| 摘要 |
<p>A hydraulically operated brake pressure modulator having a piston acted on by a secondary source of pressure for varying the volume of the hydraulic brake system to relieve and to apply the brakes during an antiskid mode of operation. The piston incorporates a valve control arrangement for operating a master cylinder isolating valve and also a valve bar closing communication from the secondary source of fluid pressure to the variable pressure chamber adjacent the piston to trap fluid in the chamber and prevent retraction of the piston which otherwise would increase the volume of the brake system.</p> |
