Patent GB-191128721-A (GB)
Title: Improvements in and relating to Fluid Pressure Systems for Operating Bulkhead and like Doors and the Valves Employed therein.
Inventor: PIKE FREDERIC JOHN
IPC: B63B19/00
Filed: 1911-12-20
Granted: 1912-12-20
Abstract: 28,721. Pike, F. J., and Neville, H. Dec. 20. [Cognate Application, 16,330/12.] Operating doors hydraulically; controlling by floats.-In a system for operating bulkhead or other doors in which the doors may be operated (1) by fluid pressure, either simultaneously from a distant point, such as the bridge, or individually by means of a local door valve, or automatically on the rise of water in a compartment, and (2) by mechanical means, when desired, or on the failure of pressure, the controlling-valves are adapted to enable the pressure and exhaust mains, or the two ends of each door cylinder, to be short-circuited or by-passed when desired, or when the pressure supply is absent, so that the mechanical means may be freely operated, the arrangement being such that upon restoration of pressure to one of the mains for simultaneously closing the doors, all the door valves that are in the by-passing position are moved by the pressure to enable closing to take place. Fig. 1 is a general arrangement of the system for operating bulkhead doors m provided with hydraulic operating - rams k and mechanical operating means r, q. The " opening " main a, that is, the main which is under pressure for opening all doors from the bridge, and the " closing " main b, are reversed by means of a main controlling-valve device A, the form shown comprising a slide valve g actuated by fluidpressure rams 2, 3, the supply of pressure to which is controlled by a hand-operated pilot valve 4. The means for short-circuiting the mains comprises a cavity or port h in the valve g adapted, when the valve is placed in an abnormal position, preferably the mid-position, to connect the mains together and to the exhaust tank through passages x, z, y. The pilot valve 4 is similarly provided with a cavity by which the pressure in the chambers 5, 6 containing the rams 2, 3 may be equalized to enable springs 10 to move the main valve g. to bypassing position. The door-valve devices are of the slide-valve type, such as described in Specifications 13,415/11 and 29,310/11, and are provided with cavities n which, when the valves are in mid-position, connect the opposite ends of the ram cylinders together and also, in some constructions of valve, with the pressure or exhaust main. Fig. 4 shows a form of door valve in which, when pressure fluid is absent from both passages a<1>, b<1> leading to the mains a, b, the valve is moved to the by-passing position shown by means of spring plungers 30, 31 engaging the valve lever 270. The plungers 30, 31 are normally held depressed and inoperative by the pressure fluid in the passage a<1> acting upon a ram 32 provided with a fork member 35 having prongs 38, 39 engaging the plungers 30, 31. The depression of the ram 32 is normally limited by a projection 41 engaging a catch 33 connected to a bilge float. In the normal position of the parts, the valve may be moved by its lever 270 to admit pressure from the passage a<1> through the port 18 and passage o to the opening end of the ram cylinder j, or through the port 18 and passage to the closing end of the cylinder, or the valve may be moved to by-passing position,' the pressure on the back of the valve maintaining it in the set position. The lever 270 works in a slot in the fork member 35. On the rise of the bilge float, the catch 33 is released and the ram 32 fully depressed, the end 45 of the slot in the fork member engaging the lever 270 to raise the valve and close the door. On reversal of the mains, the pressure fluid entering the passage b<1> depresses the valve and passes through port 34 and passage p to close the door. The prong 38 of the fork'35 may be perforated as shown to engage a shoulder 43 on the spring plunger 30 so that the valve is depressed by the fluid pressure against the pressure of the plunger 30 only. To prevent the valve from moving to the midposition during the short time required for reversing the mains, the action of the spring plungers 30, 31 may be retarded by dash-pots, or by the provision of a ported diaphragm in the passage b'. If the float control is omitted one spring plunger only need be employed and may be arranged directly beneath the ram 32. In the form of door valve shown in Fig. 1, the valve is normally held in the by-passing position by a spring plunger 31 which holds the lever 270 against the ram 32. A second plunger shown in dotted lines may be provided so that the valve is held in the mid-position under all circumstances except when the closing main b is under pressure, and also when the catch 33 has been released. In the form of valve shown in Fig. 5, the valve is normally held so that the door may be opened or closed from the bridge, by means of a ram 46 exposed to the pressure in the main a through a pipe a<2> and cock 50. The ram 32 carries a spring-pressed plunger 31 adapted, when pressure is absent from the main a and consequently from the plunger 46, to depress the lever 270 and move the valve to mid-position. The ram 46 is smaller than the ram 32 so that it is depressed when the ram 32 is released by the bilge float. In a modification of this valve, the spring plunger 31 is arranged in conjunction with the ram 46, and a second spring plunger is arranged to act on the short arm of the valve lever to move the valve to by-passing position.