Method and apparatus for measuring chassis geometry

Claim 2

Apparatus for measuring the angle of wheel inclination of vehicle wheels comprising: measuring means for obtaining a measurement of the angle of wheel inclination of each vehicle wheel with respect to a base axis of said apparatus, correlating means for determining a correction factor corresponding to the relative inclination with respect to said base axis of a predetermined vehicle base axis, and correcting means for correcting the measurement obtained by said measuring means in accordance with the correction factor determined by said correlating means so as to provide a measurement of wheel inclination with respect to the vehicle base axis, whereby it is unnecessary to align the vehicle in relation to a base axis of the apparatus.

Claim 3

Apparatus as set forth in claim 1, wherein said measuring means comprises a two-dimensional scanning device provided for each vehicle wheel for application along a path to the wheel plane of each wheel.

Claim 4

Apparatus as set forth in claim 2, wherein a counting and indicating means is provided for counting and indicating each measurement provided by said measuring means.

Claim 5

Apparatus as set forth in claim 2, wherein the measuring means are incremental measuring means for measuring the paths of application of the scanning devices and the angles of inclination of the vehicle wheels by an incremental method.

Claim 6

Apparatus as set forth in claim 3, wherein the measuring means further comprise measuring blocks having measuring heads with feeler pins which blocks and heads are electrically connected through electric conductors to the counting and indicating means.

Claim 7

Apparatus as set forth in claim 5, wherein the measuring heads are secured to push rods of the measuring blocks and carry feeler pins arranged with a first pin being stationary, a second pin being arranged horizontally thereof, and a third movable pin arranged in vertical relationship to said first pin.

Claim 8

Apparatus as set forth in claim 1, wherein measuring discs are provided which discs are secured to the vehicle wheels in exact adjustment to the geometrical wheel plane.

Claim 9

Apparatus as set forth in claim 6, wherein the movable feeler pins, respectively, are connected each with an incremental notch unit means for providing countable impulses.

Claim 10

Apparatus as set forth in claim 8, wherein stepping motor means are provided for counting and storing the impulses.

Claim 11

Apparatus as set forth in claim 9, wherein differential gear means are provided for summing up the movements of the stepping motor means.

Claim 12

Apparatus as set forth in claim 1, wherein the vehicle has front and rear wheels and the correlating means comprises pairs of cooperating measuring blocks provided, respectively, one pair for the vehicle front and one pair for the vehicle rear, with push rods connected to said blocks, said rods respectively carrying incremental notch units, photoelectric cell means for counting said notch units which cells transmit impulses through conductors to stepping motors, and differential gear means provided for each stepping motor for receiving the transferred movement of each of said stepping motors.

Claim 13

Apparatus as set forth in claim 1, wherein measuring heads are provided for measuring the angular inclination of the vehicle wheels, said measuring heads having feeler pin means for application to the wheel plane of each wheel, incremental notch units are connected with the feeler pin means for producing impulses in photoelectric cells, and stepping motor means for operating in response to said impulses are provided.

Claim 14

Apparatus as set forth in claim 1, wherein the measuring means measure the toe-in of the vehicle wheels, stepping motor means are provided for receiving said correction factor, and differential gear means are provided for summing up the correction factors of said stepping motor means.

Claim 15

Apparatus as set forth in claim 1, wherein the measuring means measure the camber of the vehicle wheels and stepping motor means are provided for directly indicating the camber value.

Claim 16

Apparatus as set forth in claim 1, wherein racks are provided for receiving the measurements of the angular inclinations of the vehicle wheels, said racks having scales and pointers so that said measurements can be read from said scales.

Claim 17

Apparatus as set forth in claim 15, wherein a printing means is connected with each of the racks for transferring the measurements onto a check chart.

