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Electronic locking apparatus for motor vehicles

  • US 4,723,121 A
  • Filed: 09/09/1986
  • Issued: 02/02/1988
  • Est. Priority Date: 09/10/1985
  • Status: Expired due to Term
First Claim
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1. An electronic locking apparatus, particularly for motor vehicles, havingan electrical lock;

  • at least one positioning means connected to and actuated by the lock;

    at least one electrical key;

    means in each of said key and said lock for generating a code signal;

    means in the key for transmitting a code signal to the lock;

    means in said lock for comparing respective code signals generated by said key and by said lock; and

    means responsive to said comparing means for actuating said positioning means;

    whereina continuously operating oscillator (11,21) is provided in each of said key and said lock, said oscillators being synchronized with one another;

    a number sequence generator, connected to an output of said oscillator, is provided in each of said key and said lock;

    said number sequence generators cyclically stepping through identical predetermined sequences of numbers, in synchrony with one another;

    a computer, having at least one input, is provided in each of said key and said lock;

    each number sequence generator has a time-varying count which is applied to said input of a respective computer;

    a fixed memory, containing a code number characteristic of each key-and-lock pair, is provided in each of said key and said lock;

    said fixed memory supplies said code number to a respective computer;

    said computers contain identical algorithms and each use said algorithm to combine said time-varying count and said code number into a combination code, said combination code being transmitted as a signal between said key and said lock;

    a re-try stage is provided in said lock which, upon failure to match respective codes derived from said key and said lock, selects numbers, in said predetermined sequence of numbers, lying above and below said count and directs the computer in said lock to sequentially produce further combination codes and attempt to match them with combination codes derived from said key;

    upon successful matching of combination codes derived respectively from said key and said lock, one of said number sequence generators adjusts its count to agree with the count of the other of said number sequence generators.

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