Brush-holder for disc commutator of rotating electric machines

Claim 1

A brush and holder assembly for a rotating electric machine having a commutator disc disposed normal to an axis of a shaft of its armature, and the machine having a body with an end surrounding the armature and commutator disc, the brush and holder assembly comprising: (a) a brush holder shaped to fit the end of the body and having axial brush guides extending toward the commutator disc, and the holder having a cavity; (b) a brush in each of said guides, each of said brushes having an inner end contacting the commutator disc and having an outer end; (c) a single spring for pressing of said brushes toward the commutator disc, the spring having two windings shaped to fit and be housed in the cavity, adjacent ends of the windings being mutually joined together by a central loop extending offset from the windings, and the spring having two legs extending respectively from other ends of the windings and each of said legs having an end extending to and overlying the outer end of each of brushes; (d) insulating means between ends of the legs and the outer end of each of the brushes; and (e) retaining catch means adjacent to the cavity and operative to receive and retain the loop, the loop and said retaining catch means being positioned with respect to said cavity to urge the ends of the legs of the spring toward the outer ends of the brushes.