US 3,941,432 AGranted

Change-over valve for two-line trailer brake systems with at least one brake circuit

AssigneeGraubremse GmbH

InventorRoland Blanz

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Abstract

A change-over valve including a housing and a slide sealingly guided therein is provided for use with a two-line trailer brake system having two brake circuits. The slide is retained in a normal position, at which supply tubes leading to compressed air supply tanks for the brake circuits are closed, by a piston loaded with compressed air from a supply tube, but is manually movable to a maneuvering position, at which the brakes of the system are released. The slide is provided with two channels and two associated check valves arranged so that when the slide is in the normal position it closes the supply tubes leading to the compressed air supply tanks for the brake circuits and so that when the slide is in the maneuvering position it connects those supply tubes via its channels and the associated check valves to a common space, which is connected to one or more emergency brake chambers for emergency brake pistons of the trailer brake system.

Claims8

Dependent claims

A change-over valve for use with a trailer brake system having two brake circuits and at least one emergency brake chamber, said change-over valve comprising:

a housing having first and second ports for connection to compressed fluid supply tanks for both brake circuits of the trailer brake system and having a third port for connection to at least one emergency brake chamber of the trailer brake system;
a slide sealingly guided within said housing for movement between a first position and a second position;
a piston guided within said housing and coupled to said slide for movement together therewith;
a fourth port formed in said housing for supplying compressed fluid to said piston to move said slide to said first position;
a common space formed within said housing and coupled to said third port;
means for manually moving said slide to said second position;
and
two channels formed in said slide and positioned so that said slide connects the first and second ports to the third port via said channels, said common space, and a check valve when said slide is moved to the second position and disconnects the first and second ports from the third port when said slide is moved to the first position.

5 more elements

Dependencies are inferred from the claim text.