Electronic combination lock with high security features
AssigneeC&M Technology, Inc.
InventorsJ. Clayton Miller, Gerald L. Dawson, Daniel L. Thompson, Michael P. Harvey
Life of this patent
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Abstract
An electronic combination lock includes a combination lock having a dial with no markings thereon. Rotation of the dial drives a generator which produces electrical pulses. The voltage pulses serves as a power source for the electronics of the lock. The lock also includes a security feature to disable the lock if the combination dial is stopped between dial rotations for a period of time which indicates dailing by an automatic dialer.
Claims11
An electronic combination lock, comprising:
- a rotary dial for enabling manual entry of a combination by rotating the dial alternately in clockwise and counterclockwise directions to prescribed orientations;
- a rotation detector coupled to said rotary dial and developing an electrical signal corresponding to dial rotation;
- and
- a microprocessor responsive to said electrical signal for
- (a) determining direction and extent of dial rotation,
- (b) measuring the duration of time the dial rotation is stopped and sensing whether said dial rotation reverses after stopping,
- (c) comparing said measured duration of time with a predetermined period of time;
- and
- (d) ignoring a sensed reversal of said dial if said measured duration of time is less than said predetermined period of time, wherein said microprocessor does not recognize said sensed reversal and said microprocessor recognizes rotation of said rotary dial after said ignored sensed reversal as dial rotation in the same direction as the direction of dialing prior to said sensed reversal to prevent lock opening and further wherein said microprocessor recognizes said sensed reversal of said dial if said measured duration of time is greater than said predetermined period of time so that said dial reversal and further rotation of said rotary dial enables manual entry of said combination by alternate rotation for lock opening.
A method of operating an electronic combination lock of a type having a rotary dial for enabling manual entry of a combination by rotating the dial alternately in clockwise and counterclockwise directions to prescribed orientations;, comprising the steps of:
- determining direction and extent of dial rotation,
- measuring the duration of time the dial rotation is stopped and sensing whether said dial rotation reverses after stopping,
- comparing said measured duration of time with a predetermined period of time, and
- ignoring a sensed reversal of said dial if said measured duration of time is less than said predetermined period of time wherein said microprocessor does not recognize said sensed reversal and said microprocessor recognizes rotation of said rotary dial after said ignored sensed reversal as dial rotation in the same direction as the direction of dialing prior to said sensed reversal to prevent lock opening and further wherein said microprocessor recognizes said sensed reversal of said dial if said measured duration of time is greater than said predetermined period of time so that said dial reversal and further rotation of said rotary dial enables manual entry of said combination by alternate rotation for lock opening.
Dependencies are inferred from the claim text.