GB1300917A - Boring machine with cutter tooth adjustment - Google Patents

Abstract

1300917 Boring machines INGERSOLL MILLING MACHINE CO 30 Oct 1970 51599/70 Heading B3C A boring machine comprises at least one tool spindle 17, Figs. 1,2, 5, having a cutting insert 41 clamped in a resilient bar 45 which is flexed so as to vary the boring diameter, by a wedge 50 movable along the axis of the spindle against the action of a return spring 54, by a piston 79 located at the top of a rod 77, the wedge engaging needle bearings 60, 65, which also engage a backing plate 63, and a follower comprising a plate 68 and a screw 73, the latter being screwed into bar 45. The tool spindle also comprises fixed cutting inserts 28, Fig. 3, so that when the spindle is moved through a workpiece 26, Fig. 5, inserts 28 carry out a roughing operation, and insert 41 is retracted. After passing through the workpiece, wedge 50 is actuated so as to flex bar 45 and set insert 41 to the required cutting radius, the spindle is retracted through the workpiece, and the rough bored hole is finish bored. The spindle is provided with a rapid approach, a slower forward feed, and a slow return feed, and a rapid retraction to the position of Fig. 1. The spindle is rotated by an electric motor through a toothed belt and pulley 23, 22, which may also drive a second tool spindle 17<SP>1</SP>, Fig. 1. An adjustable stop 93, Fig. 2, is provided for limiting the movement of the wedge and therefore determining the cutting radius of insert 41, and adjustment of the stop so as to provide for correction when the insert wears, is by a reversible stepping motor (108), Fig. 9 (not shown), which drives a timing belt and pulley 111, 112, Fig. 2. The arrangement may have an inspection assembly which operates a switch (116), Fig. 9 (not shown), in response to the detection of an undersize condition, and the switch provides for the operation of motor (108). In a modification, a spindle for boring holes of diameter less than that of the spindle comprises an insert 41, Fig. 11, secured to a snout 153 which is connected to a U-shaped flexing bar 151, 152, which is actuated by the wedge. More than one insert 41 may be provided, each of which is actuated by a tapered face of the wedge. and the inserts are equidistantly spaced, Fig. 15 (not shown).