Door lock security system

In a security apparatus for a door lock, a cylinder assembly comprising:

• a main body;
• a plurality of sensor elements mounted on said body, each sensor element including a primary and secondary winding and a core component made of low reluctance material, on which said windings are wound, each core component having a gap therein which causes said core component to have a high reluctance, whereby the electromagnetic coupling between the primary and secondary winding on each core component is loose;
• a housing portion of said body with an internal bore whereon said sensor elements are mounted, said housing portion having a plurality of opposed pairs of channels formed therein so that said pairs are spaced along said housing in the axial dimension of said bore, at least a portion of each channel extending from the exterior of said housing portion into said bore, each of said core components being generally U-shaped and having opposed legs which are closer together than the diameter of said bore, each leg having a cut-out facing the other leg, which cut-out conforms generally to the contour of said bore, said cylinder assembly further comprising a tubular insert dimensioned to be received coaxially within said bore, each core component being mounted on said cylinder assembly by inserting each of the opposed legs into a channel of a respective channel pair so that said cut-outs are generally aligned with the surface of said bore, said insert being mounted into said bore with opposed legs straddling said insert to prevent withdrawal of said cores from the respective channel pair.

In a door lock security apparatus used with a door lock adapted to be locked and unlocked with at least one of a plurality of keys where the key is oriented in a predefined arrangement with respect to the lock:

• a main body;
• a plurality of sensor elements mounted on said body, each sensor element including a primary and secondary winding and a core component made of low reluctance material, on which said windings are wound, each core component having a gap therein which causes said core component to have a high reluctance, whereby the electromagnetic coupling between the primary and secondary winding on each core component is loose;
• disabling means coupled to said lock for normally preventing the locking and unlocking thereof, and actuable to enable locking and unlocking;
• and
• an emergency key assembly including an emergency key having a shank and at least one active element positioned along said shank to align with the gap in one of said core components when the emergency key is in said predefined arrangement, each active element including a core element and an active winding wound thereon, and a source of a time-varying emergency signal coupled to at least one of said active windings;
• emergency sensing means coupled to the same winding of at least the core components having active elements aligned therewith for sensing the signal on each winding, only the windings disposed on core components aligned with an active element having a replica of the emergency signal;
• means for generating a master reference signal substantially identical to said emergency signal;
• and
• means for comparing said emergency reference signal and said replica signal, said comparing means producing an actuating signal for actuating said disabling means when said replica and emergency reference signals are substantially identical.