GB856276A - Improvements relating to multi-toothed cutting tools of sheet metal - Google Patents

Abstract

856,276. Drills; milling-cutters &c. and making drills &c. BOOTH, C. H. July 18, 1958 [July 31, 1957], No. 24212/57. Classes 83 (2) and 83 (3). [Also in Group XXIII] A cutting-element of sheet-metal comprises cutter portions 2 having sharpened and hardened cutting edges 6 with positive rake-andclearance angles, and means for controlling the depth of cut of the edges. In Fig. 1, this control is effected by a heel 10 of the portion 2, which is of arcuate form. Alternatively, the control may be effected by the wedging force of a side-cutter, portion 2 being flat, or both these controls may be provided, as in Fig. 3. Instead, a protuberance 106, Fig. 24, may be used on the cutter portion 104 and a protuberance 112 on the tapering side-cutter 102. A pair of elements 25, Fig. 7, as shown in Fig. 1, but with oppositely directed portions 28, are joined by pieces 27 and may be operated by a handle. A single element 25 of annular form (Fig. 12, not shown), which may have sidecutters, can be used for cutting annular grooves. In the rotary planing cutter 42, Fig. 14, the side-cutters 44 may control the depth-of-cut, but the main cutters 48 may also be curved for this purpose. The channel-shaped element 61, Fig. 16, of the hand-tool 68 is made by shearing and setting-up parts 71-73, Fig. 18, removing, as by grinding, the upstanding parts to form cutting edges 65, 67, and shearing off unwanted parts before bending to channelshape. Element 61, in circular form, may be used for annular grooving or, with the teeth on its outer circumference, Fig. 21, straightgrooving. With the side-cutters controlling the depth-of-feed, cutter portions 64 need not be curved to form a controlling heel. The element in the form of a drill, Fig. 22, has main cutting portions 81, 82 of curved-form for depth-of-cut control, and a ring of side-cutters 87. Cutters 92 are counterborers. Specification 856,278 is referred to.