Patent GB-191209598-A (GB)
Title: Improvements in Controlled Door Closing and Locking Apparatus.
Inventor: LARKIN ERNEST EDMUND
IPC: E05F15/02
Filed: 1912-04-23
Granted: 1913-02-13
Abstract: 9598. Larkin, E. E. April 23. Dash-pots.-Relates to apparatus for closing and locking a door or a number of doors from a distant point, such as railway-carriage doors from the brake van, or road-vehicle doors from the driver's seat. According to the invention, the door is operatively connected to a plunger which moves in a cylinder during the opening of the door and compresses a doorclosing spring, a liquid in the cylinder passing from one side of the plunger to the other through a non-return valve. The flow of the liquid is permitted or arrested by means of a rotary valve operated from the distant point. In one position of the valve, the door may be opened by hand in the usual manner, the flow of the liquid being unrestricted, but in the other position of the valve, the flow of the liquid is permitted only in the other direction to enable any open door to be closed by its spring, the closed doors then being locked hydraulically. The plunger u, Fig. 1, working in a cylinder f is connected by a flexible rope r to a cylinder b concentric with the door hinges and carried by an arm l fixed to the door. The cylinder b moves between a cylinder a integral with the cylinder f and a cylinder c screwed into the cylinder a and containing the rotary valve d. The valve is turned in one direction by a rope t passing round a pulley x on the valve spindle o and connected to a main rope t<1> operated from the seat of control and is returned to normal position by a spring s'. The cylinder b is provided with three sets of ports h, h<1>, h<2>, Figs. 1, 5, 6, and 7, which in all positions of the cylinder b register with ports h<6>, h<7>, h<8> in the cylinder c and with a port h<3> in the wall of the cylinder f and with ports h<4>, h<5> formed in a valve block v fixed in the cylinder f and provided with oppositely acting non-return valves k, k<1>. The valve d is furnished with three ports h<9>, h<10>, h<11> adapted to afford communication in one position of the valve between ports h<5>, h<3> and in the other position between ports h<4>, h<3>. The apparatus being filled with liquid and the valve d being in the position shown, the door can be opened by hand, the plunger u moving inwards to compress a closing spring s, and the liquid passing through ball valve k<1> and ports h<5>, h<11>, h<9>, h<3> to the back of the plunger. The spring s is prevented from closing the door by the closing of the valve k<1>, but the door can be closed by hand owing to the flexibility of the rope r. The rope r is connected to a screw pin r<2> passing loosely through the plunger and furnished with a stop nut r<1> and a faced washer w, which prevents leakage when the rope r is under tension but allows a gradual return of the liquid through the plunger when the door is closed so that the spring and plunger slowly assume their normal position. When the valve d is turned so that the ports h<10>, h<9> register with the ports h<4>, h<3>, the port h<5> is closed, and any open door closes under the action of the spring s, the liquid passing freely through the ports h<3>, h<4> and valve k. The doors are locked by the closing of the valve k preventing inward movement of the plunger. To enable any door to be unlocked and opened when the valve d is in the locking position, an emergency valve may be arranged between the cylinder f and the port h<3> near to the valve block v.