ELECTRICAL COMBINATION LOCK APPARATUS

• US 3,829,834 A
• Filed: 09/10/1973
• Issued: 08/13/1974
• Est. Priority Date: 09/10/1973
• Status: Expired due to Term

• Current Assignee: John T. Frankland, Richard J. Mclaughlin
• Original Assignee: John T. Frankland, Richard J. Mclaughlin
• Inventors: Frankland, John T., McLaughlin, Richard J.
• Primary Examiner(s): Pitts, Harold I.
• Application Number:
  US05/395,973
• Time in Patent Office: 337 Days
• Field of Search: 340/149R,149A,147MD,164R
• US Class Current: 340/543
• CPC Class Codes: E05B 2047/0023 Nuts or nut-like elements moving along a driven threaded axle
• CPC Class Codes: G07C 9/0069 actuated in a predetermined sequence
• CPC Class Codes: G08B 13/06 by tampering with fastening
• CPC Class Codes: Y10T 292/1021 Motor
• CPC Class Codes: Y10T 292/1033 Screw

Abstract

An electrical combination lock including a plurality of switches, connected in parallel to ground across a capacitor, for respectively producing when depressed a ground signal to corresponding first terminals of NAND gate latches. The NAND gate latches are connected in cascade to a reset signal switch at the second input terminals thereof whereby each NAND gate is switched to one state upon the depression of the reset switch and then to the other state upon depression of the corresponding combination switches. The same cascade connection of the latches will latch the latches in their switched states if the switch depression sequence follows the connection sequence and any other switch sequence will only register a change in state of one of the latch outputs concurrent with the depression of the switch while the second output will remain in its original state. Thus any switching sequence can be obtained, which, if followed, will latch all of the latches in the second state. This change in state of all of the latches is collected at a combination NAND gate, which, when receiving all signals of a particular state, activates a lock drive motor in a direction determined by the position thereof, either to open or close a lock. All other permutations of latch state, except one, are collected at other NAND gates to activate an alarm. The remaining permutation is reserved to reset the lock if a wrong sequence is depressed by error. The respective switches are connected to ground across an R-C circuit such that the depression thereof must occur within a predetermined interval. Also the power for the circuits is supplied by a battery continuously charged by a battery charger such that the combination lock is independent of an external power supply.

Claims

1. An electrical combination lock comprising, in combination:

lock means adapted to be mounted in a doorway for effecting locking and unlocking thereof upon receiving a first electrical signal;

switching means disposed for sequential manual actuation for producing a plurality of consecutively actuated parallel switching signals according to the manual actuation thereof;

first electronic latch means connected to receive said switching signals for latching to a first state to produce a predetermined combination of maintained output signals at corresponding one output terminals thereof upon receiving a predetermined sequence of said switching signals and for producing temporary signals concurrent with the manual actuation of said switching means at corresponding other output terminals thereof upon receiving corresponding other sequences of said switching signals;

combination means connected to receive corresponding one output terminals of said first latching means for producing said first electrical signal upon receiving said maintained output signals thereon;

permutation means connected to receive corresponding one and other output terminals of said first latching means output signals for producing a reset signal upon receiving a one selected combination of said temporary signals and selected ones of said maintained signals and for producing a first alarm indicative signal upon receiving any other combination of said temporary and maintained signals;

reset means connected to receive said reset signal for producing a reset output signal latching said latch means to a second state;

second latch means connected to receive said first alarm indicative signal and said reset signal for latching to an alarm state upon the first receipt of said first alarm indicative signal and for unlatching from said alarm state upon receiving said reset signal; and

alarm generating means connected to said second latch means for generating an alarm operating signal upon the latching of said second latch means in said alarm state.

2. An electrical combination lock according to claim 1, further comprising:

a reset switch connected in parallel with said reset means for alternatively producing said reset signal upon the manual actuation thereof.

3. An electrical combination lock according to claim 2, wherein:

said first latch means including first latching circuits each comprising paired first NAND gates connected to receive at one input thereof the output of the other corresponding first NAND gate of each pair and connected to receive at the other inputs of the one first NAND gate thereof respective ones of said switching signals, being connected at the other inputs of the other first NAND gates to selected other output terminals of said first latching circuits, the respective connections between said latching circuits corresponding to said predetermined sequence of said switching signals.

4. An electrical combination lock according to claim 3, wherein:

said combination means including a second NAND gate disposed to receive the output signal of the one first NAND gates of said first NAND gate pairs for producing a change in the output signal thereof when all said one NAND gate output signals are at one selected state.

5. An electrical combination lock according to claim 4, wherein:

said Permutations means including a plurality of third NAND gates selectively connected to receive predetermined combinations of said one and other first NAND gate output signals.

6. An electrical combination lock according to claim 5, wherein:

said second latch means including fourth latching circuits each comprising paired fourth NAND gates connected to receive at one input thereof the output of the other corresponding fourth NAND gate of each pair and connected to receive at the other inputs of the one fourth NAND gate thereof selected ones of said third NAND gates output signals.

7. An electrical combination lock according to claim 1 wherein:

said lock means including an electrical motor rendered operative upon receipt of said first electrical signal, a bolt disposed laterally in said doorway and connected to be actuated in response to said motor, and limit switches disposed in said doorway and aligned to be selectively switched when said bolt is at the extremes of the travel thereof producing signals for controlling the rotation of the motor in a direction opposite to the position of said bolt.

8. An electrical combination lock according to claim 1, further comprising:

environment-responsive means disposed in said doorway for producing a second alarm indicative signal to said alarm means upon sensing change in the environment.

9. An electrical combination lock according to claim 1, further including:

timing means connected to said switching means for rendering said switching means operative within a predetermined interval of time.

10. An electrical combination lock according to claim 1, further including:

a storage battery connected to supply electrical power to said lock means, first electronic latch means, combination means, permutation means, second latch means and said alarm generating means; and

charging means adapted to receive an electrical signal for providing electrical power to said storage battery.