Abstract: A brush wear detector and indicator for the brush elements contacting the rotating commutator or slip rings of a dynamoelectric machine includes, in addition to a self winding bias spring located on the brush holder for applying force to the brush assembly, a permanent magnet, located either on a brush element or the bias spring, and a reed switch located on the brush holder adjacent the assembly. The magnet moves inwardly as the brush element wears and actuates the read switch at a point indicative of a worn condition. Activation of the reed switch causes an indicator such as a lamp to become energized, signalling a need for brush element replacement.

Abstract: A brush wear indicator contact and terminal assembly having a high pressure-per-unit contactor that is formed on a first surface of the plate. A conductor for a brush wear indicator circuit is bonded to the contact plate by a high temperature resistant solder or brazing material and the contact plate is bonded to the surface of the dielectric sheet, which electrically isolates the contact from the spring when the spring is in an extended condition. By the method of the invention, a brush wear indicator contact and terminal assembly is made by adhering a sheet of dielectric material to a brush follower spring with a coating of permanently flexible adhesive, and by bonding a conductor for a brush wear indicator circuit to a contact plate having a contactor ridge on one opposite surface thereof.

Abstract: A brush wear indicator contact and terminal assembly having a high pressure-per-unit contactor that is formed on a first surface of the plate. A conductor for a brush wear indicator circuit is bonded to the contact plate by a high temperature resistant solder or brazing material and the contact plate is bonded to the surface of the dielectric sheet, which electrically isolates the contact from the spring when the spring is in an extended condition. By the method of the invention, a brush wear indicator contact and terminal assembly is made by adhering a sheet of dielectric material to a brush follower spring with a coating of permanently flexible adhesive, and by bonding a conductor for a brush wear indicator circuit to a contact plate having a contactor ridge on one opposite surface thereof.

Abstract: A direct current dynamoelectric machine characterized by having a plurality of salient field poles each comprising a rigid laminated base member, a relatively more flexible laminated face member, and a plurality of permanent magnet sub-assemblies mounted between and adhered, respectively, to the base member and face member. The magnet sub-assemblies each comprise a plurality of rare earth permanent magnet bars arranged in a predetermined configuration and compressed between a pair of flat magnetically permeable metal plates to which the bars are adhered with a partially cured adhesive.

Abstract: A dynamoelectric machine having a rotatable conductor on which a reciprocally mounted brush rides is provided with a brush wear indicator, comprising, an electro-mechanical transducer connected between a self-winding, brush-biasing spring forming part of the brush holder assembly and a brush wear signalling means in order to actuate the signalling means responsive to a predetermined degree of brush wear that causes the brush biasing spring to move an active element of the transducer a predetermined distance thereby effecting such actuation.

Abstract: In the method of the invention a permanent magnet field pole is manufactured by welding a plurality of preformed base member laminae to thereby form a rigid pole base member. A plurality of preformed face member laminae are secured together by rods extending through aligned apertures therein. A head on one end of each such rod cooperates with a spring clip member affixed to the other end thereof to continuously exert a resilient clamping force on the laminae thereby retaining them in a relatively flexible desired pole face configuration. The rare earth magnet sub-assemblies are made by arranging rectangular magnet bars of rare earth material in aligned configurations then adhering the bars to parallel plates positioned on opposite sides of the bars.