GB287439A - Improvements in and relating to multiple spindle screw machines - Google Patents

Abstract

287,439. National Acme Co., and Drissner, A. E. Dec. 20, 1926. Lathes; steady rests.-A multiple-spindle screw machine comprises a work-turret 13 provided with a number of work-spindles 14, the stock being fed in either of the two lower spindles when the turret is at rest by means of a cam-operated feedslide having at opposite sides slots within either of which is secured a feed-shoe adapted to engage the end of a feed-tube. The front end 10 of the bed carries a bearing-bracket 15 within which is journaled a tubular shaft 16 enclosing the shaft 17 which drives the work-spindles. A five-sided tool-carrier mounted on the shaft 16 is provided with a depending bracket 19 having a foot 20 guided on a hardened metal plate 23 secured to the flattened top surface of the curved bed 11. A shaft 26 removably secured to the bracket 19 has a bearing in the bracket 15 and is operated to reciprocate, the tool slide by means of a cam 32 on the main cam shaft 33, the forward movement being positively limited by adjustable locknuts 30 mounted on a screwed shaft 28 passing freely through the member 15. A hexagon shaft 34 carrying the adjustable work stop 42 is secured to a lever 36 operated by a cam 38 and a spring 39 is arranged between the lever 36 and a removable pin ,40 in the frame 11. In order that the stock may be fed in either of the two lower spindles, the work stop may be changed over from one spindle to the other by changing the position, of the lever 36 and its spring. The stop is actuated in either position by the cam 38 and is subsequently quickly withdrawn by the spring 39 to avoid interference with the tools. The stock reel is mounted in a bracket 46 and supports the end of a central shaft 47. A pair of guide shafts 48, 49 supported in the machine frame carry the stock feed slide which has two recesses 51 within either of which the feed dog 52 may be secured to feed the work in either of the two lower spindles. The feed-slide is actuated by a cam 56 on a drum 57. 'On the backward movement of the feedslide a spring 59 extending into a tube 60 is compressed, and the recoil of this spring causes the forward movement of the slide and engages the dog 52 with one of the feed tubes 63. The shaft 47 carries a disc 61 which is notched to receive the enlarged ends of the feed tubes in their normal positions, Fig. 3, and a recessed guard disc 64 rotatably mounted on the disc 61 is normally placed as shown in Fig. 3 to act as a back stop for the feed tubes. By slacking the bolts 65 the guard may be turned against a spring to permit end withdrawal of the feed tubes. A ring 54 secured to the feed slide embraces all the tubes and assists in preventing whipping action during their rotation. The ring 54 also returns each feed tube after the feeding operation. Each workspindle is provided with a chuck 14a controlled by chucking-tubes (not shown) operated by fingers 73 and sliding wedges 72. The shoe 71 for coacting with the wedge cones is removably attached to the chuck-slide 70 to feed in the first or fifth position and the chuck-slide is actuated by cams 75 on the drum 57. The entire feed mechanism is housed between covers 78, 79 pivotally mounted on a rod 77. The frame carries side supports 100. 103 for cross-slides 102, 104 respectively, the slides being actuated through lever mechanism from cams 110, 115 on the main cam-shaft. A pair of cross tool-slides may be mounted on each side of the machine. In this arrangement, toolholder supports 117 are mounted in T-slots in the slides 102, 104, and are fitted with tool-holders 120. A vertical tool-slide 131 is also provided. This is actuated from a lever 121 which is connected through a lever 122 to a link 125 pivoted to a cam-slide 126 which is fitted with cam-plates 129, 130 coacting with a roller 135 on the tool slide which carries compound, slides 138. 139 the latter being provided with a steady roller 140 and cutting tool 141.