Patent ID: 7393487
Filing Date: 2008-07-01
Classification: F16H

Abstract:
1. A method of manufacturing a synthetic resin guide for an endless, flexible, power transmission medium, said guide comprising an elongated rail having an elongated surface on one side thereof, said surface having a gradual convex curvature in a plane in which the direction of its elongation lies, and facing in a first direction for sliding engagement with said power transmission medium, and an elongated rail support fixed to the opposite side of said rail, said rail support extending along said opposite side of the rail in the direction of elongation thereof, and also extending away from said rail in a direction opposite to said first direction, the method comprising: injecting resin into a mold cavity having an elongated shape corresponding to the shape of the guide to be produced, and thereby forming a unitary molded structure comprising both said rail and said rail support, the rail support comprising an elongated portion extending along the length of the guide and spaced from the rail, and a web connecting the rail to said elongated portion, the web being narrower than the rail and the elongated portion and extending substantially the entire length of the guide; during the injection of resin into the mold cavity, forming a reinforcing rib on said web by causing said resin to flow into a rib-shaped portion of said mold cavity along a continuously curved undulating path that is alternately tangent to portions of the mold cavity in which said rail and said elongated portion are formed; and throughout the injection of resin into the mold cavity, maintaining substantially laminar flow of resin in said mold cavity; whereby eddy currents and turbulent flow in said resin, and stagnant resin in a fluid state, are avoided, and said resin has a substantially strain-free molecular orientation when solidified.