Abstract

The combination padlock is of the type having a shackle, a dial for rotating a drive cam having a gate slot, a plurality of rotatable wheels or tumblers each with gate slots, and a fence for allowing the shackle to be opened when all of the gate slots are aligned with the fence. In carrying out the method, the dial is manipulated to sequentially align the gate slot of each wheel with the fence by incremental movement thereof and while the gate slot of the drive cam is aligned with the fence, applying force between the shackle and casing to measure movement of the shackle relative to the casing at each increment position of at least two of the wheels to determine the combination number of each wheel and/or to open the shackle. A frame is provided with structure for releasably securing the casing member in a first embodiment, and the shackle member in a second embodiment, to the frame wherein the unsecured shackle member or casing member is free to move relative to the frame. Also provided is a movement sensitive device for sensing movement between the shackle and the casing while force is applied between the shackle and casing to determine the combination numbers.

IPC Classes  ?

• E05B 19/20 - Skeleton keysDevices for picking locksOther devices for similar purposes