Patent GB-464822-A (GB)
Title: Improvements in or relating to hydraulic jacking systems for vehicles
IPC: B60S9/10
Filed: 1935-10-16
Abstract: 464,822. Jacking - apparatus on vehicles. SESSIONS, D. W., and SESSIONS & CO., Ltd., D. Oct. 16, 1935, Nos. 28540 and 28541. [Class 79 (iii)] In hydraulic jacking-apparatus on vehicles, of the kind in which a pump supplies fluid to the jacks and a valve is provided for release of fluid from the jacks, a movable member mounted in the pump body or casing is connected to the valve, also mounted in the pump body, and to a clutch mounted adjacent to the pump, so that actuation of the movable member by the operator simultaneously effects closing of the valve and engagement of the clutch for driving the pump. As shown in Fig. 1, the pump 20 is attached to a dynamo 21, to the shaft of which it may be coupled, drawing liquid from a reservoir 27 and supplying it direct to front and rear jacks 33, 34. The jacks and the means for attaching them to the vehicle may be as described in Specification 459,160. The movable member controlling the clutch and valve may be actuated by mechanical or fluid transmission means 25 from a dashboard control 24 which may include an electric indicator light as described in Specification 464,821. The pump may be of the rotary annular piston type, similar to arrangements described in Specifications 352,268, 408,399, and 416,803, [all in Group XXVI]. As shown in Figs. 5 and 6, a casting 80 with end caps 81, 82, encloses the rotary pump, the clutch 127 for coupling a driving shaft thereto, the valve 106 and the movable member 108. The pump comprises an eccentric annular chamber 86 containing curved pistons 87 connected by roller-bearing pins 88 to a radially slotted disc 84 on a shaft portion 83 carrying a slidable clutch member 127 adapted to be moved into engagement against a spring 128 by a collar 126 operated through a pivoted yoke 123. The driving clutch member 130, in conjunction with an Oldham coupling 133 is mounted in a ball bearing 131 in the end-cap 82. The pump is supplied with an inlet port 90 and an outlet port 91. The inlet port communicates, through the chamber 104 surrounding the valve member 106, with a bore 105 leading to a conduit from the supply reservoir. The outlet port 91 leads through a non-return valve 100 to a passage 101 through which, providing the valve 106 is closed, fluid is supplied under pressure to the conduit 29 leading to the jacks. In the preferred arrangement all the jacks are operated simultaneously without any intermediate valves. If the valve 106 is opened, the pressure is relieved, the fluid returning to the reservoir or circulating through the pump. The movable member 108 through which the clutch and valve 106 are actuated, comprises a slidable sleeve connected to the end of the flexible transmission member 45 and formed with ears or lugs 109 engaging a flanged cap 111 closing the end of a tubular member 112 slidable in an enlarged extension of the bore 104 containing the valve member 106. The valve member 106 is carried by a rubber plug 114 seated, with a washer 115, against the shoulder between the two parts of the bore, a spring 116 in addition tending to keep the valve open. When the member 112 is drawn forward by the movable member 108, it presses a metal stud 113 in the rubber plug 114 and closes the valve. At the same time a spring pressed stud 121 within the tubular member bears against an arm or lug 122 on the clutch yoke 123 to throw the clutch member 127 into engagement. To prevent excessive pressure, when the jacks are extended, an extension 97 of the fluid passage 101 contains a plunger 99 adapted to bear against an upper arm or lug 140 on the clutch yoke, which may thereby be thrown out of action against the pressure of the spring 120, on the lower arm, leaving the valve 106 seated until the movable member 108 is released. Fig. 9 shows modified actuating means in which the cable 45 is connected to a lever 161 pivoted on the pump casing and imparting movement to the member 108 through a plunger 163. Instead of being controlled from the dashboard, the member 108 may be operated by a screw rotatable by means of a hand knob on the pump body. The first Provisional Specification describes also an arrangement wherein the pump is driven by an electric motor and the common control member actuates the valve and a switch in the motor circuit.