Variable diameter pulley

Claim 1

A centrifugally-operated, variable diameter pulley, including: a rotatable axle; a first pulley flange fixed on said axle; a second pulley flange rotatably mounted on said axle outwardly of said first pulley flange, and movable axially therealong toward and away from said first pulley flange; a cover member fixed to said axle outwardly of said second pulley flange, and including an outer annular wall portion arranged to angle inwardly toward said axle and the periphery of said second pulley flange; means on the outer face of said second pulley flange defining at least two circumferentially spaced sets of radially extending grooves arranged to face said cover member, each of said grooves including a pair of generally parallel, axially extending side walls, and a base wall inclined toward said axle and said cover member, at least the radially outer portions of said base walls being inclined toward said axle and said cover member at an angle that differs for each set of grooves; and a circular disc received in each groove of a selected one of said sets of grooves, said circular discs being unattached to said second pulley and said cover member, and being constrained by said generally parallel side walls of their associated grooves to movements only in a radial direction; said circular discs being moved radially outwardly in their respective grooves by centrifugal force when said axle is rotated in engagement with said inclined base walls of their respective grooves and said inclined annular wall portion of said cover member, whereby said rotatable and slidable second pulley flange is moved toward said fixed first pulley flange.