GB644064A - Improvements in or relating to metal-cutting machine tools employing rotary cutters - Google Patents

Abstract

644,064. Milling-machines ; gear-cutting. NATIONAL BROACH & MACHINE CO. Aug. 26, 1947, No. 23557. Convention date, Sept. 3, 1946. [Class 83 (iii)] In a metal-cutting machine-tool having a rotary work spindle and a rotary tool spindle 13, both mounted for angular adjustment on a frame 10 about a first axis perpendicular to themselves, traversing means interposed between one of the spindle supports and the frame is angularly adjustable relatively to both the frame and the support about a second axis parallel to the first axis. The machine is primarily adapted for gear finishing on the crossed-axes principle or for surface shaving as described in Specification 637,554, and is arranged so that the direction of traverse between the work-piece and tool can be adjusted without disturbing the orientation of the workpiece. A knee 22, which is vertically adjustable by a feed-screw 26, Fig. 4, manually rotatable by a shaft 34, has T-slots 41 providing for angular adjustment of a sub-table 40 and on top of the sub-table is a slide-way for another sub-table 44 which also has T-slots 46 providing for angular adjustment of a work-table 45. With the bolts in the slots 41 and 46 loosened, the sub-table 40 is rotated until the slide-way is at the required angle of traverse and the bolts are then tightened. During this adjustment, rotation of the work-table 45 is prevented by links 86, Figs. 3 and 4, pivoted on a part 85 of the knee 22 and connected by a plate 87 to links 88 pivoted on the work-table; the plate 87 is freely movable in a recess 90 in the underside of the table 45 and is supported by a pin 91 bearing on the bottom of the recess. The tool spindle head 12 is then adjusted about a vertical axis so that the tool spindle is at the desired crossed-axes angle with the work W, which is supported between centres on the table 45 and, in the case of gear finishing, is rotated by the tool, or, in the case of surface shaving, is rotated by a separate motor. The sub-table 44 is traversed by a lead-screw 71 which is rotated by bevel-gearing 70, 69 driven by a train of gears, including a worm 55 and wormwheel 56, from a motor mounted on the knee 22. The lead-screw has squared ends and can be rotated by a hand-tool so that, when the motor is stopped, the gear 70 rolls round the gear 69, which is locked by the worm drive, and thus the sub-tables 40 and 44 are rotated as a unit. A drive 72, 73 taken from the traversing drive controls timing means 74 which, in the case of gear finishing, reverse both the direction of work traverse and tool rotation or, in the case of surface shaving, may merely stop or reverse the work traverse.