Button operated combination lock

Claim 1

In a button operated combination lock of the type in which a number of button operable actuator keys are disposed with the surfaces thereof accessible in a case frame so as to be capable of being set in a selected combination lock memory state and engaging with, and disengaging from, a key plate, said key plate being engaged with a bolt lock; the improvement wherein said key plate is slidably supported inside said case frame and has a number of slits bored at predetermined positions therein; all of said actuator keys being in the form of similar flat plates, each of said said keys being loosely inserted into a corresponding one of said slits and being retractable from said case frame; a transverse slot formed in each of siad keys intersecting and engaging with said key plate loosely, each of said slots running parallel to and being displaced longitudinallly from the transverse centerline of its associated key, said keys being set in said selected memory state by mounting a preselected set of said keys in said lock with the slots thereof displaced from the transverse centerline in a first direction relative to said key plate with the remainder of said keys being mounted in said lock in inverse relationship to the preselected keys with the slots thereof displaced from said transverse centerline in a direction opposite to said first direction, the slots thereof engaging the key slits when the keys are actuated; a lock plate slidably mounted in said case frame; said lock plate and said actuator keys each including means for detachably retaining said actuator keys to said lock plate; and handle means operative in an interlocking arrangement with said bolt lock and engaging with said key plate and with said lock plate for alternatively opening said lock or resetting said keys in the selected combination memory state by detaching said actuator keys from said lock plate.