Electronic combination lock and system

Abstract

A unitary self-contained electronic combination lock is provided which includes a dead bolt manually operable from one side and operable from the other side only in response to insertion of a data combination card carrying a unique binary code in the form of selectively positioned metallic spots. Sensors located within the unit generate a binary 1 or 0 signal in response to the presence or absence of a metallic spot adjacent each sensor. The lock combination code is automatically changed to the data card's code upon insertion of a card having a code combination which includes part of the lock's code so that the previously issued cards will no longer operate to unlock the door. In this manner, the authorized code for each lock unit is automatically and independently changed to render inoperative all previously issued data cards.

What is claimed is: 
     
       1. An independently operable electronic lock and system having an alterable combination, said lock being operable in response to insertion of a correct combination code, comprising: a lock housing adapted to be secured in a door;   securing means attached to said housing;   alterable memory means within said housing storing combination information for operating said lock;   means within said housing for receiving and detecting a first stationary combination code inserted into the lock, comparing said inserted first combination code with said stored combination information, and generating a drive signal when a comparison is favorable;   said receiving and detecting means comprising a plurality of sensor coils connected to receive the output of an oscillator, each coil having a ferrous metal core and being connected to produce a first signal across said coil in the absence of a code entry and a second signal across said coil in the presence of a code entry and   a tuned circuit connected to produce a first output in response to the first signal across the respective coil and a second output in response to the second signal across the respective coil;   said inserted code entries comprising at least one electrically conductive area positioned adjacent to and within the magnetic field of at least one of said sensor coils to cause said second signal to be produced across said at least one coil, said first and second output signals providing a second combination code corresponding to said first combination code;   drive means within said housing adapted to operate said securing means in response to said drive signal;   means within said housing for changing said stored combination information to said inserted combination when a comparison is favorable; and,   an energy source connected to supply the power requirements of said lock and system.   
     
     
       2. An electronic lock and system as defined in claim 1 wherein: said receiving and detecting means includes a card reader mounting said sensor coils and a protrusion extending inwardly into the card reader to prohibit access to the portion of the card reader in the area of said protrusion; and further comprising:   a combination card adapted to be received by said card reader and having at least one plane, said card having a notch formed in at least one side to receive said card reader protrusion, said electrically conductive area being positioned on said plane to lie opposite a corresponding sensor coil when said card is positioned in said card reader so that said notch receives said protrusion. .Iadd. 3. An independently operable electronic lock and system having an alterable combination, said lock being operable in response to a correct combination, comprising:   a lock housing adapted to be secured to a door;   securing means connected to said housing;   alterable memory means within said housing storing combination information for operating said lock;   means within said housing for receiving and detecting a first received combination, comparing said first received combination with said stored combination information, and generating an activation signal when a comparison is favorable;   said receiving and detecting means comprising a plurality of sensor coils connected to receive the output of an oscillator, each coil having a ferrous metal core and being connected to produce a first signal across said coil in the absence of a received combination area and a second signal across said coil in the presence of a received combination area and   a tuned circuit connected to produce a first output in response to the first signal across the respective coil and a second output in response to the second signal across the respective coil;   said received combination comprising being represented in a form at least one magnetically reactive received combination area positioned adjacent to and within the magnetic field of at least one of said sensor coils to cause said second signal to be produced across said at least one coil, said first and second output signals providing a second combination corresponding to said first combination;   means within said housing adapted to operate said securing means in response to said activation signal;   means within said housing for changing said stored combination information to said received combination when a comparison is favorable; and,   an energy source connected to supply the power requirements of said lock and system. .Iaddend..Iadd. 4. An independently operable electronic lock and system having an alterable combination, said lock being operable in response to a correct combination, comprising:   a lock housing adapted to be secured to a door;   securing means connected to said housing;   alterable memory means within said housing storing   combination information for operating said lock;   means within said housing for receiving and detecting a first received combination, comparing said first received combination with said stored combination information, and generating an activation signal when a comparison is favorable;   said receiving and detecting means comprising a plurality of sensor coils connected to receive the output of an oscillator, each coil having a ferrous metal core and being connected to produce a first signal across said coil in the absence of a received combination area and a second signal across said coil in the presence of a received combination area and   a tuned circuit connected to produce a first output in response to the first signal across the respective coil and a second output in response to the second signal across the respective coil;   said received combination being represented in a form comprising at least one magnetically reactive received combination area adjacent to and within the magnetic field of at least one of said sensor coils to cause said second signal to be produced across said at least one coil, said first and second output signals providing a second combination corresponding to said first combination;   means within said housing adapted to operate said securing means in response to said activation signal;   means within said housing for changing said stored combination information to said received combination when a comparison is favorable; and,   an energy source connected to supply the power requirements of said lock and system. .Iaddend..Iadd. 5. An independently operable electronic lock and system having an alterable combination, said lock being operable in response to a correct combination, comprising:   a lock housing adapted to be secured to a door;   securing means connected to said housing;   alterable memory means within said housing storing combination information for operating said lock;   means within said housing for receiving and detecting a first received combination, comparing said first received combination with said stored combination information, and generating an activation signal when a comparison is favorable;   said receiving and detecting means comprising a plurality of sensor coils connected to receive the output of an oscillator, each coil having a ferrous metal core and being connected to produce a first signal across said coil in the absence of a received combination area and a second signal across said coil in the presence of a received combination area and   a tuned circuit connected to produce a first output in response to the first signal across the respective coil and a second output in response to the second signal across the respective coil;   said received combination being represented in a form comprising at least one magnetically reactive area at least temporarily positioned adjacent to and within the magnetic field of at least one of said sensor coils to cause said second signal to be produced across said at least one coil, said first and second output signals providing a second combination corresponding to said first combination;   means within said housing adapted to operate said securing means in response to said activation signal;   means within said housing for changing said stored combination information to said received combination when a comparison is favorable; and,   an energy source connected to supply the power requirements of said lock   
     
