GB797557A - Apparatus for boring tubular work - Google Patents

Abstract

797,557. Boring-heads. BISSEY, P. J. Oct. 31, 1955 [Nov. 17, 1954], No. 31031/55. Class 83 (3). A boring-head 1 comprises guide-surfaces 5, 6 pressed against the bore of the work by fluidpressure acting on the bore from a recess 7. One or each cutter 3, in the form of a triangular prism which may be rotated and turned end-forend to expose each of the six cutting-edges in turn, is secured in a slot 9 by a wedge 12, fixed as by a screw. The cutter is held at an angle α, Fig. 3 (not shown), to the axis of the head against a front-stop 15 by an adjustable backstop 14, and the corners are slightly bevelled (Fig. 3), to facilitate cutting. Two or more guides 5, 6, which may be made of tungstencarbide, cast-iron, bronze, &c., attached as by brazing, are located on the head opposite the exit-recess 7 for liquid or gaseous coolant, e.g. oil, which may be delivered around a solid drawbar 2, or, as illustrated, through the bore of a hollow bar. Channels 7a convey the coolant to the rear of the head, and a flexible packing 16 of leather, plastic, &c. on the bar or head prevents passage of the coolant back along the bar. The cuttings pass rearwardly through a throat 13 in the wedge and head. Relative rotation between the head and work may be produced by rotating either part, or by rotating both in the same or opposite directions.