Fail safe automatic headlamp dipping control - with axle signals acting as additional force on headlamp servo to dip lights if servo fails

摘要

The front and rear axles of the vehicle are fitted with pneumatic/hydraulic monitors to sense the axle loading, and these monitors are coupled to slave servos in the headlamp tilting control to adjust the headlamp inclination to compensate for axle loading. To provide a failsafe system, which ensures that the headlamps do not swing up to dazzle oncoming traffic, if one or both servos fail, the salve cylinder on each headlamp has two pistons linked by a spring and with the first piston linked to the tilt control by a spring linkage. The output of the two axle servos are introduced on opposite sides of the second piston, so that their total effective force, being the difference in the outputs, pushes against the sprung linkage to lift the headlamps.