| 摘要 |
<p>The valve comprises a body (51) in which are mounted a movable member (60) in which is formed a normally-closed valve (90b, 92) which controls the pressure supplied to the braking members of the trailer, a movable piston (100) arranged to be moved by a brake-operating pressure towards the member (60) and to cause the opening of the valve (90b, 92), a reaction piston (71) facing the member (60) and exposed to the pressure supplied to the brake members as a result of the opening of the valve (90b, 92); the reaction piston (71) being arranged to return the actuating piston (100), against the action of resilient biassing means (77), to a position in which it enables the valve (90b, 92) to close again when the pressure supplied to the brake members reaches a predetermined value dependent on the value of the said brake-operating pressure, and a manually-operable member (52, 53) or adjusting the predominance which is arranged to modify the position of the movable member (60) in the body (51). The movable member (60) and the reaction piston (71) are formed so as to be in contact with each other in the absence of a brake-operating pressure so that the member (52, 53) for adjusting the predominance can move the movable member (60) together with the reaction piston (71) while at the same time varying the loading of the resilient biassing means (77).</p> |
