GB1238555A - - Google Patents

Abstract

1,238,555. Lathes. J. E. LONERGAN CO. 29 July, 1969 [26 May, 1969], No. 37896/69. Headings B3B and B3T. In an automatic lathe in which screw cutting is to be performed means is provided for displacing the tool slide transversely to the work spindle axis and successively adjusting its position relative to the workpiece to permit successive cuts to be taken during successive traversing movements of the tool and slide. A slide 34 is supported on a slide block 33 attached to a turret 23. The block 33 has secured thereto an adjustable feed stop 58 and an adjustable cam 61 which controls the indexing movement of a rotary stop carrier 77. The carrier 77 has adjustable stop rods 78 radially spaced thereon and which are engageable with the feed stop 58, in succession, at each pass of the cutting tool during a screw-cutting operation. The slide 34 is biased by a spring 39 to urge the respective stop rod 78 against the feed stop 58. Following a cutting traverse of the cutting tool the slide 34 is acted upon by a pusher member 38 on a cross slide 37 to displace the slide transversely to clear the cutting tool from the work during its return traverse, the pusher action being against the bias of the spring 39. A dashpot device 41 on the slide block 33 and attached to the slide 34 permits a slow return movement of the slide 34 as the slide block is traversed back to its initial position with the turret. The displacement of the slide by the pusher 38 also causes the engagement between the cam 61 and roller 88 on a plunger 83 on the slide 34 which actuates and pin-wheel 76 and pawl 82 mechanism to effect indexing of the stop carrier 77 ready for the subsequent cutting pass of the cutting tool 35. In an alternative embodiment, Fig. 6 (not shown), the cam co-operates with a plunger to effect the indexing of the stop carrier, and is provided with an oblique rear face and is pivotable transversely to the slide to permit the return movement of the slide without actuating the plunger, the indexing in this embodiment occurring at the forward limit position of the slide 34 instead of during the rearward return stroke as in the first described embodiment.