Abstract: A tachometer generator for DC motors in which a brush carrier of insulating material is fastened to the tachometer housing at the end face. Brush holders are arranged on the brush carrier which, together with parts of the brush carrier, form a brush guides. A carbon brush and an associated coil spring is inserted into each brush guide and the coil spring is braced against an abutment of the brush holder. In order to simplify assembly of the brush holder and to improve the current transfer between the brush holder and the coil spring, a channel is formed on the brush carrier as a guide for each brush. The body of the brush holder has the shape of a plate and rests on the channel, forming a brush guide which is enclosed on all sides. Spreading arms are formed on the brush holder which snap into lateral cutouts alongside of the channel of the brush carrier. The coil spring is firmly connected to the brush holder by soldering.

Abstract: A brush wear indicator includes a first contactor and a second contractor movable relative to the first contactor from an open position to a closed position to connect an electrical circuit to an indicator. The second contactor is maintained in the open position against the resiliency of a leaf spring by a coil spring which urges a brush toward a commutator in response to wear to the brush. When the brush wears away to a preselected length the coil spring will have moved to a position at which the leaf spring is free to bias the second contactor to the closed position.

Abstract: A brush which presses against the commutator of a machine has secured thereto a resilient spring contact element, and as the brush wears, movement thereof causes physical engagement of the resilient spring contact element with another contact element to complete a current path. The latter contact element is secured to a yoke which surrounds the commutator.

Abstract: The brush holder comprises a cage and a detachable clip. The cage serves to accommodate a brush and has a channel. The clip has a central leg positioned in the channel. A self-winding band spring for biassing a brush is fixed at its outer end to the central leg, which also includes engaging means, e.g. in the form of a tongue, for retaining the central leg in the channel. The clip has also two side legs bearing elastically on to the outer sides of the cage to prevent rocking of the clip relative to the cage. The central leg has preferably raised side edges and the cage is preferably cut out from a hollow cross shaped section.

Abstract: A brush holder and brush assembly for a dynamoelectric machine is constructed in such a way that the holder can be moulded in one piece of electrical insulating material. The holder has an opening which receives the rotating part of the machine to be contacted by current carrying brushes. The holder includes at least two oppositely disposed brush holding housings each having an end wall remote from the aforesaid opening and being open on two opposite sides thereof. Each housing also has two spaced apart side walls facing each other and extending from the end wall, the end of the housing opposite the end wall being open and opening into the aforementioned opening which receives the rotating part of the machine. Ribs extend inwardly from the side walls of the housings and run between the two ends of the housings. These ribs extend into recesses in the side walls of current carrying brushes that are mounted in the housings with the brushes engaging the side walls of the housings.

Abstract: A brush spring and brush housing construction affording maximum operable brush wear without the danger of the brush spring contacting the commutator even if the brush might drop out of the housing. A hook on the brush end of the spring moves against an inclined wall of a tapered slot in the side of the housing and is directed to engage the end of the slot and be restrained from moving or twisting out of interlocking relation with the housing wall as well as being withheld from engagement with the commutator.

Abstract: A motor or generator having a commutator and brushes for transfer of current to and from rotor windings has a stationary conducting sensor in sliding contact with the commutator, said sensor being narrower at its contact with the commutator than the insulation between the commutator bars where contacted by the sensor, so that a sensing circuit is interrupted between the sensor and one of the brushes at a frequency proportional to the speed of the rotor.

Abstract: A brush which presses against the commutator of a direct current machine has a groove in one side thereof into which a fixed probe partially extends. As the brush wears, movement thereof causes physical engagement of the probe with the end of the groove to complete a current path through the probe. Flow through the current path energizes and latches a warning device.

Abstract: An electrically conductive helical spring has a series of closely spaced, inversely extending inner turns which receive and retain a mounting projection on a carbon brush to maintain excellent electrical continuity between the brush and the spring and to maximize the active length of the spring within the dimensional limitations of its normal mounting space.

Abstract: A brush holder structure for use in conjunction with transfer of current between a brush and a collector ring or commutator, respectively, on the rotor component of a dynamoelectric machine and which can be removed while the machine is in operation in order to renew worn-down brushes includes an electrically conductive support designed sectionally in L- or U-shaped form provided with a bore into which is screwed a combined mounting and plug-in device adapted to be removably inserted and interlocked with the brush rail structure of the electrical machine.

Abstract: The invention comprises a motor brush holder assembly including a brush holder member and a brush member which is free for reciprocal longitudinal motion in said brush holder. The assembly includes captured brush spring means for urging longitudinal motion of the brush in one direction. The configuration of the holder is such as to confine the brush spring within the holder. The brush spring confining means may include a planar member between the spring and the brush. The cross section of the interior of the holder may exceed that of the brush; or a portion of either the planar member, or of the brush spring, may project through a slot of the brush holder which does not extend the full length of the holder. By this means there is an assurance that the brush spring cannot project beyond the front of the brush holder and make contact with the commutator.