Cipher lock

Claim 2

In an electronic cipher lock comprising a plurality of electrical switches and logic circuitry, operatively connected to such switches, for generating an electrical signal in response to the activation of two or more such switches according to a predetermined sequence which constitutes a code, the improvement comprising: circuit means, operatively connected to at least one of said electric switches and responsive to the generation of said electrical signal, for rendering said logic circuitry insensitive to the first activation of any said switches following the generation of said electrical signal, whereby any of said switches can serve a switching function in addition to that of code entry.

Claim 3

The invention of claim 1 wherein said circuit means comprises: a. means for sensing the activation of any of said switches and for providing a voltage in response thereto; and b. a logic gate having at least a pair of inputs, one of said inputs being connected to said sensing means for receiving said voltage, and the other of said inputs being connected to said logic circuitry for receiving said electrical signal, said logic gate being adapted to provide an output signal upon receipt of said voltage and said electrical signal at the inputs thereof for rendering said logic circuitry insensitive to the first activation of any said switches following the generation of said electrical signal.

Claim 4

An electronic cipher lock comprising: a. at least two electrical switches, each having a switching member which is movable between first and second switching positions and means for biasing each of said members into said first position; b. logic circuitry operatively connected to said switches for generating an electrical signal in response to the sequential movement of said switching members according to a predetermined order; said logic circuitry comprising a chain of at least two flip-flop circuits, each flip-flop circuit having at least two inputs and an output and being arranged such that one of said two inputs is operatively coupled to a unique one of said switches, and the other input in said chain is operatively connected to the output of flip-flop circuit which precedes it in said chain, each of said flip-flop circuits being capable of providing an output signal in response to the simultaneous occurrence of both an output signal from the flip-flop circuit preceding it in said chain and the movement of the switching member of the switch to which it is connected from said first switching position to said second switching position; and c. circuit means, operatively coupling the output of the last flip-flop circuit in said chain with the other of said inputs of said first flip-flop circuit in said chain, for preventing said first flip-flop circuit from producing an output signal in response to the first movement of the switching member of the switch to which said first flip-flop circuit is connected from said first switching position to said second switching Position, whereby any of said switches can be used to serve switching functions other than that required for producing said electrical signal.

Claim 5

An electronic cipher lock comprising: a. at least two electrical switches, each having a switching member which is movable between first and second switching positions and means for biasing each of said members into said first position; b. logic circuitry operatively connected to said switches for generating an electrical signal in response to the sequential movement of said switching members according to a predetermined order; said logic circuitry comprising a chain of at least two flip-flop circuits, each flip-flop circuit having at least two inputs and an output and being arranged such that one of said two inputs is operatively coupled to a unique one of said switches, and the other input in said chain is operatively connected to the output of flip-flop circuit which precedes it in said chain, each of said flip-flop circuits being capable of providing an output signal in response to the simultaneous occurrence of both an output signal from the flip-flop circuit preceding it in said chain and the movement of the switching member of the switch to which it is connected from said first switching position to said second switching position; and c. circuit means, operatively coupling the output of the last flip-flop circuit in said chain with the other of said inputs of said first flip-flop circuit in said chain, for preventing said first flip-flop circuit from producing an output signal in response to the first movement of the switching member of the switch to which said first flip-flop circuit is connected from said first switching position to said second switching Position, whereby any of said switches can be used to serve switching functions other than that required for producing said electrical signal.

Claim 6

The electronic cipher lock of claim 3 wherein said circuit means further comprises means for eliminating said preventing function after the switching member of at least one of said switches is moved from said first switching position to said second position and then back to said first switching position.