Abstract: Commutators of armatures for electric motors or other dynamo-electric machines are finished by subjecting them to inspection and turning operations. The first inspection operation determines the minimum amount of material that can be cut while producing a high quality armature. This determination may indicate that no formal turning is required, only finishing. The turning operation, if applicable, cuts the commutator to a substantially cylindrical shape which is substantially concentric with the axis of rotation of the armature. The finishing operation, which may be performed by the same mechanism as the turning operation, imparts a desired axial roughness to the cylindrical commutator surface. The commutators may be inspected after the turning and finishing operations to generate data useful for such purposes as automatically modifying the turning and finishing operations performed on subsequent commutators.

Abstract: An apparatus for finishing a surface of a commutator of a motor, in which a distance between a surface to be finished and a reference position is measured in advance prior to the surface-finishing, and thereafter, turning, cutting or buffing is performed. The data of distance measuring is utilized for the surface-finishing later. Opposite ends of a shaft of the commutator are supported and the supported ends are rotated at uniform speeds. The commutator during the turning is variably controlled in accordance with a turning position.

Abstract: Grooves in an article such as a commutator are filled with a soft brittle material before a grooved surface of the article is cut. With the grooves thus filled, the cutting is performed continuously and smoothly without involving formation of burrs projecting into the groove. The soft brittle material includes a water soluble material which can easily be removed from the grooves by merely immersing the article in water. Preferably, the soft brittle material comprises a sublimable material which is self-vanishing or disappearing as it undergoes sublimation to the vapor state when it is left to stand in the atmosphere.

Abstract: An apparatus for cleaning the slots of newly assembled armatures of chips and burrs. The apparatus includes centrally or radially mounted cylinder means and a plurality of radially aligned blades, with suitable linkage means connected threrebetween for moving the blades laterally through the slots upon reciprocal movement of the respective cylinder rod(s) to thereby clean out the slots.

Abstract: An improved machine for undercutting the commutator of a DC motor. Designed specifically to undercut the mica insulation slots of a commutator, the device includes drive means to allow slippage of an undercutting assembly so that saw and spindle assembly damage are avoided. The invention also incorporates an automatic skewing attachment which indirectly senses misallignment of mica slots to be undercut and acts to reposition the commutator as needed so that the mica slot undercutting process may continue.

Abstract: Apparatus for machining the planar side face of a piston ring having a cutting tool holder reciprocable with respect to the planar side faces of the piston rings in the axial direction thereof. A cutting tool is secured to the cutting tool holder so that it cuts the side face of the piston ring from the axial direction to reduce the amount of cutting depth of the undercut portion on the ring.

Abstract: A portable turning tool for removing material from a worn component of a device such as a motor generator. The portable turning tool has a support member which is fixedly secured to the device in such a position so as to have a centrally located opening therein aligned with an opening formed in the support structure of the device. A rod having a cutter bit at one end and an actuator at the other end is passed through the pair of openings thereby positioning the cutter bit adjacent the worn component. By providing means on the support member for permitting the rod to slide but not rotate with respect thereto, sliding movement of the rod and thereby the cutter bit across the worn component while simultaneously rotating the component allows material to be removed from the component without disassembling the device during the turning operation.