Patent ID: 6023954
Filing Date: 2000-02-15
Classification: E05B,Y10T

Abstract:
A key blank in combination with a cylinder lock for the key blank, comprising:1) a cylinder lock including a generally horizontal keyway, said cylinder lock including a rotatable plug disposed in a housing and a plurality of generally vertical tumbler pins located adjacent the keyway, the tumbler pins being adapted to be engaged by bittings located on a flat key blade to permit the plug to rotate relative to the housing to operate the lock;2) a key blank adapted to be formed into a key with a plurality of bittings therein to operate said cylinder lock, the key blank comprising:a key bow;an elongated key blade extending away from the key bow, the key blade having upper and lower parallel planar surfaces and opposite parallel planar side surfaces joining the upper and lower surfaces, the upper and lower surfaces having a length greater than the length of the opposite side surfaces to provide the key blade with a substantially rectangular shape in cross-section; anda plurality of elongated grooves formed in said upper surface of the key blade and running parallel to a longitudinal axis of the key blade, said grooves forming lowered areas extending below from said upper surface of the key blade and including at least one major groove having a greatest amount of material removed from said key blade, said upper surface including an area defined by said at least one major groove which is designated to receive bittings extending across the longitudinal axis and cutting through said lowered areas, a substantially greater amount of material being removed from said upper surface of said key blade to form said plurality of grooves in said upper surface of said key blade than is removed from a lower surface of said key blade to form grooves in said lower surface of said key blade, and said at least one major groove in said upper surface of said key blade being substantially greater than any groove in said lower surface of said key blade;3) said horizontal keyway being configured to receive said key blade of said key blank, with said keyway having conforming raised areas corresponding to said lowered areas of said grooves of said key blank;4) said tumbler pins having generally vertical axes and being located generally perpendicular to said upper surface over said area designated to receive bittings, above said at least one major groove, said tumbler pins having tip portions configured to engage within bittings having generally V-shape longitudinal cross-sections and an arcuate bottom surface extending transversely across the width of the key blade from a minimum depth proximate one of said side surfaces to a maximum depth at the other of said side surfaces.