820,564. Spinning. LODGE & SHIPLEY CO. Aug. 31, 1955 [Sept. 9, 1954], No. 25069/55. Class 83 (4). [Also in Group XXXIV] A machine tool comprises a rotatable spindle adapted to carry a blank, a tool mounted for movement both along and transverse to the spindle axis and mechanism to control the relative movement between the tool and the spindle including means for automatically determining the deviation in thickness of the blank to be worked from a known thickness and automatically adjusting said mechanism in accordance with said deviation. The invention is described as applied to a spinning machine comprising a bed 1, a headstock 2 with a spindle 3 and a carriage 4 with a tailstock 5 yieldably supported therein. The carriage has a support 12 for the black B and two supports 6 and 7 for the rolls 8 and 9 which may be moved inwardly and outwardly with respect to the axis of the spindle by tracer control mechanism. Bed and carriage.-The bed is generally H- shaped in cross-section and is made by welding relatively heavy rolled-steel plate and provides a channel 26 to receive the lower U-shaped portion 28 of the carriage 4 which has sets of rollers such as 44, 46; 50, 52 and 53, 55 engaging runners 33, 32 and 34 secured to the bed. These rollers may be preloaded. The upper body portion 36 of the carriage is also constructed of welded steel plates and has two upwardly extending sections 56, 57 which form a central channel in which is mounted the tail stock 5. The part 56 carries electric motors 58, 59 and 60 connected to pumps 58a, 59a and 60a which drive hydraulic motors for operating parts of the machine, current being supplied to the motors through brushes engaging bus-bars along the bed. Mounted on the lower portion of the carriage is a cross-guide 35 on which is a channel 68 to receive the base portions of the supports 6 and 7 for the blank-working rolls 8 and 9. These supports have rollers engaging runners on the carriage and carry nuts 102, 105 on a lead screw 100 mounted in the carriage, the nut 105 being secured to a worm 109 which may be rotated through a knob 125 for the fine manual adjustment of the support 7 relatively to the support 6. End plates 65 and 67 of the cross-guide carry hydraulic motors 131, 132 connected to the lead screw through couplings which permit a slight axial floating of the screw. The motors, of known type, lock the screw against rotation when not operative. Beneath the screw 100 is an hydraulic cylinder with opposed piston secured to the cross-members 78 and 107 of the roll supports and urged outwardly in order to eliminate backlash. Roll mountings.-The roll 9 is mounted on a segmental block 160 which is mounted on a segmental table 161 which is in turn mounted on the top plate 114 of the support 7. Roll 8 is similarly mounted on the support 6. Table 161 is adjustable on the plate 114 by a knob 178 on an eccentric spindle, the adjustment being in a direction parallel to the rotational axis of the spindle. The block 160 is acurately adjustable on the table 161 by a pinion 213 meshing with a segmental rack 210 in the table and rotatable by a hand wheel 230. After adjustment it may be clamped by bolts 204. Tailstock.-The tailstock 5 comprises a generally rectangular frame 231 positioned between the body portions 56, 57 of the carriage. Slidable within frame 231 is an inner frame 242 carrying the rotatable head 270 of the tailstock which is adjustable by means of a knob 271 and housing four piston and cylinder assemblies, pistons P1 and P2 being secured to a forward head 243 and pistons P3 and P4 to a rear head 244. When fluid is admitted to cylinders C1, C2 pistons P1, P2 move forward until an abutment 250 on the head 244 engages an adjustable stop screw 251. When the carriage moves forward the tailstock moves with it until the head 270 engages the blank B at the spindle, cylinders C1 and C2 thereafter sliding over pistons P1, P2 which displace the fluid therein into cylinders C3, C4. The shaft 293 of the head 270 is supported by roller bearings 296 and a roller thrust bearing 302 which allows slight axial play but limits movement to the left, as seen in Fig. 18. Movement to the right is limited by an hydraulic thrust bearing 301 (see Group XXXIV). Work support.-This is of V-shape and comprises plates 362 and 370 spaced apart by a V- block 369. Plate 362 has a vertical key running in a keyway in a frame 352 slidable on a guide 343 bolted to a vertical plate 341 bolted to the carriage. A screw 373 permits vertical manual adjustment of the blank support on the frame 352 which is itself movable vertically by hydraulic cylinders 345, 346 formed in the block 352. Templet support.