ELECTRONIC LOCK SYSTEM

• US 3,848,229 A
• Filed: 07/20/1972
• Issued: 11/12/1974
• Est. Priority Date: 04/09/1971
• Status: Expired due to Term

• Current Assignee: John T. Fowler, Robert R. Perron
• Original Assignee: John T. Fowler, Robert R. Perron
• Inventors: Perron, Robert R., Fowler, John T.
• Primary Examiner(s): Pitts, Harold I.
• Application Number:
  US05/273,529
• Time in Patent Office: 845 Days
• Field of Search: 340/149A
• US Class Current: 235/382
• CPC Class Codes: G07C 2009/00761 with data transmission performed by connected means, e.g. mechanical contacts, plugs, connectors
• CPC Class Codes: G07C 9/00182 operated with unidirectional data transmission between data carrier and locks

Abstract

An electronic lock system in which a coded data word is stored in a key and, upon insertion of the key into a lock, compared with a master code, a positive comparison providing actuation of the lock. Lack of correspondence between the key code and the master code causes actuation of an alarm and can also cause seizure of the key in the lock. Digital circuitry is employed in both the key and lock and is configured to permit easy alteration of the stored code to greatly enhance system security. Only four interconnections need couple the key to the lock and the stored key code can be selectively altered to further enhance system security.

Claims

1. An electronic lock system comprising:

a key including a structural member adapted for engagement with an associated lock and an electronic data memory therein having a plurality of interconnected stages operative to store an electrically alterable multiple bit key code and terminal means for coupling said key to an associated lock by which said key code can be conveyed from said electronic data memory in response to a clock signal;

a lock adapted for operation with said key and including a receptacle for receiving the structural member of said key in operative engagement therewith;

an electronic data memory for storing a multiple bit master code;

means for comparing said key code stored in said key data memory with said master code stored in said master code memory;

clock means for providing a clock signal to said key data memory to cause readout of said key code to said comparison means for comparison of said key code with said master code;

said comparison means being operative to provide an output indication upon receipt of a key code from said key data memory corresponding to said master code; and

logic means receiving said output indication from said comparison means and operative in response thereto to provide an output signal.

2. An electronic lock system according to claim 1 wherein:

said comparison means is also operative to provide a second output indication upon receipt of a key code from said key data memory which does not correspond to said master code; and

said logic means is operative in response to said second output indication to provide a second output signal.

3. An electronic lock system according to claim 1 wherein said lock includes means operative after comparison of said key code with said master code for reentering a key code into the electronic data memory of said key.

4. An electronic lock system according to claim 1 wherein said lock includes:

means for detecting the presence of said structural member in operative position with said lock receptacle and for providing a signal indication of key presence; and

means operative in response to said key presence signal indication to initiate comparison of said key code with said master code.

5. An electronic lock system according to claim 2 wherein said lock includes means within said receptacle for preventing removal of said key therefrom during comparison of said key code with said master code.

6. An electroNic lock system according to claim 5 wherein said removal preventing means is operative in response to said second output indication from said comparison means to capture said key in said lock receptacle upon non-identity between said key code and master code.

7. An electronic lock system according to claim 2 wherein said comparison means is operative to compare said key code and said master code on a bit by bit basis and to provide said second signal indication upon detection of a bit of said key code which does not compare with the corresponding bit of said master code.

8. An electronic lock system according to claim 1 wherein said key data memory is of a data capacity to store predetermined data in addition to said key code;

and wherein said lock includes;

a second electronic data memory for storing said predetermined additional data received from said key;

decoding means coupled to said second data memory and operative to provide an output signal in response to said predetermined data in said second data memory; and

gate means operative in response to the presence of both said output indication from said comparison means and said output signal from said decoding means to provide a utilization signal.

9. An electronic lock system comprising:

a key having a structural member adapted for engagement with an associated lock and including therein;

a first electronic data memory having a plurality of interconnected stages operative to store an electrically alterable multiple bit key code;

a second electronic data memory having a plurality of interconnected stages operative to store a predetermined multiple bit code different than said key code; and

comparator means coupled to said first and second electronic data memories and operative to compare said predetermined code in said second data memory with an enable code provided by said lock and to provide in response to correspondence between said enable code and said predetermined code a command signal to said first data memory to cause readout of said key code stored therein to said lock;

a lock adapted for operation with said key and including;

a receptacle for receiving the structural member of said key in operative engagement therewith;

an electronic data memory for storing a multiple bit master code;

means for comparing said key code with said master code and to provide a signal indication upon receipt of a key code which corresponds to said master code; and

logic means receiving said signal indication from said lock comparing means and operative to provide an output signal in response thereto.

10. An electronic lock system according to claim 9 wherein:

said lock comparing means is also operative to provide a second signal indication upon receipt of a key code from said key data memory which does not correspond to said master code; and

said logic means is operative in response to said second signal indication to provide a second output signal.

11. An electronic lock system according to claim 10 wherein said lock comparing means is also operative to provide said second signal indication in response to non-comparison between said enable code and said predetermined code.

12. An electronic lock system comprising:

a key adapted for insertion into an associated lock;

a multiple bit shift register within said key operative to store an electrically alterable multiple bit key code representing key identity and operative in response to clock signals from said lock to convey said key code from said shift register to said lock and to receive a key code from said lock;

a lock adapted for operation with said key and including a receptacle for receiving said key in operative engagement therewith;

circuitry operative to provide an output signal upon correspondence between said key code and a master code, said circuitry comprising;

means for detecting the presence of said key in operative engagement with said lock receptacle and for providing a signal indication of key presence;

timing means operative in response to said signal indication of key presence for providing clock pulses for controlling operation of said circuitry;

a master code register for storing a multiple bit master code;

digital comparator means operative to compare said key code received from said shift register and said master code received from said master code register and to provide a signal indication upon correspondence between said key code and master code; and

logic means operative in response to said signal indication from said digital comparator means to provide an output signal.

