GB977837A - Improvements in metal-cutting circular saws - Google Patents

Abstract

977,837. Sawing. FIRTH BROWN TOOLS Ltd., and W. H. CRISP. June 26, 1963 [July 9, 1962], No. 26321/62. Heading B5L. A metal cutting circular saw comprises a disc 10 forming a body of the saw and a rim of separately constructed segments 12 fixed around the disc and having circumferential cutting teeth 17, 18 and side cutting edges 22 which stand proud, in the axial direction, of the remainder of the segments and have clearance angles. The segments are secured to each other by rivets passing through holes 16 and to the disc 20 by rivets 14, the segments being of a hard steel, such as tool steel, with inserted cutting tips of tungsten carbide, and the disc of carbon steel. Each segment is formed with three roughing teeth 17 alternating with three finishing teeth 18. The roughing teeth extend further radially from the centre of the saw than the finishing teeth and have a centre straight portion with the corners 20 cut away, whereas the finishing teeth have a straight cutting edges 19. A side cutting edge 22 extends radially inward from both ends of the edges 19 to form the side cutting edges. The edges 22 may be parallel, tapered or hollow ground, the body of the segment being parallel. In other embodiments, a series of three teeth may have one tooth having one corner cut away, a second tooth the opposite corner cut away, and the third tooth retaining both corners, the corners may be rounded, the roughing teeth have a centre point instead of a straight portion, and more or less of each or both kinds of teeth on each segment.