Patent GB-603286-A (GB)
Title: Improvements in control means for the power drive of turret lathes and like machine tools
IPC: B23B3/18
Filed: 1944-10-11
Abstract: 603,286. Lathes. WARNER & SWASEY CO. Oct. 11, 1944, No. 19603. Convention date, June 11, 1943. [Class 83 (iii)] [Also in Group XXXVII] Control means for the power drive of a turret lathe or like machine having tool and work carrying members, the former carrying an indexible element, comprises an electrical control circuit for the power drive including control devices and actuating members associated with said indexible element for actuating at least some of said control devices for determining the operation of the power drive and is characterized in that the actuating members associated with the indexible element are adapted to actuate certain of said control devices by an indexing movement of said indexible element and that other actuating members are provided which are adapted to actuate other of said control devices by movement of said other member, the speed and the direction ot movement of the power drive being thus controlled. The lathe spindle 39, Fig. 1, is driven through V-belts from a two-speed electric motor 40 carried by the pedestal 36 and a turret - slide 44 which may be clamped in adjusted position along the ways 43, has a turnstile hand-lever 47 for moving a turretslide through a rack and pinion gear. Indexing mechanism operated by the movement of the slide and locking and clamping gear for the turret may be by known arrangements and is not described. Selector stop bar mechanism. - Rotatably connected to the turret 46, Fig. 7, by bevel gears 50, 51, is a selector stop drum 54 carried by bearings in the turret slide and provided at its end remote from the turret with a ring gear 86 which meshes with three similar ring gears 87, 88, 89, Fig. 12, secured to switch drums carried on shafts 93 in a housing 57 at the end of the slide. The adjustable selector rods 58 are adapted to contact a buffer member 59, Fig. 7, on approaching the limit of their forward movement which may act as a dead stop against the fixed abutment 61 or during threading operations may, through the plunger 60 and switch mechanism (not shown), operate a reversing switch for the lathe spindle. This switch mechanism may be arranged to operate either early or late according to whether the threading operation is effected by chasers or by a self-opening die-head. Hand-control. The switch drums connected to the selector gear rotate inactively during hand-control of the machine and the control for different operations is through the main control lever 108, Figs. 19 and 20, which operates a number of main switches MS1-MS4 and a reverse switch LS1. The latter reverses the direction of spindle rotation when the handle is pulled forwardly to the dash-line position of Fig. 20 and gives a high- or low-speed reverse according to the radial setting of the lever. The other positions of the lever 108 condition various switches and relays to give, Fig. 19, " Neutral "-Reversal of current to driving motor to slow it down and subsequent intermittent application of a solenoid-operated brake which finally stops the spindle in a predetermined position. " Release Brake "- Brake held in off position enabling spindle to be rotated freely by hand. " Start and " Stop " buttons 135 and 136 respectively are provided on the control panel, Fig. 19, and two further switches 137, 138. The first of these switches is positioned at " Run " and the latter at " Hand " during hand-control of the machine. The operation of the turret slide and selector gear is otherwise effected in the normal manner. Automatic control. For automatic working, studs 97, Fig. 13, numbered to correspond with the corresponding faces of the turret are rotated through a part-turn to bring their engaging cam-heads into position to operate switches LS2, LS4 and LS6. These switches control respectively Fig. 30 (not shown)- automatic reversal of the lathe spindle; high and low spindle speed; and stopping and starting of the spindle. The cam studs controlling the last-named switch may be arranged to give : (1) continuous running of spindle during turret indexing; (2) stopping of spindle during indexing and re-start as turret slide is moved forward; (3) stopping of spindle during indexing and spindle remaining stationary when turret slide is advanced. The switches 137 and 138 on the control panel are turned to " set-up " and " auto and with the control lever 108 in either of the running positions " high " or " low " the machine spindle will continue to operate automatically. A warning light 190 indicates when the " start " button has been depressed and control circuits conditioned so that on forward operation of the turret slide a switch LS5 (not shown) is closed and the main spindle commences to rotate. The warning light 223 is connected to the threading control circuit and comes on when the selector rod for threading is adjusted to the point at which the reversing switch LS3 will operate to reverse the main spindle.