Patent ID: 7172718

Claim:
A method of manufacturing a power transmission belt comprising a body with a length and a cushion rubber layer in which at least one load carrying member is embedded so as to extend lengthwise of the body, said method comprising the steps of: providing a mold having a flow passage with a discharge port; extrusion molding (a) a first rubber composition comprising rubber with short fibers therein and (b) a second rubber composition that is different than the first rubber composition to produce a first sheet in which the second rubber composition defines at least a part of the cushion rubber layer, the step of extrusion molding the first and second compositions comprising the steps of causing the first rubber composition to flow downstream through the flow passage and to and from the discharge port and causing the second rubber composition to be directed against the first rubber composition and to flow with the first rubber composition through the flow passage to and through the discharge port, the step of extrusion molding the first and second rubber composition further comprising causing the first rubber composition to flow through a portion of the flow passage without the second rubber composition directed against the first rubber composition; applying the at least one load carrying member to the second rubber composition to produce a preform assembly; and processing the preform assembly to produce a power transmission belt.