GB860034A - Control valve for air suspension system - Google Patents

Abstract

860,034. Adjusting body height. NEW PRODUCTS CORPORATION. June 5, 1959 [July 18, 1958], No. 19368/59. Class 108(2). A levelling valve for an air suspension system, has flexible diaphragms 63, 64, Fig. 2, which are deflected by air pressure to move rods 57, 60, to move ball valves 50, 51 respectively to admit air to an air spring or exhaust air therefrom. The operation of the valve is as follows. Assuming that the load on a spring is increased, a pilot valve 91 will be moved to the left as viewed in Fig. 2 by conventional linkages connected to the suspension system, to unseat a ball 94. This movement of the ball puts a chamber 75 in connection with the high pressure air supply port 37 through ducts 77, 78, 79, 100, 107,83, 102, 105, and 55. The duct 107 comprises a thin tube the length of which may be varied to provide a variable time lag during which air pressure builds up in the chamber 75: As pressure builds up in chamber 75 the diaphragm 63 moves to the right taking with it the plunger 57 which abuts the ball 50 and when sufficient pressure is built up to overcome the force of a spring 52 and the pressure of air in a spring which is connected through the orifice 39, the ball 50 will be unseated to admit air to the interior of a bore 41 and out through orifice 39 to the air spring. As the spring height reaches equilibrium position, the pilot valve 91 will be moved away from the ball 94 when the ball will seat on a seat 96 and close duct 100 to air under pressure. When the end of the pilot valve 91 is withdrawn from the ball 94, a vent passage 121 is opened and immediately vents passage 100 and its connected chamber 75. The: resilience of diaphragm 63 withdraws the plunger 57 from the ball 50 and spring 52 reseats the ball 50 on its seat 48 to cut off further supply of air under pressure to outlet opening 39. The air which is within the air spring is thus locked therein by the ball 50. When the air spring expands, the pilot valve 91 moves to the right, a vent passage 122 is first closed by a ball 95 and then the ball is raised off its seat to allow air under pressure to enter passage 101 and the connecting passages 82, 81, 80, to chamber 76. Here again a time delay is effected by the thin tube 107 interposed between passage 103 and the interior of sleeve 86. When sufficient pressure has built up plunger 60 is moved to the left to unseat ball valve 51 and open the outlet 39 to vent the air spring through orifice 38. As the spring collapses the valve 91 moves to the left to reseat ball 95 and open chamber 76 to vent passage 122 through the connected passages. The diaphragm 64 returns to its normal position withdrawing the plunger 60 and allowing the ball valve 51 to close the outlet opening 39 to the exhaust opening 38. The two tubes 107 used in the embodiment described may be replaced by a single tube 131, Fig. 6, which is located between the valve 50 and a common air inlet passage 104 from which the air is conducted by passages 102, 103, Fig. 2, to each of the valves 94, 95. The tube 131, Fig. 6, may be withdrawn from the valve body by removing a plug 129 a filter 133 and a fitting 130.