GB1024467A - Improvements relating to brazing hard metal tips to shanks - Google Patents

Abstract

1,024,467. Cutter picks. WICKMAN WIMET, Ltd. Sept. 28, 1964 [Sept. 30, 1963], No. 38457/63. Heading E1F. [Also in Division B3] In brazing a sintered hard metal tip to a steel shank to form a tool suitable for cutting coal, stone and rock, mating surfaces are formed on the tip and shank, one of which has two or more ridges to form a narrow gap between the surfaces when they are brought together with line contact between the ridges on the one surface and the other surface, the surfaces are brought together, the shank and tip are heated by furnace, induction of torch heating and brazing metal is supplied to the gap to be held therein by capillary attraction. The ridges may be formed on the tip or the shank but preferably on the tip. A tip 1, Fig. 1 (not shown), having two semi-circular section ridges traversing it is placed in contact with a shank, the tip and shank are heated and brazing metal is applied to the gap to be sucked in by capillary action. In another embodiment a tip 1, Fig. 4, having a convex surface 6 carries two ridges 3 and mates with a concave surface 6<SP>1</SP> of the shank 5. Brazing is effected as before. Ridges may radiate outwards from the centre of a flat tip and brazing metal may be placed at the centre of the tip, between the tip and shank surfaces. The tip may have ridges radiating from a point on one edge of a flat tip. In examples a flat tip having three rounded parallel ridges is brazed to a steel shank using high frequency induction, brazing metal and flux being applied to the gap. The cross section of the ridges may be triangular and brazing metal the wires, strip or rod form may be used.