Abstract: A sliding electrical contact part is disclosed. The contact part includes a base of carbonaceous material and copper. The contact part is lead-free and contains zinc and iron-base particles having a size less than 500 ?m. The contact part is particularly suitable for electrical devices which require high friction densities and friction velocities, such as motor vehicle starters with a high power-to-weight ratio.

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.

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.

Abstract: A sliding electrical contact part comprising a base containing carbon, copper, zinc and iron, wherein said part is multi-layer, with at least one layer composed of a material with a low electrical resistivity and at least one layer composed of a material with a higher electrical resistivity, the material comprising the layer with a low electrical resistivity containing zinc and iron based particles, whose size is less than 500 ?m.

Abstract: Applying, onto graphite discs or blocks, especially carbon brushes of electric. machines, a metal coating which should have a high content of at least one metal, especially from the group comprising copper and tin, and which should reliably adhere to the graphite disc, so that the application is done in an environmentally friendly manner. To accomplish this, the metal is thermally sprayed onto a surface of the graphite disc or the graphite block.

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.

Abstract: Carbon brush including at least one pressed-in stranded copper wire arranged as a plait-woven hollow stranded wire, formed from a plurality of copper strands of diameter 0.05 to 0.1 mm, and recrystallized by heat treatment. The hollow stranded wire contains at least one stiffening inner wire having a diameter of 0.1 to 0.5 mm, the diameter of the at least one stiffening inner wire being at least twice the diameter of any of the copper strands.

Abstract: A process for fixing a graphite-rich material onto a metallic body by mixing graphite powder with a plastic material to obtain a graphite-rich material, pressing the graphite-rich material onto a layer of a metal-rich material, in a single step, forming thereby a green pressing formed of a graphite-rich component and a metal-rich layer, aligning the green pressing with the metallic body to which it is to be fixed, and subjecting the aligned metallic body and green pressing to a heat treatment to bond the metal-rich layer to the metallic body.

Abstract: An electrical commutator machine which serves to actuate units is proposed. The commutator machine comprises a ring-like carrying plate, which surrounds the axis of rotation of the commutator, for tubular guide casings which are made of metal, have a square cross section, are permanently connected to said carrying plate and in which brushes belonging to the commutation device are guided along the longitudinal axis of the tube and are placed under load on a contact face of the commutator. A particularly simple and advantageous structure of the commutator machine is produced if, in order to secure the casing on the carrying plate, at least two tongues which are upright with respect to the wall plane are arranged on one of the casing walls, to which tongues there are assigned insertion slits which are located in the one end of the carrying plate and detain the tongues.