CA1142346A - Line of sight wheel alignment apparatus for vehicles - Google Patents
Line of sight wheel alignment apparatus for vehiclesInfo
- Publication number
- CA1142346A CA1142346A CA000331647A CA331647A CA1142346A CA 1142346 A CA1142346 A CA 1142346A CA 000331647 A CA000331647 A CA 000331647A CA 331647 A CA331647 A CA 331647A CA 1142346 A CA1142346 A CA 1142346A
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- Canada
- Prior art keywords
- target
- wheel
- sight
- line
- vehicle
- Prior art date
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Abstract
ABSTRACT OF THE DISCLOSURE
Disclosed is an apparatus for detecting the alignment of the wheels of a vehicle includes an adjustable, wheel-engaging and target supporting structure mountable upon a vehicle wheel rim and has spaced arms extended laterally from cardinal points of the wheel. Indicia bearing targets respectively located on the arms provide scales for indicating the angular alignment of the vehicle wheels for conventional measurements such as caster, camber, toe-in, and steering axis cant. A sighting instrument establishes a line of sight parallel to and longitudinally spaced from the vehicle. The line of sight is directed toward a target and impinges upon a discrete mark on the scale thereof. Comparison of the points of impingement upon targets located at opposite cardinal points establishes angular relations therebetween which corres-pond to alignment measurements.
Disclosed is an apparatus for detecting the alignment of the wheels of a vehicle includes an adjustable, wheel-engaging and target supporting structure mountable upon a vehicle wheel rim and has spaced arms extended laterally from cardinal points of the wheel. Indicia bearing targets respectively located on the arms provide scales for indicating the angular alignment of the vehicle wheels for conventional measurements such as caster, camber, toe-in, and steering axis cant. A sighting instrument establishes a line of sight parallel to and longitudinally spaced from the vehicle. The line of sight is directed toward a target and impinges upon a discrete mark on the scale thereof. Comparison of the points of impingement upon targets located at opposite cardinal points establishes angular relations therebetween which corres-pond to alignment measurements.
Description
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This invention relates to alignment apparatus for indicating the angular relationships of the vehicle wheels such as caster, camber, toe-in, and steering axis cant and, in particular, relates to an apparatus employing a line of sight alignment instrument.
Vehicles, such as cars, truck trailers and light trucks, typically require periodic maintenance checks and adjustment of front end alignment.
Normally, alignment is correctly set when the vehicle is manufactured, howelter, after extensive use, damage to the front end or hard usage, such as occurs by hitting curbs, potholes and the like, misalignment may occur and the vehicle will encounter handling difficulties, a poor ride and excessive tire wear characteristics related to the incorrect alignment.
Such handling difficulties include vehicle wandering and pulling to one side~ which requires constant and annoying steering wheel correction by the driver, hard steering and front tire shimmy.
Front end alignment centers on the precise geometric relationship of a number of parts, even when they are changing relative pOSitiOIIS, ; which provide front wheel stability and control. These geometric angles include toe-in, camber~ caster, and steering axis cant (sometimes termed king pin inclination).
Camber is the angle which the center line of the wheel makes with a vertical axis. The top of the wheel tilts away from the car so that the tire is inclined vertically. Closely related to camber is toe-in, which is the amount that both wheels are closer together a-t the front than at the rear of the wheel. Both camber and toe-in are related to vehicle weight on the wheel and to compression forces occurring on the steering linkage with forward speed. Normally, the greater the camber, the greater is the toe-in.
Caster is the cant of the upper ball joint toward the rear of the car.
Caster moves the pivot point of the wheel forward of the tire's center and provides yet another type of directional stahility by causing a drag on the bottom of the wheel when it turns, there~y resisting the turn and ~ending to hold the wheel steady in the directi.on of straight ahead vehicle moven-ent.
This invention relates to alignment apparatus for indicating the angular relationships of the vehicle wheels such as caster, camber, toe-in, and steering axis cant and, in particular, relates to an apparatus employing a line of sight alignment instrument.
Vehicles, such as cars, truck trailers and light trucks, typically require periodic maintenance checks and adjustment of front end alignment.
Normally, alignment is correctly set when the vehicle is manufactured, howelter, after extensive use, damage to the front end or hard usage, such as occurs by hitting curbs, potholes and the like, misalignment may occur and the vehicle will encounter handling difficulties, a poor ride and excessive tire wear characteristics related to the incorrect alignment.
Such handling difficulties include vehicle wandering and pulling to one side~ which requires constant and annoying steering wheel correction by the driver, hard steering and front tire shimmy.
Front end alignment centers on the precise geometric relationship of a number of parts, even when they are changing relative pOSitiOIIS, ; which provide front wheel stability and control. These geometric angles include toe-in, camber~ caster, and steering axis cant (sometimes termed king pin inclination).
Camber is the angle which the center line of the wheel makes with a vertical axis. The top of the wheel tilts away from the car so that the tire is inclined vertically. Closely related to camber is toe-in, which is the amount that both wheels are closer together a-t the front than at the rear of the wheel. Both camber and toe-in are related to vehicle weight on the wheel and to compression forces occurring on the steering linkage with forward speed. Normally, the greater the camber, the greater is the toe-in.
Caster is the cant of the upper ball joint toward the rear of the car.
Caster moves the pivot point of the wheel forward of the tire's center and provides yet another type of directional stahility by causing a drag on the bottom of the wheel when it turns, there~y resisting the turn and ~ending to hold the wheel steady in the directi.on of straight ahead vehicle moven-ent.
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It will be appreciated that too slight a caster angle will cause the wheels to wander or weave at high speed and steer erratically when the brakes are applied. In contrast, too great a caster angle encourages hard steering and low speed shimmy. Additionally, placing the weight of the car directly over the pivot point allows the easiest possible steering and removes load from the outside wheel race bearings.
Steering axis cant, or king pin inclination in vehicles having a king-pinl is the angle Erom the vertical at which the steering knuckle is attached to the upper and lower ball joints. The canted steering knuckle lo controls wheel directional stability by forcing the wheel to lift the chassis in order to turn from a straight ahead direction. As the steering arm releases its force Oll the wheel, the wheel automatically tends to return to its straight ahead position under the downward force of the chassis weight.
Additionally, the vehicle must track properly to make for easier steering and prevent excessive tire wear. Tracking is the condition whereby the rear wheels of the car follow the front wheels in parallel relation.
Further, the dual rear wheels of truck tractors and trailers may be out of alignment specification and trackingl toe and camber may need to be properly set.
The present invention provides mean.s and a method of use thereof whereby all of the above alignment checks can be accurately accomplished.
l`he principal objects of the present invention are: to provide a wheel alignment apparatus utilizing a minimum of .'~-,.
components; to provi~e a wheel alignment apparatus employing an accurate sighting means for de-termining angular relationships;
to provide a wheel alignment apparatus using scaled targets which are easy to read and located for the convenience of the operator; to provide a wheel alignment apparatus which is mobile and can be easily moved into and out of operational position; to provide a wheel alignment apparatus which is capable of a high degree of accuracy; to provide a wheel alignment apparatus in which certain components thereof may be conveniently stored after use in a relatively small area;
to provide a wheel alignment apparatus for checking caster, camber/ toe-in and steering axis cant; to provide such a wheel alignment apparatus which a method of use therefor is easily and quickly learned by laymen; to provide a method for the use of the wheel alignment apparatus which is re:Latively easy and quickly accomplished whereby an operator may align the vehicle in a reIatively short period of time; to provide such an alignment apparatus utilizing laser beams wherein the lasers are adjustably and movably mounted for accurate positioning relative to a vehicle and targets located relative thereto for alignment checks; to provide such alignment apparatus usable on garage floors and the like whereby special platforms and pits are not necessary; to provide such alignment apparatus wherein laser support structure permits variatation of spacing, elevational and -tilt to accommodate different size and types of vehicles; to provide such alignment apparatus with scaled targets and mountings which are adjustable for accommodating different wheel and tire sizes for accurate checking of substantially all vehicles;
and to provide a wheel alignment apparatus which is relati~ely inexpensive, sturdy and efficient in use and i.n which a method for use thereof is simply and easily accomplished.
Accordiny to one aspect of the invention there is provided apparatus Eor checking wheel alignment of a wheeled vehicle comprising: (a) a base structure having a surface supporting a vehicle Eor alignment checks thereof; (b) target structure mountable on the wheels of a vehicle and having scaled targets located thereon in diametrically opposed relation and laterally outwardly of the wheels; (c) laterally spaced laser beam projecting members positioned longitudinally from and aligned with the target structure and spaced generally laterally from the longitudinal axis of the vehicle; (d) a support structure for said laser beam members having spaced apart standards and a shaft member extending therebetween; said shaft having spaced arms; (e) means rotatably mounting said spaced arms on said standards with said shaft radially outwardly from said rotatable mounting means; (f) means adjustably rotating said arms for raising and lowering said arms and the shaft thereon to vary the spacing from the base surface; (g) means piutally mounting the shaft on the arms for adjusting the angle of said laser beams relative to ~he base surface; (h~ means movably mounting the laser beam members on the shaft for adjusting the lateral spacing thereof; and (i) means for positioning the vehicle and laser beam members relative to the base surface for the laser beam members to project beams parallel to the longitudinal axis of said vehicle and equally spaced therefrom for impingement on the scaled targets on the respective wheels of said vehicle.
According to another aspect of the invention there is provided a method for checking the alignment of the wheels of a vehicle, which comprises: (a) establishing a line of sight from a sighting instrument parallel to and longitudinally spaced from a longitudinal axis of a vehicle; (b) mounting a target structure on a wheel, said target structure having a target ~- 4 -
It will be appreciated that too slight a caster angle will cause the wheels to wander or weave at high speed and steer erratically when the brakes are applied. In contrast, too great a caster angle encourages hard steering and low speed shimmy. Additionally, placing the weight of the car directly over the pivot point allows the easiest possible steering and removes load from the outside wheel race bearings.
Steering axis cant, or king pin inclination in vehicles having a king-pinl is the angle Erom the vertical at which the steering knuckle is attached to the upper and lower ball joints. The canted steering knuckle lo controls wheel directional stability by forcing the wheel to lift the chassis in order to turn from a straight ahead direction. As the steering arm releases its force Oll the wheel, the wheel automatically tends to return to its straight ahead position under the downward force of the chassis weight.
