US3710136A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic combination lock
Assignee: Smiths Group PLC
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Filing: 1971-01-27
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Granted: 1973-01-09
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Expires: 1991-01-27
Abstract
Abstract A combination lock includes four capacitors that are connected via rectifier-intercoupled plugs to the sockets of selected ones of 10 switch units which have individual push-buttons annotated with the digits ''''0'''' to ''''9.'''' Operation of the push-buttons of the selected switch units in turn to enter a four-digit combination programmed by the plugging, transfers electric charge from one to the other of the capacitors and thence to energize a solenoid to release a latch mechanism of the lock. Digit-entry deviating from the programmed sequence discharges the capacitors to inhibit charge transfer to the solenoid until the sequence is restarted. In a modification the four capacitors are replaced by capacitors in the individual switch units, charge transfer in response to entry of the correct combination being only between the capacitors of those units selected by rectifier-intercoupled plugging.
Inventors
- 👤 G Constable
- 👤 G Holter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:15
CPC Classifications
G; G07; G07C; G07C9/00; G07C9/00174; G07C9/00658; G07C9/00674; G07C9/0069
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
286 words
Access-control apparatus comprising a plurality of selectively-operable switching means, a plurality of capacitive means, electrically-energizable release means that is operable for enabling access in response to the application of electrical energy to said release means, and circuit means connecting at least some of the switching means in cascade to the release means, said circuit means including means interconnecting at least some of said capacitive means with the cascade-connected switching means to form thereby a plurality of sub-circuits each of which comprises an individual one of said switching means and an individual one of said capacitive means, means responsive to operation of the switching means of a first of said sub-circuits to establish electrical charge in the capacitive means of that sub-circuit, means connecting the capacitive means of the other said sub-circuits to the capacitive means of said first subcircuit through the switching means of their respective subcircuits to transfer at least part of said electric charge from one to another of these capacitive means in succession upon operation of the cascade-connected switching means of said other sub-circuits in a predetermined sequence, means connected to said release means to apply charge transferred in succession from one to another of the capacitive means as aforesaid to operate said release means, and means coupled to said sub-circuits and responsive to operation of the switching means of any said subcircuit to discharge the capacitive means of all said subcircuits except the capacitive means individual to the operated switching means, such that following operation of the switching means of said first sub-circuit said electric charge is dissipated, and said release means thereby remains unoperated, unless the switching means of said other sub-circuits are operated one after the other in said sequence.
Claim 2
Dependent Claim
286 words
Access-control apparatus comprising a plurality of selectively-operable switching means, a plurality of capacitive means, electrically-energizable release means that is operable for enabling access in response to the application of electrical energy to said release means, and circuit means connecting at least some of the switching means in cascade to the release means, said circuit means including means interconnecting at least some of said capacitive means with the cascade-connected switching means to form thereby a plurality of sub-circuits each of which comprises an individual one of said switching means and an individual one of said capacitive means, means responsive to operation of the switching means of a first of said sub-circuits to establish electrical charge in the capacitive means of that sub-circuit, means connecting the capacitive means of the other said sub-circuits to the capacitive means of said first subcircuit through the switching means of their respective subcircuits to transfer at least part of said electric charge from one to another of these capacitive means in succession upon operation of the cascade-connected switching means of said other sub-circuits in a predetermined sequence, means connected to said release means to apply charge transferred in succession from one to another of the capacitive means as aforesaid to operate said release means, and means coupled to said sub-circuits and responsive to operation of the switching means of any said subcircuit to discharge the capacitive means of all said subcircuits except the capacitive means individual to the operated switching means, such that following operation of the switching means of said first sub-circuit said electric charge is dissipated, and said release means thereby remains unoperated, unless the switching means of said other sub-circuits are operated one after the other in said sequence.
Claim 3
Dependent Claim
90 words
Access-control apparatus according to claim 1 wherein there are fewer capacitive means than switching means, said circuit means includes means for selectively establishing electrical connections from the capacitive means to respective, selected ones of the switching means to form said sub-circuits, and said means for selectively establishing electrical connections from the capacitive means includes means for establishing electrical connections from one to another of the said selected switching means to said release means to connect the said selected switching means to the said release means in the said cascade connection.
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) | 1976-01-09 | 1976-07-10 | 1977-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-09 | 1980-07-10 | 1981-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-09 | 1984-07-10 | 1985-01-09 | $7700.00 | Window Closed / Lapsed |