Abstract: A blade sharpening apparatus for sharpening a serrated blade includes a blade holder configured to securely hold a serrated blade in a position that exposes a toothed edge of the serrated blade. A grinding wheel rotates about a rotational axis and engages teeth spaced along the toothed edge of the serrated blade that is secured in the blade holder. An oscillating mechanism laterally oscillates the blade holder or the grinding wheel relative to the other at an oscillating distance greater than a depth between the teeth on the serrated blade. A linear actuator longitudinally moves the blade holder or the grinding wheel relative to the other and substantially parallel with the rotational axis of the grinding wheel. The linear actuator is operable with the oscillating mechanism to coincide the longitudinal and lateral movement to correspond to the depth and spacing of the teeth disposed along the serrated blade.

Abstract: A polishing machine in which adverse influence caused by a surface condition of a retainer ring can be reduced with a simple structure. The polishing machine includes a rotatable polishing plate; a top ring including a holding plate for holding and pressing a wafer onto a polishing cloth of the polishing plate; an independently rotating retainer ring in which the holding plate is freely inserted; and a positioning member for correctly positioning the retainer ring on the polishing cloth while the retainer ring is rotated. The retainer ring includes a pressing member which presses the polishing cloth along an outer edge of the wafer to make the level of the polishing cloth pressed by the pressing member substantially equal to that of the polishing cloth pressed by the wafer.

Abstract: A combination abrasive disc and backing plate provide workpiece viewing and blowing collectively through aligned viewing apertures. The backing plate has a bottom surface adapted to support the abrasive disc and an opposed top surface. Coordinated alignment of the viewing apertures of the disc and plate allows observation of a workpiece collectively through the disc and plate during rotary drive thereof. The plate's viewing aperture is partially adjoined by a scoop formation on the plate's top surface. The scoop is arranged for deflecting air from above the plate's top surface and consequently forcing such in a current collectively through the aligned viewing apertures of the disc and plate. This blowing current acts to both blow away debris from the field of view and thereby reduce viewing impairment, as well as to provide some cooling to the workpiece.