JPS6483952A - Toothed belt - Google Patents

Abstract

PURPOSE:To improve durability by forming a warp of canvas forming a reinforcing cloth layer using a core yarn made of undrawn synthetic fiber and a covering yarn wound round the core yarn in a toothed belt having a reinforcing cloth layer formed by canvas. CONSTITUTION:A warp 3 is orientated in the longitudinal direction of a belt of canvas forming a reinforcing cloth layer 5 integral with the surface of a tooth portion of a belt main body 1. The warp is formed by a core yarn 6 made of undrawn synthetic fiber and a covering yarn 9 wound round the core yarn 6. Accordingly, the elastic modulus of a toothed belt can be increased by property of fiber forming the core yarn 6, and lowering of heat-resisting property, and wear-resisting property, which is the disadvantage of the core yarn 6, can be prevented by fiber forming the covering yarn 9, so that even if the toothed belt is used for a long period of time, a shearing crack can not be caused in the root of tooth and lowering of strength can be avoided to improve durability. Furthermore, as the core yarn 6 is covered with the covering yarn 9, core yarn drawing operation is not obstructed at the time of molding.