     
        and system. .Iaddend..Iadd. 6.  An independently operable electronic lock and system having an alterable combination, said lock being operable in response to a correct combination, comprising: a lock housing adapted to be secured to a door;   securing means connected to said housing;   alterable memory means within said housing storing combination information for operating said lock;   means within said housing for receiving and detecting a first received combination, comparing said first received combination with said stored combination information, and generating an activation signal when a comparison is favorable;   said receiving and detecting means comprising a plurality of sensor coils connected to receive the output of an oscillator, each coil having a ferrous metal core and being connected to produce a first signal across said coil in the absence of a received combination area and a second signal across said coil in the presence of a received combination area and   a tuned circuit connected to produce a first output in response to the first signal across the respective coil and a second output in response to the second signal across the respective coil;   said received combination being represented in a form comprising at least one magnetically reactive received combination area for causing, by its presence adjacent to and within the magnetic field of at least one of said sensor coils, said second signal to be produced across said at least one coil, said first and second output signals providing a second combination corresponding to said first combination;   means within said housing adapted to operate said securing means in response to said activation signal;   means within said housing for changing said stored combination information to said received combination when a comparison is favorable; and,   an energy source connected to supply the power requirements of said lock and system. .Iaddend..Iadd. 7. An independently operable electronic lock and system having an alterable combination, said lock being operable in response to a correct combination, comprising:   a lock housing adapted to be secured to a door;   securing means connected to said housing;   alterable memory means within said housing storing combination information for operating said lock;   means within said housing for receiving and detecting a first received combination, comparing said first received combination with said stored combination information, and generating an activation signal when a comparison is favorable;   said receiving and detecting means comprising at least one sensor coil connected to receive the output of an oscillator, said coil having a ferrous metal core and being connected to produce a first signal across said coil in the absence of a received combination area and a second signal across said coil in the presence of a received combination area and   a tuned circuit connected to produce a first output in response to the first signal across said coil and a second output in response to the second signal across said coil;   said received combination being represented in a form comprising at least one magnetically reactive received combination area adjacent to and within the magnetic field of said coil to cause said second signal to be produced across said coil, said second output signal providing at least part of a second combination corresponding to said first combination;   means within said housing adapted to operate said securing means in response to said activation signal;   means within said housing for changing said stored combination information to said received combination when a comparison is favorable; and,   an energy source connected to supply the power requirements of said lock and system. .Iaddend. .Iadd. 8. An independently operable electronic lock and system having an alterable combination, said lock being operable in response to a correct combination, comprising:   a lock housing adapted to be secured to a door;   securing means connected to said housing;   alterable memory means within said housing storing combination information for operating said lock;   means within said housing for receiving and detecting a first received combination, comparing said first received combination with said stored combination information, and generating an activation signal when a comparison is favorable;   said receiving and detecting means comprising a plurality of sensor coils connected to receive the output of an oscillator, each coil having a ferrous metal core and being connected to produce a first signal across said coil in the absence of received combination area and a received second signal across said coil in the presence of a combination area and   a tuned circuit connected to produce a first output corresponding to the first signal across the respective coil and a second output corresponding to the second signal across the respective coil;   said received combination being represented in a form comprising at least one magnetically reactive received combination area adjacent to and within the magnetic field of at least one of said sensor coils to cause said second signal to be produced across said at least one coil, said first and second output signals providing a second combination corresponding to said first combination;   means within said housing adapted to operate said securing means in response to said activation signal;   means within said housing for changing said stored combination information to said received combination when a comparison is favorable; and,   an energy source connected to supply the power requirements of said lock and system. .Iaddend..Iadd. 9. An independently operable electronic lock and system having an alterable combination, said lock being operable in response to a correct information, comprising:   a lock housing adapted to be secured to a door;   securing means connected to said housing;   alterable memory means within said housing storing combination information for operating said lock;   means within said housing for receiving and detecting a first received combination, comparing said first received combination with said stored combination information, and generating an activation signal when a comparison is favorable;   said receiving and detecting means comprising a plurality of sensor coils connected to receive the output of an oscillator, each coil having a ferrous metal core and being connected to produce a first signal across said coil in the absence of a received combination area and a second signal across said coil in the presence of a received combination area and   a circuit connected to produce a first output in response to the first signal across the respective coil and a second output in response to the second signal across the respective coil;   said received combination being represented in a form comprising at least one magnetically reactive received combination area adjacent to and within the magnetic field of at least one of said sensor coils to cause said second signal to be produced across said at least one coil, said first and second output signals providing a second combination corresponding to said first combination;   means within said housing adapted to operate said securing means in response to said activation signal;   means within said housing for changing said stored combination information to said received combination when a comparison is favorable; and,   an energy source connected to supply the power requirements of said lock and system. .Iaddend..Iadd. 10. An independently operable electronic lock and system having an alterable combination, said lock being operable in response to a correct combination, comprising:   a lock housing adapted to be secured to a door;   securing means connected to said housing;   alterable memory means within said housing storing combination information for operating said lock;   means within said housing for receiving and detecting a first received combination, comparing said first received combination with said stored combination information, and generating an activation signal when a comparison is favorable;   said receiving and detecting means comprising a plurality of sensor coils connected to receive the output of an oscillator, each coil having a ferrous metal core and being connected to produce a first signal across said coil in the absence of a received combination area and a second signal across said coil in the presence of a received combination area and   a circuit connected to produce a first output corresponding to the first signal across the respective coil and a second output corresponding to the second signal across the respective coil;   said received combination comprising at least one magnetically reactive received combination area adjacent to and within the magnetic field of at least one of said sensor coils to cause said second signal to be produced across said at least one coil, said first and second output signals providing a second combination corresponding to said first combination;   means within said housing adapted to operate said securing means in response to said activation signal;   means within said housing for changing said stored combination information to said received combination when a comparison is favorable; and,   an energy source connected to supply the power requirements of said lock   
     