-The side 20 of the bed has two longitudinally extending guides 376, 377 between which is a slide 380 carrying two uprights 381 and 382. Templet 16 is carried by an arm 395 secured by a pivot 396 on another arm 395<SP>1</SP> pivotally mounted on the upright 381. A coarse adjustment of the templet is made by movement of the arm 395 about pivot 396 by a knob 433, Fig. 21, and a fine adjustment by the movement of arm 395<SP>1</SP> about pivot 396<SP>1</SP> by means of a cylindrical extension 406 within a sleeve 410 rotatable on a pin 411 on a slide 414 movable along the upright 382. The templet support is yieldably held with respect to the carriage by means of a cylinder 442 secured to the upright 381 and a piston 449 secured to a bracket 448 on the main body of the carriage. When fluid is supplied to the cylinder, the templet support moves to the left as seen in Figs. 1 and 5 until an adjustable stop screw 461 engages the bracket, Thereafter the support normally moves with the carriage but may be locked to the bed by means of pistons 464 pressed by fluid pressure against the slide 380. Usually the templet will be locked to the bed just after the head of the tailstock or the rolls 8 and 9 have engaged a blank on the spindle. Tracer valve.-This comprises a main body portion 473, Fig. 20, mounted on the top plate 114 of the roller support 7 and having two fluid lines 474 and 475 connected with the body portion 36 of the carriage and with the drive motors 132 and 131 for the roll supports. To the body 473 is bolted an upper disc 485 to which a spacer 490 and a lower disc 491 are secured by bolts 492 to form a cylindrical chamber 493 in which a slide 495 is supported by a spring 514. A reduced lower portion 523 of a central bore of the slide supports a ball 524 on which rests the lower end of a shaft 526 which, above the slide, carries a ball 532 bearing against a cap 533 at the upper end of the body 473 and prevented from rotating by an inwardly projecting pin 528 entering a vertical slot in the ball. The cap 533 has a conical aperture in which is disposed a conical member 535 integral with the ball. Above the conical member the shaft 526 is threaded and receives a cylindrical member 541 to which is also screwed a disc 543 with a conical finger 10 bearing against the templet 16. The height of the finger is adjustable by turning a ring 536, a spring 546 taking up backlash and a friction disc 538 holding it in adjusted position. When the roll support is moved forward by the carriage, the finger 10 and shaft 526 are tilted causing the ball 524 to move to alter valve openings G1 and G2 thus controlling further movement of the rolls. The roll supports can also be moved by deflecting the finger 10 through a manually operated cam moved through hand wheels 571 and 572. Carriage feed.-The carriage carries a nut on a lead screw 585 extending along the bed of the machine. For power operation of the carriage, a motor 620 rotates the nut through gearing while the screw 585 is held against rotation by a brake in the headstock. For manual operation, the gearing between the motor 620 and nut 606 is locked and the screw 585 is rotated by a hand wheel 632 at the headstock. Headstock.-The upper part of the headstock carries bearings 640 and 657 for the shaft 641 of the spindle 3, the shaft having secured thereto drive gears 661 and 670 adapted to be alternately engaged by gears 671 and 672 on a shaft 673 movable axially by known fluid-operated gear-shifting mechanism and geared to a driving motor 694 through a clutch 704. The motor is coupled by a belt drive to a shaft 703 slidable along which is a sleeve 713, Fig. 26, having at one end a plate 714 of the friction disc clutch 704 and at the other end the plate 715 of a friction disc brake 704<SP>1</SP>. The sleeve is movable by a piston 732 in one direction and by a spring 730 in the other direction so that the clutch is engaged and the brake released or vice versa. The thrust on the shaft 641 is taken by an hydraulic thrust bearing (see Group XXXIV). Operation.-The ports of the machine are actuated by electric motors or hydraulically by fluid supplied by electrically driven pumps. The headstock includes a pump which supplies fluid under pressure from a reservoir to the headstock hydraulic bearing, to the headstock gear-shifting mechanism and to the control mechanism for the headstock clutch and brake. The carriage includes a closed hydraulic system supplied by the pump 58a for driving the rolls inwardly and outwardly, another system supplied by the pump 59a for moving the carriage along the bed and a third independent system supplied by the pump 60a. This last system contains a restriction to give a pressure drop providing fluid at both operating and suboperating pressures. In addition to priming the other two systems it energizes the hydraulic means for holding the carriage and templet in yielding engagement and for taking up the backlash in the roller supports driving mechanism and also supplies fluid to a rotary valve mounted on the carriage. This valve controls the supply of pressure fluid to various valves which in turn operate or condition for operation certain components of the machine. In the stand-by position, the carriage is at the rear of th