Additionally, the vehicle must track properly to make for easier steering and prevent excessive tire wear. Tracking is the condition whereby the rear wheels of the car follow the front wheels in parallel relation.
Further, the dual rear wheels of truck tractors and trailers may be out of alignment specification and trackingl toe and camber may need to be properly set.
The present invention provides mean.s and a method of use thereof whereby all of the above alignment checks can be accurately accomplished.
l`he principal objects of the present invention are: to provide a wheel alignment apparatus utilizing a minimum of .'~-,.
components; to provi~e a wheel alignment apparatus employing an accurate sighting means for de-termining angular relationships;
to provide a wheel alignment apparatus using scaled targets which are easy to read and located for the convenience of the operator; to provide a wheel alignment apparatus which is mobile and can be easily moved into and out of operational position; to provide a wheel alignment apparatus which is capable of a high degree of accuracy; to provide a wheel alignment apparatus in which certain components thereof may be conveniently stored after use in a relatively small area;
to provide a wheel alignment apparatus for checking caster, camber/ toe-in and steering axis cant; to provide such a wheel alignment apparatus which a method of use therefor is easily and quickly learned by laymen; to provide a method for the use of the wheel alignment apparatus which is re:Latively easy and quickly accomplished whereby an operator may align the vehicle in a reIatively short period of time; to provide such an alignment apparatus utilizing laser beams wherein the lasers are adjustably and movably mounted for accurate positioning relative to a vehicle and targets located relative thereto for alignment checks; to provide such alignment apparatus usable on garage floors and the like whereby special platforms and pits are not necessary; to provide such alignment apparatus wherein laser support structure permits variatation of spacing, elevational and -tilt to accommodate different size and types of vehicles; to provide such alignment apparatus with scaled targets and mountings which are adjustable for accommodating different wheel and tire sizes for accurate checking of substantially all vehicles;
and to provide a wheel alignment apparatus which is relati~ely inexpensive, sturdy and efficient in use and i.n which a method for use thereof is simply and easily accomplished.
Accordiny to one aspect of the invention there is provided apparatus Eor checking wheel alignment of a wheeled vehicle comprising: (a) a base structure having a surface supporting a vehicle Eor alignment checks thereof; (b) target structure mountable on the wheels of a vehicle and having scaled targets located thereon in diametrically opposed relation and laterally outwardly of the wheels; (c) laterally spaced laser beam projecting members positioned longitudinally from and aligned with the target structure and spaced generally laterally from the longitudinal axis of the vehicle; (d) a support structure for said laser beam members having spaced apart standards and a shaft member extending therebetween; said shaft having spaced arms; (e) means rotatably mounting said spaced arms on said standards with said shaft radially outwardly from said rotatable mounting means; (f) means adjustably rotating said arms for raising and lowering said arms and the shaft thereon to vary the spacing from the base surface; (g) means piutally mounting the shaft on the arms for adjusting the angle of said laser beams relative to ~he base surface; (h~ means movably mounting the laser beam members on the shaft for adjusting the lateral spacing thereof; and (i) means for positioning the vehicle and laser beam members relative to the base surface for the laser beam members to project beams parallel to the longitudinal axis of said vehicle and equally spaced therefrom for impingement on the scaled targets on the respective wheels of said vehicle.
According to another aspect of the invention there is provided a method for checking the alignment of the wheels of a vehicle, which comprises: (a) establishing a line of sight from a sighting instrument parallel to and longitudinally spaced from a longitudinal axis of a vehicle; (b) mounting a target structure on a wheel, said target structure having a target ~- 4 -
3~
situated laterally of said wheel and spaced radially of the axle of said wheel; (c) locating said target at a first cardinal axial point of said wheel; (d) directing said line of sight to impinge on said target at said first cardinal point; ~e) locat~
ing said target at a second cardinal axial point of said wheel;
(f) directing said line of sight to impinge on said target at said second cardinal point; (g~ measuring the lateral difference between the impingement of said line of sight on sa.id target in said first cardinal position and in said second cardinal position, the difference measurement corresponding to a measure-ment of angular alignment of said ~heel.
Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings wherein are set orth, by way of illustration and example, cextain embodiments of this invention.
Figure 1 is a top plan view of a wheel alignment apparatus .~ - 4a -3~
embod~ing the present invention and shown in connection with an automotive vehicle.
Fig. 2 is a side elevational view of the wheel alignment apparatus with target components thereof mounted upon front wheel rims of the vehicle.
Fig. 3 is a diagrammatic, fragmentary, elevational view of components of the wheel alignment apparatus positioned adjacent rear wheels of the vehicle.
Fig. 4 is a front elevational view of sighting instruments and support structure therefor comprisiny portions of the alignment apparatus~
Fig. 5 is a side elevational view of the sighting instrument and support structure therefor.
Fig. 6 is a fragmentary, rear elevational view of the support structure for the sighting instruments and showing details of an elevating mechanism therefor.
Fig. 7 is a side elevational view of a wheel engaging and target support structure having sighting targets mounted thereon.
Fig. 8 is a front elevational view of the wheel engaging and target support structure and having portions broken away to show engagment thereof with the wheel rim.
Fig. 9 is a diagrammatic, front elevational view of the front wheels of the vehicle showing the wheels lifted from ground support and with wheel engaging and target support structures mounted thereon.
Fig. 10 is a diagrammatic front elevational view of the vehicle front wheels in ground supporting contact and with target structures mounted thereon.
Fig. 11 is a diagrammatic elevational view of a front wheel with targets mounted thereon and shown with regard to the measurement of camber, the angle of which is exaggerated L ~
for purposes of illustration.
Fig. 12 is a diagrammatic, front elevational view illustrating toe-in measurement, the angle of which is exaggexated for purposes of illustration.
Fig. 13 is a diagrammatic, top plan view of a vehicle axle and front wheels thereof and illustrating caster measurement.
Fig. 14 is a diagrammatic, front elevational view depicting a measurement of caster in one turning direction of the wheel.
Fig. 15 is a diagrammatic, front elevational view showing caster measurement in the opposite turning direction to that shown in Fig. 14.
Fiy. 16 is a diagrammatic, front elevational view showing the vehicle front wheel lifted from ground contact and turned in one direction to provide a measurement for determining steering axis cant.
Fig. 17 is a diagrammatic, front elevational view of the vehicle front wheel lifted from ground contact and turned in the opposite direction to that shown in Fiy. 15 to provide a second measurement for steering axis cant and which, in combination with the measurement provided in Fig.
16, corresponds to the angle of steering axis cant.
Fig. 18 is an enlarged, fragmentary view of a sighting instrument and movable support structure therefor.
Flg. 19 is a perspective view of a modified form of sighting instrument support structure and showing a cabinet enclosing same and providing storage space for tools and components associated with the wheel aliynment apparatus.
Fiy. 20 is an elevational view of a front target used in the measurement of toe-in and toe~out.
Fig. 21 is an elevational view of a rear target used in the measurement of toe-in and toe-out.
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Fig. 22 is an elevational view of a front target used in the measurement of king pin inclination or steering axis cant.
Fig. 23 is an elevational view of a rear target used in the measurement of king pin inclination or steering axis cant.
Fig. 24 is an elevational view oE a lower, or first target used in the determination of camber and caster of the vehicle's left front wheel.
Fig. 25 is an elevational view of an upper, or second target used in the determination of camber and caster o the vehicle left front wheel.
Fig. 26 is an elevational view of a lower, or first target used in the determination of camber and caster of the vehicle right front wheel.
Fig. 27 is an elevational view of an upper, or second target used in the determination of camber and caster of the vehicle right front wheel.
Referring to the drawings in more detail:
As required, detailed embodiments of the present invention are disclosed herein, however, it is to be understood that the disclosed embodiments are merely exemplary of the invention which may be embodied in various forms, therefore, specific structural and functional details as disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.
The reference numeral 1 generally indicates a line of sight wheel alignment apparatus embodying the present invention.
The apparatus 1 includes a movable support means 2 with sighting instruments 3 mounted thereon from which lines of ~42~
sight 5 are respectively dire,ted at dïscrete indicia or scale marks on targets 4 mounted upon the wheels of a vehicle.
An automotive vehicle 7, such as a truck or car of which the front end alignment is to be checked is positioned 50 that access is gained to the underside thereof, as by raising on roller plates 6 movable on the flat surface of the garage floor 8~ however, a ramp or other vehicle elevating and supporting structure may be used ïn those situations where a permanent or semi-permanent installation is desired. It will be appreciated that the movable sighting instrument support means 2 and the roller plates 6 permit vehicle align-ment to be conducted on a ~are base or floor, that is, a floor having no fixed or permanent mountings or structures. Therefore, the alignment apparatus I requires a minimum of floor space and is particularly suited for Erame and body shops, service stations, or the like where there is little or no space avail-able for permanent installations.
The support means 2 rests upon the garage floor 8, Figs.
situated laterally of said wheel and spaced radially of the axle of said wheel; (c) locating said target at a first cardinal axial point of said wheel; (d) directing said line of sight to impinge on said target at said first cardinal point; ~e) locat~
ing said target at a second cardinal axial point of said wheel;
(f) directing said line of sight to impinge on said target at said second cardinal point; (g~ measuring the lateral difference between the impingement of said line of sight on sa.id target in said first cardinal position and in said second cardinal position, the difference measurement corresponding to a measure-ment of angular alignment of said ~heel.
Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings wherein are set orth, by way of illustration and example, cextain embodiments of this invention.
Figure 1 is a top plan view of a wheel alignment apparatus .~ - 4a -3~
embod~ing the present invention and shown in connection with an automotive vehicle.
Fig. 2 is a side elevational view of the wheel alignment apparatus with target components thereof mounted upon front wheel rims of the vehicle.
Fig. 3 is a diagrammatic, fragmentary, elevational view of components of the wheel alignment apparatus positioned adjacent rear wheels of the vehicle.
Fig. 4 is a front elevational view of sighting instruments and support structure therefor comprisiny portions of the alignment apparatus~
Fig. 5 is a side elevational view of the sighting instrument and support structure therefor.
