Improvements in cutters


1300773 Trepanning tool E D HOUGEN 22 May 1970 [5 June 1969] 24854/70 Heading B3C A trepanning tool comprises teeth 26 Fig. 1, 2, each tooth having a downwardly projecting cutting edge 38, and an upwardly projecting cutting edge 40. Edge 38 has a front rake 28, Fig. 3, and edge 40, Fig. 4, has a front rake 30 whose angle b is smaller than the angle a of rake 28, and the teeth are formed on a thickened portion 18 of the wall 16 Fig. 2. Cutting edge 38 has a clearance c, Fig. 3, which is less than the clearance d of edge 40. The rakes may be positive, negative, or zero, so long as rake angle a is greater than rake angle b. The rake angle may progressively diminish in a radially outward direction. A gullet 48 Fig. 2 is provided so as to assist the removal of cuttings. In a modification, the teeth are arranged in three groups 26a, 26b, 26c, Fig. 8, or 26d, 26e, 26f, Fig. 8a, staggered in the radial direction. Gullet (70), Fig. 10 (not shown) is of different shape to gullet 48, Fig. 2. In a modification, the tool comprises a cylindrical blade 80, Figs. 13, 14, which is press fitted into a sheet metal cup 78, the blade 80 is not thickened at its lower end, and the cutting teeth 82a, 82b, are set radially inwardly and outwardly so as to provide clearance.




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Cited By (8)

    Publication numberPublication dateAssigneeTitle
    BE-1006328-A5July 26, 1994Unibit CorpMetal cutting tool.
    FR-2635032-A1February 09, 1990Unibit CorpOutil de coupe de metaux
    GB-2128510-AMay 02, 1984Hougen Everett DAnnular hole cutter
    GB-2160129-ADecember 18, 1985Omi Kogyo KkHole cutter
    GB-2167983-AJune 11, 1986Nitto Kohki CoAnnular hole cutter
    GB-2247199-AFebruary 26, 1992Nitto Kohki CoAnnular hole cutter
    GB-2247199-BOctober 12, 1994Nitto Kohki CoAnnular hole cutter
    US-5217334-AJune 08, 1993Nitto Kohki Co., Ltd.Annular hole cutter