Patent GB-630310-A (GB)
Title: Improvements in turret lathes or like machine tools
IPC: B23B7/12
Filed: 1946-06-24
Abstract: 630,310. Turret lathes. WARNER & SWASEY CO. June 24, 1946, No. 18902. Convention date, Sept. 11, 1945. [Class 83 (iii)] [Also in Group XXXVII] A turret lathe or like machine-tool having a variable-speed reversible power drive for the spindle and control devices for the drive, is characterized in that a pair of drums provided with pre-settable means for selectively actuating said control devices for each indexed position of the turret is mounted on a shaft carried by a support on the turret slide, the pre-settable means being accessible from opposite sides of the support. The turret 25, Fig. 4, is connected by gearing 29, 30 and shaft 31 to a drum 32, so that the latter indexes with the turret. The drum 32 carries a number of adjustable selector stop-rods equal to the number of turret faces. A sleeve 33 extends from the drum towards the rear of the machine, the rods being adjustable through the open end of the sleeve. A gearring 34 is secured to the outer end of the sleeve and through a pinion 53 drives gears 54, 55, carried by drums 56, 57 respectively. The latter are carried on shafts 58, 59, parallel to the machine spindle, and arranged in a support 51 carried at the rear of the turret slide 24. Each of the drums carries switch-operating spring-pressed plungers 64, Fig. 9, similar to those described in Specification 603,286, and equal in number to the number of turret faces. The plungers may be pre-set to project inwardly sufficient to operate a switch when a projection 66 on the plunger head engages a notch 67 in the housing. A similar pair of drums 60, 61 is arranged at the other ends of the shafts 58, 59 and the combination of switch-operating plungers thus provided may be pre-set to control switches LS2, LS4, LS6, and LS7. The turret slide 24 is operated in the usual manner by means of a turnstile handle and rack-andpinion gearing, the drums operating preselected switches to condition the spindle for either slow or fast rotation, clockwise or anticlockwise. A switch at the rear of the drum support is manually operated where rapid rotation in the reverse direction is required of the spindle. The selector stop-rods 35 are adapted in the operative position to strike a buffer stop 36 which is carried forward against the resistance of a spring 40 until it strikes a fixed member 38 which limits the forward feed. A rod 37 secured to the buffer member has a recessed portion 42, Fig. 3, which moves over the end of a spring-pressed plunger arranged perpendicularly thereto and operates a switch LS3 for the reversal of the spindle when the control circuit is conditioned therefor. A limit switch LS5, fixed to the machine bed, is also operated momentarily by a dog on the turret slide, this serves to establish a holding circuit for the driving motor at the start of a set of operations. The reversible variable-speed spindle driving motor 21, Fig. 10, is supplied from multiphase lines 78, 79, 80, through a main disconnect switch 81 and thence connected through a forward contactor 82, a reverse contactor 83, a low-speed contactor 84, and a high-speed contactor 85. The latter has five pairs of contacts and when the low-speed contactor is closed the wire 78 extends to the fifth pair and thence to inner terminal 86 of the motor while the wire 79 extends to the other contact and thence to inner motor terminal 87. Under the same condition the line 80 extends to one of the contacts of the fourth pair and thence to inner motor terminal 88, the other contact of the fourth pair being connected to the contact of the fifth pair to which the wire 78 is connected. Thus for low-speed running in forward and reverse directions the three inner terminals 86-88 of the -motor are connected in the primary circuit and for high-speed operation the outer terminals 89-91 are employed. The wires. 78 and 80 of the motor circuit are connected by wires 92, 93 to the primary of a transformer 94, the secondary of which is connected to wires 95, 96 of a control circuit which operates at reduced voltage and includes the switches referred to above in connection with the control, drums. Specification 603,286 is referred to.