Abstract: Brush card or holder assemblies are disclosed. The assemblies avoid any need for a separate plastic cap and utilize a lead wire (which could be or include a rod or other electrically-conductive device) both electrically to connect a brush to an external component and mechanically to fix the position of one end of a mechanism, such as a spring, for biasing the brush toward the surface of a commutator or other rotating machine element.

Abstract: Addressed herein are commutators and methods of manufacturing them. The methods permit the carbonaceous material and core of a commutator to be molded simultaneously, rather than in a two-step process, and can eliminate one of two curing procedures used in connection with other manufacturing techniques. The necessity of machining the inner surface of the commutator shell to remove undesired excess phenolic or other material additionally is avoided by use of the techniques detailed herein. Commutators formed according to these methods may have increased useful lives and provide better performance than others presently available.

Abstract: An electrical brush has a brush wear sensor incorporated in the brush body to indicate when the brush has worn to a predetermined point. The sensor comprises a length of insulated electrical wire doubled back onto itself intermediate its ends and located in a passageway, preferably a blind bore, extending from a surface remote from the wear surface at least to the point at which brush wear is to be sensed. The end of the doubled back portion extends to the point at which wear is to be sensed, and the ends extend from the brush body for connection to one or more electrical sensors. A cement in the passageway retains the doubled wire, and the wires of the doubled wire may be twisted or looped about each other to increase adherence and retention. When the brush wears to the tip of the doubled wire, the wire insulation wears away, and contact of the conducting wire or wires with the commutator or the like is sensed.