Patent GB-452166-A (GB)
Title: Improvements relating to hydraulically operated machine tools
IPC: B23Q5/26
Filed: 1935-04-26
Abstract: 452,166. Hydraulic transmission of power. ARCHDALE & CO., Ltd., J., Ledsam Street, Birmingham.-(Wegerdt, F. ; 2, Kyffhõuserstrasse, Chemnitz, Germany) April 26, 1935, No. 12527. [Class 69 (ii)] Hydraulically operated machine tools comprise a main system containing the working cylinder 11, and a main variable delivery pump 1, a subsidiary system containing a cylinder 20 and a variable delivery pump 18, the pressure variations in the subsidiary system being utilized as described in Specification 452,165, to vary the delivery of the pump, pilot valves 4, 5, and main valves 7, 8 actuated by liquid under pressure under the control of the pilot valves. A member 6 may be turned or slid by a lever or by stops such as 6a on the operated member 12, the turning movement acting to slide a shaft 6b and actuate the valve 5, and the sliding movement acting to rock the shaft and actuate the valve 4. The valves 4, 5, each have four operative positions, and the valves 7, 8 three operative positions. By suitable operation of the valves 4, 5, and hence of the valves 7, 8, the table 12 may be moved rapidly or at a slower speed to the right or left. When the valves 4, 5, are positioned as shown in Fig. 1, the pump 1, which may be constructed as in Specification 424,609, [Group XXVIII], forces a small supply of constant volume through a pipe 3, and the valve 7 is forced to the left, while the valve 8 is in mid-position ; liquid from the pump 1 passes through a pipe 2, valves 7, 8 and pipe 9 to feed the table to the right. Should irregularities in speed occur, the pressure from the pump 18 varies, and acts on a spring-pressed valve 22, to allow pressure liquid to pass from a pipe 23 and act on a plunger 27 or 28 to alter the capacity of the main pump 1 to restore the speed to its desired value. The pump 18 is reversed to accord with the direction of the table by pilot valve controlled pressure acting on a plunger 32a or 33a. Different rates of slow speed are obtained by varying the discharge of the pump 18 by pressure acting on a plunger 34, the admission or discharge of this pressure being controlled by a valve 43 acted on by table stops 43a, 43b, or by a valve 45. The latter is moved to its end positions by a solenoid 46 or 47 ; when the power demand on the motor 53 driving a rotary tool increases, a solenoid 51 overcomes the action of an adjustable spring 51a and causes the solenoid 46 to be de-energized and the solenoid 47 to be energized, so that pressure acts on the plunger 34 to reduce the capacity of the pump 18. The exhaust side of the main system includes a cylindrical member 14 capable of being turned through 180‹. When in the position shown, pressure from the pump 1 may act on a piston 14b against a spring 14c, and at a predetermined pressure open a port 14d, so that the exhaust liquid can pass to and open a valve 15. In the opposite position of the member 14, the pump pressure is cut off from the piston 14b, and the exhaust pressure opens the valve 14f. When a quick traverse is in operation, the member 14 is byepassed by a port 8a.