Abstract: In a small to medium-sized commutator having segments which are circumferentially spaced from each other and are insulated from a hub, with at least one concentric annular groove in the body formed by the segments, in which groove a biased reinforcing ring is arranged. The body formed by the segments is free of arch compression at least in its dynamically and thermally unloaded condition. The segments, under a compression loading of the insulated or insulating hub and/or shaft, are acted upon radially with a compression force corresponding to the total biasing of all present reinforcing rings.In the manufacture of the commutator, each reinforcing ring is in its expanded condition when it is brought into the position provided in the annular groove. Thereafter, spacing elements used to position the segments are removed from the intermediate spaces between the segments.

Abstract: A commutator for electric machines is disclosed. The commutator comprises a cylindrical body of insulating material having a plurality of lamella segments affixed by means of projecting anchoring elements about the periphery thereof. Each lamella segment is provided at one end with a hook base and hook to the latter of which a coil wire is electrically and mechanically connected by welding. The insulating body has radially and axially projecting ribs which support the respective hook bases of the lamella segments. The width of each supporting rib and associated hook base gradually increases from a point adjacent the hook toward the transition from the hook base to the lamella segment to provide better support and heat conductivity during the process of welding the coil wire to the hook.