Patent ID: 6481255
Filing Date: 2002-11-19
Classification: E05B,Y10T

Abstract:
A cylinder lock comprising:a shell, said shell having an interior surface which defines a core receiving chamber having an axis, said shell having at least a first longitudinal cam groove extending along said interior surface, said shell being mounted with a fixed orientation in the use environment of said lock; a rotatable core cooperating with said shell to form the relatively movable component of said lock, said core having an exterior surface and being disposed within said core receiving chamber of said shell for rotation about said chamber axis, said core defining a longitudinally extending keyway having oppositely disposed sides which define a central plane, said core having at least a first array of tumbler receiving chambers, said tumbler receiving chambers extending between said keyway and said exterior surface of said core, said core further having a longitudinal slot in said exterior surface, said longitudinal slot being alignable with said shell longitudinal cam groove, said core longitudinal slot intersecting said chambers of said array, said core additionally having a cut-out which has upper and lower ends and extends from said exterior surface in the direction of said keyway, said cut-out intersecting said longitudinal slot and being in communication with said keyway via an opening in the first side of said keyway, an arcuate shear line for said lock being defined by the interface between said interior surface of said shell and said exterior surface of said core, said shear line having a radius of curvature; tumblers reciprocally disposed in respective of said core tumbler receiving chambers, said tumblers each having at least a first notch in a side thereof which faces generally in the direction of said shell interior surface, said tumblers each further having an activation surface which is disposed in said keyway; an elongated side bar located in said longitudinal slot in said core exterior surface, said side bar having outwardly projecting fingers which extend into said tumbler receiving chambers, said fingers being sized and shaped to cooperate with said tumbler notches; means resiliently biasing said side bar in the direction of said shell whereby said side bar engages said shell cam groove and bridges said shear line when said lock is in the locked condition; and a plate loosely disposed in said cut-out in said core, said plate having a first, inner side confronting said core, a second outer side confronting the shell adjacent said groove, an upper end adjacent the upper end of the cutout and a lower end adjacent the lower end of the cut-out, said plate being movable relative to said core between first and second positions along a direction generally extending between the upper and lower ends of the cutout, said plate having a cam follower projection on the first side thereof, said plate projection being located to extend into said keyway via said opening whereby force to impart movement to said plate between said first and second positions may be delivered to said projection by direct, rigid contact with a key inserted in said keyway, said plate having at least a pair of adjacent surfaces on the second side thereof, said adjacent surfaces respectively being displaced first and second distances from said first side of said keyway, said first of said adjacent surfaces being juxtapositioned to said sidebar in said first position of said plate whereby said plate will prevent movement of said sidebar in a direction of said keyway and out of engagement with said shell cam groove, said second of said adjacent surfaces being in registration with said sidebar when said plate is in said second position whereby said plate does not impede movement of said sidebar out of said shell cam groove and in the direction of said keyway.