Claim 18

Apparatus for measuring vehicle chassis geometry, especially for measuring the angle of wheel inclination of vehicle wheels of the type having at least two pairs of vehicle wheels sapced longitudinally from one another with the wheel plane of each wheel of a pair beIng spaced equidistantly from a longitudinal vehicle centerline; said apparatus comprising: a measuring place for accepting a vehicle, said measuring place having a longitudinally extending fixed centerline, wheel plane measuring means provided at said measuring place for determining the distance between the wheel plane of each individual wheel from said fixed centerline, said wheel plane measuring means including means supplying an output signal corresponding to each of the distances determined, wheel inclination measuring means provided at said measuring plane for determing the angular orientation of each individual wheel of at least one pair of the vehicle wheels with respect to said fixed centerline, said wheel inclination measuring means including means supplying an output signal corresponding to each of the angular orientations determined, and vehicle angular orientation compensating means for utilizing said output signals of said wheel plane measuring means to automatically modify said output signals of said wheel inclination means so as to compensate for any difference in angular orientation of said fixed centerline and said vehicle centerline and thereby relate the angular orientation of each wheel to the longitudinal vehicle centerline, whereby alignment of the vehicle centerline with respect to the fixed centerline is unnecessary for obtaining an indication of the wheel inclination with respect to the vehicle centerline.

Claim 19

Apparatus for measuring vehicle chassis geometry, especially for measuring the angle of wheel inclination of vehicle wheels of the type having at least two pairs of vehicle wheels sapced longitudinally from one another with the wheel plane of each wheel of a pair beIng spaced equidistantly from a longitudinal vehicle centerline; said apparatus comprising: a measuring place for accepting a vehicle, said measuring place having a longitudinally extending fixed centerline, wheel plane measuring means provided at said measuring place for determining the distance between the wheel plane of each individual wheel from said fixed centerline, said wheel plane measuring means including means supplying an output signal corresponding to each of the distances determined, wheel inclination measuring means provided at said measuring plane for determing the angular orientation of each individual wheel of at least one pair of the vehicle wheels with respect to said fixed centerline, said wheel inclination measuring means including means supplying an output signal corresponding to each of the angular orientations determined, and vehicle angular orientation compensating means for utilizing said output signals of said wheel plane measuring means to automatically modify said output signals of said wheel inclination means so as to compensate for any difference in angular orientation of said fixed centerline and said vehicle centerline and thereby relate the angular orientation of each wheel to the longitudinal vehicle centerline, whereby alignment of the vehicle centerline with respect to the fixed centerline is unnecessary for obtaining an indication of the wheel inclination with respect to the vehicle centerline.

Claim 20

Apparatus according to claim 17, wherein said wheel inclination measuring means includes means for determining the angular orientation of all of the vehicle wheels.

Claim 21

Apparatus according to claim 17, wherein a fixed measuring station is positioned at said measuring place for each wheel of the vehicle to be measured, wherein each of said wheel plane measuring means includes a movable first plunger mounted in one of said measuring stations, wherein wheel engaging means are mounted at one end of each of said first plungers and wherein digital counting means are mounted at each of said fixed stations for detecting movement of said respective first plungers and for supplying output signals corresponding to said movement.

Claim 22

Apparatus according to claim 19, wherein each of said wheel inclination measuring means includes a movable second plunger mounted adjacent the wheel engaging end of one of said respective first plungers, said second plungers being directly engageable with a wheel at a position spaced from the engagement of the first plunger, and wherein digital counting means are mounted at said first plungers for detecting relative movement of respective ones of said first plungers and second plungers and for supplying output signals corresponding to said movement.

Claim 23

Apparatus according to claim 20, wherein the output signals of the digital counting means of said wheel plane measuring means are supplied to stepping motors operatively arranged to adjust a readout mechanism which is operated by output signals from the digital counting means of said wheel inclination measuring means to further stepping motors.

Claim 24

Apparatus according to claim 21, wherein said wheel inclination measuring means includes means for determining the angular orientation of all of the vehicle wheels.

Claim 25

Apparatus according to claim 21, wherein said digital counting means include photoelectric cells for detecting movement of notches in said plungers.