Process for manufacturing a sliding contact piece for medium to high current densities

Abstract

A process for manufacturing a sliding contact piece for medium to high current densities including a step of warm premixing of graphite and plastic binder, a step of cold mixing of the resulting premixture with copper, a step of pressing of the resulting main mixture into the sliding contact piece, and finally a step of sintering of it; and so as to improve the operating characteristics of the sliding contact piece, which is free of any environmentally harmful additives, a metal such as zinc, tin, bismuth or an alloy of such metals is added during the premixing of the graphite and plastic binder.

1 . (canceled) 
   
   
       2 . A process for manufacturing a sliding contact piece for medium to high current densities comprising the steps of warm premixing graphite and plastic binder, cold mixing the resulting premixture with copper, pressing the resulting main mixture into a sliding contact piece, and executing sintering thereon, wherein
 during the step of mixing the main mixture with copper, a metal selected from the group consisting of zinc, tin, bismuth and an alloy thereof is added.   
   
   
       3 . The process according to  claim 2 , wherein during mixing the main mixture with copper, brass powder is added. 
   
   
       4 . (canceled) 
   
   
       5 . A process for manufacturing a sliding contact piece for medium to high current densities comprising the steps of warm premixing graphite and plastic binder, cold mixing the resulting premixture with copper, pressing the resulting main mixture into a sliding contact piece, and executing sintering thereon, wherein
 during the step of mixing the main mixture, an oxide of a metal selected from the group consisting of zinc, tin, bismuth and an alloy thereof is added.   
   
   
       6 . (canceled) 
   
   
       7 . A process for manufacturing a sliding contact piece for medium to high current densities comprising the steps of warm premixing graphite and plastic binder, cold mixing the resulting premixture with copper, pressing the resulting main mixture into a sliding contact piece, and executing sintering thereon, wherein
 during the step of mixing the main mixture, a subcarbonate of a metal selected from the group consisting of zinc, tin, bismuth and an alloy thereof is added.   
   
   
       8 - 12 . (canceled) 
   
   
       13 . A sliding contact piece for medium to high current densities based on copper and carbon with an admixture of a metal, wherein the sliding contact piece is produced using the process according to at least one of  claims 2 ,  3 ,  5 ,  7  and  12 .