GB694292A - Improvements in or relating to milling cutters and like tools - Google Patents

Abstract

694,292. Milling-cutters. HOOLE, C. B., and WATSON, C. April 16, 1952, No. 9517/52. Classes 83 (i) and 83 (iii). [Also in Group XXIII] Casting composite articles.-A multi-edged milling cutter, or the like, has a body 1 cast from high tensile bronze and cutting tips 2 of tungsten-carbide or like sintered hard metal so shaped as to be secured against movement relatively to the body when the latter is cast around them. The front and the back faces of the tips may be of irregular shape to key with the body. Ribs, extending lengthwise and across the back faces of the tips, may retain the tips against movement axially and radially of the body. The tips may have dove-tail ribs 4, Fig. 4, extending lengthwise thereof and of greater width at the root of the tip than at its outer edge. Instead of the ribs tapering, or in addition thereto, they may be thicker towards the root of the tip or recessed as at 10 in Fig. 7. In this Figure, the tip has a rounded rib 9 and may be tapered or thickened as in the case of the rib 4. The tips may be arranged on the body in other than a radial direction, or with their front faces set at an angle to the axis of the body, e.g. as in staggeredtooth cutters; the cutting edges may be interrupted by removing parts thereof or by spacing a number of tips in line with each other along the length of the body. The tips may also be shaped for form-milling, end-milling or multiple counter-boring. A hub 16, Fig. 1, which may have been machined previously and formed with holes 20 and a flat 19 to key with the cast body, is cast into the body 1. A block (not shown), may be used instead of a complete bush and may be formed with a balancing mass. The body may be cast from an aluminium-bronze alloy on a jig-plate 12, Fig. 10, in a mould of sand, the tips having been positioned in grooves 13 in the plate 12 before applying a sand-cover 14. The body metal and that of the tips may unite during casting as in a brazing operation. This effect may be assisted by coating the tips with silver solder or silicon-bronze. Shrinkage of the body upon setting also assists it to grip the tips.