US3921040A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Locking system
Assignee: Individual
•
Filing: 1973-11-02
•
Granted: 1975-11-18
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Expires: 1993-11-02
Abstract
Abstract A locking system is provided which includes a key device which includes at least one electrical impedance. The key can be inserted into circuitry which contains adjustable impedances. The circuitry is such that when the adjustable impedances are set to predetermined values which match those of the impedances in the key device, a locking device which is operated from the circuitry is released. The exact circuitry can take many different forms. It may include provision for energizing an alarm after one or more incorrect attempts have been made to release the system by inserting the key and setting the variable impedances to incorrect values.
Inventors
- 👤 Walter Wilson Hugh Clarke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 13:31
CPC Classifications
G; G07; G07F; G07F7/00; G07F7/08; G07F7/10; G06; G06Q; G06Q20/00; G06Q20/30; G06Q20/34; G06Q20/347; G07F7/1025; G07F7/1058
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
179 words
A locking system comprising a key device which includes at least one impedance, key receiving means, circuitry in which said at least one impedance can be connected by associating said key with said key receiving means, said circuitry including at least one variable impedance, manually operable means for setting the value or values of said at least one variable impedance, a locking device, means for releasing the locking device when said at least one variable impedance has been correctly set to a value or plurality of values having a predetermined relationship with the value or values of the at least one impedance in the key device when the key device is associated with the key receiving means, including alarm means, said circuitry being adapted to energise the alarm means in response to an incorrect setting, and wherein the circuitry is adapted to energise the alarm means in response only to the last of a plurality of incorrect settings, whereby to permit at least one incorrect attempt at releasing the locking device to be made without energising the alarm means.
Claim 2
Dependent Claim
179 words
A locking system comprising a key device which includes at least one impedance, key receiving means, circuitry in which said at least one impedance can be connected by associating said key with said key receiving means, said circuitry including at least one variable impedance, manually operable means for setting the value or values of said at least one variable impedance, a locking device, means for releasing the locking device when said at least one variable impedance has been correctly set to a value or plurality of values having a predetermined relationship with the value or values of the at least one impedance in the key device when the key device is associated with the key receiving means, including alarm means, said circuitry being adapted to energise the alarm means in response to an incorrect setting, and wherein the circuitry is adapted to energise the alarm means in response only to the last of a plurality of incorrect settings, whereby to permit at least one incorrect attempt at releasing the locking device to be made without energising the alarm means.
Claim 3
Dependent Claim
31 words
A locking system as claimed in claim 1 comprising warning means, the circuitry being adapted to energise the warning means in response to a first incorrect setting of the variable impedances.
Claim 4
Dependent Claim
55 words
A locking system as claimed in claim 2 wherein a plurality of settings of said at least one variable impedance are required to constitute a correct setting and the circuitry is adapted to energise the warning means only after all the plurality of settings have been completed, whichever of said plurality of settings was incorrect.
Claim 5
Dependent Claim
170 words
A locking system comprising a key device which includes at least one impedance, key receiving means, circuitry in which said at least one impedance can be connected by associating said key with said key receiving means, said circuitry including at least one variable impedance, manually operable means for setting the value or values of said at least one variable impedance, a locking device, means for releasing the locking device when said at least one variable impedance has been correctLy set to a value or plurality of values having a predetermined relationship with the value or values of the at least one impedance in the key device when the key device is associated with the key receiving means, wherein said circuitry includes first circuit means for generating a control signal depending upon the correct or incorrect setting of said at least one variable impedance, and said releasing means is responsive to said control signal, and further including switch means manually operable to couple said first circuity means to said releasing means.
Claim 6
Dependent Claim
170 words
A locking system comprising a key device which includes at least one impedance, key receiving means, circuitry in which said at least one impedance can be connected by associating said key with said key receiving means, said circuitry including at least one variable impedance, manually operable means for setting the value or values of said at least one variable impedance, a locking device, means for releasing the locking device when said at least one variable impedance has been correctLy set to a value or plurality of values having a predetermined relationship with the value or values of the at least one impedance in the key device when the key device is associated with the key receiving means, wherein said circuitry includes first circuit means for generating a control signal depending upon the correct or incorrect setting of said at least one variable impedance, and said releasing means is responsive to said control signal, and further including switch means manually operable to couple said first circuity means to said releasing means.
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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) | 1978-11-17 | 1979-05-19 | 1979-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-17 | 1983-05-19 | 1983-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-17 | 1987-05-19 | 1987-11-18 | $7700.00 | Window Closed / Lapsed |