Fig. 6 is a fragmentary, rear elevational view of the support structure for the sighting instruments and showing details of an elevating mechanism therefor.
Fig. 7 is a side elevational view of a wheel engaging and target support structure having sighting targets mounted thereon.
Fig. 8 is a front elevational view of the wheel engaging and target support structure and having portions broken away to show engagment thereof with the wheel rim.
Fig. 9 is a diagrammatic, front elevational view of the front wheels of the vehicle showing the wheels lifted from ground support and with wheel engaging and target support structures mounted thereon.
Fig. 10 is a diagrammatic front elevational view of the vehicle front wheels in ground supporting contact and with target structures mounted thereon.
Fig. 11 is a diagrammatic elevational view of a front wheel with targets mounted thereon and shown with regard to the measurement of camber, the angle of which is exaggerated L ~
for purposes of illustration.
Fig. 12 is a diagrammatic, front elevational view illustrating toe-in measurement, the angle of which is exaggexated for purposes of illustration.
Fig. 13 is a diagrammatic, top plan view of a vehicle axle and front wheels thereof and illustrating caster measurement.
Fig. 14 is a diagrammatic, front elevational view depicting a measurement of caster in one turning direction of the wheel.
Fig. 15 is a diagrammatic, front elevational view showing caster measurement in the opposite turning direction to that shown in Fig. 14.
Fiy. 16 is a diagrammatic, front elevational view showing the vehicle front wheel lifted from ground contact and turned in one direction to provide a measurement for determining steering axis cant.
Fig. 17 is a diagrammatic, front elevational view of the vehicle front wheel lifted from ground contact and turned in the opposite direction to that shown in Fiy. 15 to provide a second measurement for steering axis cant and which, in combination with the measurement provided in Fig.
16, corresponds to the angle of steering axis cant.
Fig. 18 is an enlarged, fragmentary view of a sighting instrument and movable support structure therefor.
Flg. 19 is a perspective view of a modified form of sighting instrument support structure and showing a cabinet enclosing same and providing storage space for tools and components associated with the wheel aliynment apparatus.
Fiy. 20 is an elevational view of a front target used in the measurement of toe-in and toe~out.
Fig. 21 is an elevational view of a rear target used in the measurement of toe-in and toe-out.
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Fig. 22 is an elevational view of a front target used in the measurement of king pin inclination or steering axis cant.
Fig. 23 is an elevational view of a rear target used in the measurement of king pin inclination or steering axis cant.
Fig. 24 is an elevational view oE a lower, or first target used in the determination of camber and caster of the vehicle's left front wheel.
Fig. 25 is an elevational view of an upper, or second target used in the determination of camber and caster o the vehicle left front wheel.
Fig. 26 is an elevational view of a lower, or first target used in the determination of camber and caster of the vehicle right front wheel.
Fig. 27 is an elevational view of an upper, or second target used in the determination of camber and caster of the vehicle right front wheel.
Referring to the drawings in more detail:
As required, detailed embodiments of the present invention are disclosed herein, however, it is to be understood that the disclosed embodiments are merely exemplary of the invention which may be embodied in various forms, therefore, specific structural and functional details as disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.
The reference numeral 1 generally indicates a line of sight wheel alignment apparatus embodying the present invention.
The apparatus 1 includes a movable support means 2 with sighting instruments 3 mounted thereon from which lines of ~42~
sight 5 are respectively dire,ted at dïscrete indicia or scale marks on targets 4 mounted upon the wheels of a vehicle.
An automotive vehicle 7, such as a truck or car of which the front end alignment is to be checked is positioned 50 that access is gained to the underside thereof, as by raising on roller plates 6 movable on the flat surface of the garage floor 8~ however, a ramp or other vehicle elevating and supporting structure may be used ïn those situations where a permanent or semi-permanent installation is desired. It will be appreciated that the movable sighting instrument support means 2 and the roller plates 6 permit vehicle align-ment to be conducted on a ~are base or floor, that is, a floor having no fixed or permanent mountings or structures. Therefore, the alignment apparatus I requires a minimum of floor space and is particularly suited for Erame and body shops, service stations, or the like where there is little or no space avail-able for permanent installations.
The support means 2 rests upon the garage floor 8, Figs.
4 and 5 and preferably has a frame or base 16 having sets of front and rear casters or wheels 14 and 15 mounted on the underside thereof Eor movement on the floor 8. Upright mounts 18 and 19 are secured to opposite ends of the base 16 and have respective front and rear vertical legs 21 and 22 connected by a top bar or arm 23 extending therebetween.
The elongate frame or base 16 is movable upon the floor 8 to locate, or "square", the longitudinal axis of the support means 2 transversely to the longitudinal axis of the vehicle 7. Once the frame or base 16 has been properly positioned, as described below, the same is retained in position by adjustable jack screws 26 adjacent each Eront wheel 14 and having a lower floor engaging pad 27 and an upper crank arm 28.
An elongate back beam 33 extends between the mounts 18 and 19 and has opposite ends connected to the respective arms 23 by journal boxes 34 and 35 with interior, self-aligning bearings permitting rotation of the back beam 33.
Transverse arms 36 and 37 are rigidly secured to the back beam 33 spaced from and adjacent the journal boxes 34 and 35. Respective front ends 38 and 39 thereof are split inwardly to bearing surfaces 40, Fig. 5, for receiving and rotatably supporting an elongate sighting instrument supporting front beam 41. Fasteners 32, such as bolts, extend through the ends 38 and 39 and cause the same to clamp around ends 43 of the beam 41 ~or preventing excessive free rotation.
Means for rotating the back beam 33 and thereby moving the front beam 41 upwardly or downwardly relative to the back beam 33 are included and, in the illustrated example, Fig.
6. the arm 36 has a mid portion ~2 connected to a jack screw 4~ via a swivel connector 45 on the arm 42. A journal 46 affixed to the base 16 mounts the bottom end of the jack screw 44 thereto. ~ hand wheel 47 facilitates rotation of the jack screw 44 for moving the front beam 41 upwardly and downwardly.
The front beam 41 supports the sighting instruments 3 such as telescopes, light beam projectors and the like. In the illustrated example, the sighting instruments 3 comprise low power lasers 50 and 51 which project respective lines of sight 5 beams of coherent, collimated radiation capable of great accuracy for alignment. The sighting instruments 3, exemplified as by the lasers 50 and 51, are preferably sufficiently sensitive to minor misalignment angles to permit relatively precise alignment of front end parts. The sighting instruments 3 are preferably sturdily mounted to supports andl in the ill-lstrated example, the lasers 50 and 51 are mounted within respective housings 49 rigidly connecte~
to sleeves 52 and 53 selectively movable along the front beam 41.
Preferably, the front beam 41 ls transversely polygonal, such as square or rectangular and the sleeves 52 and 53 do not rotate relative thereto. In the illustrated example, the front beam 41 has cylindrical ends 43 which are rotatable within the arm remote ends 3~ and 39 and thereby enable both lasers 50 and 51 to rotate upwardly and downwardly together and move lines of sight 5 respectively projected therefrom in parallel vertical planes. The sleeves 52 and 53/ Fig.
18, each have a rectangular body portion 54 with front and rear sides 55 and 56 spaced from the front and rear surfaces of the beam 41. Ears 57 project outwardly from the front side 55 and wheels 58 are mounted thereto, as by pin 59.
The front wheels 58 extend through an opening 55' in the front side 55 for rolling engagement with the beam 41. A
rear tension wheel 60 is mounted to the rear side 56 by a lever arm 61 pivotally connected to the rear side 56 by an ear 57' and having a spring 61' held in compression at an end of the arm 61. The rear wheel 60 contacts the beam 41 through an opening 56' in the rear side 56 of the body portion 54 and permits rolling movement of the respective sleeves 52 and 53 on the beam 41. The upper side of each body portion 54 slides on the beam 41 and frictionally inhibits free movement thereon while the rear tension wheels 60 inhibit wobbling movement or misalignment of the sleeves 53 and 52 thereon. Thus, the sleeves 52 and 53 and thereby the lasers 50 and 51 are selectively movable on the beam 41 and are maintained in s-traight ahead posltion.
The sighting instruments 3, such as the lasers 50 and 2~3~6
The elongate frame or base 16 is movable upon the floor 8 to locate, or "square", the longitudinal axis of the support means 2 transversely to the longitudinal axis of the vehicle 7. Once the frame or base 16 has been properly positioned, as described below, the same is retained in position by adjustable jack screws 26 adjacent each Eront wheel 14 and having a lower floor engaging pad 27 and an upper crank arm 28.
An elongate back beam 33 extends between the mounts 18 and 19 and has opposite ends connected to the respective arms 23 by journal boxes 34 and 35 with interior, self-aligning bearings permitting rotation of the back beam 33.
Transverse arms 36 and 37 are rigidly secured to the back beam 33 spaced from and adjacent the journal boxes 34 and 35. Respective front ends 38 and 39 thereof are split inwardly to bearing surfaces 40, Fig. 5, for receiving and rotatably supporting an elongate sighting instrument supporting front beam 41. Fasteners 32, such as bolts, extend through the ends 38 and 39 and cause the same to clamp around ends 43 of the beam 41 ~or preventing excessive free rotation.
Means for rotating the back beam 33 and thereby moving the front beam 41 upwardly or downwardly relative to the back beam 33 are included and, in the illustrated example, Fig.
6. the arm 36 has a mid portion ~2 connected to a jack screw 4~ via a swivel connector 45 on the arm 42. A journal 46 affixed to the base 16 mounts the bottom end of the jack screw 44 thereto. ~ hand wheel 47 facilitates rotation of the jack screw 44 for moving the front beam 41 upwardly and downwardly.
The front beam 41 supports the sighting instruments 3 such as telescopes, light beam projectors and the like. In the illustrated example, the sighting instruments 3 comprise low power lasers 50 and 51 which project respective lines of sight 5 beams of coherent, collimated radiation capable of great accuracy for alignment. The sighting instruments 3, exemplified as by the lasers 50 and 51, are preferably sufficiently sensitive to minor misalignment angles to permit relatively precise alignment of front end parts. The sighting instruments 3 are preferably sturdily mounted to supports andl in the ill-lstrated example, the lasers 50 and 51 are mounted within respective housings 49 rigidly connecte~
to sleeves 52 and 53 selectively movable along the front beam 41.
