Patent GB-700049-A (GB)
Title: A machine tool of the single spindle lathe type
IPC: B23Q15/00
Filed: 1951-12-03
Abstract: 700,049. Lathes. WARNER & SWASEY CO. Dec. 3, 1951 [Dec. 2, 1950], No. 28259/51. Addition to 653,706. Class 83 (3) [Also in Groups XXIV and XXXVII] A lathe having a single work or tool carrying spindle as claimed in the parent Specification is modified by the provision of a reversible electric motor 72 (not shown), for rotating the spindle 64, Fig. 3, whereby the machine may be used for effecting screwing or tapping operations The feed train of the machine of the prioi Specification is provided with additional shafts 149a, 149b, Figs. 1 and 3, and pick-off gears thereon to permit the reversal of the spindle 64 without reversing the direction of movement of the tool-carrier and cross-slides. An eighth switch CDLS-8, Fig. 5, is introduced into the box 264 and is actuated by an additional cam lug 271e on the cam ring 271. Also, provision is made for a further dog 282 on each face of the index member 217, Fig. 8, to actuate a switch ILS-8 in the switch-box 286. A switch SOS (not shown), enables the machine to be stopped after a single operation. For automatic right-hand screwing operations, a dog is positioned to actuate the switch ILS7 to prevent operation of the cross-slides and a further dog is positioned to actuate the switch CDLS-3 (not shown), when the carrier is about one inch from the end of its movement to render ineffective the switches which would cause the carrier to be returned at a fast speed. The carrier is thus moved first at a rapid traverse forward speed, is then fed and returned at the selected feeding speed, and only the final part of the withdrawal movement is at a rapid speed. For cutting lefthand threads, one or both of the feeds controlled by the clutches F2, F3 is reversed by changewheels. As shown in Fig. 1 only the train controlled by the clutch F2 is changed. Dogs are then positioned to actuate the switches ILS-7 and ILS-8 to cause the spindle 64 to rotate in a reverse direction while the carrier is advancing and vice versa. The gears 153, 166 are not changed so that the clutch F1 is always effective to drive the shaft 157 in the same direction as the spindle. Thus, even when set up for left. hand threading, the machine may still be used for the normal operations of turning, boring drilling and right-hand screwing by the use of the clutch F1, the dog for operating the switch ILS-8 then being omitted. It is thus possible to provide two feeding rates for left-hand tapping operations and one feeding rate for normal operations or vice versa. A time relay TR (not shown), ensures that the feed clutch is not engaged before the rapid traverse brake has been effective long enough to slow the gears to a speed not more than the feed speed. The machine, as before, may be operated simply by knobs and push-buttons. If, during manual operation of the machine, it is desired to reverse the carrier 66 before a screwing operation is completed, the spindle control is momentarily turned from " Run " to " Tap reverse " and back again. An under-voltage relay HUV (not shown), is not energized during automatic operation and thereby prevents inadvertent operation of the hand control circuits. As in the prior Specification, the machine may be automatically stopped after the carrier has indexed to a new position, a turret face may be skipped, or a dwell may occur at the end of the carrier feed stroke. The cross-slides may be moved at rapid traverse and feed speeds and be operated simultaneously with the carrier, or at the completion of its movement for a pusher tool to be operated. Specifications 632,869 and 647,906 also are referred to.