| 摘要 |
<p>A hydraulic braking system for vehicles which experience variable loading conditions comprises two proportioning valves 14 and 16, hydraulically in series with one another, one, 16, of which includes a spring axle driven stepped cam 25 which, in response to a predetermined compression of the vehicle suspension system, holds the valve 16 open. The output pressure characteristic of the first valve 14 is suitable for a fully laden vehicle but is not effective until the second valve 16 is held open by a cam 25 when its lightly laden characteristic is no longer effective. <IMAGE></p> |
