Patent GB-190406541-A (GB)
Title: An Improved Method of Opening and Closing Valves.
Inventor: SEATON ALBERT EDWARD
Filed: 1904-03-17
Granted: 1904-07-28
Abstract: 6541. Seaton, A. E. March 17. Actuating valves; sliding valves; casings; spindles.-Relates to means for facilitating the opening and closing of sluice, sliding and stop valves of large size,by utilizing the pressure of the fluid passing through such valves when open. One or more cylinders attached to, or cast with, the main valve, are adapted to slide over stationary pistons. The pressure fluid is admitted to the cylinders on one side or the other of the pistons, according to the direction in which it is desired to move the main valve, by means of one or more externally-operated controlling-valves ; while the opposite ends of the cylinders are, by the same means, put in communication with a lower pressure exhaust. A small movement of the main valve automatically returns the controlling-valve to mid position, and the main valve then remains at rest until a further initial displacement is given to the controlling- valve, the operations being repeated until the main valve is moved the required distance. Fig. 1 is a longitudinal section, half being through the main-spindle axis, and half through the exhaustpipe axis of the form of the invention in which one actuating cylinder is used ; Fig. 3 is a section of the controlling-valve, gear, and ports. To open the main valve V, the lever L and nut N, Fig. 1, are turned so as to raise the screwed main-valve spindle S slightly with respect to the main valve. The spindle S is prevented from turning by its squared lower end engaging a recess in the cylinder cover D, in which recess it can have the required amount of free longitudinal movement. The upward movement of the spindle S is transmitted by levers H, Fig. 3, through a pin Q to the controlling-valve E, the levers H being pivoted on a pin M in the cylinder cover, and connected to the spindle S by a pin O. When the controlling- valve is raised, the port T<1> admits pressure fluid to the space in the cylinder C above the piston P. The port T<2>, leading from the opposite end of the cylinder, is, at the same time, put in communication with a lower pressure exhaust through the exhaust port R, an exhaust chamber U, and an exhaust pipe W ; the pipe W is attached to the casing cover and passes through a stuffing-box F into the exhaust chamber. The difference in pressure on the two sides of the piston P causes the main valve to rise slightly, and in so doing, to return the controlling-valve to mid position by means of the levers H, the pivot of which is now the pin 0, when the upward movement of the main valve ceases. To close the valve, the controlling-valve is given an initial displacement in the opposite direction, in which case the port T<2> is opened to pressure, and the port T<1> to the exhaust. If the main valve does not respond to the initial displacement of the controlling-valve, the lever L and nut N are turned until the squared end of the spindle comes in contact with the cylinder cover D, when the main valve may be moved directly by the force applied to the lever L. The piston-rod G passes fluid-tight through the lower end of the cylinder, and has an enlarged end K fitting into a recess X in the valve-casing. The spindle S, the piston-rod G, and the exhaust pipe W have all sufficient play to allow the main valve to slide in contact with the valve face on the casing A. When two or more actuating cylinders are used, the piston-rods pass through stuffing-boxes in the cylinder covers and are hung from depending lugs in the casing cover. A controlling-valve may be fitted to each cylinder, or one controlling-valve may be used for all the cylinders. The action is similar to that described above. Fig. 8 shows a modified construction of the main-valve spindle S and nut N. In this case, the spindle is turned and the nut travels along it. The levers H, which operate the controlling-valve, are pivoted at M to the nut N, and at 0 to the valve casing. In this case also the main valve may be operated, if necessary, by force applied to the lever L. In both forms of the invention, the exhaust may be taken through a passage Z, Fig. 1, in the main-valve casing, instead of through the exhaust pipe W.