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 having a cylindrical first space with a first inner diameter and a cylindrical second space with a second inner diameter larger than said first inner diameter, said first and second space being coaxially arranged adjacently with each other; (b) a drum provided within said first space for rotational movement within said housing, said drum having a first side surface provided with first ratchet teeth, a second side surface provided with a first engaging portion for engaging a first wire end, and a peripheral surface as winding surface; (c) a ratchet plate coaxially adjacent to said drum, said ratchet plate having a front side surface provided with second ratchet teeth, a back side surface provided with a coaxially positioned boss, and a second engaging portion on said front side surface for engaging a second wire end, said winding surface of said drum being provided for winding both wires, said ratchet plate being positioned so as to separate said first space from said second space, said boss extending into said second space; (d) a spiral spring positioned in said second space so as to surround said boss, said spiral spring having one end engaged with said boss of said ratchet plate and having the other end engaged with an inner surface of said second space of said housing, an outer diameter of said spiral spring in a state of setting in said housing being larger than a diameter of said drum, said spiral spring 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 engaged with said drum for rotating said drum.