GB1328952A - Broaching tools - Google Patents

Abstract

1328952 Broaching tools CINCINNATI MILACRON Inc 11 Jan 1972 [12 Jan 1971] 1355/71 Heading B3L A broaching tool comprises a longitudinally extending support 10, a plurality of tool holder members 14, each holder member separately or each pair of adjacent holder members collectively affording at least one tool holder pocket the sides of which are defined by the holder member or holder members, the pockets extend in at least one row with the pockets of part of the length thereof being laterally off-set relative to each other whereby movement of the tool, when equipped with cutting bits across a workpiece forms one or more progressively widening grooves therein. The particular embodiment consists of four sections mounted in alignment on a suitable carrier member. Fig. 1 shows the first section in which the holder members are attached to a bar 22 via flat portions 19 thereof. The flats correctly align the holder members. In the first section the tool bits are aligned but are of increasing radial length so that a groove formed in a workpiece is gradually deepened. The following sections have the tool bits progressively offset so that the initially formed grooves are widened until they meet. The offsetting of the bits may alternate along the length from one side to the other or they may be continuously offset in one direction. In the latter case the direction of offsetting of the four rows would be different to equalize the cutting forces. The arrangement of the offsetting is by differing the position of the flat 19 relative to the pockets.