US 4,148,092 A · Electronic combination door lock with dead bolt sensing means

Abstract

The electronic combination door lock uses a push button keyboard in combination with a door provided with a dead bolt manually operable by an outer turning knob. The electronic circuitry for the keyboard compares an input code with a stored code and generates an enabling signal only if the input code is the same as the stored code. The outer turning knob is restrained from being manually moved to retract the dead bolt when the door is in its locked condition. This restraining of the outer knob is removed by the enabling signal which requires very little energy so that the dead bolt can then be manually retracted. Since the major portion of the work involved in unlocking the door is a manual operation, very little electrical energy is required for the keyboard and circuitry and a battery can thus be used to thereby eliminate complicated wiring to exterior power sources. Further major features of the invention include the ability to store several different combinations and to reprogram or change such combinations by means of the keyboard itself. The combination itself can comprise any number of digits within the capacity of memory storages in the electronic circuit.

Claims17

Dependent claims

An electronic combination lock for use with a door including, in combination:

(a) a dead bolt on said door manually operable by an outer turning knob;
(b) an electronic circuit for comparing an input code with a stored code and generating an enabling signal only if said input code is the same as said stored code;
(c) restraining means responsive to said enabling signal to move from a first position locking said outer turning knob from being manually turned to retract said dead bolt, to a second position releasing said outer turning knob so that said outer turning knob can be manually turned to retract said dead bolt to unlock said door;
(d) bolt position sensing means for sensing a change in the position of said bolt, said restraining means being responsive to said bolt position sensing means to return to said first position when said bolt is manually extended by said outer turning knob to lock said outer turning knob from being manulaly turned to retract said dead bolt;
(e) battery means for said electronic circuit to provide said enabling signal and operation of said restraining means, manual retraction of said dead bolt avoiding the necessity for expending any battery power to retract said dead bolt whereby less battery drain results than would be the case were the bolt electrically retracted.

2 more elements

An electronic combination door lock for use with a door provided with a dead bolt manually operable by inner and outer turning knobs on opposite sides of the door respectively, including:

(a) a keyboard having a plurality of manually operable pushbuttons corresponding to a plurality of different digits on said door adjacent to said outer turning knob;
(b) a keyboard storage means;
(c) an enter key on said keyboard for entering into said keyboard storage means a keyboard master code generated by said keyboard by manual operation of said push buttons;
(d) a master memory containing a stored master code;
(e) comparator means connected to said keyboard storage means, operation of said enter key connecting said comparator means to said master memory for comparing said keyboard master code to said stored master code, said comparator means generating an enabling signal only if said keyboard master code is the same as said stored master code;
(f) restraining means responsive to said enabling signal to move from a first position locking said outer turning knob from turning to retract said dead bolt, to a second position releasing said outer turning knob so that said turning knob can be turned to retract said dead bolt to unlock said door;
and
(g) bolt position sensing means for sensing a change in the position of said bolt, said restraining means being responsive to said bolt position sensing means to return to said first position when said bolt is manually extended by said outer turning knob to lock said outer turning knob from being manually turned to retract said dead bolt.

5 more elements

Dependencies are inferred from the claim text.

Electronic combination door lock with dead bolt sensing means

Life of this patent

Electronic combination door lock with dead bolt sensing means

Life of this patent

Abstract

Claims17