Ruehl, F.F.RuehlWauer, G.G.Wauer2022-03-082022-03-081993https://publica.fraunhofer.de/handle/publica/302768DE 3840049 A UPAB: 19930928 A wire spark erosion machine tool has a actting wire that is continuously fed over guide rollers and receives electrical current from contacts within a holder. The contacts are in the form of inserts (5) that are produced of a sintered material with a hard base that includese a metal, such as copper or silver, that provides high electrical conductivity. The contacts can be set into holders (6) that are retained within carriers (7), hinged at a suitable point to the machine frame. This allows the contacts to be moved clear of the wire that passes through the groove (8). ADVANTAGE - Provides good contact with low wear for erosion wire. 2,3/21de608621patent1988-3840049