Abstract: Apparatus is provided for determining the relationship between a vehicle's thrust line and the vehicle's body center line. A movable light source is located externally of and independent of the vehicle and serves to establish a pair of reference light beams falling in parallel planes and which are spaced apart sufficient to permit a vehicle to be positioned longitudinally therebetween. The vehicle's thrust direction is determined by mounting sensors on the nonsteerable wheels so as to extend transversely away from the vehicle's body to intercept the light beams, together with circuitry for providing output indications dependent upon the location of light interception and which indications are representative of the vehicle thrust direction. The body center line is determined by employing targets which are mounted to body sides of the vehicle to intercept reference light beams.

Abstract: A wheel alignment system uses head units attached to each of the four wheels. The front head units contain photodetector arrays which view across the front of the vehicle and to the rear. The rear units carry photodetector arrays which look forward. Each photodetector array views a target on one of the other head units. A microcomputer in each head unit determines an angular value based upon the position of the target image on the photodetector array. The angle values determined by the microcomputers of the individual head units are supplied to a master computer in a main console which determines individual toe angles with respect to a tread centerline for either the front two wheels or for all four wheels. The master computer controls a display at the main console, as well as a remote display to guide the mechanic in making alignment adjustments.

Abstract: A selectible beam/plane projecting laser is particularly useful for vehicle frame and body alignment. A lens contained in a holder mechanism mounted on a laser projector housing flips into and out of the laser beam path and when in the path, changes the beam to a plane. When used for vehicle frame and body alignment, the plane of the laser generated light allows the operator to spot targets any place in the plane of light and makes easier determination of alignment conditions.

Abstract: An arrangement for mounting measuring devices of axle measurement equipment with a fastening plate that is adapted to be installed at the vehicle wheel aligned parallel to a flat reference surface of the vehicle axle by means of abutment pins extending through the wheel disk by way of through-openings. An incorrect alignment of the plane of the fastening plate which causes an incorrect adjustment of camber, toe-in or caster, is avoided with a completely satisfactory abutment of all abutment pins at the reference surface.

Abstract: An apparatus and method is disclosed which utilizes modified wheel aligner heads and which accomplishes measurement of individual wheel toe on a vehicle having a pair of non-steerable rear wheels and a pair of steerable front wheels. The apparatus and method provides measurement of a steering or a rolling direction for the front and the rear wheel pair as a result of optical measurements taken relating the orientation of the planes of the wheels to the centerline of the vehicle chassis. Once the steering direction of the front wheels is obtained, individual toe measurements for the front wheels may be made relative to the chassis centerline. Alternatively, once the steering or average rolling direction of the rear wheels is obtained individual toe measurements for the rear wheels may be made relative to the chassis centerline and individual toe measurements for the front wheels may be made relative to the rear wheel rolling direction.

Abstract: A wheel alignment process using manually operable alignment apparatus wherein all four wheels of a vehicle having a front steerable wheel pair and a rear nonsteerable wheel pair may be set in toe without turning the vehicle around part way through the process. The process provides for setting both front and rear toe relative to the chassis centerline in one aspect of the disclosure and for setting rear toe as close as practical to the chassis centerline and the front toe relative to the rear wheel rolling direction in another aspect of the disclosure. A lock is also disclosed which assures stability of the reference for the front and rear toe settings during the practice of the toe setting process.

Abstract: The invention relates to measuring apparatus and its use, primarily for checking vehicle wheels, and more specifically the alignment of the rotational axes thereof. Two wheels, opposite each other on a vehicle, are provided with projecting stub axles which are disposed accurately coaxial with the respective wheel. The measuring apparatus comprises a scale unit (40) which is mounted on the axle of one of the wheels by means of a locating and fastening means (46, 48) so as to project at right angles therefrom and carrying a movable rider (50) with a scale (55), and a light beam unit (60) preferably comprising a laser (65) and disposed for mounting on the axle of the other wheel, by means of a locating and fastening means (66, 67), to send a light beam (33) onto the scale (55) carried by the movable rider (50) which is locked in an initial position.

