Conveyor belt

Abstract

A thermoplastic endless belt has a smooth outer surface substantially free of discontinuities and an inner surface with a plurality of teeth at a given belt pitch. The teeth are adapted to engage a sprocket with circumferentially spaced sheaves at a sprocket pitch greater than the belt pitch. The belt is slightly stretchable so that the sprocket can drive the endless belt when engaging the teeth within a range of load on the belt. The belt is preferred for use in conveyors in food processing industries where the smooth outer surface can transport food items and is easier to clean and keep free of impurities.

1 . A method of making a conveyor belt segment with integrally formed teeth for a conveyor belt in a conveyor where the belt is driven by engagement of the teeth with sheaves on a pulley, comprising the steps of:
 providing a substantially unreinforced flat ribbon of thermoplastic material, having an inner surface and an outer surface substantially free of discontinuities; and   molding teeth onto the inner surface of the flat ribbon;   wherein the teeth extend from the inner surface at a given belt pitch and the belt is stretchable through its length;   whereby to form a belt segment that can be made to a selected length and the ends spliced together to form an endless conveyor belt of predetermined size.   
     
     
         2 . The method of  claim 1  wherein the molding step comprises injection molding. 
     
     
         3 . The method of  claim 1  wherein the teeth extend from one edge of the belt to the other. 
     
     
         4 . The method of  claim 1  wherein the belt is stretchable within a range of up to three percent of its total length. 
     
     
         5 . The method of  claim 1  wherein the inner surface and the teeth are treated with an antibacterial agent. 
     
     
         6 . The method of  claim 1  wherein the teeth are formed of urethane and the rest of the belt is formed of copolyester. 
     
     
         7 . The method of  claim 1  wherein the molding step comprises friction molding. 
     
     
         8 . The method of  claim 7  wherein the teeth extend from one edge of the belt to the other. 
     
     
         9 . The method of  claim 7  wherein the belt is stretchable within a range of up to three percent of its total length. 
     
     
         10 . The method of  claim 7  wherein the inner surface and the teeth are treated with an antibacterial agent. 
     
     
         11 . The method of  claim 7  wherein the teeth are formed of urethane and the rest of the belt is formed of copolyester.