Abstract: An improvement in a locking device of the type having a series of reference combinations arranged serially upon a tape. A combination is entered into the system by a set of push buttons. The combination entered is compared with the reference combination. If both combinations are complementary, the system can be unlocked. The improvement prevents the unauthorized ascertainment of the combination needed to release the device. An isolation or restraining bar acts as a buffer between an internal gate and a set of tumbler levers. When an actuator knob is turned to unlock the system, the tumbler levers normally will engage with the gate when the combination push buttons are not set to the proper combination. The combination then becomes ascertainable, because the tumbler levers that require actuation, transmit movement to the push buttons when contacted by the gate.

Abstract: A combination lock of the type having peripherally gated tumbler wheels rotating about a common axis and adjusted by a rotatable dial and driving cam assembled on a spindle and supported for axial as well as rotary movement, the lock has an over-center spring coupled to a fence lever which normally holds the fence lever at a raised inactive position and has a fence lever accelerator which includes an anvil surface portion and a hammer portion supported by a spring formation which is stressed to an energy storage position responsive to rotation of the driving cam so that the hammer portion can be released from that position to impact against the anvil surface and impel the fence lever toward the driving cam to cause the fence lever to shift to a lowered coupled condition with the driving cam if the tumbler wheels are properly aligned and to cause it to be spring returned to the raised inactive position if they are not properly aligned.

Abstract: A combination lock is disclosed that has a plurality of separately dialed tumblers mounted for rotation around spaced parallel axes. The tumblers extend through openings in a plate and each carries a fence that cannot pass through the opening. Each opening has a lateral gate slot to receive the fence of the tumbler in the opening. The plate must move over the fences to open the lock which it cannot do until the tumblers are positioned so the fences are positioned in alignment with the gate slots. Provision is made for changing the combination when desired and for opening the lock with a master combination when the current combination is forgotten. Also, in one embodiment, the lock can be opened with a spare combination in addition to the master when the current combination is forgotten or lost.