GB579405A - Improvements in or relating to broaching machines - Google Patents

Abstract

579,405. Broaching. LAPOINTE MACHINE TOOL CO., Ltd. (Lapointe Machine Tool Co.). April 13,.1944, No. 6828. [Class 83 (iii)] A broaching-machine is particularly designed for making U-shaped collars C, Fig. 3, from strip stock S by means of slotting broaches B, B' and a final slitting broach B<2>, all mounted on the same tool ram. Two superimposed strips S, Fig. 6, may be acted upon simultaneously and are supported on a work-holder 44 attached to a main slide 30 movable to and from the broach head 20 on a base 22. A work clamp 41a is carried by levers 41 pivoted at 43 on the slide 30 and is actuated by levers 42 pivoted at 42a on the slide 30, a hydraulic cylinder 40 on the slide, Figs. 1 and 6, having its piston 81 connected to a rock shaft 83 journalled in the levers 42 and provided with eccentrics 85 engaging abutments 86 on the slide so that advance of the piston will rock the levers 42, 41 and clamp the work. The broaches B, B<2> are carried by the head 20 sliding in fixed guides.21 and the broach B' has a T-slot connection 24 with the head 20 and slides in guides 37 mounted on a slide 34 movable in horizontal guides on the slide 30. An eccentric 60 on a shaft 56 journalled at 57, 58 on the base 22 engages a slot 61 in the slide 34 and is oscillated to move the slide by means of a rack and pinion 53, and a hydraulic cylinder 50 on the base. A lug 65 on the slide 34 has a bush 66 adjustably screwed therein which slides on a fixed guide rod 72 and is adapted'to engage a lug 70 on the slide 30 to move the latter at the required times. In operation, when the broach head 20 has completed its downward cutting stroke, oil is admitted to cylinder 50 to rotate the eccentric 60 and move the slide 34 to the left in Figs. 1 and 6, thus withdrawing the broach B<1> along the bracket 24 clear of the work. When the bush 66 meets a cross bar 75 on the slide 30, this slide moves with the slide 34 to withdraw the work from the broaches B, B<2> and the broach head is then raised on its return stroke, after which oil is admitted to the cylinder 40 to unclamp the work. Oil is next admitted to a cylinder 90, Fig. 1, slidable on guide rods 91 attached to the slide 30 and having a piston 96 attached to the slide. The cylinder carries pivoted grippers in contact with the work so that movement of the cylinder will feed the work by an amount determined by stops 112, 113 on the guide rod 91 whereupon cylinder 40 is reversed to clamp the work and cylinders 50, 90 are reversed to return the work and broach B<1> to operative position and return the cylinder 90 ready for another feed. The eccentrics 60, 85 lock the slide 34 and work clamps in operative position and a spring 74 on the guide rod 72 engages bar 75 on the slide 30 to assist the operative movement of the slide and cushion the idle movement. The hydraulic valves may be operated automatically or manually.