Laser-based wheel alignment system

Abstract

A device and method to align the wheels of motor vehicles. A beam of collimated light from a low power visible laser is split into two generally parallel beams by a partially transmitting mirror and a series of plane front surface mirrors positioned in front and along side the vehicle being serviced. The two beams are reflected from a set of plane mirrors attached to the rims of the wheels to be aligned. The vertical and horizontal angles of each of the wheel-mounted mirrors are set by calibrated lead-screws to cancel the angular displacement of the wheels expected when the wheels are properly aligned. The reflected beams are imaged through a large aperture beam combiner on a common viewing screen. Correct toe-in and camber settings are indicated when the laser beams reflected from the wheel-mounted mirrors overlap at the center of the viewing screen. The caster settings of the front wheels are measured by observing the angle at which the reflected spots travel across the screen when the steering wheel is turned the system can be used to align the front wheels only, or alternatively all four wheels simultaneously.

Dependencies are inferred from the claim text.