Patent GB-411159-A (GB)
Title: Improvement in multiple spindle automatic lathe
IPC: B23B9/02
Filed: 1932-12-02
Abstract: 411,159. Automatic lathes. CONE, F. L., 129, State Street, Windsor, Vermont, U.S.A. Dec. 2, 1932, No. 34211. [Class 83 (iii).] A multiple-spindle automatic lathe comprises a rotatable drum carrying work spindles arranged in circular series about the axis of the drum, means for indexing the drum, a carriage movable axially of the drum and provided with tool spindles corresponding to the work spindles, and means for rotating the tool spindles including a rotary band in driving relation thereto. In the construction shown, the drum comprises vertical end walls, connected by horizontal ribs 12, and rotatably mounted in openings in frame members 6, 7. Work-holding arrangements. An end wall 10 of the drum, Fig. 16, has a central portion 16 secured to a shaft 18 which extends outwardly and may support the pieces of bar stock passing to the work holders. A shaft 20 having a thrust bearing 22 is rotatably mounted in the end wall 11 of the drum. Arranged round the axis of the shafts 18, 20 are right work-holders 25, each comprising an inner stock-feeding tube 31, a collar-carrying tube 32, and an outer tube 35. A collar 45 slidable on the tube 35 has a cam face 46 adapted to engage arms 47 pivotally mounted on a block 40, and has a lost-motion connection through screws 50 with the block. A groove 55 in the collar is engaged by a finger 56 on a slide 57 which is grooved at 60 for engagement by a shoe 61 on an actuating arm 62. Movement of the collar 45 away from the wall 10 causes the cam 46 to actuate the arms 47 whereby the block 40 is moved to draw the collar 33 rearwardly, thereby gripping the stock 37. Reverse movement of the collar causes the release of the stock. The tube 35, which is rotatably mounted in bearings 70, 71 is provided with a gear wheel 75 meshing with a central gear 76 carried by the shaft 20. In this way all the work-holders are driven from the shaft 20. Tool-carriers. Corresponding to each workholder is a tool-holder 83 mounted in a carriage 82, and being fixed to a shaft 84 keyed to a sleeve 90 provided with a sprocket wheel 91. All the sprocket wheels are driven by an endless chain 92 arranged, as shown in Fig. 5, to cause the sprocket 91a to rotate in a direction opposite to that of the other sprockets, so that the tool associates with the sprocket 91a. operates at a relatively low speed. The carriage 82 is moved towards or from the work by means of a vertically-journalled rocking member 130 the lower and upper arms of which are connected to the slide 82. The member 130 is operated by means of a cam follower on the arm 132 controlled by cams on a drum 135 which is fixed to a cam-shaft 120. In addition to rotary tools acting axially on the work, various turning tools may be provided carried by slides 100, 101 which are actuated by means of rocking members 110 operated from the cam-shaft 120. The upper frame member 3 of the machine has slanting side walls 400, Fig. 7, to which may be attached mechanisms for producing special cuts on the work. One wall supports an eccentric cam 408 bearing against a roll 409 carried by a sliding tool bar 410. This bar is mounted to slide towards and from the cam on a carriage 411 which is adapted to slide parallel to the axis of the drum and is connected to the tool slide 82. The roll 409 is pressed by springs 427 against the cam 408. The shaft 407 is driven by chain gearing from the shaft 20 Fig. 3 shows an arrangement providing for axial movement of the tools different from that produced by the slide 82. Levers 450, 451 pivoted at 452, 453, respectively, are connected at their lower ends, through adjustable links, to blocks 460, 461 which are secured to a pair of tool spindle shafts. Indexing mechanism and work feed. The drum carrying the work spindles is indexed by means of a crank arm 140, Fig. 9, fixed to the cam-shaft 120 and having a roll 142 which is adapted to engage between plates 143 arranged in pairs on the wall 10 of the drum. The drum is locked in indexed positions by means of a slidable latch bar 150, Fig. 8, adapted to engage in one of a number of sockets 152 on the drum, the bar being withdrawn automatically against the action of a spring 163, by means of a cam 167 on the cam-shaft and a three-armed lever 155. The latch may be released by hand through the medium of a cam 170 journalled on the shaft 120 and adapted to depress the roller 166 on the lever 155, when the handle 171 is manipulated. During indexing, the heads 65, Fig. 10, of the work spindles move between arcuate track members 300 and a disc 301. When a work spindle moves to the lowest position the head 65 passes within a slot 306 in a block 307 carried by a rod 308. This rod is slidably mounted and has a resilient connection with a slidable rod 311, Fig. 3, which is moved, to advance the work spindle against a stop, by means of a U-shaped rocking member 321 operated from the cam-shaft 120. This shaft also operates a U-shaped rocking member 290, Fig. 9, provided with the shoe 61 which acts to release the collet gripping the work. The disc 301 is provided with a cut-away portion 330 normally in the position shown in full lines in Fig. 10, but the disc may be positioned with the cut-away portion at the bottom of the disc to permit removal of the stock feeder when the stock is exhausted. The feeding mechanism described relates to a machine having eight different rotary operations on the work, but where the machine is adapted to complete a cycle in four operations, the machine may be modified so that the stock is advanced at the top position of the drum as well as at the bottom position. Drive mechanism. The drive for the machine is obtained from an electric motor 200 which drives a main shaft 202, Fig. 4. This shaft through gearing drives shaft 95 whereby the tool spindles are driven through the endless chain 92, Fig. 5. The shaft 95 is provided with a sprocket wheel adapted to drive a sprocket wheel on the shaft 20 whereby the work holders are rotated. The shaft 202, Fig. 15, has journalled thereon a bevel gear 210 connected to one member 211 of a clutch which is adapted to engage a second member 213 keyed to the shaft 202. The clutch may be engaged automatically under the control of a shaft arm 215 operated from the cam-shaft 120, or it may be actuated manually from the front or back of the machine. The gear 210 meshes with a bevel gear 230 on a shaft 231, Fig. 4, which has a worm 233 engaging a worm wheel 234 on the cam-shaft 120. The wheel 234 has a stepping clutch connection with the shaft 120 which may be such that the worm wheel 234 has one or two bevelled surfaces adapted to engage frictionally a corresponding surface or surfaces on a member connected to rotate with the shaft 120. When the shaft 231 is clutched to the shaft 202 the cam-shaft 120 is driven at a high speed, but when unclutched, a low-speed drive for the shaft 120 is obtained from the shaft 95 through shaft 20, shafts 263, 265, and worm gearing 268, 270. The gear 270 is connected to the shaft 231 through an over-running roller clutch 271 which allows the shaft to be driven by the high speed drive when in operation, and otherwise transmits a low speed drive. The worm ring 270 is connected to the sleeve 272 of the clutch by a stop connection comprising a spring- pressed ring 273 engaging the inner face of the ring 270 and pressing its conical inner face against a mating face of the outer sleeve 274. A manually-operated clutch may be interposed between the sleeve 272 and the shaft 231 to facilitate turning this shaft by hand for adjustment of the cams on the shaft 120.