Patent GB-923604-A (GB)
Title: Machine tool
IPC: B24B47/04
Filed: 1962-01-23
Abstract: 923,604. Grinding. CINCINNATI MILLING MACHINE CO. Jan. 23, 1962 [July 10, 1961], No. 2374/62. Class 60. A grinding machine comprises a slide 10 movable on ways 14, a rotatable control member 34 connected for movement of the slide in accordance with the direction and amount of rotation of the control member, means 1EC, 2EC selectively to connect a feed motor to the control member for rotation in one direction or the other, a positive stop 68 adapted to engage a stop dog 66 associated with the control member to stop rotation of the member in one direction, and presettable means consisting of a plurality of trip members 2LS ... 5LS and cams 110, 112, 114 relatively rotatable by movement of the slide to control means to connect a feed motor to the control member to effect a predetermined rotary movement of the control member in one direction to move the stop dog to the positive stop and in the other direction away from the stop to a predetermined angular position to produce a cycle movement of the slide. The presettable means control the movement of the slide to produce a rapid advance of the wheel followed by slow and fine feeds until the stop dog engages the positive stop and after a time delay returns the slide to its initial position. The slide 10 of the machine is connected by a rack 14 and gear 20 to the shaft 26 of a vanetype hydraulic motor 2MTR, the movement of the vane 272 of which is used to effect the rapid movements of the slide. The body of the motor is connected by a worm 22 to a shaft 28 rotatable by the control member to effect the slow and fine feeds of the slide. The shaft 28 is secured to a handwheel shaft 32 which carries a gear 40 connected by a gear 46 to a gear 44 having a different number of teeth to the gear 40. A dial 52 is connected to the gear 40 and rotation of the dial rotates the gear 44 at a reduced speed for set-up purposes. The dial 52 can be connected by a screw 54 to the control handwheel 34 which, in turn, can be connected by a pin 38 to a gear 36 on the shaft 32. A ring 64 is carried by the handwheel and supports the stop dog 66. The position stop 68 is movable by solenoids 5SOL, 6SOL between operative and inoperative positions to permit the hand wheel to make more than one rotation during the movement of the slide. The hand wheel is formed with a sleeve carrying a gear 98 which is connected by gearing 94, 108, magnetic clutches 1EC, 2EC and gearing 78, 80, 76 to a shaft 74 driven by an hydraulic motor. Energization of both clutches prevents movement of the slide and energization of one or the other of the clutches rotates the handwheel in one direction or the other. The gear 94 is connected by gearing to shafts 120, 134, 142 on which are adjustable cams 110, 112, 114, co-operating with trip members in the form of limit switches for controlling the speed of the motor 1MTR and the cycle of movement of the slide. In operation, when a start button is pressed, fluid from a pump 162 is supplied by a solenoid-controlled valve 166 to a line 178 to move the vane 172 of the motor 2MTR, the movement of the vane rapidly advancing the slide by way of the gear 20 and rack 14 until the vane abuts a wall 174. The consequent rise in pressure in line 178 actuates a pressure switch PS to energize a solenoid 2SOL to move a valve 182 so as to connect the pump to the motor 1MTR, the exhaust from which passes to a line 186. At this time a solenoid 4SOL positions a valve 194 to connect the pump also to a valve 192 which is moved so that the exhaust fluid from the motor passes through a slow-rate valve 198 as well as through a fine rate valve 190, the slide thus being moved at a slow rate. After a predetermined slow feed, the solenoid 4SOL is de-energized so that valves 194 and 192 return to their initial position and the speed of the motor is reduced to effect the fine feed, the exhaust from the motor flowing only through valve 190. The cams 110, 112 are driven at a faster speed than cam 114 and it is not until cams 112 and 114 are in predetermined positions that the switches are operated so as to actuate solenoid 5SOL and advance the stop 66 into its operative position. When the stop dog 66 engages the stop 68 to limit the forward movement of the slide, a rod 70 is displaced to actuate a limit switch 1LS and energize a timer which is effective to retain the slide in its forward position for a predetermined time to allow for spark-out. At the end of the predetermined time, the timer actuates the solenoid-operated valves and the clutches 1EC, 2EC so that the vane is returned to its initial position to retract the slide at a fast rate and the fluid from the pump drives the motor 1MTR at a fast rate to return the body of the motor 2MTR to its initial position, the limit switches actuated by the cams stopping the motor when the slide is in its initial position and energizing both clutches to prevent further movement of the slide until another cycle is initiated.