Abstract: A rekeyable look includes at least one chamber housing a tumbler pin stack having a master pin disposed between the driver pin and the bottom pin. The bitting of a change code key inserted in the keyway displaces the tumbler pin stack containing the master pin such that the interface between the master pin and the bottom pin is placed on the shear line defined by the cylinder shell and plug. Rotation of the change code key aligns a first slot on the change code key with the master pin wherein the master pin is received by the first slot. The master pin is carried with the change code key on removal of the key from the keyway. A replacement master pin disposed in the first slot is inserted into the keyway with the change code key. Rotation of the change code key aligns the replacement master pin with the drive pin.

Abstract: A lock, particularly well suited for installation in the T-handle of a vending machine or the like, which acts as a spring latch during opening and as a deadbolt in the locked position. The lock has a cylinder with a rotatable plug supporting a drive pin, the drive pin being parallel to and offset from the axis of plug rotation. The drive pin engages a ramped guide groove in a spring biased bolt, the guide groove being configured to return the drive pin to a position where it is in registration with, but displaced from, its starting position after a complete rotation of the plug.

Abstract: A machine for coding or duplicating a pattern of bits onto a key blank employs a locator block which forms reference slots for receiving a key to be duplicated. A template having a matrix of openings which correspond to possible pre-established bit locations is positioned in registration with the key receiving slots. A depth gauge is employed so that a guide selectively seated in a bit defining cut-out of the pattern key indicates the correct incremental depth of the bit to be duplicated. A cutter having a preestablished relationship to the depth gauge guide is employed to obtain the correct cutting depths for the key blank bits.