GB488341A - Improvements in method of and apparatus for locating the teeth of rotary cutting tools - Google Patents

Abstract

488,341. Re - conditioning rotary cutting-tools. PACKARD MOTOR CAR CO. Oct. 20, 1937, No. 28553. Convention date, Oct. 23, 1936. [Class 83 (iv)] In a method of and apparatus for relocating and reconditioning the cutting-edges of a rotary tool, particularly a reaming tool as described in Specification 470,236, the peripheral edges of a worn cutter are shifted radially outwards by axial pressure and the cutter, if necessary, refinished to size. The cutter end is ground normal to the axis and has radial cutting-edges 16 terminating at the peripheral land portions 13, which may as shown have a slight rearward taper from the face 14. When the corners 28 of the teeth become worn, a pair of cutters 10 are placed on a base 20 with an intervening cage 22 of balls 21 arranged on a circle slightly smaller than the base circle of the teeth. An upper member 26 with a pilot portion 27 engaging bores in the cutters and the cage is then pressed downwards and rotated to form circular grooves in the cutter face, and press the cutting ends of the teeth outwardly. In some cases this operation is sufficient to recondition the cutter, but subsequent grinding operations on the face 133, Fig. 4, or 38 or both, may be required. In a modification, Fig. 6, the cutter 10 mounted on a holder as described in Specification 470,236 is pressed downwards onto balls located in a cage 22 which is centred over a member 34 guided in the base 32. A similar method may be applied to a cutter having internal cutting- edges adapted to finish a cylindrical work piece.