Patent GB-190506670-A (GB)
Title: Improvements in Air Brake Mechanism.
Inventor: DILLANDER JOHN
Filed: 1905-03-29
Granted: 1905-08-31
Abstract: 6670. Dillander, J. March 29. Brakes.-Relates to air brakes and consists of modifications of and additions to the triple valve for the purpose of providing for both positive gradual and positive emergency applications, retaining the brake cylinder pressure while the auxiliary reservoir is being recharged, venting the train-pipe at each triple valve during an emergency application, and causing. a free flow of air from the auxiliary reservoir to the cylinder in highspeed trains in an emergency application. The triple-valve piston is made in two telescoping parts 20, 50, of which the outer main part is connected by its stem 48 to the graduating-valve 47, while the inner part 50 is connected by a double stem 52, Fig. 7, to the main valve 43. An additional piston 28 in an extension of the triple-valve casing is connected to a valve 35 which normally connects the triple-valve exhaust port 33 with an open exhaust port 34. With the parts in the running position as shown, air can pass from the trainpipe connexion 60 through a small hole 29 in the piston 28, through a leakage groove 17, and through a notch 25, to the auxiliary reservoir. The air can also pass to the space 23 between the two pistons 20, 50 through a leakage passage around the stem 48 of the piston 20. A slow reduction of the train-pipe pressure for a gradual application, causes the piston 20 to move to the left for a short distance by itself, taking with it the graduating-valve 47 and uncovering the graduating-port 46 in the main valve 43. A pin 55 on the stem 48 then comes against the boss of the piston 50, and both pistons then move together and bring the graduating-port 46 of the main valve 43 over the brake-cylinder port 45, thus permitting a gradual flow of air to the brake cylinder. The piston 20 in completing its movement comes against the piston 28 and moves it and the valve 35 to the left, thus blanking the port 33. To re-charge the auxiliary reservoir without taking off the brakes, the train-pipe pressure is slowly increased, and air then passes through the hole 29 and moves the pistons 20, 50 back to running position. To release the brakes, the train-pipe pressure is suddenly increased ; this causes the piston 28 with the valve 35 to move to the right, thus connecting the brakecylinder port 33 with the exhaust port 34. In an emergency application, both pistons 20, 50 move together and the main valve 43 is moved far enough to uncover the brake-cylinder port 45 and cause a full application of the brakes. At the same time the piston 28 is moved to the extreme left against the action of a spring 41, thus bring- ing the valve 35 into a position in which it connects the train-pipe with the exhaust port 34. On an equalization of pressure taking place through the port 29, the spring 41 moves the piston 28 and the valve 35 back into the retaining position, into which it is moved in ordinary applications as described above. The auxiliary reservoir can then be re-charged in the same way, or the brakes released. A pin 39 limits the movement of the piston 28, and a movable perforated plate 40 limits the movement of the spring. The piston 20 in its extreme left-hand position seats against a rubber ring 19. In high-speed trains, an additional valve 80 is mounted between the triple valve and the brake-cylinder head. This valve is lifted by a piston 74 in the event of an emergency application, and a direct connexion is made between the auxiliary-reservoir connexion 66 and the brake-cylinder connexion 67. In gradual applications, this valve is inoperative, the air passing to the brake cylinder through port 46, port 45, a leakage groove 73 in the bushing 72 of the piston 74, around the stem 75 of the piston 74, and through port 67. In an emergency application, the piston 74 is lifted by excess pressure on its lower side and the valve 80 thus also lifted. The valve 80 can be put out of action by removing a cap 76 and taking out the piston 74.