| US3445936A | 1969-05-27 | |||
| US4800651A | 1989-01-31 | |||
| US4625419A | 1986-12-02 | |||
| US4157618A | 1979-06-12 | |||
| US2488043A | 1949-11-15 |
| 1. | A vehicle wheel alignment device, comprising a pair of elongated upright parallel bodies (3) respectively disposed adjacent vehicle wheels (6) to be aligned and in perpendicular relation with respect to a floor, a first plate (2) supported parallel to the floor by the upper limit of each body of said pair of bodies (3) , each said first plate (2) having a protrac¬ tor on its upper surface disposed in cooperative opposition with respect to the protractor on the opposite first plate (2) , a second plate (15) normal to and slidably supported by each said first plate (2) in vertically aligned relation with the second plate (15) on said opposite first plate (2) for fore and aft movement with respect to an adjacent vehicle wheel (6) , each said second plate (15) having a protractor on its forwardly disposed surface in cooperative opposition with the protractor on the opposite second plate (15) , each said protractor having a center; and, a pair of elongated angle indicating strings (1) respectively extending between and connected at their respective end portions with the centers of oppositely disposed cooperating protractors on said first and second plates for respectively indicating the wheel toein and camber angle. |
| 2. | The device according to claim 1 and further including, indicia scored on said first plates (2) for indicating the linear displacement of said sliding plates (15) relative to said first plates. |
| 3. | The device according to claim 1 in which said first plates (2) are provided with an opening cooperatively receiving the respective said body (3) for sliding movement therealong and positioning said body adjacent the respective wheel of a vehicle to be aligned. SUBSTITUTE SHEET . |
| 4. | A vehicle wheel alignment device, comprising first and second elongated upright parallel bodies (3) respectively disposed adjacent vehicle front wheels (6) to be aligned and in perpendicular relation with respect to a floor, a protractor plate (2) supported parallel to the floor by the upper limit of each body (3) , each said plate having a protractor on its upper surface disposed in cooperative opposition with respect to the protractor on the opposite plate, a third elongated upright body (3) disposed equidistant from and parallel with said first and second bodies, and, a string extending between the centers of the protractors on the protractor plates, and, other strings extending, respectively, between the top center of said third body and the center of the protractor on the respective protractor plate. |
| 5. | A vehicle wheel alignment device, comprising first and second elongated upright parallel bodies (3) respectively disposed adjacent vehicle front wheels (6) to be aligned and in perpendicular relation with respect to a floor, a protractor plate (2) supported parallel to the floor by the upper limit of each body (3) , each said plate having a protractor on its upper surface disposed in cooperative opposition with respect to the protractor on the opposite plate, and, a string (1) extending between the centers of the protractors on the protractor plates (2) for indicating the toein angle of the front wheels. |
| 6. | The device according to claim 5 and further including a right angular tu'bular adapter (5) interposed between each said body (3) and each said protractor plate (2) for measuring vehicle wheel camber or caster angles. SUBSTITUTE SHEET. |
Technical-Field This invention reduces the number of devices used for vehicle wheel alignment to a pair of identical tools. The wheel alignment process is simplified by the wheels and tools remaining at one location for the toe-in, camber and caster angle measurements.
Brief Description Of The Drawinqs Figure 1 is a fragmentary perspective view of the device in operative position on vehicle front wheels for toe-in angle measurement;
Figure 2 is a view similar to Fig. 1 illustrating another embodiment of the device in operative position on vehicle front wheels for toe-in and camber angle measurements;
Figure 3 is a view similar to Fig. 2 illustrating another arrangement of the device for camber angle measurement;
Figure 4 illustrates the device arranged for caster angle measurement;
Figure 5 illustrates the device in position for measuring the toe-in angle of a vehicle back wheel;
Figure 6 is a perspective view of a protractor plate bottom surface;
Figure 7 is a top view illustrating another embodiment of the device for wheel toe-in angle measurement;
Figure 8 is a perspective view, to an larger scale, of an adapter, per se;
Figure 9 is a fragmentary perspective view of the device of Fig. 7 in operative position on a vehicle;
Figure 10 is a perspective view, to a larger scale, of the sliding protractor with portions broken away for clarity;
Figure 11 is a perspective view illustrating protractor plates connecting a portion of the device to a vehicle wheel; Figure 12 is perspective view, to a larger scale, illus-
SUBSTITUTE SHEET
trating another embodiment of the protractor plate;
Figure 13 is a fragmentary perspective view, to another scale, illustrating the embodiment of Fig. 12 in position for obtaining vehicle wheel toe-in measurement; and.
Figure 14 is a perspective view similar to Fig. 13 illus¬ trating the embodiment of Fig. 12 in position for vehicle wheel camber measurement.
The Best Mode For Carrying Out The Invention
In the drawings:
Referring more particularly to Figs. 1 and 2, the device comprises a pair of upright identical, preferably tubular (Fig. 13), elongated bodies 3, each supporting a fixed position protractor plate 2 or a sliding protractor 15 on its top.
The protractor plate 2 has a protractor scale on its top surface for measuring angular displacement of a wheel. The position of a first string 1 extending between the centers of the protractors indicates toe-in angles of the wheels 6 (Fig. 1) . A second string 1 extends between the centers of the sliding protractors 15 disposed in a vertical plane as illus¬ trated by Fig. 2. The two protractor plates 2 parallel to a floor, not shown, are for toe-in angle measurement. The two protractor plates 15 perpendicular to the floor are for camber angle measurement.
