Pneumatic adjusting mechanism for headlamp beam aiming - is direct acting and causes maximum beam depression in event of failure

摘要

A pneumatic actuator (3) is mechanically connected to the headlamp (2) through a linkage. It is pneumatically connected to a vehicle load sensor (14), for example by a linkage (13) coupled to the rear axle. Auxiliary power may be obtained from a connection to the engine exhaust manifold (28). As the vehicle settles on its springs due to increasing load, the pneumatic circuit acts to depress the head lamp beam in order to keep the aiming point at a fixed distance ahead of the vehicle. The actuator (3) is fitted with a device (10), typically a coil spring (10a), which acts to depress the headlamp fully in the event of a pneumatic failure. Oncoming drivers are thus not dazzled by lights which are aimed too high.