Method and apparatus for finishing grooved articles

摘要

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.