| 摘要 |
869,772. Maintaining constant height of road vehicles. BENDIX-WESTINGHOUSE AUTOMOTIVE AIR BRAKE CO. May 8, 1959 [Oct. 21, 1958], No. 15907/59. Addition to 838,810. Class 108(2). A level-control valve 10 is adapted to maintain a road vehicle at constant height at either of two different selected levels. The valve 10 comprises a combined inlet and exhaust valve element 46 which in the normal position of the vehicle is adapted to seaf jointly on a shoulder 47 of the casing and a seat formed on the end of a member 50 to close a passage 51. The member 50 is formed with a piston 56 slidable in a cylinder 58 which is connected by a conduit 32 with a valve 28. The latter is also connected to atmosphere at, 34, and by a conduit 30 to a conduit 24 leading from the source 22 of compressed air to a connection 26 at the top of the casing 10. As shown in Fig. 1, the valve, 28 is set in accordance with the lower of the two desired riding levels of the vehicle and thus closes the conduit 30 and connects the conduit 32 with atmosphere. Since atmospheric pressure thus exists in cylinder 58, the member 50 is downwardly urged by a spring 80 so that the upper face of a slot 60 formed in the member 50 engages with the upper surface of a cam 62. The latter is adapted to be rotated by a lever 18 on relative movements occurring between the axle 16 and the vehicle frame 14. When the vehicle loading increases above the normal, the member 50 is thus raised and lifts the valve 46 to permit air from the connection 26 to pass through a one way valve 42 past the valve 46 to a connection 12 leading to the air spring 11. When vehicle load decreases, the member 50 is lowered and air from the springs passes via the connection 12 into the passage 51 within the member 50, and thence to atmosphere via a porous plug 53a. When it is desired to maintain the vehicle at the upper of the two riding levels, the valve 28 is set to its second position in which it connects the conduit 32 to the conduit 24 and closes the outlet to atmosphere. Pressure applied in the cylinder 58 thus raises the member 50 so as, to lift the valve 46 and permits air to pass to the spring 11 until the lever 18 is rotated into a position in which the lower face 66 of the cam 62 lowers the member 50 into the position shown in Fig. 3. The vehicle height is then regulated at the new level as described previously. |