Preferably, the front beam 41 ls transversely polygonal, such as square or rectangular and the sleeves 52 and 53 do not rotate relative thereto. In the illustrated example, the front beam 41 has cylindrical ends 43 which are rotatable within the arm remote ends 3~ and 39 and thereby enable both lasers 50 and 51 to rotate upwardly and downwardly together and move lines of sight 5 respectively projected therefrom in parallel vertical planes. The sleeves 52 and 53/ Fig.
18, each have a rectangular body portion 54 with front and rear sides 55 and 56 spaced from the front and rear surfaces of the beam 41. Ears 57 project outwardly from the front side 55 and wheels 58 are mounted thereto, as by pin 59.
The front wheels 58 extend through an opening 55' in the front side 55 for rolling engagement with the beam 41. A
rear tension wheel 60 is mounted to the rear side 56 by a lever arm 61 pivotally connected to the rear side 56 by an ear 57' and having a spring 61' held in compression at an end of the arm 61. The rear wheel 60 contacts the beam 41 through an opening 56' in the rear side 56 of the body portion 54 and permits rolling movement of the respective sleeves 52 and 53 on the beam 41. The upper side of each body portion 54 slides on the beam 41 and frictionally inhibits free movement thereon while the rear tension wheels 60 inhibit wobbling movement or misalignment of the sleeves 53 and 52 thereon. Thus, the sleeves 52 and 53 and thereby the lasers 50 and 51 are selectively movable on the beam 41 and are maintained in s-traight ahead posltion.
The sighting instruments 3, such as the lasers 50 and 2~3~6
5]., project respective lines of sight 5 toward targets 4 located on wheel~ 10 o the vehicle 7. In the illustrated example, Figs. 7 and 8, an adjustable target supporting and wheel engaging structure 62 is mounted to the inner surface of the tire bead flange 63 of the wheel rim 64. The wheel engaging structure 62 includes a vertical sha:Et 66, such as formed of rectangular metal tubing, and a cross bar 67 rigidly and normally connected thereto as by welding, at a structure center 68. Movable up and down on the vertical shaft 66 are a pair of upper and lower vertically curved legs 69 and 70 having respective thumbscrew secured sleeve ends 71 and 72 selectively slidable upwardly and downwardly on the vertical shaft 66 relative to the center 68 to coaxially align the center 68 with the wheel hub center or vehicle axle. The upper and lower legs 69 and 70 have respectïve stra.ight portions 69' and 70' extending parallel to the vertïcal shaft 66 and spaced laterally therefrom toward the rim 64. An upper rim engaging post 7~ has a sleeve end 75 slidably connecting the post 74 to the upper leg straight portion 69'. A hi.nged tip end 76 2Q of the post 74 engages the interior surface of the tire bead flange 63 and is tightly maintained in engagement by adjust-ment of a primary thumb screw 77 extended through the sleeve end 75 and a secondary thumb screw 78 extended through a lever arm portion 79 of the hinged tip end 76 and contacting the sleeve end 7~.
Extending outwardly .fron~ the lower leg 70 and inwardly toward the wheel rim 64 are a pair of diverging, spaced lower rim engaging posts 81 and 82 which have short, threaded, shaft ends 83 and 84 extended horizontally and laterally therefrom for engag:ing the tire bead flange 63. The posts 81 and 82 are connected to a central sleeve 85 through which is extended a thumb screw 86 for selectively positioning the sleeve 85 along the stxaight portion 70'.
The targets 4 are mounted upon the wheel engaging structure 62 and extend outwardly and horizontally from portions of the vertical shaft 66 and the cross bar 67. It will be appreciated that the vertical shaft 66 and the horizontal cross bar 67 are of the same length and that certain targets 4, described below, are located at cardinal points, that is, along the horlzontal and vertical axis thereof, relative to the front wheel 10, such as top, bottom, front and rear with 90 spacing between each target 4. Further, placement of the center 68 of the wheel engaging structure 62 is adjusted by the use of the various sleeves and thumb screws and, when correctly adjusted, the center 68 should be aligned coaxially with t.he center of the wheel axle shaft or hub cap of the vehicle to space certain targets 4 equidistantly from the center 68 and at 90 angles from each other.
The targets 4 are preferably laterally adjustable toward and away from a respective vertical shaft 66 and cross bar 67 so as to be the same distance from the wheel rim 64. In the illustrated example, the targets 4 are mounted upon shafts 91 having mid portions 94 which are square in cross section and which have connector ends 90 rigidly mounted on sleeves 88 movable along the vertica:L
shaft 66 and the cross bar 67 and fixed in position therealong by thumbscrews 89. Flanged nuts 92 on threaded free ends 96 of the bolt shafts 91 facilitate manual adjustment of the : targets 4 inwardly and outwardly relative to the wheel rim 64. Coil springs 93 are sleeved on the shafts 91 between the sleeve 88 and ends of target tubular members 9S sleeved on the shafts 91 and urge the targets 4 laterally away from a respective sleeve 88.
~
When the wheel en~aging and target supporting structure 62 is mounted to the wheel rim 64, certain targets 4 are spaced circumferentially and laterally of the wheel axle and cardinally located at opposite vertical and horizontal positions around the rim 64; these respective target positions are hereafter designated as upper and lower targets 97 and 98 and front and rear targets 99 and lO0. Each of the targets 4 have indicia thereon providing scale measurements described below, for determining alignment angles of the front wheels 10. The targets 4 are preferably comprised of a sturdy, shatter resistant transparent material, such as plexiglass, which permits a line of sight 5 from a sighting instrument 3 to pass therethrough, as for example through the front target 99 to the rear target 100 and thereby visibly impinge upon a discrete scale mark thereof as described below.
The targets 4 are individually illustrated in Figs. 20 through 26. Figs. 20 and 21 show targets which are used to measure horizontal angular relationships, such as toe-in or toe-out, and are consequently mounted upon the opposite ends 67' of the cross bar 67. A front target 99 has vertical and horizontal lines 104 and 105 which cross at 106 and thereby form a central aiming point for impingement of a line of sight 5 thereon. rrhe transparency of the front target 99 permits the line of sight 5 to pass therethrough and impinge upon the rear target lO0, Fig. 21 which may have a frosted or lightly textured surface to better permit seeing the point of impingement of the line of sight 5 thereon, as for example, a laser light beam from the lasers 50 and 51.
The rear target lO0 includes an inch scale 108 showing up to two inches of toe-out or toe-in and a metric scale lO9 with up to 4 1/2 cm of toe-out or toe-in and which are separated by a horizontal line 110. A vertical zero line 111 divides a toe-ollt side 113 and a toe-ïn side 114 of the target 100.
Figs. 25 through 27 show left and rïght sets of targets 4 which are used to measure vertical angular relationships, such as camber, and measurements which are predominately vertical angular relationships, such as caster. The lower targets 98 for the vehïcle left and right front wheels 10, ~igs. 24 and 26 respectively are preferably identical and have horizontal and vertical lïnes 117 and 118 which cross at point 119 and provïde an aiming point for the lïne of sight S. A left front wheel upper target 971 Fig. 25 and a right front wheel upper target 97, Fïg. 27 each have a lower caster scale 120 showing caster in degrees from zero to eight and an upper camber scale 121 showing camber in degrees from zero to six and separated from the caster scale 120 by a horizontal line 122. A vertical zero line 124 divides positive and negative sides 125 and 126 of the camber and caster scales 120 and 121. The positive and negative sides 125 and 126 accord with the wheels as the alignment apparatus operator would look at them from the sighting instruments 3 and, for example, a positive camber measurement means that the bottom of the wheel 10 tilts inwardly toward the longitudinal axis, or center or the vehicle 7.
Figs. 22 ancl 23 show targets 4 which are used to measure the predominately horizontal angular relationship of king pin inclination or steering axis cant and which are positioned along the cross bar 67 and preferably located radially inwardly of the front and rear targets 99 and 100. A front steering axis cant target 127, Fig. 22, has a horizontal line 128 extending thereacross and a central vertical line 129 dividing the target 127 into equal left turn and right turn aiming portions 130 and 131 for receiving the line of sight 5 as the forward portion of the front wheel 10 moves outwardly and inwardly about the vehicle turning axis. Each portion 130 and 131 has a vertical line 132 for directing a line o~ sight 5 therethrough when the front wheel 10 is turned 20.
A rear steering axis cant target 135, Fig. 23, has left turn and right turn aiming portions 136 and 137 oppositely placed of the front steering axis cant target 127 left turn and right turn aiming portions 130 and 131 and positioned for receiving a line of sight 5 as the rearward portion of the front wheel 10 moves outwardly and inwardly. The left turn and right turn aiming portions 136 and 137 are separated by a vertical dividing line 139 and each have a vertical line 140 for indicating 20 of turn in the according direction.
A vertical scale 142 in each of the respective portions 136 and 137 shows the steering axis cant in degrees from five to twenty for the direction of turn.
The steering axis cant targets 127 and 135 are each located on the cross bar 67 between the ends 67' and the center 68. Clips or sleeves 155 are open on the rear side thereof for outward detachment from the cross bar 67 and are mounted to the targets 127 and 135 as described in connection with the sleeves 88 and the targets 97 through 100. To maintain a set relationship to the center 68, the clips or sleeves 155 are preferably connectible to the cross bar 67 only at 157 and 158 and have an interior pin insertable within a bore (not shown) in the cross bar 67, the distance of the bore from the center 68 being known and set to accord with the degree scales 142 of the rear steering axis cant target 135. The steering axis cant targets 127 and 135 . . .
extend upwardly to not interfere with a line of sight 5 directed toward the front and rear targets 99 and 100 during determination of toe-ln and toe-out. The steering axis cant targets 127 and 135 are located at cardinal positions, that is, along the horizontal cross bar 67, radially inward of the front and rear targets 99 and 100.
