Patent ID: 8443639

Claim:
A combination lock with a combination dial operatively linked to a drive cam and a plurality of tumbler wheel assemblies rotatably stacked on a hub to form a tumbler stack within a lock case, each of said plurality of tumbler wheel assemblies having a tumbler gate, said drive cam having a drive cam gate for engaging a nose of a pivotable fence lever arm, and said pivotable fence lever arm for retracting a slideable lock bolt when a correct combination is dialed, said combination lock comprising: (a) a combination tumbler ring having an inside radius for engaging said hub and an outside circumference digitated with a plurality of tumbler ring micro-fingers, each of said plurality of tumbler ring micro-fingers having a tumbler ring micro-finger root and a tumbler ring micro-finger crown, said outside circumference having radius R′ at said tumbler ring micro-finger root and radius R at said tumbler ring micro-finger crown; (b) at least one interlock lever arm for opposingly contacting said outside circumference of said combination tumbler ring, each said at least one interlock lever arm having a first end and a second end, each said at least one interlock lever arm having a fulcrum, said first end of each said at least one interlock lever arm having a plurality of interlock lever arm micro-fingers disposed on an arcuate member with a concave radius, each of said plurality of interlock lever arm micro-fingers having an interlock lever arm micro-finger root and an interlock lever arm micro-finger crown, said plurality of interlock lever arm micro-fingers for interdigitatingly engaging said plurality of tumbler ring micro-fingers; and (c) each of said plurality of opposing flat-on-flat flank faces being generally perpendicular to an angular direction of torque tangential to said outside circumference at radius R at the point at which each of said flat-on-flat flank faces intersect said outside circumference where said plurality of tumbler ring micro-fingers and said plurality of interlock lever arm micro-fingers interdigitatedly engaged; wherein said plurality of tumbler ring micro-fingers and said plurality of interlock lever arm micro-fingers form a plurality of opposing crowns and roots and a plurality of opposing flat-on-flat flank faces for cooperatively resisting rotational torque when interdigitatedly engaged.