Patent ID: 6516643
Filing Date: 2003-02-11
Classification: E05B,Y10T

Abstract:
A lock having a face, a core, an indicator means, a first key and a second key, said core having a keyway adapted for the insertion into said core either of said first key or said second key, said core being rotatable in said lock after insertion of said first key into said keyway, and said core being rotatable in said lock after insertion of said second key into said keyway, said indicator means having an armed position and an indicator position, said indicator means when in said armed position extending at most a short distance from said face of said lock, said indicator means when in said indicator position extending a substantially greater distance from said face of said lock, and in which a rotation of said first key, after insertion of said first key into said keyway, results in a movement of said indicator means from said armed position to said indicator position, and in which, said movement of said indicator means having occurred, a rotation of said second key, after insertion of said second key into said keyway, permits said indicator means to be moved from said indicator position to said armed position, but in which, said movement of said indicator means having occurred, rotation by said first key of said core does not permit said indicator means to be moved from said indicator position to said armed position.