Patent GB-190318762-A (GB)
Title: Improvements relating to Cocks and Valves.
Inventor: LOMOFF WASSILY
Filed: 1903-08-31
Granted: 1904-08-31
Abstract: 18,762. Lomoff, W. Aug. 31. Brakes.-Relates to devices for locking plug cocks in pipes used in automatic air brakes on railway vehicles. The locking is effected by causing a pin in the casing to be thrust by pressure in the main or a subsidiary pipe into a hole in the plug, electric or hand power being used in some cases. In the arrangement shown in Fig. 1, fluid under pressure in the main pipe passes by a passage a to a chamber b and moves a piston c so as to place the end of the piston spindle e into a hole f in the plug g. A port w allows fluid which leaks past the piston to escape. When the main contains rarefiel air, the piston is moved by atmospheric pressure, the ports a, w being dispensed with. Air is in this case admitted to one side of the piston through a port w<1> and taken from the other side by a port a<1> which communicates with the main pipe. A spring d returns the piston and spindle to position. The piston may be actuated by hand, a buffer spring being interposed between it and the nut n or a projection formed on the nut to engage the piston. The latter is screwed into and out of the casing to lock and unlock the valves. The piston c shown in Figs. 1 and 2 (Sheet 3) is made to act vertically in the casing and operate a subsidiary piston with a spindle e by means of wedges q and bell-crank lever p respectively. Instead of forcing the locking-pin in these modifications into the plug itself, it may be made to project outside of the casing into a hole either in the handle of, or in an extension of, the plug. All the locking-mechanisms, instead of operating in the casing, may be situated bodily in the plug, and the locking-pin projected into a hole in the casing. A simpler method of locking the plug consists in screwing an ordinary pin through the casing into a hole in the plug, and unscrewing to release the plug. Two spring- actuated locking-catches are shown in Figs. 1 and 2 (Sheet 6). In Fig. 1, the pin a is pressed up by a spring b into a hole i in an extension of the plug, thereby locking the plug. To release the latter, the pin is drawn down by a catch k on it. In the arrangement shown in Fig. 2, the end of a pivoted bar a<1> mounted on the handle of the plug is pressed by a spring c into a recess in the casing. In all the devices in which fluid pressure is used, this may be obtained not from the main pipe but a subsidiary pipe M, Fig. 1 (Sheet 7). Actuating- fluid under pressure passes in this case through a branch a to the piston, leakage escaping by a port k<5>. For rarefied air, a different branch a<0> would withdraw air from one side of the piston k<1>, and a port k<7> passing through the nut admit atmospheric air to the other side. In the arrangement shown in Fig. 1 (Sheet 8), in which the piston is inside the plug, the branch g is in position for passing compressed air to the plug from the pipe M, but, in the case in which the latter contained rarefied air, the branch would enter the other side of the casing, connecting directly with the port r<5>. Modifications of the locking-parts are described in which the spindle of the piston, instead of itself entering a recess in the plug, is provided with an extension having inclined surfaces. These surfaces bear against the ends of pivoted levers. When the piston is moved, the levers are turned on their pivots, and projections on them enter recesses in the plug. In a modification, there are two pistons z<1>, z<3>, Fig. 6 (Sheet 9), of different sizes and both mounted on the locking-spindle z<2>. Air under pressure from the main pipe passes through a port z<7>, pressing the spindle against a apring z<4> into a recess in the plug, and slowly passing through a port z<6> in the larger piston. When pressures on both sides of the latter are equalized, sudden reduction of pressure in the main pipe causes the compressed air in the chamber z<10> to lift the spindle out of the plug. The space z<10> may be virtually increased by the employment of subsidiary chambers z<8>, z<9> connected with it and situated either inside or outside the casing. The pistons may be arranged side by side in separate chambers, their spindles both connected to a pivoted lever, and a check valve applied to the port z<6> to retard the back rush of air when pressure in the main pipe is reduced. A similar construction of parts is adopted when the main pipe contains rarefied air, but, in the vertical position as in Fig. 6 (Sheet 9), the larger piston is underneath. In a further modification, pressures both in the main and in an independent subsidiary pipe are used, or pressures in two such subsidiary pipes. In this case, pressure in the main pipes or one subsidiary pipe acts on one side of the piston to lock the plug, and pressure in the other subsidiary pipe acts on the other side of the piston to raise the locking-spindle and release the plug.