Patent GB-155019-A (GB)
Title: Improvements in or relating to the operation of watertight bulkhead doors on ships
IPC: B63B19/00
Filed: 1919-09-08
Abstract: 155,019. Reed, G. H. Sept. 8, 1919. Operating and controlling doors hydraulically. - Relates to an hydraulic system for operating ships' bulkhead doors of the kind in which the doors are under the control of a valve at a central station, local manual and float operation being also provided, each local control valve being subjected to continuous pressure from the pressure main tending to move it into the door-closing position, this pressure being counterbalanced by air opposing pressure from a pressure-controlling main connected to the central control valve whereby the doors may be moved simultaneously into the open or closed position as desired. According to the invention, the door valves in a system of the kind specified are adapted to connect either end of a dooroperating ram cylinder to pressure or exhaust according as the controlling-main is connected with the exhaust main or pressure main by the central control valve to close or open the doors. Several construction of local door control valves are described, in each case provided with manual operating-devices and with or without additional bilge float controls. The arrangement of the system is shown in Fig. 1, the local control valves B<1>, B<2> being alternative constructions which may be employed. Each valve comprises a chamber 4 with ports 5, 6, 7 connected by pipes 8, 9, 10 with the door-closing end of a cylinder E, the exhaust pipe 2, and the door-opening end of cylinder respectively. The D-slide valves are moved by a ram 13 subjected to a continual pressure from the pressure main 1 in communication with a control pipe 3 through a central control valve chamber a. When the bridge valve C is in the position shown, pressure fluid passes through the control pipe to act on the ram 16 which has a greater effective pressure area than that of the ram 13. The slide valve is thus normally maintained in a position in which the pressure fluid from the main 1 passes through the chamber 4 and pipe 10 to the door opening end of the cylinder E. By moving the bridge valve C to put the control pipe 3 into communication with the exhaust pipe 2, the pressure in the chamber 15 is relieved and the valves B<1>, B<2> are moved so that pressure fluid passes through the pipes 8 to the door closing ends of the cylinders. A similar result is obtained by breakage of the pipe 3. Each valve is provided with an operating handle 19 for manually raising the valve from the door closing position into a door opening position, the door being returned automatically into the closed position when the handle is released. The valve B<1> is also shown provided with an auxiliary float control mechanism for closing the door should the bilge water rise above a predetermined limit. For this purpose, an auxiliary ram 21<a> is provided, of the same diameter as the ram 16, and these two members are connected to allow of lost motion. When a plunger 23 is retracted so as to allow the pressure fluid in the chamber 15 to move the ram 21a downwardly, the pressure in the chamber 4 forces the slide valve 12 into the door closing position. This is effected so soon as a float G is raised sufficiently by incoming water to rotate a disk 28 against the action of a spring 32 until the spindle 25 registers with an eccentrically-placed hole in the rotated disk. Several modifications of the local door control valve are described, in which the connexion of the exhaust pipe 2 is arranged on the opposite side of the valve chamber to the pipes 8, 10 leading to the cylinder E, as in the construction shown in Fig. 4. In this arrangement, the pipes 8, 10 are placed to exhaust through a port 34 passing centrally through the slide valve. The pressure pipe may be arranged to make connexion with the upper end of the valve casing, as in Fig. 1, or it may be arranged to act on the lower part of the ram 16 as shown in Fig. 4. In this latter arrangement, the pipe 1 communicates also with the bilge control ram chamber. The door valves may also be arranged to remain' normally in any position to which they may be set manually, while they are closed automatically when the main 3 is connected to exhaust by operation of the bridge valve C. To provide for this, the effective pressure areas of the controlling and valve rams are made equal and of the differential type. A construction of one form of valve of this kind is shown in Fig. 6, in which the pressure main 1 is connected to the bilge control chamber 40. A local manually-operating lever 19 is also provided. Local door operating valves with equal effective pressure areas and of the differential type are also described in connexion with through-ported valves of the kind shown in Fig. 4. For valves of the kind in which the valves are normally in the door opening position, as shown in Fig. 1, the operating lever of the bilge control may be moved manually for maintaining a door in the closed position, irrespective of the setting of the bridge valve.