| 摘要 |
<p>A tractor protection valve for use in the air brake system of a tractor-trailer vehicle combination to protect and maintain the braking system of the tractor includes a housing having tractor supply and control ports, trailer supply and control ports, and a pair of exhaust ports. The housing has a chamber with the exhaust ports being positioned at opposite ends of the chamber. First and second spring-biased pistons are axially movable in the chamber to control communication between the ports.</p> |
