Abstract: A system and method are provided using a photodetector array for producing an output signal which is compensated for the effects of ambient light, photodetector bias, and the like, wherein the output signal contains information indicative of the position of the object. The preferred embodiment is useful for vehicular wheel alignment and includes left and right wheel units for coupling to respective left and right steerable wheels of a vehicle, and a central microcomputer and CRT display operably coupled with each wheel unit. Each preferred wheel unit includes a photodetector array operably connected to a wheel unit microcomputer and a laser beam source directing a laser beam toward the array of the other wheel unit.

Abstract: Disclosed is automotive frame and body correcting equipment having a main bed or frame for supporting a motor vehicle while correcting operations are performed. The underside of the bed has a rectilinear track therein about which one or more correcting accessories may be selectively positioned. Such accessory, here in the form of a pulling tower, is equipped with rollers for riding over the bed, and the tower is further moved inwardly and outwardly generally crosswise of the track and is capable of being positioned at various angles about a vertical pivot. The tower has a base that follows the track and an upright tower part that is selectively adjustable among several positions angularly spaced about a horizontal axis, whereby the versatility of the equipment is improved.

Abstract: A pulling tower structure especially adapted for use in automotive frame-straightening equipment is improved by structure providing easy and simple vertical adjustment of a sheave over which a chain or the like is trained for attachment to a vehicle to be repaired so as to assure a straightline pulley. The tower includes an upright support of channel section having within its side walls a pair of members having semicircular notches for selectively receiving a sheave-supporting shaft. Handle structure is provided for enabling manual vertical adjustment of the sheave among selected pairs of transversely alined notches.

Abstract: A cam locking pin for temporarily securing together a pair of members such as plates having confronted faces and aligned apertures. The pin is inserted through the apertures, as from below. A pawl member at the upper end of the position is pivoted ninety degrees to a position in which its long dimension lies crosswise of the pin and apertures and that dimension is greater than the diameter of the pin so that the pin cannot fall out of the apertures. A lower portion of the pin depends below the bottom plate and has a stud or lug thereon for receiving a swingable tool having cam or eccentric surfaces acting against the lower plate to draw the plates together. The cam is so shaped as to retain its locking position until released.