US3657928A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Angular velocity and acceleration measuring apparatus
Assignee: National Aeronautics and Space Administration
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Filing: 1970-06-11
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Granted: 1972-04-25
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Expires: 1990-06-11
Abstract
Abstract Disclosed is a combined angular velocimeter and accelerometer formed by a film of cholesteric phase liquid crystalline material retained between rotary and stationary discs. Shear-stress exerted on the liquid crystalline film by movement of the rotary disc changes the initial uniform coloration into either differently colored bands or colorless bands that are observed through the transparent stationary disc. The radii of the colored or colorless rings are proportional to the rotation rate while the radial velocity of the band of rings is proportional to the angular acceleration.
Inventors
- 👤 Louis Melamed
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 00:59
CPC Classifications
G; G01; G01P; G01P15/00; G01P3/00; G01P3/02; G01P3/24
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
115 words
Angular movement measurement apparatus comprising: a. base means, b. a circular rotatable disc mounted for rotation on said base means, c. a circular stationary disc of transparent material spaced from said circular rotatable disc, d. support means restraining said stationary disc to said base means, and e. a disc of cholesteric phase liquid-crystalline material filling the space between said stationary and rotatable discs, said liquid-crystalline material contacting both said stationary and rotatable discs so as to be subjected to sheer stress in response to rotation of said rotatable disc, said liquid-crystalline material having a sheer stress threshold value which when exceeded causes said material to change color thereby indicating angular movement of said rotatable disc.
Claim 2
Dependent Claim
115 words
Angular movement measurement apparatus comprising: a. base means, b. a circular rotatable disc mounted for rotation on said base means, c. a circular stationary disc of transparent material spaced from said circular rotatable disc, d. support means restraining said stationary disc to said base means, and e. a disc of cholesteric phase liquid-crystalline material filling the space between said stationary and rotatable discs, said liquid-crystalline material contacting both said stationary and rotatable discs so as to be subjected to sheer stress in response to rotation of said rotatable disc, said liquid-crystalline material having a sheer stress threshold value which when exceeded causes said material to change color thereby indicating angular movement of said rotatable disc.
Claim 3
Dependent Claim
28 words
Angular movement measurement apparatus according to claim 1 including coupling means for coupling said rotatable element to an object, the angular motion of which is to be measured.
Claim 4
Dependent Claim
36 words
Angular movement measurement apparatus according to claim 1 wherein the adjacent surfaces of said stationary and rotatable discs are planar, and including an annular spacer between said planar surfaces forming a reservoir for said liquid-crystalline material.
Claim 5
Dependent Claim
30 words
Angular movement measurement apparatus according to claim 3 wherein one surface of said rotatable disc is darkened to provide a high contrast background for color changes in said liquid-crystalline material.
Claim 6
Dependent Claim
20 words
Angular movement measurement apparatus according to claim 1 including graduated measurement indicia disposed along a surface of said liquid-crystalline material.
Claim 7
Dependent Claim
21 words
Angular movement measurement apparatus according to claim 5 wherein said measurement indicia are disposed on a surface of said stationary disc.
Claim 8
Dependent Claim
19 words
Angular movement measurement apparatus according to claim 6 wherein said measurement indicia comprise concentric circles on said stationary disc.
Claim 9
Dependent Claim
36 words
Angular movement measurement apparatus according to claim 7 wherein the adjacent surfaces of said stationary and rotatable discs are planar, and including an annular spacer between said planar surfaces forming a reservoir for said liquid-crystalline material.
Claim 10
Dependent Claim
30 words
Angular movement measurement apparatus according to claim 8 wherein one surface of said rotatable disc is darkened to provide a high contrast background for color changes in said liquid-crystalline material.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-04-25 | 1975-10-25 | 1976-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-25 | 1979-10-25 | 1980-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-25 | 1983-10-25 | 1984-04-25 | $7700.00 | Window Closed / Lapsed |