| 摘要 |
<p>1,046,873. Valves. WAGNER ELECTRIC CORPORATION. Nov. 8, 1963 [April 23, 1963], No. 44123/63. Heading F2V. Upon applying a manual force to the operating plate 77 of tandem valves in a dual-brake system, a piston 66 is moved against a spring 70a to engage an extension 70 with a movable closure element 63 to close an outlet 24 from an exhaust port 75. Concomitantly the spring 70a displaces a piston 41 against a spring 65 to cause a piston extension 50 to abut a second movable-closure element 38 and disconnect a second outlet 24 from a second exhaust port 31. Further motion of pistons 66, 41 moves elements 63, 38 from seats 58, 22 and place inlets 26, 27 in communication with the outlets 24, 25, respectively. The fluid pressures metered by elements 63, 38 are made equal by balancing the forces of springs 64, 70a and 39, 65 as well as the fluid pressures in the chambers 57 and 19 tending to seat the valve elements 63, 38. Sequential instead of simultaneous operation of the valves is effected by unbalancing the spring and fluid pressure forces. When the reaction force in a chamber 68 equals the manually applied force the pistons 41, 66 move upwards so that the elements 63, 68, extensions 70, 50 and seats 58, 22 are in a " lapped " condition; the reaction force acting through the spring 76 provides the operator with " feel ". Should either system fail the other one can still be operated with only a small lost-motion of the input manual force. Either of the exhaust ports 75, 31 may be blanked-off, the remaining port serving both valves. In a modification, the upper valve element 63 and its seat 58 are part of the piston to which the input manual force is applied whilst the extension 50 is located on piston 41. In a further modification, the element 38 and seat 22 are part of piston 41 whilst extension 50 is fixed and forms the valve casing around the exhaust port 31.</p> |