Abstract: This apparatus comprises, in combination, two similar devices disposed in opposite directions. The devices are adapted to be fixed respectively to the two opposite wheels of a vehicle and parallel to the latter. Each device comprises a first rigid hollow tubular bar and a fixing structure for fixing the bar to a projector carrier. A structure inside the bar projects a beam of light longitudinally inside the bar. The beam is reflected at one end of the bar by a mirror which is rigid with a screen and so disposed as to project the beam transversely toward the screen pertaining to the opposite device. The mirror is mounted on the first bar of at least one of the devices so as to be movable toward or away from the fixing structure. A structure for receiving a sub-assembly for inspecting the pivot and castor angles of the vehicle wheel is provided. An apparatus for measuring the camber angle of the vehicle wheel is also provided.

Abstract: Apparatus for aligning vehicle front and rear wheels and a method of applying such apparatus in which projectors of light beams on the front wheels direct beams forwardly to a cooperating alignment stand and direct beams rearwardly to cooperate with devices on the rear wheels which include scales and reflective surfaces used in aligning the front wheels and determining the positions of the rear wheels relative to the vehicle longitudinal axis or geometric center line. The projectors on the front wheels support screens in positions to cooperate with the light beams when reflected back from the stand and from the rear wheels.

Abstract: A projector is disclosed which is constructed as an integral part of a wheel alignment head for use in an alignment system for the wheels supporting a vehicle chassis. The projector causes a beam to be emitted from the "back" of the alignment head toward the supporting wheels at the opposite end of the chassis. The projector is configured so that the direction of the projected beam relative to a reference direction may be adjusted within about plus or minus 5.degree. of arc by turning a manually accessible adjustment knob. The adjustment knob also causes a corresponding adjustment to a signal generator so that a signal output is obtained therefrom which is indicative of the angular departure of the beam from the referenced direction.

Abstract: Apparatus and method are disclosed by which toe is measured relative to a vehicle centerline or a nonsteerable wheel rolling direction for all four wheels on a vehicle having a pair of front steerable wheels and a pair of rear nonsteerable wheels. An alignment head is placed on one of the front wheels and another alignment head is placed on one of the rear wheels, both wheels being on the same side of the vehicle. The alignment heads project a beam pattern across the vehicle at the front and the rear. Reflectors are mounted on the other wheels at the front and the rear to intercept and reflect the beams back toward detectors included in the alignment heads. A beam pattern is also projected rearwardly along the length of the vehicle chassis from the alignment head mounted on the front wheel. A rear wheel mounted reflector intercepts the rearwardly projected beam pattern and reflects it back toward a detector in the front wheel mounted alignment head.

Abstract: Apparatus for guiding the alignment adjustment on vehicle wheels in which a computer is used to receive vehicle alignment specifications and tolerances data for a known vehicle, and to receive actual alignment information from that known vehicle, these two sources of alignment data being conditioned such that on recall it can be displayed in visual format or through a system of light bars which are driven by the computer to display only differences between the known vehicle specifications and tolerance data and the actual alignment data. The display of alignment data and actual data is made available on a CRT screen, as well as being transmitted to a portable display for movement about a vehicle during alignment adjustment.

Abstract: Four alignment housings are mounted on a garage floor adjacent a conventional lift, so that when a vehicle has been elevated by the lift each of its four independently suspended four wheels will register with an alignment chart that is adjustably mounted on the face of each housing. A beam of light is directed through registering openings in each housing and its attached chart toward a mirror releasably mounted on each vehicle wheel. The mirrors reflect the beams back onto the associated charts, which are calibrated to provide camber, caster and toe-in readings. In one embodiment each housing contains a light source (for example a laser) which directs a beam onto a reflecting surface which is inclined at 45.degree. to the horizontal, so that it projects the beam at right angles out of the housing toward the adjacent wheel.

Abstract: An electronic aligner head is mounted on one rear wheel of a vehicle. The aligner head projects a light beam toward the front wheel on the same side of the vehicle. A centering gage is adapted to contact lower points on the inner flanges of each of the rear wheel rims. A lateral arm is connected to a housing on the centering gage. The lateral arm extends past the one rear wheel and carries a centering gage head on the free end. The arm is adjustable in length to place the centering gage head at the same lateral distance from the chassis centerline as the light beam projector. The centering gage is removed from the position between the rear wheel rims and placed in a similar position between the front wheel rims. The centering gage head is configured to either reflect the beam back to a light beam detector on the aligner head or alternatively to direct the beam to a detector in the gage head. The detector provides a signal indicative of the toe of the one rear wheel.