Additionally, indicia bearin~ left and right rear wheel targets 145 and 146 are positioned adjoining left and right rear tires 147 and 148~ Fig. 3, during an initial or vehicle positioning phase of alignment. In the illustrated example, each rear target 145 and 146 includes an upright standard 150 for positioning the target by the wheel and having supportive feet 151 spaced whereby the rear wheel targets 145 and 145 abut the rear tires 147 and 14~ and extend normally therefrom. Preferably, each rear wheel target 145 and 146 has vertical scale lines spaced in centimeters or inches, and with numbers thereof progressing serially toward outside edges 152 thereof.
To use the alignment apparatus 1 the vehicle 7 is lifted, as by power jacks 160 and the front wheels 10, and pre~erably the rear wheels 145 and 146 are positioned atop the roller plates 6. The vehicle 7 is aligned by the driver as much as possible transversely to the front beam 41.
As is conventional, the vehicle front end is checked for worn or loose fitting parts which must be replaced before alignment. The mechanic uses a jack to raise the ~ront wheels above the roller plates 6 and shakes them both horizontally and vertically to detect any looseness. The mechanic spins the whee]s to test for deteriorated bearings.
30 Shock absorbers are checked for proper snubbing action by lowering the front wheels 10 to the roller plates 6 and bouncing the car up and down by hand. Frame damage which ;
~ -16-would alter -tracking and turning characteristics is checked by measuring carefully between common points, such as from the rear edge of the front wheel rim to the rear edge of the back wheel rim. A twisted or distorted chassis may make front end alignment difficult if not impossible. Additionally, the front tires should be equally worn and be equally inflated for best alignment results.
Precise positioning of the vehicle 7 relative to the sighting instrument support means 2 is accomplished by placing the left and right rear wheel targets 1~5 and 146 against the rear wheels 147 and 148 so that they extend normally therefrom. Wheel engaging and target supporting structures 62 are connected to each of the front wheels 10, as described in connection with Figs. 7 and 8, so that the shaft 66 is vertical and the cross bar 67 is horizontal. A
bubble level (not shown) may be used for proper positioning of the structure 62. Using a measuring tape or rule, the targets 4 are adjusted toward or away from the vertical shaft 66 and the cross bar 67 so that they are laterally equidistant from the tire rim 64 and thereby aligned parallelly to the side of the front wheel.
The sleeves 88 of the front and rear targets 99 and 100 are moved along the cross bar 67 until they are even with the margins of the front wheel 10 so that the front and rear targets 99 and 100 provide a true measurement of toe-in and toe-out. Preferably, the sleeves 88 of the upper and lower targets 97 and 98 are not moved as the scales thereof are calibrated with respect to a set distance or radius between the targets 97 and 98 and the structure center 68. Accordingly, it is preferred that the upper target 97 be adjusted to extend downwardly and the lower target 98 adjusted to extend upwardly for equidistant spacing from the center 68.
x~
Using a rule to measure the radius of the front tire to the floor 8, the jack screw 44 is rotated to adjust the front beam 41 upwardly or downwardly until the lines of sight 5 of the sighting instruments 3, such as the lasers 50 and 51, are horizontally directed through the axle or hub center of the rim 64. The lasers 50 and 51 are selectively moved inwardly or outwardly on the front beam 41 until the lines of sight 5, such as laser light beams, extend parallel to the sides of the vehicle 7 and laterally equldistant from the front and rear wheels as determined by the left and right rear wheel targets 145 and 146 and means such as the front and rear targets 99 and 100 or a transparent ruled card or plate (not shown) held manually against the front wheel 10. If the car 7 i5 located properly with respect to the front beam 41, the lines of sight will impinge at points 162 and 163 on the left and right rear wheel targets 145 and 146 and equidistantly from the outside edges 152. If the lines of sight 5 are not parallel to the vehicle sides, the sighting instrument support means 2 is moved relative to the vehicle 7 until the lines of sight 5 become parallel thereto and then the floor engaging jack screws 26 are set to maintain the elongate base 16 in fixed position. Additionally, the front wheels 10 may be found to be turned relative to the longitudinal axis of the vehicle 7. This will be detected by comparing the position of impingement of the line of sight 5 on the rear targets 100 relative to the front targets 99 for deviation, or difference of the scale markings.
Rotation of the steering wheel may be required to move the front wheels 10 to a straight ahead position.
A twisted or distorted chassis, which would effect the tracking characteristics of the vehicle, will become apparent during this initial calibration and "setting-up" phase.
,:
' 4~
Small deviations may be acceptable but certain conditions may require frame straightening before front end alignment can be accurately accomplished.
After the fron~ beam 41 is "squared", or aligned normally to the front wheels 10 and the rear tires 104 and 105, each of the front wheels 10 are checked for both lateral run-out;
i.e., misalignment in a plane perpendicular to the center axis and radial run-out; i.e., misalignment or eccentricity in the center axis. In this procedure, the front wheels 10 are raised from contact with the roller plates 6 by pneumatic or hydraulic power jacks 160 so that the front wheels 10 are substantially vertical Fig. 9. The front beam 41 is acljusted either upwardly or downwardly until the line of sight 5 from the sighting instrument 3 extends horiæontally through the vehicle wheel center or axle. Next, the line of sight 5 is rotated in a vertical plane toward either the upper target 97 or the lower target 98 to check for proper camber or vertical run-out. The impingement of the line of sight 5, such as the laser beam, with a scale mark on the target 97 20 or 98, as at point 164 is noted by marking with a grease pencil, recording, or other means. Next, the wheel is rotated 180 degrees and the impingement of the line of sight 5, as at point 165, noted upon the opposite target now in the line of sight 5. The point of impingement of the line of sight should be at the same lateral scale mark on both targets. If there is deviation from proper vertical run-out, suspension parts, such as the upper control arm, should be adjusted until the points 164 and 165 lie in the same vertical plane.
Next, horizontal or toe-in run-out is checked by adjusting the front beam 41 until the line of sight 5 passes through the horizontal front and rear targets 99 and 100.
Horizontal run-out is checked by noting the point of line of sight impingement upon the front target 99 as at point 166 and the reciprocal rear tar~et lO0. The point of impingement upon the rear target 100 should be at the same lateral scale marking as on the front target 99. If there is deviation, suspension parts, such as the tire rod, should be adjusted.
Run-out checks are now complete and accordingly, the wheel, when raised in the air and spun, should not wobble on its axis.
The front wheels lO are then lowered onto the roller plates 6, Fig. lO, or checking camber, illustrated in an exaggerated angle thereof in Fig. ll or purposes of illustration.
First, the front beam 41 and the sighting instruments 3 are adjusted so that the lines of sight 5 extend horizontally and through the cross point ll9 of the bottom target 98.
The line of sight 5 in then moved upwardly in a vertical plane to spot a point of impingement 167 on the camber scale marks of the upper target 97, indicating, for example, 2 of negative camber to the lower target 98. The deviation, or degree of vertical angle~ appears as the difference from the vertical between the line of sight impingement points of the upper and lower targets 97 and 98 and the camber scale 121 provides a measurement corresponding to actual degrees of camber. Adjustment of the suspension and steering parts may be necessary to set in the manufacturer's specified camber angle.
Measurement of toe-in or toe-out, Fig. 12, is accomplished by procedures similar to camber measurement. Keeping the front beam 41 in the same position as above, the sighting instruments 3, such as the lasers 50 and 51 are located thereon to direct the lines of sight 5 through the cross point 106 of the front target 99. The line of sight 5 extends through the front target 9~ and impinges the surface of the rear target 100 on either the toe-in side 114 or the toe-out side 113. As the front and rear targets 99 and 100 are adjacent the front wheel margins, the deviation, or degree of horizontal angle from straight ahead~ indicated on the rear target 100 is a true toe-in or toe-out measurement.
Here again, adjustment of the proper vehicle steering and suspension parts, such as the tie rod, may be requiredO
Next to be checked is caster, Figs 13-15, which is the cant of the upper ball joint toward the rear of the vehicle.
Caster, like car~er and toe-in, is measured with the weight of the vehicle upon the front wheels. First, using the degrees of turn scales of the front and rear steering axis cant targets 127 and 135 for example, the wheels 10 are turned 20 degrees either left or right from a s~ralgh~ ahead direction Fig. 13. The lasers 50 and 51 are adjusted to direct respective lines of sight 5 through cross points 119 of the lower targets 98 on the front wheels 10. The lines of sight 5 are flipped upwardly and a point of impingement 168, for example, upon each caster scale 120 of the upper targets 97 is noted, for example negative 2 ln a wheel right turn, Fig. 14~ This is one direction of the angular rotational deviation caused by the cant of the upper ball joints. The wheels 10 are then turned 40 degrees in the opposite direction or 20 degrees past the straight ahead position, Fig. ]5 and using the same procedures as above, the angular rotational deviation is noted upon the caster scale 120 of the upper target 97, for example 3/4 degree Fig. 15. The difference between the two measurements, for example 1 1/4 degrees, is the angle of caster of the wheel Steering axis cant, or kingpin inclination, is determined with the weight of the vehicle 7 off the front wheels 10 and 3~
with the front end raised, as by the jacks 160, Figs. 16 and 17. The vehicle brakes are applied and held down to prevent axial rotation of the front wheels 10. Next, the front beam 41 is adjusted upwardly so that a line of sight 5 extends horizontally through the front and rear steering axis cant targets 127 and 135. The sighting instruments 3 are adjusted laterally to direc-t lines of sight 5 through the vertical lines 132 of respective left and right turn portions 130 and 131 of the front steering axis cant target 127 and toward the 20 turn lines 140 of left and right turn portions 136 and 137 of the rear steering axis cant target 135. The line of sight 5 will align with one of the vertical lines 132 and an opposite 20 turn line 140 when the front wheel is turned 20 from straight ahead posit.ion in either direction.
Using the above method to determine degrees of turn, the front wheels 10 are turned right 20 degrees Fig. 16 and the point of line of sight 5 impingement upon the vertical scale 142 of the right turn portion 137 of the rear steering axis cant target 135 no-ted, as for example lOU. The front wheels 10 are turned left 40 degrees in the opposite direction, or 20 degrees past the straight ahead position, Fig. 17, and as determined the point of line of sight 5 impingement upon the vertical scale 142 of the left turn portion 136 of the rear steering axis cant target 135 noted, as for 8. The angle of steering axis ~ant is then determined by the average of tha right and left turn measurements for example 9.
