GB190804233A - Improvements in Vent Valves for Automatic Train Stopping Systems. - Google Patents

Abstract

4233. Sedgwick, H. G. June 29, 1907, [date applied for under Section 91 of Patents &c. Act, 1907]. Rotary or oscillating disk or sector valves; actuating valves. -In an automatic train-stopping device, the vent valve for the pneumatic brakes has a port, part-circular in form, which is narrowed at its forward end, and the valve is given an initial quick movement and a subsequent slower movement so as to give a preliminary part reduction followed by a full reduction of pressure. The train pipe a<1>, Fig. 1, is connected to a valve chest b<1> provided with a venthole c<1>. The vent valve d<1> is formed with a port d<11> having a narrow forward end d<2>, Fig. 3. The valve d<1> is mounted on a spindle e<1> driven by clockwork motor. The spindle e<1> carries a cam f<1> so shaped that at a certain point in the rotation of the valve, the cam will press a brake lever g<1> against a drum h<1> mounted on one of the shafts of the motor. A solenoid f is contained in the circuit of the battery D, which is closed when a brush g, contacting with electrical devices on the permanent way as described in Specification No. 24,203, A.D. 1907, [Abridgment Class Railway signals &c.], is electrically connected to the axle h of the locomotive. The solenoid f attracts its armature e and lifts a rod l<1> carrying an arm m<1> which releases the fan k<1> of the motor. When the armature e is raised, contacts d close a second circuit of the battery D containing the solenoid f and keep this solenoid f energized until this circuit is broken by the passage of a pair of contact fingers e<11>, forming part of the circuit, off an insulated metal plate p<1> on the spindle e<1>. A cam o<1> on the spindle e<1> holds the rod l<1> with its arm m<1> away from the fan until the valve completes a single rotation, when the rod drops off the shoulder of the cam and stops the motor. When the fin k<1> is released the narrow end d' of the valve port quickly passes over the opening of the vent opening c<1>; but when the larger part d<11> is passing over the opening c', the speed of the motor is reduced by the cam f<1> operating the brake lever g<1>, so that the brakes are fully applied by a 'single rotation of the valve.