| 摘要 |
<p>A brake valve, more particularly a dual concentric brake valve for controlling the pressure in primary and secondary circuits, such that the pressure in the two circuits is matched by a balancing piston (11) responsive to differential pressure between the two circuits and through which is an exhaust passage for the release of fluid from the primary circuit. A restriction which is variable by movement of the valve actuating member (22) provides a resistance to the flow of fluid from the primary circuit except in the absence of an input load transmitted from the brake pedal to the actuating member. The restriction creates a lag in the response of the vehicle brakes to a reduction in pedal load so that oscillatory feedback, arising for example, due to "cab nod" in large commercial vehicles, is largely prevented.</p> |