     
        and system. .Iaddend..Iadd. 11.  An independently operable electronic lock and system having an alterable combination, said lock being operable in response to a correct combination, comprising: a lock housing adapted to be secured to a door;   securing means connected to said housing;   alterable memory means within said housing storing combination information for operating said lock;   means within said housing for receiving and detecting a first received combination, comparing said first received combination with said stored combination information, and generating an activation signal when a comparison is favorable;   said receiving and detecting means comprising at least one sensor coil connected to receive the output of an oscillator, said coil having a ferrous metal core and being connected to produce a first signal across said coil in the absence of a received combination area and a second signal across said coil in the presence of a received combination area and   a circuit connected to produce a first output corresonding to the first signal across said coil and a second output corresponding to the second signal across said coil;   said received combination being represented in a form comprising at least one magnetically reactive received combination area adjacent to and within the magnetic field of said coil to cause said second signal to be produced across said coil, said second output signal providing at least part of a second combination corresponding to said first combination;   means within said housing adapted to operate said securing means in response to said activation signal;   means within said housing for changing said stored combination information to said received combination when a comparison is favorable; and,   an energy source connected to supply the power requirements of said lock   
     
     
        and system. .Iaddend..Iadd. 12.  An independently operable electronic lock and system having an alterable combination, said lock being operable in response to a correct combination, comprising: a lock housing adapted to be secured to a door;   securing means connected to said housing;   alterable memory means within said housing storing combination information for operating said lock;   at least one sensor coil within said housing connected to receive the output of an oscillator, said coil having a ferrous metal core and being connected to produce a first detection signal across said coil corresponding to lack of proximity to said coil of a combination area of a first received combination representation and a second detection signal across said coil corresponding to proximity to said coil of a combination area of said first received combination representation;   a circuit connected to produce a first comparison signal corresponding to the first detection signal across said coil and a second comparison signal corresponding to the second detection signal across said coil;   said received combination representation being in a form comprising at least one magnetically reactive received combination area causing, by at least the temporary proximity of said area to said coil within the magnetic field of said coil, said second detection signal to be produced across said coil, said second comparison signal providing at least part of a second combination representation corresponding to said first received combination representation;   means within said housing for comparing said second combination representation with said stored combination information and generating an activation signal when a comparison is favorable;   means within said housing adapted to operate said securing means in response to said activation signal;   means within said housing for changing said stored combination information to correspond to said received combination representation when a comparison is favorable; and,   an energy source connected to supply the power requirements of said lock and system. .Iaddend.