GB1133245A - Commutators - Google Patents

Abstract

1,133,245. Making commutators. MANUFACTURE DE VILEBREQUINS DE LORETTE. 8 July, 1966 [12 July, 1965], No. 30909/66. Heading B3A. [Also in Division H2] In a method of making a face commutator a sheet metal strip is fed intermittently through a sequence of work stations, a disc is partially or completely stamped out of the strip, the radial grooves defining commutator segments being formed in the disc by a series of stamping operations whereafter the disc is deburred and peripheral notches are made in the segments for connections thereto. When the disc is completely stamped out in the initial stage it is left in the strip, which is notched at its edges so as to provide accurate locating at each forming station. The partially stamped disc 3 is formed in strip having edges 1e of reduced thickness so that the retaining lugs lie therein. In successive stages an annular groove 4 is formed, the groove is given a dovetail cross-section, the individual segments are formed by slots 5 which are progressively deepened, the disc is separated or removed from the strip, and peripheral slots 6 are formed. The commutator is then offered up to a tapered rotor and is secured by plastics material (P) in which the windings (R1) are also embedded and which fills the groove 4 and the slots 5, Fig. 12 (not shown). The face of the commutator is then ground to remove the bottoms of the slots 5, thereby separating the individual segments.