A plumb bob 13 depending from the protractor plate 2 (Fig. 1) is for alignment of the body 3 with an axis perpendicular to the floor.
An adapter 5 (Fig. 8) comprising a right angular tubular member may be interposed between the body 3 and the protractor plate 2 for camber angle measurements. The adapter 5 similarly positions the longitudinal plane of the protractor plate 2 vertically with an attached plumb bob 9 (Fig. 4) for caster angle measurements.
The adapter 5 has one end opening for axially receiving one external end portion of the body 3 and its other end opening is equally dimensioned with the end opening of the body 3. The adapter 5 selectively positions the protractor plate 2 for measuring toe-in, camber, and caster angles (Figs. 1, 3, and 4) , respectively.
SUBSTITUTE SHEET
Figure 5 illustrates a vehicle back or rear wheel 12 toe- in measurement. The orientation of the string 1 is such that it is perpendicular to the sides of the protractor plate 2 parallel with the axle 7 extending between the front wheels 6. With the front wheel 6 in a straight ahead direction, the toe- in angle of the back wheel 12 is shown by the intersection of the string 1 with the protractor scale on the protractor plate 2 on the back wheel attached body 3.
Industrial Applicability To determine the toe-in and camber angles of a car front wheels, position the steering wheel at straight ahead; identi¬ cally attach a body 3 to each wheel 6; install a protractor plate 2 and plumb bob 13 on each body 3; adjust the bodies 3 with respect to the wheel rims to align the respective plumb bobs 13 with the longitudinal surfaces of the respective bodies 3; install a sliding protractor 15 on each protractor plate 2 (Fig. 2); attach the end portions of the respective strings with the centers of the protractors on the protractor plates 2 and the centers of the protractors on the protractor plates 15; observe the toe-in angles at the intersections of the string on the protractor scales parallel to the floor; observe the camber angles on the protractor scales perpendicular to the floor; and, slide the protractor plates 15 forward or backward on the protractor plates 2 to obtain the smallest toe-in angles of the wheels in the event one wheel is not in its normal position.
Alternatively, determine car front wheels toe-in and camber angles as follows: perform the toe-in angle measurement steps described hereinabove without the sliding protractor plate 15 (Fig. 1) ; observe the toe-in angle at the intersection of the string with the p rotractor scale on the protractor plates 2; interpose an adεster 5 between each protractor plate 2 and each body 3 (Fig. 3 , ; and, observe the camber angle at the intersection of the string and the protractor scale on the protractor plates 2.
SUBSTITUTE SHEET
To measure the caster angle of vehicle wheels: reposition the protractor plates 2 on the respective adapter 5 as illus¬ trated by Fig. 4; attach the plumb bob 9 to the center of the protractor scale on the protractor plate 2; position the wheels 6 in a straight ahead direction to establish a reference line ; scribe a 20 degree angle forwardly from one wheel 6 contact with a supporting floor and on each side of the wheel forward reference line; turn one wheel 6 inward 20 degrees and observe the camber angle; and, turn the same wheel 6 outward 20 degrees beyond the reference line and observe the camber angle. The difference between the camber angles is the caster angle for one wheel. Repeat these steps to obtain the caster angle of the other wheel 6.
For measuring the toe-in angle of a vehicle back wheel: attach one body 3 to the front wheel 6 and another body 3 to the back wheel 12 (Fig. 5) ; with both bodies 3 perpendicular to the floor and protractor plates 2 thereon, attach a plumb bob to one end of one string 1; connect the other end of the string to the center of the protractor on the protractor plate 2 on the back wheel 12; and, orient the string so it is perpendicu¬ lar to the front wheel protractor plate sides parallel with the front wheel axle 7. The intersection of the string with the angular scale on the back wheel protractor plate 2 is the toe- in angle of the back wheel 12 with reference to the front wheel 6. Repeat these steps for the toe-in angle of the opposite rear wheel of the car.
Determine the camber angles of a vehicle back wheel 12 as follows: mount a body 3 and protractor plate 2 on the back wheel 12 as described hereinabove for camber angle measurement as illustrated by Fig. 4; and, observe the camber angle of the back wheel 12 by the intersection of the plumb bob string with the protractor scale on the protractor plate 2.
Alternatively, the toe-in angle of vehicle front wheels may be determined as follows: position a body 3 having a protractor plate 2 on its top as described hereinabove for Fig. 1; with a string 1 extending between the protractor centers, vertically position a third elongated body 3 with its vertical
SUBSTITUTE SHEET
axis spaced from the two centers of the protractor plates 2 spaced equidistant with the spacing between the two centers of the protractor plates; and, connect one end portion of the two strings 14 with the top center of the third body 3 and other end portions of the strings 14 with the respective centers of the protractor on the protractor plates 2, thus creating the sides of an equilateral triangle (Fig. 7) . When the angle between the strings 14 and the string 1 between the protractor plates 2 equal 60 degrees, the wheels 6 are parallel with each other. The angle between the strings 14 and the zero degree mark string of the protractor plate 2 is negative when the string 14 does not intersect the circular scale of the protrac¬ tor.
SUBSTITUTE SHEET