IE40937L - Wheel alignment testing apparatus - Google Patents

Abstract

1501086 Measuring vehicle wheel alignment DUNLOP Ltd 3 Feb 1975 [9 Feb 1974] 6033/74 Heading G1X Wheel alignment testing apparatus comprises two elongate members 1, 2 which, in use are mounted in a horizontal plane by legs 4 so as to be each aligned with one of a pair of vehicle wheels, a beam 14 pivotally mounted at one end to member 1 so as to pivot about a vertical axis, and optical alignment indicating means which anables the beam 14 to be aligned accurately parallel with member 2. Said alignment indicating means is moved by an adjustment member 16 mounted on member 1 and comprises a measuring unit in engagement with the beam 14, the member 16 being positionable at any required distance from the pivotal axis of the beam 14. The unit includes a scale and a reference marker for indicating the transverse distance through which the beam 14 moves from a first position where it is parallel to member 1 to a second position where it is parallel to member 2. The optical alignment indicating means may comprise a mirror 13 mounted in a vertical plane on member 2 and a sight mark 20, a periscope 15 and a datum line 17 which are mounted for movement with the beam 14. The reflected image of the sight mark 20 is viewed in the periscope, the beam 14 being moved by the adjustment member, alignment of the reflected image of the mark 20 with line 17 indicating that the beam 14 is parallel to the member 2, beam 14 being preferably spring- biased towards said first position. The adjustment member 16 may comprise as shown, an eccentrically mounted circular cam the periphery of which abuts the beam 14, the amount of rotation being determined by a scale on the cam and a pointer. Alternatively the transverse movement of the beam may be effected by a micrometer screw gauge type member, Fig. 5, (not shown). The member 16 is moved along a scale 27 on member 1 to a position corresponding to a figure for the diameter laid down by the vehicle manufacturer, so that scale 27, 41 gives the toe-in or toeout directly, which terms are usually expressed in terms of the difference in distance, transversely of the vehicle, between the two leading edges of the wheel and the two trailing edges for said given diameter. [GB1501086A]