US3793737A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-timed reaction-mass compass
Assignee: Individual
•
Filing: 1970-10-09
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Granted: 1974-02-26
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Expires: 1990-10-09
Abstract
Abstract Two horizontal discs of identical mass and dimensions are rotated in opposite directions at identical and fixed speed. Each disc is pierced by a radial slot. Coincidence of said slots provides an index spot on a compass card. Said coincidence is independent of the device support and holds its direction in space despite support movement and rotation. The discs may be rotated by any means. A counter may be employed to read out the slot-coincidence position in degrees relative to any fixed angular position about the axis of said discs.
Inventors
- 👤 M Alth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:14
CPC Classifications
G; G01; G01C; G01C17/00
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
116 words
A compass as claimed in claim 1, further comprising a steady source of light in fixed position relative to the case beneath the lower of said discs; a photo1cell in fixed position between the discs; a plurality of photo-cells in fixed position above the upper one of said discs; bands shielding said plurality of photo-cells from light other than that which may come up from below; and an electronic counter connected to said alternating current source; and said photo-cell between the discs and said plurality of photo-cells above the discs being suitably connected to said electronic counter so that said photo cell between the discs initiates counting and said plurality of photo cells stops the counting.
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) | 1977-02-25 | 1977-08-27 | 1978-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-25 | 1981-08-27 | 1982-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-25 | 1985-08-27 | 1986-02-26 | $7700.00 | Window Closed / Lapsed |