Patent GB-368792-A (GB)
Title: Improvements in or relating to hydraulic actuator systems for controlling the movements of machine parts
IPC: B23Q5/26
Filed: 1930-09-05
Abstract: 368,792. Hydraulic transmission of power. BARNES CORPORATION, J. S., 301, South Water Street, Rockford, Illinois, U.S.A. Sept. 5, 1930, No. 26618. Convention date, March 27. [Class 69 (ii).] A hydraulic system for operating machine parts comprises separate low and high pressure pumps for effecting quick traverse and slow feed motions, the slow feed pump and actuator cylinder being arranged in a closed circuit, which during the feed action is independent of the quick traverse circuit. Control is effected by a valve disposed in the low pressure circuit. The invention is described with reference to a lathe described in Specification 366,928, having a headstock with spindle 36, Fig. 3, adjustable tailstock 64, and front and rear carriages 86, 140, Fig. 5. The front carriage comprises a base 88 clamped on a bar 90 capable of rotary and longitudinal movement. A depending screw 98 carries a roller 100 resting on a guide bar 102, Fig. 2, pivoted at 104, the opposite end of the bar being capable of being raised by a hydraulic piston 126 until an inclined surface on it engages a similar surface on an adjustable stop 130. The longitudinal movement of the bar 90 is effected by a piston 137, and the rear carriage is operated by a piston 154. The hydraulic system shown in Fig. 23 comprises a continuously driven gear pump 136 of variable output supplied from a reservoir. 244, a control valve 138, and high pressure pumps 172, 172a driven from the spindle 36. When the valve 138 is moved into the position shown in Fig. 24, liquid from the pump 136 actuates the pistons 126, 154 to effect a rapid approach movement of the rear carriage and to swing the front carriage into operative position. Simultaneously a piston 292 is actuated to engage a clutch in the driving means for the spindle 36. The valve 138 is returned to its neutral position, the pump 172 supplies liquid to effect the feed movement of the rear carriage, and a valve 230 is opened to allow the pump 172a to effect the longitudinal movement of the front carriage. When the valve 138 is moved into the position shown in Fig. 25, the clutch in the spindle driving means is thrown out, and the carriages returned to their initial positions, after which the valve 138 is returned to its neutral position. The valve is operated manually to initiate or complete a cycle of operations by a lever 270, Fig. 11, or automatically dnring the cycle ; the automatic means comprise a dog-carrying slide 304 operated from the rear carriage, and acting on a slidable member 336 connected to the lever 270 and on a valve 348 which unbalances the valve 138. The valve 230 is also actuated from the slide, and bleed passages 380, 382, Fig. 18, may be provided in the casing of the valve 138. The output of the gear. pump 136 is varied by the adjustment of a central .valve 253, Fig. 6, one of its pinions has radial passages 257, and the pumps 172, 172a, each comprise a fixed cylinder body, the pistons of which engage pivoted fingers 208, Fig. 22, bearing on a rotary ring 178; the eccentricity of the ring is varied by means of a longitudinally movable member 224, Fig. 21, having a member 222 inclined to the axis of rotation of the ring, and a tapered rotary distributing valve 186 is provided.