Patent GB-361931-A (GB)
Title: Improvements in and relating to machines for boring metal
IPC: B23Q5/02
Filed: 1930-05-22
Abstract: 361,931. Variable-speed and reversing gearing. TRIGGS, W. W., 57, Lincoln's Inn Fields, London.-(Giddings & Lewis Machine Tool Co. ; 16, Doty Street, Fond du Lac, Wisconsin, U.S.A.) May 22, 1930, No. 29391/31. [Class 80 (ii).] In a horizontal boring, drilling, milling &c. machine a headstock carrying the tool spindles is vertically movable on a column by a feed screw driven by power means, including a clutch which is opened when a reversing clutch for the spindledrive is moved from either operative position into neutral. The headstock 132, Fig. 1, has parallel main and auxiliary spindles 138, 139, driven by a shaft 151 from transmission mechanism in a gear box 542 and is fed vertically on a column 134 by a screw 135 also driven from the transmission mechanism. The screw 135 is rotatably journalled on the vertical column 134 and is rotated from a constant-speed shaft 557, Fig. 4, through an eighteen-speed and reverse gear. An electric motor 548 is connected by a belt drive 546 to a shaft 545 rotatably mounted in the cover 543 of the gear case 542, the cover supporting the gearing shown at the right-hand side of Fig. 4 and forming a removable unit therewith. The shaft 545 drives a coaxial shaft 552 through a movable friction clutch element 556 and either the directly coupled co-operating clutch 550 or the clutch 555 driven in the opposite direction at the same speed through gearing 558, shaft 557 and idler gear 560. A bevel gear 580 on the shaft 552 rotates a vertical shaft 151, Fig. 1, which rotates the tool spindles through gearing in the headstock. A second friction clutch 582, Fig. 4, on the shaft 557 transmits the drive to a lower shaft, bevel geared at 590 to a shaft geared at 592 to a shaft 594 which constitutes a rapid power traverse shaft for the headstock. The lower shaft also drives, through pick-off gears 596, shaft 697 and bevel gears 599, the inlet shaft 600 of the change-speed gear for the screw 135. The shaft 600, Fig. 8, has splined thereon a double gear 611, 612, and a single gear 613. A second shaft 601 has rotatable thereon gears 605, 607, 608 for selective engagement by the gears 611, 612, 613 and gears 606, 608, 619 for selective engagement by gears 616, 617, 618 splined to a third shaft 591, thus constituting a nine-speed drive for a pinion 649 on the shaft 591. A shaft 654, coaxial with the shaft 591 may be driven directly thereby through a clutch 656 or at a reduced speed through a back shaft 651 and a clutch gear 653, thus providing eighteen speeds for the shaft 654. A clutch 679, Fig. 4, is provided to connect either a friction clutch 677 on a rapid traverse shaft 594 or a gear 675 driven by the shaft 654 to a shaft 676 which is connected by a reversing gear to the feed screw 135. In the reversing gear, gears 691, 693, Figs. 4 and 11, are secured to the shaft 676 and respectively drive gears 697, 698 loose on a shaft 694, the former directly and the latter through an idler 699. A clutch 703 connects either of the gears 697, 698 to the shaft 694 and a bevel gear 700 on the shaft drives the feed screw 135. To disconnect the power traverse when the head reaches either end of its travel the yoke 706, Fig. 11, for moving the clutch 703 is slidable on a rod 707 and is notched at 730 to engage a lever 731 connected by a shaft 732 to a lever 733. A pin 734 on the lever 733 lies between cam surfaces formed on two vertically slidable rods 735, 736, the former being normally pressed upwards by a spring 739 but depressed when the head reaches its lowest position. The rod 736 extends up to the pillar 134 and has a head 740, Fig. 1, which, is raised by the headstock in its highest position, movement of either of the rods by the head causing the cam surfaces to move the clutch to its neutral position. The clutch 677 is actuated by a rock shaft 683 and a handle 689, and the clutch 703 by a shaft 710 and a handle 714 which is mounted for universal movement, by means of a ball joint, in the removable corner of the gear casing but is constrained to work in a vertical plane by means of a slot in a securing gland. The main spindle drive clutch 556, Fig. 4, and the main feed clutch 582 are operated simultaneously and have their yokes both actuated by the same sliding control rod which is connected by a bell-crank lever 575, link 576 and a further lever to a handle 579 so that actuation of the handle 579 will disengage the milling feeds when the spindle drive clutch 556 is moved into neutral position from either operative position. The four clutch elements in the nine-speed gear 612, 617, Fig. 8, for the headstock feed are controlled simultaneously and interlocked by four cams 622, 623, 631, 632, Fig. 7. The clutch shoes 626, 627, 635, 636 are slidable on rods 628, 638 and have pins engaging grooves in the cams. A mutilated gear 642 secured to the cam 623 has teeth on one third of its periphery which engage three spaced sets of teeth on a mutilated gear 641 secured to thecam 636, the gear 642 being rotated through bevel gearing 644 from a handle. The gear 641 has three plain bands 648 to engage the plain portion of gear 642. Actuation of the handle thus gives threepositions of cams 622, 623 for each of the three positions of cams 631, 636. The clutch 655, Fig. 8, of the back gear 651 is actuated by a shoe 658, Fig. 7, attached to the rod 638 and controlled by a lever 660 and a handle. A pinion on the shaft 645, Fig. 7, which carries the handle for operating the clutch-controlling cams 621 &c. has a 1 :3 ratio with a gear provided with two concentric scales, each scale being observable selectively through an aperture in a bar which is slid laterally of the scales by the handle controlling the back gears 651. Each of the eighteen speeds of the headstock feed is thus indicated by the two scales.