Patent ID: 7056243

Claim:
A plastic movable guide for a transmission device comprising: a guide body including an elongated shoe having front and back sides facing in opposite directions, a surface on the front side of the shoe for sliding engagement with a traveling, flexible, power transmission medium, and a plate-receiving portion extending longitudinally along the back side of the shoe, the shoe and plate-receiving portion being integrally molded as a unit from a synthetic resin, and the plate-receiving portion having a slot with an opening facing in a direction opposite to the direction in which said front side faces; and a unitary, elongated, reinforcing plate for reinforcing said guide body, said plate being fitted into said slot; the guide body having a mounting hole adjacent to an end of said plate-receiving portion for mounting the plastic movable guide on a frame of a machine, and the reinforcing plate having a through hole adjacent an end of the reinforcing plate, said mounting hole and said through hole being in register with each other whereby a mounting shaft on which said plastic movable guide is pivoted can extend through both of said holes along a shaft axis, for pivoting the guide body so that it rotates in a plane of rotation to which said shaft axis is perpendicular; the guide body having a plunger-receiving portion at a location remote from said holes, said slot extending at least into said plunger-receiving portion of the guide body, and the reinforcing plate protruding from said slot at the location of said plunger receiving portion to expose at least a portion of an edge of said reinforcing plate, whereby a plunger of a tensioner may press directly against said portion of said edge of the reinforcing plate at said location; and the cross-sectional shape of said edge of the reinforcing plate in planes perpendicular to said plane of rotation being convex, and free of angles of 90° or less, at the location of said plunger-receiving portion of the guide body, whereby contact between a plunger and a sharp corner of the reinforcing plate is avoided even if the plastic movable guide is tilted relative to its plane of rotation about said mounting shaft.