PURPOSE: To enable simultaneous operation of two of the right and the left system in the titled suspension system of a trailer drawing tractor by constituting a leveling valve and a changeover valve of each of the right and left suspension systems that those valves can be opened to the atmosphere by the operation of a common change valve.
CONSTITUTION: In each of suspension systems 1, and 2, detection of ground clearance by relating leveling levers 4a and 6a induces the circuits of an air tank 5, a cut valve 3 and a change-over valve 7 to be changed over, adjusting ground clearance as appropriate. When the ground clearance of a tractor is adjusted to separate a trailer from the tractor, a lever 8 is operated to have a change-over valve 8 set up to a position 8B so that the positions of the change- over valve 7 and a cut valve 3 are sequentially changed over to positions 7A and 3A, respectively. The output pipes 4b and 6b of the leveling valves 4a and 6a are therefore closed and the suspension systems 1 and 2 are opened to the atmosphere through pipe passages 7e, 7d and 7c, so that the ground clearance is reduced. By the constitution as above, two systems of the right and left suspension units can be operated simultaneously.
MURATA YUKIO
KAJIZUKA HIROBUMI
Next Patent: GROUND CLEARANCE ADJUSTER OF AUTOMOBILE