GB465068A - Improvements in or relating to hydraulic remote control systems - Google Patents

Abstract

465,068. Hydraulic control systems. CLENCH, E. C. S., and AUTOMOTIVE PRODUCTS CO., Ltd. Nov. 2, 1935, Nos. 30332 /35 and 23157 /36. [Class 69 (ii)] Comprises a double-acting, liquid-pressure, telemotor control with master and slave elements connected by a pair of pipe lines. To prevent liquid under pressure returning to the reservoir when the breathing valves are opened, the pressure of the liquid in the pipe lines at the end of a resetting operation is reduced by enlarging the space containing said liquid, and then said pipe line is opened to the reservoir. The master unit comprises a reservoir body 10 and aligned cylinders 11, 12. The pistons 13, 15 are connected by a sleeve 14. The pistons are moved by a lever 16 with an arm 20 carrying a roller 22 which engages the heads 23, 24 of spring-pressed plungers 25, 26 with reduced valve heads 28 mounted in the pistons. The pistons have elongated bores 30, transverse bores with spring-pressed ball valves 34 and caps 35, and transverse passages 36 which normally permit equalization of pressure. The master cylinder is connected to a slave cylinder of the self-locking kind described in Specification 443,871. When the lever 16 is moved e.g. to the right, liquid trapped by the plunger 25 is forced into the line 38 thus raising its pressure until the piston 13 is moved. At the termination of the setting, the expanding spring 27 returns the plunger 25 and causes a predetermined quantity of liquid to be drawn from the line 35 and cylinder 11. Liquid to make up leakage is drawn through valve 34. In the construction shown in Fig. 3, the arm 20 rigidly operates the pistons. The body 10 comprises two compartments, one of which houses the handle, and the other 43 forms a reservoir. The compartment is connected to the cylinders by passages 45 controlled by byepass, spring- pressed valves 46 urged towards seats 49. The valve 46 is normally held off its seat by a pushrod 53 on a lever 50 pivoted at 51 and acted on at the other end by a spring 52 stronger than spring 48. The levers 50 are moved by cam arms 55 on a sleeve 54 rotated on moving the handle 16 by a friction clutch on the shaft 17. The arms and sleeve are returned to their central position by spring action. Adjustable stops 60 limit the movement of the lever 50. Upon moving the lever 16 to the right e.g., the piston 13 moves idly until the ball valve 46 closes. When the lever and piston 13 have been moved to the desired extent and the operator lets go, the springs tend to centralize the member 54 which movement is transmitted to the friction clutch and thus causes the piston 13 to be returned to a slight extent. During the first part of this movement when the valve is closed, the enlargement of the space 37 reduces the pressure. When the valve 46 is opened, the pressure is atmospheric so that loss of phase is avoided. Specification 443,839 also is referred to.