Method and apparatus for decoding a pin tumbler lock

Apparatus for decoding a lock having a lock housing, a locking member supported in said housing for movement between a locked and unlocked position;

• said lock housing and said locking member, each, having a like plurality of bores arranged in an array of columns and rows and any given bore in said lock housing adapted to be in and out of registry with a related bore in said locking member depending on the position of said locking member;
• each aligned bore in said housing and in said locking member having a ball, first and second tumblers and spring biasing means urging said tumblers to one end of said bore;
• a key card slot and a program card slot within said lock housing and extending through each bore and a key card and a program card in each's respective slot, said key card and said program card having a predetermined opening or closed space in alignment with each bore to position within each bore said first tumbler in said lock housing and said second tumbler in said locking member to permit said locking member to move along a shear line relative to said lock housing, said apparatus comprising:
• a decoding key card for insertion into said key card slot and having a plurality of pressure sensitive areas formed therein in an array at least equal in number to a row of said bores in a matrix, each pressure sensitive area equal to the area of each bore, pressure sensitive means associated with each pressure sensitive area for sensing the force of said tumblers in the bore which the pressure sensitive area overlies, and means associated with said pressure sensitive means for physically displaying the force sensed by each pressure sensitive area whereby said lock can be decoded once the force for all bores have been sensed and displayed.

Lock decoding apparatus for use in a lock having a housing, a locking member supported in said housing for movement between locked and unlocked positions, said housing and said locking member having aligned bores, tumbler means supported in each of said aligned bores for movement between a first position in which the locking member is movable relative to the housing and a second position in which the tumbler means blocks movement of the locking member relative to the housing, a plate-like key card member, a plate-like program card member, said housing being provided with two slots each for respectively receiving one of said plate-like card members, said bores in the housing and locking member being arranged in a pre-determined pattern, said plate-like card members having respective regions corresponding to the location of said bores in said pattern, said plate-like card members when inserted in said slots positioning said regions in superimposed relation with one another for cooperating with said tumbler means, the thickness of the plate-like members in said regions being correlated in a code such that the combined thickness of said plate-like members in the superimposed regions is different from the combined thickness of said plate-like members outside the superimposed regions to constitute means for acting on said tumbler means to mechanically move the same to said first position when said code corresponds to the pattern of the bores, said decoding apparatus comprising:

• an especially constructed plate-like member having a plurality of pressure sensitive areas formed therein, said plurality of pressure sensitive areas corresponding in number, size, and location to be identical to said bores in said lock, microprocessor means for determining the pressures sensed by each pressure sensitive area and generating a force signal indicative of the forces generated by said tumbler means and LED means for generating for each pressure sensitive area a lighted signal when the force signal for such pressure sensitive area exceeds a predetermined value.