Abstract: The method for diagnosing vehicle wheel alignment characteristics in which the longitudinally spaced steerable and non-steerable wheels are equipped with means for permitting the practice of displaying the alignment characteristics of the planes of rotation of the steerable wheels in relation to the geometric center line and the thrust line effect of the non-steerable wheels on the steerable wheels, in combination with the steps of adjusting the plane of rotation of the non-steerable wheels for bringing the thrust line effect thereof into substantial tracking relation with the geometric center line of the vehicle, and monitoring the effect of the adjustment imparted to the non-steerable wheels.

Abstract: A target structure for use with an alignment apparatus, such as a line of sight alignment apparatus for detecting the alignment of wheels of vehicles such as automobiles, truck tractors and trailers comprises an adjustable, wheel engaging and target supporting structure mountable upon a vehicle wheel rim. The target structure has an inner wheel mounting member with upper and lower arm members extending therefrom and engageable with the vehicle wheel rim. An outer target mounting member is pivotally connected to the inner wheel mounting member through coaxial center portions thereof for relative rotation of the outer target mounting member relative to the inner wheel mounting member. The outer target mounting member has spaced shaft members extended outwardly of the wheel and holding a plurality of targets at cardinal points around the wheel, the targets providing scales for determining the angular position of the vehicle wheels for conventional measurements such as caster, camber, toe and kingpin inclination.

Abstract: An apparatus for detecting the alignment of the wheels of vehicles such as automobiles, truck tractors and trailers, 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 correspond to alignment measurements.

Abstract: This mechanism includes a housing having three, equi-angular spaced, radially projecting arms which carry pivotal hook members that are releasably engagable with the rim of a wheel to secure the housing on the wheel for rotation therewith. Each hook member is adjustable longitudinally of its associated arm so that the mechanism can be mounted on wheels of various diameters. A circular casing, which is mounted on the housing normally to rotate therewith, carries an adjustable mirror having on its rear face a triangular plate held resiliently against a plane surface on said casing. A plurality of adjusting screws on the casing are engagable with the mirror to tilt it selectively about any one of the three edges of the triangular plate to position the mirror's reflecting surface in a plane normal to the axis of the rotation of the wheel. The casing can be rotated manually relative to the housing to adjust the tilting edges of the plate.

Abstract: An alignment checking and measuring apparatus for vehicle frame and body portions includes two or more measurement scale carriers which have connectors on opposite end portions thereof for attachment transversely to the vehicle. One of the measurement scale carriers has targets movably mounted on the end portions and another of the measurement scale carriers has sighting instruments, such as laser beam emitting instruments, mounted on the end portions. The measurement scale carriers are longitudinally spaced from each other. Longitudinally aligning the sighting instruments with the targets facilitates determination and correction of any damaged or misalignment condition in the vehicle frame and body. Comparison is made of the deviation, if any, in the parallelism of the lines of sight created by the longitudinally aligned targets and sighting instruments. Angular deviation of the lines of sight to symmetrical points on the vehicle frame and body tends to indicate damage or misaligned conditions.

Abstract: Apparatus for determining the alignment characteristics of vehicle wheels in which electronic signal generators are coupled to each of the vehicle wheels and is so arranged that wheel position signals are produced in terms of angular relationship to a line of sight from another wheel of the vehicle, and are fed into a computer where calculations are performed to develop results related to a known reference axis of the vehicle and capable of being displayed. The preferred apparatus employs transducers in which signals substantially free of surrounding noise are easily produced and of such as to be readily processed for display.

Abstract: A laser beam emitter is placed at the level of each front wheel and a first laser beam is projected transversely in front of the vehicle onto a first receiver placed in front of the other front wheel. A second laser beam emerging from the same emitter is projected onto a reflecting mirror placed at the level of the corresponding rear wheel and the reflected laser beam is transmitted to a second receiver. The different distances read on the receivers are transmitted to the memory of an electronic computer which automatically determines the values of the angles of toe-in and toe-out of the front or rear wheels as well as the set-back or relative axial displacement between the front wheels.

Abstract: There is described an instrument and method for adjusting toe relative to the tracking axis of the vehicle by initially measuring the toe angles of the two front or rear wheels relative to the planes of the other two wheels on the same respective sides of the vehicle, and then adjusting the toe angles by one-half the difference between the initially measured angles.

