Mechanism for automatically regulating tension of wires employed in a window regulator

Claim 1

A mechanism for automatically regulating tension of wires employed in a window regulator comprising: (a) a housing; (b) a drum being provided for rotational movement within said housing, and having a first side surface provided with a first ratchet teeth, a second side surface provided with a first engaging portion for engaging a first wire end, and a peripheral surface as a winding surface, said first side surface of said drum having a cylindrical groove around the axis of said drum having a spiral winding groove extending from said peripheral surface of said drum adajacent to said first side surface toward said cylindrical groove; (c) ratchet plate being adajacent to said drum coaxially, and having a surface provided with a second ratchet teeth engaging said first ratchet teeth of said drum and a second engaging portion for engaging a second wire and located inside said second ratchet teeth in the radial direction, said ratchet plate further having a cylindrical projection capable of being insserted in said cylindrical groove, said cylindrical projection having said second engaging portion, and a winding surface is mounted on a peripheral surface of said cylindrical projection; (d) a spiral spring having one end engaged with said ratchet plate and having the other end engaged with said housing, and urging said ratchet plate in such direction that said first ratchet teeth and said second ratchet teeth are moved idly; (e) an elastic member axially urging said drum toward said ratchet plate; and (f) a shaft for rotating said drum by means of engaging with said drum.