GB505654A - Improvements relating to valve arrangements in fluid pressure systems - Google Patents

Abstract

505,654. Hydraulic transmission of power; aircraft controls. DOWTY, G. H. Oct. 11, 1937, No. 27576. [Classes 69 (ii) and 135] [Also in Group XXXIII] A hydraulic system comprising pressure generating means, receiver means and a hydraulic circuit therebetween, includes a valve and union device for making a temporary branch connection to the circuit, so constructed that making the said temporary connection moves the valve so as to open it for flow through said branch against which flow it is normally closed, and to close it against flow through the circuit, for which flow it is normally open. A device 9 is provided in the pipe 4 leading from the pump 3 to the control valve 5, and a similar device 9A is provided in the pipe 8 leading from the control valve 5 to the reservoir 1. The device 9 includes a ball 10 normally, urged by a spring 11 on to a seat 12 whereby the two parts of the pipe 4 are in communication. On removal of a capping plug and insertion of a union plug 18, a seat 20 on the latter acts through a push rod to lift the ball 10 from the seat 12 and press it on to a seat 21 whereby the horizontal line 4 is cut off from the vertical line 4 but placed in communication with the pipe 19. The push rod comprises two. parts 13, 14 separated by a compression spring 15 to prevent excessive loads being transmitted by the composite push rod. The invention is stated to be particularly applicable to the hydraulic systems of aircraft; thus, when the aircraft is on the ground, an auxiliary pressure source can be plugged in at 9 for replenishing the system or for testing the valve 5 and slave units ; in the latter case, a reservoir may be plugged in at 9A to prevent overcharging of the system. Alternatively a reservoir may be plugged in at 9A for relieving the system of liquid. Specification 480,674 is referred to.