US3876913A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic circuit for activating an electric lock
Assignee: Individual
•
Filing: 1973-11-12
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Granted: 1975-04-08
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Expires: 1993-11-12
Abstract
Abstract An electronic circuit is provided for operating an electric lock. The circuit is activated by switching a pre-selected combination of switches in a pre-selected sequence. Any number of switches may be provided and there may be more switches than switches forming the pre-selected combination. Furthermore, circuitry may be provided such that the circuit is only activated if each switch is switched within a pre-selected time delay of the switching of the preceding switch.
Inventors
- 👤 Richard Frederick Perry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:04
CPC Classifications
G; G07; G07C; G07C9/00; G07C9/00174; G07C9/00658; G07C9/00674; G07C9/0069
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
174 words
An electronic circuit for operating an electric lock comprising an array of switches, at least some of said switches forming a pre-selected combination, logic circuitry having a series of logic gates connected to said switches forming said pre-selected combination, and delay circuitry connected between the switches forming said combination, whereby said circuit is only activated when the switches of the combination are switched in a pre-selected sequence within a pre-selected time delay, said delay circuitry including a series of monostable multivibrators having a predetermined pulse width, the monostable multivibrators being connected between the output of one logic gate and an input of a following logic gate, except for the output of the last but one logic gate which is connected through a monostable multivibrator to the input of an AND gate whose output is connected to the input of a further monostable multivibrator whose output is connected to a relay for operating said lock, a second input of said AND gate being connected to said last switch of said combination through a logic gate.
Claim 2
Dependent Claim
174 words
An electronic circuit for operating an electric lock comprising an array of switches, at least some of said switches forming a pre-selected combination, logic circuitry having a series of logic gates connected to said switches forming said pre-selected combination, and delay circuitry connected between the switches forming said combination, whereby said circuit is only activated when the switches of the combination are switched in a pre-selected sequence within a pre-selected time delay, said delay circuitry including a series of monostable multivibrators having a predetermined pulse width, the monostable multivibrators being connected between the output of one logic gate and an input of a following logic gate, except for the output of the last but one logic gate which is connected through a monostable multivibrator to the input of an AND gate whose output is connected to the input of a further monostable multivibrator whose output is connected to a relay for operating said lock, a second input of said AND gate being connected to said last switch of said combination through a logic gate.
Claim 3
Dependent Claim
60 words
The circuit of claim 1 in which said logic gates connected to said switches are NOR gates, and the QBar outputs of said monostable multivibrators are connected to the inputs of said NOR gates except for the multivibrator connected to the last but one NOR gate, said multivibrator having its Q output connected to an input of said AND gate.
Claim 4
Dependent Claim
46 words
The electronic circuit of claim 2 comprising additional logic gates connected to at least some of said switches forming said combination, said additional logic gates producing an output when selected combinations of said switches are switched simultaneously, said output being arranged to deactivate the electronic circuit.
Claim 5
Dependent Claim
67 words
The electronic circuit of claim 3 in which the switches of said combination apart from said first switch are double pole switches, and wherein the circuit comprises a counter, means for decoding the output of said counter, and means for activating an alarm, whereby said alarm is activated when said switches are pressed a number of times equal to the number of digits in said pre-selected combinations.
Claim 6
Dependent Claim
37 words
The electronic circuit of claim 4 in which the output of said additional logic gates for indicating when selected combinations of said switches are switched simultaneously is also connected to a circuit for activating said alarm system.
Claim 7
Dependent Claim
51 words
The electronic circuit of claim 5 in which said output of said additional logic gates, the outputs from a first logic gate connected to said first switch of said combination, and the outputs of said alarm activating system are connected to the reset input of said counter for resetting said counter.
Claim 8
Dependent Claim
57 words
The electronic circuit of claim 6 comprising a counter connected between logic gates connected to consecutive switches, decoding circuitry connected to the output of said counter, said decoding circuitry only providing an output when a switch of the combination is pressed a pre-selected number of times, said counter thus providing consecutive repetitions of digits in said combinations.
Claim 9
Dependent Claim
51 words
The electronic circuit of claim 6 comprising a retriggerable monostable multivibrator between adjacent logic gates connected to adjacent switches of said combinations, the pulse width of said retriggerable monostable multivibrators being chosen such that the following gate cannot be opened unless the preceding switch is switched the requisite number of times.
References Cited (Backward Citations)
US3633167A
Cited
US3754164A
Cited
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 |