US3875773A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dual control lock
Assignee: HUDSON LOCK Inc
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Filing: 1973-09-05
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Granted: 1975-04-08
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Expires: 1993-09-05
Abstract
Abstract Disclosed is a lock comprising a housing that defines on its inner surface a primary spline and, generally parallel thereto, a secondary spline. A trapping spline is also defined on the inner surface. A plug, defining a keyway, is rotatably retained in the housing. A primary tumbler projects from the plug and interacts with the primary spline to selectively retain the lock in an unlocked position and interacts with the secondary spline to selectively retain the lock in a locked position. Furthermore, a trapping tumbler projects from the plug and selectively retains the plug in the locked position by interacting with the trapping spline. The trapping tumbler does not interact with the primary spline or the secondary spline. Two keys are supplied. One operates only the primary tumbler and the other operates the primary and trapping tumblers.
Inventors
- 👤 Robert P Thimot
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 12:42
CPC Classifications
E; E05; E05B; E05B29/00; Y; Y10; Y10T; Y10T70/00; Y10T70/70; Y10T70/7441; Y10T70/7446; Y10T70/7458; Y10T70/7486; Y10T70/7508; Y10T70/7559; Y10T70/7588; Y10T70/7593; Y10T70/7599
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
198 words
A lock apparatus comprising: housing means defining, on an inner surface thereof, primary spline means and secondary spline means substantially parallel thereto and further defining trapping spline means; plug means rotatably retained in said housing, said plug means defining a keyway therethrough; a primary tumbler for releasably restraining said plug means in an unlocked position with said primary tumbler interacting with said primary spline means, and for releasably restraining said plug means in a locked position with said primary tumbler interacting with said secondary spline means and wherein said primary tumbler is releasable by a primary key to allow rotation of said plug from said unlocked to said locked position; and a trapping tumbler non-responsive to the primary key and engageable with said trapping spline means to releasably trap said plug means in the locked position so as to prevent rotation thereof, both said primary tumbler and said trapping tumbler being releasable by an auxiliary key so as to permit rotation of said plug to said unlocked position, and wherein said trapping tumbler is disposed so as not to engage said primary spline means or said secondary spline means during plug rotation between said locked and unlocked positions.
Claim 2
Dependent Claim
198 words
A lock apparatus comprising: housing means defining, on an inner surface thereof, primary spline means and secondary spline means substantially parallel thereto and further defining trapping spline means; plug means rotatably retained in said housing, said plug means defining a keyway therethrough; a primary tumbler for releasably restraining said plug means in an unlocked position with said primary tumbler interacting with said primary spline means, and for releasably restraining said plug means in a locked position with said primary tumbler interacting with said secondary spline means and wherein said primary tumbler is releasable by a primary key to allow rotation of said plug from said unlocked to said locked position; and a trapping tumbler non-responsive to the primary key and engageable with said trapping spline means to releasably trap said plug means in the locked position so as to prevent rotation thereof, both said primary tumbler and said trapping tumbler being releasable by an auxiliary key so as to permit rotation of said plug to said unlocked position, and wherein said trapping tumbler is disposed so as not to engage said primary spline means or said secondary spline means during plug rotation between said locked and unlocked positions.
Claim 3
Dependent Claim
22 words
A lock apparatus according to claim 1 wherein said secondary spline means and said trapping spline means comprise a single elongated spline.
Claim 4
Dependent Claim
13 words
A lock apparatus according to claim 1 comprising a plurality of primary tumblers.
Claim 5
Dependent Claim
17 words
A lock apparatus according to claim 1 wherein said tumblers are of a substantially rectangular cross section.
Claim 6
Dependent Claim
17 words
A lock apparatus according to claim 1 wherein said primary tumbler and said trapping tumbler comprise wafers.
Claim 7
Dependent Claim
20 words
A lock apparatus according to claim 1 wherein said primary tumbler and said trapping tumbler are of the same shape.
Claim 8
Dependent Claim
18 words
A lock apparatus according to claim 1 wherein said spline means are of a substantially rectangular cross section.
Claim 9
Dependent Claim
31 words
A lock apparatus according to claim 1 wherein the keyway defines a keyway opening and said trapping spline means is spaced farther from said opening than is said primary spline means.
Claim 10
Dependent Claim
33 words
A lock apparatus according to claim 8 comprising a primary key to which said primary tumbler is responsive and an auxiliary key to which said primary tumbler and said trapping tumbler are responsive.
Claim 11
Dependent Claim
17 words
A lock apparatus according to claim 9 wherein said auxiliary key is longer than said primary key.
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) | 1978-04-07 | 1978-10-07 | 1979-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-07 | 1982-10-07 | 1983-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-07 | 1986-10-07 | 1987-04-08 | $7700.00 | Window Closed / Lapsed |