Abstract: Vehicle wheel alignment apparatus having active alignment determining means operatively mounted on the steerable and non-steerable wheels so as to be substantially insensitive to mechanical distortion of the vehicle wheels and operable in combination with wheel run out compensation means to produce wheel alignment results of improved accuracy, and utilizing the improved arrangement of alignment apparatus for supplying information which can be used for computing the important angular relationship of the wheels to a vehicle reference.

Abstract: Apparatus for measuring the road wheel hub alignment of a vehicle on its production line includes a pair of electro-optical units for attachment to a pair of road wheel hubs and a master control and display unit. The electro-optical units each comprise an array of photo-sensitive devices which are illuminated by a directional beam of light from the other unit, and include a display for indicating to an operator the state of alignment of the hub to which the unit is attached. Alignment of both hubs can be monitored by a display on the master control unit, which includes an output to a data recording means so that the state of alignment of the hubs on each vehicle passing down the line can be automatically recorded. The photo-sensitive devices are arranged in a radial plane of the axis about which the hubs swivel for adjustment, and in a plane perpendicular to the axis of rotation of the road wheels to enable simultaneous independent adjustment of the hubs.

Abstract: Apparatus for compensation of vehicle wheel alignment measurements in which plano-reflective means mounted on certain wheels cooperate with radiant energy projector means mounted on other wheels to have radiant energy sensor means carried thereby in position to pick up the radiant energy returned from the plano-reflective means, such that alignment compensation of the first mentioned wheels may be measured including compensation for the lateral or wobble run-out. The apparatus is also capable of compensating camber measurement of the first mentioned wheels with the aid of camber measuring means associated with the support for the plano-reflective means.

Abstract: Apparatus utilizing solid state electronic components embodying circuit varifying means in the form of lights which provide a quick indication of the operability of important circuits contained in the electronic vehicle wheel alignment equipment, and indicate which of several circuits is functional, so that service persons operating the alignment apparatus are able, upon visual inspection of the console panel, to determine whether the instruments on the vehicle are functioning properly to produce the needed alignment information.

Abstract: Apparatus comprising active alignment sensors mounted on the steerable wheel of a vehicle to follow the plane of rotation of these wheels, cooperating passive alignment means positionable selectively on the non-steerable wheels and on the adjacent vehicle body in view of the active sensors, and associated electronic equipment assembled in a console and responsive to signals generated by the active sensors for displaying alignment characteristics important to achieve motion balance in the vehicle for proper rolling response of the wheels and directional attitude of the vehicle body with steering wheel center-point position.

Abstract: The system of the present invention provides means for quick and accurate measurement of various wheel alignment parameters of motor vehicles by the use of reflected light beams. A laser source mounted near the front end of the vehicle provides a pair of light beams directed 180 degrees apart across the front end of the vehicle. Each of the beams is reflected along the side of the vehicle by a roof mirror set mounted near each front corner of the vehicle. The mirror sets each deflect a beam through a constant net angle of 90 degrees for a wide range of angles of incident light so that the laser source can be rotated to quickly provide parallel beams which are aligned substantially parallel to the sides of the vehicle. These mirror sets also provide stable beams and present small movements thereof from affecting the accuracy of the measurements being made.

Abstract: A system for diagnosing the alignment characteristics of the wheels on a vehicle so that the planes of rotation of the wheels may be determined in relation to each other and with respect to the effect the wheels have on the attitude of the vehicle body while in motion. The system is made up of several instruments which develop signals which can be processed through electronic computation means capable of performing the necessary processing steps rapidly, with a high degree of accuracy and to a state in which the information can be displayed as soon as it is developed, stored for subsequent use, or transposed into a print-out.

Abstract: A mirror is mounted in the open end of a circular housing by means of a universal joint formed by a stud which projects from the rear of the mirror into a spherically-shaped knuckle joint that is seated at diametrally opposite sides in a pair of "Teflon" ring bearings carried by two plates that are held over opposite sides of the knuckle by a pair of adjusting screws which can be selectively tightened or loosened to control the resistance to movement of the mirror universally about the center of the joint. The housing is releasably attachable to the hub cap of a front wheel by a plurality of clamps adjustably mounted on arms which project radially from the housing.

Abstract: An apparatus and method for measuring the angle between two members is disclosed. A wheel aligner has a projector mounted on each front wheel of the vehicle to project a beam toward the other projector. Each projector has a detector to sense the presence of a beam from the opposite projector. Each projector has a plurality of light sources to project a plurality of beams, one at a time, in a diverging pattern. Circuitry is provided to identify the beam which is detected, at any angle of toe of the wheel, to thereby give the angle of toe.

