, said liner being formed of a metallic material having a generally high modulus of elasticity and degree of compressive strength relative to said outer tube so as to impart a flexural rigidity to the latter; a wire extending coaxially through said assembled outer tube and liner; means for maintaining a predetermined tension on said wire; and an electromagnetic plucking device disposed substantially centrally of said assembled outer tube and liner and adapted upon energization to set up vibrations in said wire.
Claim 3
Dependent Claim
24 words
A strain gauge as claimed in claim 1, wherein said outer tube is formed of ebonite, and said liner is formed essentially of brass.
Claim 4
Dependent Claim
86 words
A strain gauge as in claim 1 in which the liner comprises three lengths of tube so dimensioNed that when the liner tube parts are in place with the outer end of one part flush with one end of the outer tube and the outer end of a second tube part flush with the opposite end of said outer tube there will be gaps or spaces present between the inner ends of the said two tube parts and the outer ends of a central tube part.
Claim 5
Dependent Claim
18 words
A strain gauge as in claim 1 in which the space is of the order of one-eighth inch.
Claim 6
Dependent Claim
45 words
A strain gauge as in claim 1 in which at each end of the tube assembly a radially extending disc or platen is located, each such disc or platen being fixedly attached to or formed integrally with a part of the liner or inner tube.
Claim 7
Dependent Claim
23 words
A strain gauge as in claim 5 in which each disc or platen incorporates or supports clamping means adapted to grip the wire.
Claim 8
Dependent Claim
20 words
A strain gauge as in claim 1 in which the outer surface of the outer tube is grooved or ribbed.
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) | 1975-07-11 | 1976-01-10 | 1976-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-11 | 1980-01-10 | 1980-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-11 | 1984-01-10 | 1984-07-11 | $7700.00 | Window Closed / Lapsed |