Method of grinding a spherical surface by relatively rotating a work piece in engagement with the shaped periphery of a grinding wheel while spinning the wheel about its axis.
This is a division of my copending application, Ser. No. 652,743, filed July 12, 1967, now U.S. Pat. No. 3,522,678 dated Aug. 4, 1970, which in turn was a division of may earlier filed copending application, Ser. No. 452,787, filed May 3, 1965, now abandoned.
A method of grinding a toothed cutter for hair-cutting apparatus, the cutter having at least one strip-shaped row of cutting teeth, comprises pressing the entire row into engagement with the circumferential surface of a rotating grinding shaft while longitudinally orienting such row of cutting teeth parallel to the axis of the grinding shaft.
A shaving system of the wet shave type includes support structure and blade structure secured to the support structure. The blade structure has an aperture with an annular sharpened shaving edge that is defined by main facet portions that converge at an angle of less than 40.degree., and supplemental facet portions that are extensions of the main facet portions and converge at an included angle of less than 60.degree. to define an annular ultimate tip portion. The annular ultimate tip of the sharpened edge defines a shaving plane and the bisector of the included angle defined by the supplemental facets is disposed at an angle (shaving angle) in the range of 15.degree.-35.degree. to the shaving plane.
