US Patent 10113866 Portable axle alignment apparatus and method

A portable laser emitter, laser targets, and method for aligning commercial truck and trailer axles are disclosed. The laser emitter is mounted to the wheel of a truck drive axle while the laser targets are mounted to the truck's steer wheels. Measurements are taken of the laser dot position on the laser targets for both ends of the axle. The measurements taken from either end of the axle are compared to determine the angle of the drive axle. This method may also be applied to a commercial trailer by using a floor standing laser target centered on the trailer king pin.