Patent ID: 8667821
Filing Date: 2014-03-11
Classification: E05B,Y10T

Abstract:
1. A fence control feature for use with a combination lock, said combination lock having 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, said pivotable fence lever arm for retracting a slideable lock bolt when a correct combination is dialed, and an excentric trigger pin mounted on an outside face of said drive cam, said fence control feature comprising: (a) a trigger plate pivotably mountable at a lock case fulcrum on said lock case; (b) said trigger plate having an overcenter arm, a stop arm, and a cam follower arm disposed around a common pivot point; (c) an overcenter spring; and (d) said trigger plate further comprising an apron formed on said overcenter arm, said apron extending under said overcenter spring and over said nose and said drive cam gate; wherein said overcenter arm is operatively coupled to said pivotable fence lever arm by said overcenter spring such that said nose is normally biased to a first position raised above said drive cam and drops down toward said drive cam gate in a second position for a transitional arc of less than 35 degrees of rotational arc when resiliently urged by said excentric trigger pin acting on said cam follower arm.