A modified form of elongate base 16 of the sighting instrument support 2 is shown in Fig. 19 whereby a cabinet 170 co~ers the base 16 and encloses the sight instruments 3 for providing a storage facility for the associated wheel engaging and target support structures 62 and the rear wheel targets 144 and 145. In the illustrated example, opposite sides 172 and 173 and a back 174 extend upwardly from margins of the base 16 and are covered by a top 175. Doors 177 and 178 are slidably mounted in a ~ront opening 179 of the cabinet 170 and are movable thereacross to close o~f the cabinet 170 and secure materials and tools therein.
It will be apparent from the preceeding description that the wheel alignment apparatus of the present invention has features which enable it to be easily and quickly used by even a relatively inexperienced vehicle mechanic. Intensive training is not required to enable the operator to understand the theory and procedures of operation of the apparatus, thus offering relatively few opportunities for error.
Further, relatively precise scale measurements are indicated by a well defined, narrow beam of light for a readily apparent visual display.
It is to be understood that while one form of this invention has been illustrated and described, it is not to be limited to this specific form or arrangement of parts herein described and shown, except insofar as such limitations are included in the following claims.
Extending outwardly .fron~ the lower leg 70 and inwardly toward the wheel rim 64 are a pair of diverging, spaced lower rim engaging posts 81 and 82 which have short, threaded, shaft ends 83 and 84 extended horizontally and laterally therefrom for engag:ing the tire bead flange 63. The posts 81 and 82 are connected to a central sleeve 85 through which is extended a thumb screw 86 for selectively positioning the sleeve 85 along the stxaight portion 70'.
The targets 4 are mounted upon the wheel engaging structure 62 and extend outwardly and horizontally from portions of the vertical shaft 66 and the cross bar 67. It will be appreciated that the vertical shaft 66 and the horizontal cross bar 67 are of the same length and that certain targets 4, described below, are located at cardinal points, that is, along the horlzontal and vertical axis thereof, relative to the front wheel 10, such as top, bottom, front and rear with 90 spacing between each target 4. Further, placement of the center 68 of the wheel engaging structure 62 is adjusted by the use of the various sleeves and thumb screws and, when correctly adjusted, the center 68 should be aligned coaxially with t.he center of the wheel axle shaft or hub cap of the vehicle to space certain targets 4 equidistantly from the center 68 and at 90 angles from each other.
The targets 4 are preferably laterally adjustable toward and away from a respective vertical shaft 66 and cross bar 67 so as to be the same distance from the wheel rim 64. In the illustrated example, the targets 4 are mounted upon shafts 91 having mid portions 94 which are square in cross section and which have connector ends 90 rigidly mounted on sleeves 88 movable along the vertica:L
shaft 66 and the cross bar 67 and fixed in position therealong by thumbscrews 89. Flanged nuts 92 on threaded free ends 96 of the bolt shafts 91 facilitate manual adjustment of the : targets 4 inwardly and outwardly relative to the wheel rim 64. Coil springs 93 are sleeved on the shafts 91 between the sleeve 88 and ends of target tubular members 9S sleeved on the shafts 91 and urge the targets 4 laterally away from a respective sleeve 88.
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When the wheel en~aging and target supporting structure 62 is mounted to the wheel rim 64, certain targets 4 are spaced circumferentially and laterally of the wheel axle and cardinally located at opposite vertical and horizontal positions around the rim 64; these respective target positions are hereafter designated as upper and lower targets 97 and 98 and front and rear targets 99 and lO0. Each of the targets 4 have indicia thereon providing scale measurements described below, for determining alignment angles of the front wheels 10. The targets 4 are preferably comprised of a sturdy, shatter resistant transparent material, such as plexiglass, which permits a line of sight 5 from a sighting instrument 3 to pass therethrough, as for example through the front target 99 to the rear target 100 and thereby visibly impinge upon a discrete scale mark thereof as described below.
The targets 4 are individually illustrated in Figs. 20 through 26. Figs. 20 and 21 show targets which are used to measure horizontal angular relationships, such as toe-in or toe-out, and are consequently mounted upon the opposite ends 67' of the cross bar 67. A front target 99 has vertical and horizontal lines 104 and 105 which cross at 106 and thereby form a central aiming point for impingement of a line of sight 5 thereon. rrhe transparency of the front target 99 permits the line of sight 5 to pass therethrough and impinge upon the rear target lO0, Fig. 21 which may have a frosted or lightly textured surface to better permit seeing the point of impingement of the line of sight 5 thereon, as for example, a laser light beam from the lasers 50 and 51.
The rear target lO0 includes an inch scale 108 showing up to two inches of toe-out or toe-in and a metric scale lO9 with up to 4 1/2 cm of toe-out or toe-in and which are separated by a horizontal line 110. A vertical zero line 111 divides a toe-ollt side 113 and a toe-ïn side 114 of the target 100.
Figs. 25 through 27 show left and rïght sets of targets 4 which are used to measure vertical angular relationships, such as camber, and measurements which are predominately vertical angular relationships, such as caster. The lower targets 98 for the vehïcle left and right front wheels 10, ~igs. 24 and 26 respectively are preferably identical and have horizontal and vertical lïnes 117 and 118 which cross at point 119 and provïde an aiming point for the lïne of sight S. A left front wheel upper target 971 Fig. 25 and a right front wheel upper target 97, Fïg. 27 each have a lower caster scale 120 showing caster in degrees from zero to eight and an upper camber scale 121 showing camber in degrees from zero to six and separated from the caster scale 120 by a horizontal line 122. A vertical zero line 124 divides positive and negative sides 125 and 126 of the camber and caster scales 120 and 121. The positive and negative sides 125 and 126 accord with the wheels as the alignment apparatus operator would look at them from the sighting instruments 3 and, for example, a positive camber measurement means that the bottom of the wheel 10 tilts inwardly toward the longitudinal axis, or center or the vehicle 7.
Figs. 22 ancl 23 show targets 4 which are used to measure the predominately horizontal angular relationship of king pin inclination or steering axis cant and which are positioned along the cross bar 67 and preferably located radially inwardly of the front and rear targets 99 and 100. A front steering axis cant target 127, Fig. 22, has a horizontal line 128 extending thereacross and a central vertical line 129 dividing the target 127 into equal left turn and right turn aiming portions 130 and 131 for receiving the line of sight 5 as the forward portion of the front wheel 10 moves outwardly and inwardly about the vehicle turning axis. Each portion 130 and 131 has a vertical line 132 for directing a line o~ sight 5 therethrough when the front wheel 10 is turned 20.
A rear steering axis cant target 135, Fig. 23, has left turn and right turn aiming portions 136 and 137 oppositely placed of the front steering axis cant target 127 left turn and right turn aiming portions 130 and 131 and positioned for receiving a line of sight 5 as the rearward portion of the front wheel 10 moves outwardly and inwardly. The left turn and right turn aiming portions 136 and 137 are separated by a vertical dividing line 139 and each have a vertical line 140 for indicating 20 of turn in the according direction.
A vertical scale 142 in each of the respective portions 136 and 137 shows the steering axis cant in degrees from five to twenty for the direction of turn.
The steering axis cant targets 127 and 135 are each located on the cross bar 67 between the ends 67' and the center 68. Clips or sleeves 155 are open on the rear side thereof for outward detachment from the cross bar 67 and are mounted to the targets 127 and 135 as described in connection with the sleeves 88 and the targets 97 through 100. To maintain a set relationship to the center 68, the clips or sleeves 155 are preferably connectible to the cross bar 67 only at 157 and 158 and have an interior pin insertable within a bore (not shown) in the cross bar 67, the distance of the bore from the center 68 being known and set to accord with the degree scales 142 of the rear steering axis cant target 135. The steering axis cant targets 127 and 135 . . .
extend upwardly to not interfere with a line of sight 5 directed toward the front and rear targets 99 and 100 during determination of toe-ln and toe-out. The steering axis cant targets 127 and 135 are located at cardinal positions, that is, along the horizontal cross bar 67, radially inward of the front and rear targets 99 and 100.
Additionally, indicia bearin~ left and right rear wheel targets 145 and 146 are positioned adjoining left and right rear tires 147 and 148~ Fig. 3, during an initial or vehicle positioning phase of alignment. In the illustrated example, each rear target 145 and 146 includes an upright standard 150 for positioning the target by the wheel and having supportive feet 151 spaced whereby the rear wheel targets 145 and 145 abut the rear tires 147 and 14~ and extend normally therefrom. Preferably, each rear wheel target 145 and 146 has vertical scale lines spaced in centimeters or inches, and with numbers thereof progressing serially toward outside edges 152 thereof.
To use the alignment apparatus 1 the vehicle 7 is lifted, as by power jacks 160 and the front wheels 10, and pre~erably the rear wheels 145 and 146 are positioned atop the roller plates 6. The vehicle 7 is aligned by the driver as much as possible transversely to the front beam 41.
As is conventional, the vehicle front end is checked for worn or loose fitting parts which must be replaced before alignment. The mechanic uses a jack to raise the ~ront wheels above the roller plates 6 and shakes them both horizontally and vertically to detect any looseness. The mechanic spins the whee]s to test for deteriorated bearings.
30 Shock absorbers are checked for proper snubbing action by lowering the front wheels 10 to the roller plates 6 and bouncing the car up and down by hand. Frame damage which ;
~ -16-would alter -tracking and turning characteristics is checked by measuring carefully between common points, such as from the rear edge of the front wheel rim to the rear edge of the back wheel rim. A twisted or distorted chassis may make front end alignment difficult if not impossible. Additionally, the front tires should be equally worn and be equally inflated for best alignment results.
Precise positioning of the vehicle 7 relative to the sighting instrument support means 2 is accomplished by placing the left and right rear wheel targets 1~5 and 146 against the rear wheels 147 and 148 so that they extend normally therefrom. Wheel engaging and target supporting structures 62 are connected to each of the front wheels 10, as described in connection with Figs. 7 and 8, so that the shaft 66 is vertical and the cross bar 67 is horizontal. A
bubble level (not shown) may be used for proper positioning of the structure 62. Using a measuring tape or rule, the targets 4 are adjusted toward or away from the vertical shaft 66 and the cross bar 67 so that they are laterally equidistant from the tire rim 64 and thereby aligned parallelly to the side of the front wheel.
