GB523973A - Improvements in and relating to lathes and like machine tools - Google Patents

Abstract

523,973. Driving machines. WARNER & SWASEY CO. Jan. 18, 1939, No. 1724. Convention date, Jan. 19, 1938. [Class 83 (iii)] [Also in Group XXIV] Change speed means for operating various parts of a lathe or like machine tool is associated with means for selecting or preselecting the rate of movement. As applied to the apron mechanism of a saddle Fig. 3 shows a twelve speed change gear comprising a pair of gears movable by a rod 47, a triple gear movable by a rod 48 and a double gear movable by a rod 49. The drive is transmitted to the saddle and cross-slide feeds by a worm 46a and friction clutches as described in Specification 524,441. In some cases the last double gear and its rod 49 are omitted six speeds only being thus obtained. A selector mechanism for this form comprises slides 59, 59a, carried by an extension of the apron and provided with shafts having fingered discs 61, 61a, at one end and spiral gears 61b at the other meshing with gears 64 mounted between ears on the slides and splined on a shaft 63 provided with a setting knob and indexed collar 63a. The setting is effected when the slides are separated as in Fig. 5 and on actuation of a shaft 65 having a two armed lever 66 links 67 close the slides which then cause the selected fingers to control the positions of the short arms of bell cranks 69, 69a as in Fig. 8. The longer arms engage slots in the rods 47, 48. The shaft 65 may be worked by hand or by linkage from a three armed lever operatively connected with the feed control levers as described in the prior Specification. Modifications are described for controlling three rods 47, 48, 49. In this case the fingered discs have twelve sets of fingers each controlling three bell cranks. To avoid interference between sets of fingers adjacent the operative position the discs are skewed in opposite directions or in a further modification are offset laterally. Similar means may control the saddle or headstock change speed gearing for driving the spindle.