US3714824A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for measuring skin friction
Assignee: United States Department of the Army
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Filing: 1970-12-21
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Granted: 1973-02-06
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Expires: 1990-12-21
Abstract
Abstract A RING SHAPED ELEMENT IS PLACED IN THE PATH OF FLOWING FLUID. Gravity holds the element down until skin frictional forces of the flowing fluid lift it off its seat. At the point of lift-off the precise degree of skin friction is known.
Inventors
- 👤 C Bush
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 10:50
CPC Classifications
G; G01; G01N; G01N13/00
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
127 words
Skin friction measuring apparatus comprising an upright nozzle to conduct a fluid stream therethrough in an upwardly direction, an extension ring loosely seated on top of said nozzle, the inner width of said extension ring being substantially the same as the inner width of the tip of said nozzle, said extension ring remaining seated on top of said nozzle by gravity until the skin frictional force exerted by the fluid stream on the inner surface of said extension ring becomes great enough to lift off said extension ring from the top of said nozzle, and electrical make and break means mounted on said nozzle and said extension ring for actuating an electrical signal when said extension ring is lifted from said nozzle by said skin frictional force.
Claim 2
Dependent Claim
127 words
Skin friction measuring apparatus comprising an upright nozzle to conduct a fluid stream therethrough in an upwardly direction, an extension ring loosely seated on top of said nozzle, the inner width of said extension ring being substantially the same as the inner width of the tip of said nozzle, said extension ring remaining seated on top of said nozzle by gravity until the skin frictional force exerted by the fluid stream on the inner surface of said extension ring becomes great enough to lift off said extension ring from the top of said nozzle, and electrical make and break means mounted on said nozzle and said extension ring for actuating an electrical signal when said extension ring is lifted from said nozzle by said skin frictional force.
Claim 3
Dependent Claim
127 words
Skin friction measuring apparatus comprising an upright nozzle to conduct a fluid stream therethrough in an upwardly direction, an extension ring loosely seated on top of said nozzle, the inner width of said extension ring being substantially the same as the inner width of the tip of said nozzle, said extension ring remaining seated on top of said nozzle by gravity until the skin frictional force exerted by the fluid stream on the inner surface of said extension ring becomes great enough to lift off said extension ring from the top of said nozzle, and electrical make and break means mounted on said nozzle and said extension ring for actuating an electrical signal when said extension ring is lifted from said nozzle by said skin frictional force.
Claim 4
Dependent Claim
127 words
Skin friction measuring apparatus comprising an upright nozzle to conduct a fluid stream therethrough in an upwardly direction, an extension ring loosely seated on top of said nozzle, the inner width of said extension ring being substantially the same as the inner width of the tip of said nozzle, said extension ring remaining seated on top of said nozzle by gravity until the skin frictional force exerted by the fluid stream on the inner surface of said extension ring becomes great enough to lift off said extension ring from the top of said nozzle, and electrical make and break means mounted on said nozzle and said extension ring for actuating an electrical signal when said extension ring is lifted from said nozzle by said skin frictional force.
Claim 5
Dependent Claim
16 words
Apparatus as in claim 1, wherein said nozzle extension ring has a sharp circular top edge.
Claim 6
Dependent Claim
16 words
Apparatus according to claim 1, wherein the mouth of said nozzle has a sharp circular edge.
Claim 7
Dependent Claim
16 words
Apparatus according to claim 3, wherein said nozzle extension ring has a sharp circular top edge.
Claim 8
Dependent Claim
13 words
Apparatus according to claim 1, wherein said signal is a lighted electric lamp.
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) | 1976-02-06 | 1976-08-07 | 1977-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-06 | 1980-08-07 | 1981-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-06 | 1984-08-07 | 1985-02-06 | $7700.00 | Window Closed / Lapsed |