The sleeves 88 of the front and rear targets 99 and 100 are moved along the cross bar 67 until they are even with the margins of the front wheel 10 so that the front and rear targets 99 and 100 provide a true measurement of toe-in and toe-out. Preferably, the sleeves 88 of the upper and lower targets 97 and 98 are not moved as the scales thereof are calibrated with respect to a set distance or radius between the targets 97 and 98 and the structure center 68. Accordingly, it is preferred that the upper target 97 be adjusted to extend downwardly and the lower target 98 adjusted to extend upwardly for equidistant spacing from the center 68.
x~
Using a rule to measure the radius of the front tire to the floor 8, the jack screw 44 is rotated to adjust the front beam 41 upwardly or downwardly until the lines of sight 5 of the sighting instruments 3, such as the lasers 50 and 51, are horizontally directed through the axle or hub center of the rim 64. The lasers 50 and 51 are selectively moved inwardly or outwardly on the front beam 41 until the lines of sight 5, such as laser light beams, extend parallel to the sides of the vehicle 7 and laterally equldistant from the front and rear wheels as determined by the left and right rear wheel targets 145 and 146 and means such as the front and rear targets 99 and 100 or a transparent ruled card or plate (not shown) held manually against the front wheel 10. If the car 7 i5 located properly with respect to the front beam 41, the lines of sight will impinge at points 162 and 163 on the left and right rear wheel targets 145 and 146 and equidistantly from the outside edges 152. If the lines of sight 5 are not parallel to the vehicle sides, the sighting instrument support means 2 is moved relative to the vehicle 7 until the lines of sight 5 become parallel thereto and then the floor engaging jack screws 26 are set to maintain the elongate base 16 in fixed position. Additionally, the front wheels 10 may be found to be turned relative to the longitudinal axis of the vehicle 7. This will be detected by comparing the position of impingement of the line of sight 5 on the rear targets 100 relative to the front targets 99 for deviation, or difference of the scale markings.
Rotation of the steering wheel may be required to move the front wheels 10 to a straight ahead position.
A twisted or distorted chassis, which would effect the tracking characteristics of the vehicle, will become apparent during this initial calibration and "setting-up" phase.
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' 4~
Small deviations may be acceptable but certain conditions may require frame straightening before front end alignment can be accurately accomplished.
After the fron~ beam 41 is "squared", or aligned normally to the front wheels 10 and the rear tires 104 and 105, each of the front wheels 10 are checked for both lateral run-out;
i.e., misalignment in a plane perpendicular to the center axis and radial run-out; i.e., misalignment or eccentricity in the center axis. In this procedure, the front wheels 10 are raised from contact with the roller plates 6 by pneumatic or hydraulic power jacks 160 so that the front wheels 10 are substantially vertical Fig. 9. The front beam 41 is acljusted either upwardly or downwardly until the line of sight 5 from the sighting instrument 3 extends horiæontally through the vehicle wheel center or axle. Next, the line of sight 5 is rotated in a vertical plane toward either the upper target 97 or the lower target 98 to check for proper camber or vertical run-out. The impingement of the line of sight 5, such as the laser beam, with a scale mark on the target 97 20 or 98, as at point 164 is noted by marking with a grease pencil, recording, or other means. Next, the wheel is rotated 180 degrees and the impingement of the line of sight 5, as at point 165, noted upon the opposite target now in the line of sight 5. The point of impingement of the line of sight should be at the same lateral scale mark on both targets. If there is deviation from proper vertical run-out, suspension parts, such as the upper control arm, should be adjusted until the points 164 and 165 lie in the same vertical plane.
Next, horizontal or toe-in run-out is checked by adjusting the front beam 41 until the line of sight 5 passes through the horizontal front and rear targets 99 and 100.
Horizontal run-out is checked by noting the point of line of sight impingement upon the front target 99 as at point 166 and the reciprocal rear tar~et lO0. The point of impingement upon the rear target 100 should be at the same lateral scale marking as on the front target 99. If there is deviation, suspension parts, such as the tire rod, should be adjusted.
Run-out checks are now complete and accordingly, the wheel, when raised in the air and spun, should not wobble on its axis.
The front wheels lO are then lowered onto the roller plates 6, Fig. lO, or checking camber, illustrated in an exaggerated angle thereof in Fig. ll or purposes of illustration.
First, the front beam 41 and the sighting instruments 3 are adjusted so that the lines of sight 5 extend horizontally and through the cross point ll9 of the bottom target 98.
The line of sight 5 in then moved upwardly in a vertical plane to spot a point of impingement 167 on the camber scale marks of the upper target 97, indicating, for example, 2 of negative camber to the lower target 98. The deviation, or degree of vertical angle~ appears as the difference from the vertical between the line of sight impingement points of the upper and lower targets 97 and 98 and the camber scale 121 provides a measurement corresponding to actual degrees of camber. Adjustment of the suspension and steering parts may be necessary to set in the manufacturer's specified camber angle.
Measurement of toe-in or toe-out, Fig. 12, is accomplished by procedures similar to camber measurement. Keeping the front beam 41 in the same position as above, the sighting instruments 3, such as the lasers 50 and 51 are located thereon to direct the lines of sight 5 through the cross point 106 of the front target 99. The line of sight 5 extends through the front target 9~ and impinges the surface of the rear target 100 on either the toe-in side 114 or the toe-out side 113. As the front and rear targets 99 and 100 are adjacent the front wheel margins, the deviation, or degree of horizontal angle from straight ahead~ indicated on the rear target 100 is a true toe-in or toe-out measurement.
Here again, adjustment of the proper vehicle steering and suspension parts, such as the tie rod, may be requiredO
Next to be checked is caster, Figs 13-15, which is the cant of the upper ball joint toward the rear of the vehicle.
Caster, like car~er and toe-in, is measured with the weight of the vehicle upon the front wheels. First, using the degrees of turn scales of the front and rear steering axis cant targets 127 and 135 for example, the wheels 10 are turned 20 degrees either left or right from a s~ralgh~ ahead direction Fig. 13. The lasers 50 and 51 are adjusted to direct respective lines of sight 5 through cross points 119 of the lower targets 98 on the front wheels 10. The lines of sight 5 are flipped upwardly and a point of impingement 168, for example, upon each caster scale 120 of the upper targets 97 is noted, for example negative 2 ln a wheel right turn, Fig. 14~ This is one direction of the angular rotational deviation caused by the cant of the upper ball joints. The wheels 10 are then turned 40 degrees in the opposite direction or 20 degrees past the straight ahead position, Fig. ]5 and using the same procedures as above, the angular rotational deviation is noted upon the caster scale 120 of the upper target 97, for example 3/4 degree Fig. 15. The difference between the two measurements, for example 1 1/4 degrees, is the angle of caster of the wheel Steering axis cant, or kingpin inclination, is determined with the weight of the vehicle 7 off the front wheels 10 and 3~
with the front end raised, as by the jacks 160, Figs. 16 and 17. The vehicle brakes are applied and held down to prevent axial rotation of the front wheels 10. Next, the front beam 41 is adjusted upwardly so that a line of sight 5 extends horizontally through the front and rear steering axis cant targets 127 and 135. The sighting instruments 3 are adjusted laterally to direc-t lines of sight 5 through the vertical lines 132 of respective left and right turn portions 130 and 131 of the front steering axis cant target 127 and toward the 20 turn lines 140 of left and right turn portions 136 and 137 of the rear steering axis cant target 135. The line of sight 5 will align with one of the vertical lines 132 and an opposite 20 turn line 140 when the front wheel is turned 20 from straight ahead posit.ion in either direction.
Using the above method to determine degrees of turn, the front wheels 10 are turned right 20 degrees Fig. 16 and the point of line of sight 5 impingement upon the vertical scale 142 of the right turn portion 137 of the rear steering axis cant target 135 no-ted, as for example lOU. The front wheels 10 are turned left 40 degrees in the opposite direction, or 20 degrees past the straight ahead position, Fig. 17, and as determined the point of line of sight 5 impingement upon the vertical scale 142 of the left turn portion 136 of the rear steering axis cant target 135 noted, as for 8. The angle of steering axis ~ant is then determined by the average of tha right and left turn measurements for example 9.
A modified form of elongate base 16 of the sighting instrument support 2 is shown in Fig. 19 whereby a cabinet 170 co~ers the base 16 and encloses the sight instruments 3 for providing a storage facility for the associated wheel engaging and target support structures 62 and the rear wheel targets 144 and 145. In the illustrated example, opposite sides 172 and 173 and a back 174 extend upwardly from margins of the base 16 and are covered by a top 175. Doors 177 and 178 are slidably mounted in a ~ront opening 179 of the cabinet 170 and are movable thereacross to close o~f the cabinet 170 and secure materials and tools therein.
It will be apparent from the preceeding description that the wheel alignment apparatus of the present invention has features which enable it to be easily and quickly used by even a relatively inexperienced vehicle mechanic. Intensive training is not required to enable the operator to understand the theory and procedures of operation of the apparatus, thus offering relatively few opportunities for error.
Further, relatively precise scale measurements are indicated by a well defined, narrow beam of light for a readily apparent visual display.
It is to be understood that while one form of this invention has been illustrated and described, it is not to be limited to this specific form or arrangement of parts herein described and shown, except insofar as such limitations are included in the following claims.
Claims (24)
PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Apparatus for checking wheel alignment of a wheeled vehicle comprising: (a) a base structure having a surface supporting a vehicle for alignment checks thereof; (b) target structure mountable on the wheels of a vehicle and having scaled targets located thereon in diametrically opposed relation and laterally outwardly of the wheels; (c) laterally spaced laser beam projecting members positioned longitudinally from and aligned with the target structure and spaced generally laterally from the longitudinal axis of the vehicle; (d) a support structure for said laser beam members having spaced apart standards and a shaft member extending therebetween; said shaft having spaced arms; (e) means rotatably mounting said spaced arms on said standards with said shaft radially outwardly from said rotatable mounting means; (f) means adjustably rotating said arms for raising and lowering said arms and the shaft thereon to vary the spacing from the base surface; (g) means pivotally mounting the shaft on the arms for adjusting the angle of said laser beams relative to the base surface; (h) means movably mounting the laser beam members on the shaft for adjusting the lateral spacing thereof; and (i) means for positioning the vehicle and laser beam members relative to the base surface for the laser beam members to project beams parallel to the longitudinal axis of said vehicle and equally spaced therefrom for impingement on the scaled targets on the respective wheels of said vehicle.
