Toothed power transmission belt with back fabric

Abstract

A toothed power transmission belt with a smooth back side surface has a back jacket on the back side surface; wherein the back jacket comprises a closed-mesh, knit fabric tube. The fabric tube may be knitted on a circular weft knitting machine and may be heat set after knitting. The fabric tube may be treated with an epoxy, RFL or other treatment to provide for oil resistance, adhesion, frictional properties, etc.

What is claimed is: 
     
         1 . A toothed power transmission belt comprising: a rubber belt body with a toothed surface on one side thereof and a smooth back side surface opposite the one side; a tooth jacket covering the toothed surface; a tensile cord embedded in the belt body; and a back jacket on the back side surface; wherein the back jacket comprises a closed-mesh, knit fabric tube. 
     
     
         2 . The belt of  claim 1  wherein the fabric tube is knitted with an elastic yarn and an inelastic yarn. 
     
     
         3 . The belt of  claim 1  wherein the fabric tube is knitted with an elastic yarn and an inelastic yarn fed separately into a circular, weft-knitting machine. 
     
     
         4 . The belt of  claim 3  wherein the elastic yarn comprises polyurethane and the inelastic yarn comprises nylon. 
     
     
         5 . The belt of  claim 1  wherein the back jacket further comprises a coating comprising an epoxy on the fabric tube. 
     
     
         6 . The belt of  claim 1  wherein the back jacket further comprises a coating comprising an epoxy and a latex rubber on the fabric tube. 
     
     
         7 . A method of making the toothed power transmission belt of  claim 1  comprising:
 providing the closed-mesh, knit fabric tube; 
 treating the knit fabric tube with a coating to make the back jacket; 
 applying the back jacket to a belt slab on a belt-building mandrel; 
 curing the belt slab and cutting to a desired width, resulting in the toothed power transmission belt. 
 
     
     
         8 . The method of  claim 7  wherein the treating comprises drying the coated fabric tube in a stress-free process. 
     
     
         9 . The method of  claim 8  wherein the stress-free process comprises drying the coated fabric tube on a carrier fabric. 
     
     
         10 . The method of  claim 9  wherein the knit fabric tube comprises an elastic yarn and an inelastic yarn. 
     
     
         11 . The method of  claim 10  wherein the elastic yarn comprises polyurethane and the inelastic yarn comprises nylon. 
     
     
         12 . The method of  claim 10  wherein the elastic yarn and the inelastic yarn are fed separately into a circular, weft-knitting machine. 
     
     
         13 . The method of  claim 7  wherein the coating is an epoxy-based coating. 
     
     
         14 . The method of  claim 13  wherein the coating comprises a rubber latex. 
     
     
         15 . The method of  claim 7  further comprising heat setting the knit fabric tube. 
     
     
         16 . A method of using the toothed power transmission belt of  claim 1  comprising:
 supplying the belt of  claim 1  for installation on a belt drive to be used in an oil-wet environment. 
 
     
     
         17 . The method of  claim 16  further comprising installing the belt on an automotive timing drive in an oil-wet environment.