13. An electronic lock system according to claim 12 wherein:

said digital comparator means is also operative to provide a second signal indication upon receipt of a key code from said key data memory which does not correspond to said master code; and

said logic means is operative in response to said second signal indication to provide a second output signal.

14. An electronic lock system according to claim 13 wherein said logic means includes:

a first AND gate coupled to the output of said digital comparator and to said timing means and operative to provide an output signal upon detection of non-correspondence between said master code and said key code;

a second AND gate;

a flip-flop maintained in one binary state by the presence of a signal derived from said key detection means and providing in this binary state an output signal to said second AND gate;

said flip-flop being operative in response to the output signal from said first AND gate to switch to its second binary state causing removal of the flip-flop output signal to said second AND gate;

alarm circuitry operative upon detection of the output signal of said first AND gate to provide an output indication of non-correspondence between said master code and said key code; and

decoding means for recognizing the last bit of said master code to denote the end of the code comparison process and to provide an enabling signal for said second AND gate to cause production of said logic means output signal.

15. An electronic lock system according to claim 14 wherein said timing means includes means for providing first clock pulses and second clock pulses delayed with respect to said first clock pulses by a predetermined amount, said first clock pulses being employed to control data bit transitions in said logic circuitry, said second clock pulses being employed to control data bit comparisons in said logic circuitry.

16. An electronic lock system according to claim 14 wherein said lock includes:

means for storing a new master code; and

means for transferring said new master code to said key shift register and to said master code register.

17. An electronic lock system according to claim 14 wherein said lock includes:

means for storing a new master code;

a second flip-flop coupled to the output of said second AND gate and operative to remain in one binary state in the presence of an output signal from said second AND gate and an opposite binary state in the absence of an output signal from said second AND gate; and

a third AND gate coupled to the output of said second flip-flop and to said timing means and operative to provide a gating signal to said new code storage means to transfer said new master code to said master code register and to said key shift register.

18. An electronic lock system according to claim 12 wherein said key shift register is of a data capacity to store a multiple bit code longer than said key code, said key code being stored in said shift register as part of the stored code.

19. An electronic lock system comprising:

a key having a structural member adapted for insertion into an associated lock;

an electronic data memory within said structural member and having plural interconnected stages each operative to storE a bit of an electrically alterable multiple bit code representing key identity;

a plurality of first terminals on said structural member connected to said electronic data memory and operative to couple said member to an associated lock;

a lock adapted for operation with said key and including;

a receptacle for receiving the structural member of said key therein;

a plurality of second terminals within said receptacle for coupling to respective ones of said first terminals of said key with said key in said receptacle;

logic circuitry coupled to said second terminals and having an electronic data memory for storing a multiple bit master code;

first logic means operative with said key inserted in said receptacle to compare the key code stored in said key data memory, and to provide an output indication of correspondence between said key code and master code; and

second logic means operative in response to said output indication from said first logic means to provide an output signal.

20. An electronic lock system according to claim 19 wherein:

said first logic means is also operative to provide a second output indication upon receipt of a key code from said key data memory which does not correspond to said master code; and

said second logic means is operative in response to said second output indication to provide a second output signal.

21. An electronic lock system comprising:

a key including a structural member adapted for engagement with an associated lock;

an electronic shift register disposed in said structural member and operative to store an alterable multiple bit code representing key identity and to read out said code in response to clock pulses from said lock; and

a plurality of first terminals disposed in predetermined disposition on said structural member and connected to said shift register, said first terminals including a clock terminal, a data input terminal and a data output terminal;

a lock including a receptacle for receiving the structural member of said key and having a plurality of second terminals operative to couple to respective ones of said first terminals of said key;

means in said receptacle for detecting the presence of a key and for providing an output indication of key presence; and

circuitry for decoding said key code and including clock means operative in response to an output indication from said key detection means for providing clock pulses for controlling the key decoding process;

a master code register for storing a multiple bit master code;

a digital comparator operative in response to said clock pulses to receive said master code and said key code and to provide a signal indication upon detection of correspondence between said key code and master code; and

logic means operative in response to said signal indication from said digital comparator to provide an output signal.

22. An electronic lock system according to claim 21 wherein:

said comparator is also operative to provide a second signal indication upon receipt of a key code from said key shift register which does not correspond to said master code; and

said logic means is operative in response to said second signal indication to provide a second output signal.

23. An electronic lock system comprising:

a key adapted for use with an associated lock and having an electronic data memory therein with a plurality of interconnected stages operative to store an electrically alterable multiple bit key code and terminal means for coupling said key to an associated lock by which said key code can be conveyed from said electronic data memory in response to a command signal;

a lock adapted for operation with said key and including receptacle means for receiving said key in operative association therewith;

an electronic data memory for storing a multiple bit master code;

means for providing a command signal to said key data memory to cause readOut of said key code to comparison means for comparison of said key code with said master code;

means operative to compare said key code stored in said key data memory with said master code stored in said master code memory and to provide a signal indication upon receipt of a key code from said key data memory corresponding to said master code; and

logic means operative in response to said signal indication from said comparison means to provide a utilization signal upon correspondence between said key code and said master code.