2. Apparatus for checking wheel alignment as set forth in Claim 1 wherein: (a) said support structure includes a mobile frame having the spaced standards for selective movement over the base surface; (b) means carried by said mobile frame and selectively engageable with the base structure for retaining said mobile frame in a selected position relative to a vehicle to be checked; (c) target members associated with remaining wheels of a vehicle to be checked and adapted for impingement of the beams from the laser beam members for determining parallelism of said beams relative to the longitudinal axis of the vehicle.
3. Apparatus for checking wheel alignment as set forth in Claim 2 wherein: (a) said shaft member is non-circular; (b) said means movably mounting the laser beam on said shaft member include sleeves, rollers and springs permitting movement along the shaft by application of force thereto and a gripping of the shaft member to retain said mounting means and laser beam member against movement along said shaft member.
4. An apparatus for checking the alignment of the wheels of a vehicle, said apparatus comprising: (a) a target structure mountable upon a wheel of a vehicle; (b) a target connected to said target structure, said target being situated laterally of said wheel and spaced radially from the axle of said wheel when said target structure is mounted upon said wheel;
(c) a sighting instrument for directing a line of sight at said target and impinging said line of sight at a point thereon; and (d) support structure locating said sighting instrument spaced from said target and establishing a line of sight from said sighting instrument parallel to and laterally spaced from a longitudinal axis of said vehicle.
(c) a sighting instrument for directing a line of sight at said target and impinging said line of sight at a point thereon; and (d) support structure locating said sighting instrument spaced from said target and establishing a line of sight from said sighting instrument parallel to and laterally spaced from a longitudinal axis of said vehicle.
5. The apparatus set forth in Claim 4 including: (a) four said targets, said target structure positioning said targets respectively on horizontal and vertical axial cardinal points around said wheel.
6. The apparatus set forth in Claim 5 wherein: (a) said cardinal points include vertical upper and lower points and horizontal front and rear points.
7. The apparatus set forth in Claim 5 wherein: (a) said target structure includes elongate shafts mountable to said wheel in parallel orientation relative thereto, said targets being connected to said shafts and located thereon equidistantly from said wheel axle.
8. The apparatus set forth in Claim 7 including: (a) adjustable arms interconnecting said targets with said elongate shaft members for situating said targets laterally equidistant from said wheel and aligned in a vertical plane when said target structure is mounted upon said wheel.
9. The apparatus set forth in claim 4 wherein: (a) said sighting instrument includes a laser device emitting a line of sight comprising a coherent, collimated light beam.
10. The apparatus set forth in claim 4 wherein: (a) said support structure includes means connecting said sighting instrument thereto and permitting movement of said line of sight in a vertical plane.
11. The apparatus set forth in claim 4 wherein: (a) said support structure includes a standard with said sighting instruments located thereby a distance above a floor, said standard having horizontally adjustable means for moving said line of sight from said sighting instrument in a horizontal plane.
12. The apparatus set forth in claim 11 wherein: (a) said standard includes vertically adjustable means for varying said distance between said sighting instrument and the floor.
13. A method for checking the alignment of the wheels of a vehicle, which comprises: (a) establishing a line of sight from a sighting instrument parallel to and longitudinally spaced from a longitudinal axis of a vehicle, (b) mounting a target structure on a wheel, said target structure having a target situated laterally of said wheel and spaced radially of the axle of said wheel; (c) locating said target at a first cardinal axial point of said wheel; (d) directing said line of sight to impinge on said target at said first cardinal point; (e) locating said target at a second cardinal axial point of said wheel; (f) directing said line of sight to impinge on said target at said second cardinal point; (g) measuring the lateral difference between the impingement of said line of sight on said target in said first cardinal position and in said second cardinal position, the difference measurement corresponding to a measurement of angular alignment of said wheel.
14. The method set forth in Claim 13 including: (a) locating said target at a first upper vertical axis cardinal point of said wheel; (b) directing said line of sight at said target at said upper cardinal point; (c) locating said target at a second lower vertical axis cardinal point of said wheel; and (d) directing said line of sight at said target at said lower cardinal point, thereby checking vertical upper to lower alignment of said wheel.
15. The method set forth in Claim 14 including: (a) directing said line of sight at a toe-in scale of said target.
16. The method set forth in Claim 13 including: (a) locating said target at a first front horizontal axis cardinal point of said wheel; (b) directing said line of sight at said target at said front cardinal point;
(c) locating said target at a second rear horizontal axis cardinal point of said wheel; and (d) directing said line of sight at said target at said rear cardinal point, thereby checking horizontal front to rear alignment of said wheel.
(c) locating said target at a second rear horizontal axis cardinal point of said wheel; and (d) directing said line of sight at said target at said rear cardinal point, thereby checking horizontal front to rear alignment of said wheel.
17. The method set forth in Claim 16 including: (a) directing said line of sight at a camber scale of said target.
18. The method set in Claim 16 including: (a) positioning said wheel a number of degrees of turn from straight ahead; (b) directing said line of sight to said target at said front and rear cardinal points; (c) measuring the lateral difference between the impingement of said line of sight on said target at said front cardinal point and at said rear cardinal point;
(d) positioning said wheel said number of degrees of turn in an opposite direction of turn from straight ahead; (e) measuring the lateral difference between the impingement of said line of sight in a said target at said front cardinal point and at said rear cardinal point; (f) noting the difference of impingement of said line of sight between the wheel oppositely turned positions.
(d) positioning said wheel said number of degrees of turn in an opposite direction of turn from straight ahead; (e) measuring the lateral difference between the impingement of said line of sight in a said target at said front cardinal point and at said rear cardinal point; (f) noting the difference of impingement of said line of sight between the wheel oppositely turned positions.
19. The method set forth in Claim 18 including: (a) directing said line of sight at a caster scale of said target.
20. The method set forth in Claim 16 including: (a) raising said wheel from contact with a supportive surface; (b) turning said wheel in a first direction of turn from straight ahead; (c) directing said line of sight to said target at said front and rear cardinal points; (d) measuring the difference between the impingement of said line of sight on said target at said front cardinal point and at said rear cardinal point, said difference corresponding to the number of degrees of turn in said first direction of turn of said wheel from straight ahead.
21. The method set forth in Claim 20 including: (a) turning said wheel in a second and opposite direction of turn from straight ahead; (b) direct-ing said line of sight to said target at said front and rear cardinal points; (c) measuring the difference between the impingement of said line of sight on said target at said front cardinal point and at said rear cardinal point, said difference corresponding to the number of degrees of turn in said second direction of turn of said wheel from straight ahead.
22. The method set forth in Claim 21 including: (a) directing said line of sight at a degree of turn and a steering axis cant scale of said target.
23. The method set forth in Claim 21 including: (a) turning said wheel approximately 20 degrees in a first direction of turn from straight ahead;
(b) directing said line of sight to said target at said rear cardinal point; (c) noting a first point of impingement of said line of sight on said steering axis cant scale of said target; (d) turning said wheel approximately 20 degrees in a second direction of turn from straight ahead; (e) directing said line of sight to said target at said rear cardinal point; (f) noting a second point of impingement of said line of sight on said steering axis cant scale of said target; and (g) averaging said first and second points of impingement, the average value between said first and said second points of impingement corresponding to the cant of the vehicle steering axis.
(b) directing said line of sight to said target at said rear cardinal point; (c) noting a first point of impingement of said line of sight on said steering axis cant scale of said target; (d) turning said wheel approximately 20 degrees in a second direction of turn from straight ahead; (e) directing said line of sight to said target at said rear cardinal point; (f) noting a second point of impingement of said line of sight on said steering axis cant scale of said target; and (g) averaging said first and second points of impingement, the average value between said first and said second points of impingement corresponding to the cant of the vehicle steering axis.
24. A method for checking the alignment of the wheels of a wheeled vehicle comprising: (a) establishing a line of sight from a sighting instrument positioned parallel to and laterally spaced from a longitudinal axis of a vehicle; (b) mounting a target structure on a wheel, said target structure spaced longitudinally from and aligned with the sighting instrument and having upper, lower, front and rear targets situated laterally of said wheel and spaced circumferentially of the axle of said wheel; (c) locating said upper target at a first upper vertical axis cardinal point of said wheel; (d) directing said line of sight to impinge on said upper target at said first upper vertical axis cardinal point; (e) locating said lower target at a second lower vertical axis cardinal point of said wheel; (f) directing said line of sight to impinge on said lower target at said second lower vertical axis cardinal point, thereby checking vertical upper to lower camber alignment of said wheel; (g) locating said front target at a first front horizontal axis cardinal point of said wheel; (h) directing said line of sight to impinge on said front target at said first front horizontal axis cardinal point; (i) locating said rear target at a second rear horizontal axis cardinal point of said wheel; and (j) directing said line of sight at rear target at said second rear horizontal axis cardinal point, thereby checking horizontal front to rear toe alignment of said wheel.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US94082378A | 1978-09-08 | 1978-09-08 | |
| US940,823 | 1978-09-08 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1142346A true CA1142346A (en) | 1983-03-08 |
Family
ID=25475484
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000331647A Expired CA1142346A (en) | 1978-09-08 | 1979-07-12 | Line of sight wheel alignment apparatus for vehicles |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1142346A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113548135A (en) * | 2021-07-20 | 2021-10-26 | 安徽江淮汽车集团股份有限公司 | Vehicle Y datum plane positioning device |
-
1979
- 1979-07-12 CA CA000331647A patent/CA1142346A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113548135A (en) * | 2021-07-20 | 2021-10-26 | 安徽江淮汽车集团股份有限公司 | Vehicle Y datum plane positioning device |
| CN113548135B (en) * | 2021-07-20 | 2022-04-15 | 安徽江淮汽车集团股份有限公司 | Vehicle Y datum plane positioning device |
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| MKEX | Expiry |