Patent ID: 8096154

Claim:
A door lock operable in poor lighting conditions mounted in a cavity through a door, comprising: a bolt, extensible from the edge of a door to lock the door; means for enabling a first key, from a first side of the door, to withdraw the bolt; and means for enabling a permutation device selectable according to a memorized spatial orientation, from the second side of the door, to withdraw the bolt; the permutation device selectable according to a memorized spatial orientation being either a) an array of push buttons; b) an array of sliding rods; c) at least one dial, or d) a simulated clock face having at least one clock hand; the means for enabling the permutation device selectable according to a memorized spatial orientation, from the second side of the door, to withdraw the bolt, comprising a plug that can be turned from the second side of the door that withdraws the bolt when turned; a crank at one end of the plug for manually turning the plug; the plug disposed through a second hole in the second side of the door; a hollow cylinder disposed coaxially to the second hole and extending from the second side of the door perpendicularly into the cavity, and the plug disposed within the hollow cylinder so that the plug can rotate slidably and coaxially within the hollow cylinder; the inner wall of the hollow cylinder and the outer wall of the plug forming a common cylindrical surface; at least one pin having a first end and a second end; the first end of the at least one pin being linearly translatable in response to orientation of the permutation device, the second end of the at least one pin being linearly translatable perpendicularly through the inner wall of the hollow cylinder, so that the second end of the at least one pin can move into and out of a mating socket in the plug; the at least one pin preventing rotation of the plug when the second end of the at least one pin is in a mating socket, and allowing rotation of the plug only when the at least one pin is moved out of the mating socket in response to orientation of the permutation device.