Patent GB-344037-A (GB)
Title: Improvements in or relating to apparatus for operating regulator valves on locomotives
IPC: F01B25/00
Filed: 1929-11-28
Abstract: 344,037. Fluid-actuated valves. SUPERHEATER CO., Ltd., Bush House, Aldwych, London.-(Superheater Co. ; 17, East 42nd Street, New York, U.S.A.) Nov. 28, 1929, No. 36570. [Class 135.] Valves controlled by pilot or relay valves.- Comprises fluid-pressure servomotor means for controlling the regulator or throttle-valve of a locomotive in which the piston of a servomotor cylinder is connected to the regulator valve or valves and has ports and passages and carries valve means for controlling the fluid supply and exhaust, and sliding connections are provided between the manually-actuated throttle lever and the piston whereby the lever can actuate the appropriate valves as desired and can also actuate the piston mechanically in case of failure of the fluid supply. In the construction shown in Figs. 1, 3, 5, and 6, the regulator valve shaft 4 has an arm 3 connected to a piston 2 working in a cylinder 1. The piston is urged to the right, in the direction to close the regulator by a spring 14, and the regulator is opened when compressed air, supplied by a pipe 13 is admitted to the right-hand end 24 of the piston. The piston has two heads and the space between these is always open to the air supply. Air is admitted to the end of the cylinder by means of a valve 9 and passes through a port 19, Fig. 5, and a non-return valve 20. The valve 9 is opened by a head 7 on a rod 5 connected to the throttle lever 6 in the driver's cab, the head 7 being capable of a small amount of movement in a space 11 in the piston. Thus, when the regulator is to be opened the rod 5 is moved to the left, the valve 9 is opened, air is admitted to the right of the piston, and the latter is moved to the left following up the movement of the rod 5. When the rod stops the piston moves on slightly until the valve 9 closes after which the piston stops. To close the regulator an exhaust valve 15 is opened by means of a rod 21 passing through the rod 5 and operated by a latch handle 22 on the throttle lever 6, the spring 14 then pressing the piston to the right and the air exhausting through the hollow rod 21 and ports 16, 17 in both rods. The handle 22 is pivoted at 28 on the lever 6 and has a lug 34 connected by a link 35 and bell crank 36 to the rod 21. The handle is formed with a double cam slot 29, 30 engaged by a pin 31 on a sliding toothed block adapted to engage a fixed quadrant 33 and lock the lever 6 when the parts are in the position shown in Fig 6. In the modification shown in Figs. 14 and 16 the compressed air can act at both ends 47, 48 of the cylinder and the piston has two similar valves 43, 44 each comprising an admission valve 9 or 91 and an exhaust valve 51 or 15. The throttle lever (not shown) is connected to a single rod 5 having two heads, 7, 77 thereon. Air is admitted through the pipe 13 and the space between the piston heads 24, 42 and ports 60, 61 to the admission valve chambers. Air can leak slowly through ports 56, 59 and passages 46, 45 to both ends of the cylinder so that normally these are both under pressure. To move the piston to the left (say) the rod 5 is moved to the left, the head 7 opens the exhaust valve 51 and the admission valve 9. The valve 51 allows air to exhaust from the left end of the cylinder through the passage 45, port 57, valve 51, passage 49, and a port 53 in the hollow piston rod 52, while the valve 9 admits compressed air freely through port 56 and passage 46 to the right end of the cylinder, so that the piston is moved to the left to follow up the movement of the rod 5. The heads 7, 77 on the rod 5 are adjustably spaced by means of nuts 550. When the air supply fails the heads 7, 77 act directly on shoulders 54, 62 of the piston. In another modification the piston is formed with two diameters, compressed air is always acting on the smaller area on one side of the piston, and is admitted to and exhausted from the larger area on the other side of the piston as desired.