Abstract: An optical toe gauge for measuring the toe-in and toe-out of vehicle wheels includes a pair of support arms respectively mounted from the wheel hubs and carrying light beam projector assemblies at the forward ends thereof so that the direction of each beam is dependent upon the toe of the associated wheel. Each arm also carries therebelow a screen on which is projected the beam from the opposite projector, each screen being disposed at approximately a 45.degree. angle to the corresponding wheel axis and facing inwardly between the wheels, each screen having toe increment lines thereon with enlarged spacing therebetween to facilitate reading of the toe measurement on the screen.

Abstract: A adaptor for mounting a wheel alignment instrument on a wheel has a frame provided with a slideway and a slide assembly on the slideway of the frame. Both the frame and the slide assembly have gripping elements that are capable of bearing against and gripping axially directed surfaces on the wheel rim. Once the adaptor is positioned on the wheel rim with its gripping elements located along an axially directed surface, one of two actuating elements on the slide assembly is turned. The one actuating element causes the slide assembly to grip the slideway and then move outwardly so that the gripping elements firmly grip an inwardly presented surface, such as the inside face of a rim flange. The other actuating element causes the slide assembly to grip the slideway and then move inwardly so that the gripping elements firmly grip an outwardly presented surface, such as the outside face of a rim flange.

Abstract: A wheel alignment measuring system for measuring front wheel toe including a laser beam light projector mounted on a front wheel of a motor vehicle which projects a beam of light onto a pivotally mounted front mirror on the projector which oscillates back and forth through a ten degree angle about a reference line. The beam of light reflected from the oscillating mirror swings ten degrees on either side of a central reference beam line, and during its swing the beam strikes a fixed roof mirror mounted on the opposite front wheel of the vehicle. The thus reflected beam sweeps back and forth across the light projector and is successively intercepted by each of a pair of closely spaced photocells on the light projector, the cells being equally spaced on opposite sides of the reference beam line. The cells develop signals when they intercept the light beam which signals control and up/down counter through a flip-flop.

Abstract: A light projector mounted on a front wheel of a vehicle uses a single laser to develop a beam which is split into a pair of light beams. The first light beam is projected to a calibrated mirror mounted on an adjacent rear wheel and is reflected to a target mounted near the projector on the front wheel of the vehicle so that the front wheel may be aligned with the rear wheel. The second light beam is projected to a mirror mounted on the other front wheel and is reflected to a target mounted adjacent the projector to check the toe of the front wheels. The target comprises a multichannel encoder which develops a plurality of Gray-coded binary signals in response to the position of the return beam. A rotating prism causes the light beams to sweep repetitively in a vertical plane so that the beams will strike the mirrors and the targets even when the projector is not mounted in a level position.

Abstract: An improved method and apparatus for aligning the front wheels of a motor vehicle utilizing a beam projector and detector assembly on each wheel and an electronic computing means for determining the toe angles of the wheels in response to measured toe signals generated by the detectors. The computing means first subtracts one of the toe signals from the other, multiplies the difference by a selected correction factor to produce a correction signal, and then adds the correction signal to the larger of the measured toe signals and subtracts the correction signal from the smaller one to provide the true individual toe angles of the wheels. The signals derived by the computing means are applied to display devices which read out the correct values of the right and left toe angles. Although the correction factor is dependent on the dimensions of the frame of the vehicle, the steering suspension, and the mounting of the projector and detector assembly, it has been found that a correction factor of approximately 0.

Abstract: Two rectangular housings are mounted in a pair of spaced recesses in a garage floor to have cover means thereon moved to closed positions flush with the floor surface. Mounted in one end of each housing beneath a first cover is a rotatable wheel-supporting pad, which is slidable longitudinally of the housing, and is reciprocable vertically by a pneumatically operated scissors jack. Each housing has pivoted on its opposite end a second cover which carries on its inside surface a laser, a mirror, and a conventional alignment chart for denoting toe in, toe out, camber, etc., all of which items are disposed within one section of the housing when the pivotal cover is closed. When the pivotal covers are swung to upright positions, each laser directs a beam of light upwardly onto the associated mirror, which is inclined at 45.degree. to the vertical, so that the mirrors direct their beams horizontally through an aperture in the center of the associated chart and coaxially toward one another.

Abstract: An optical assembly is provided which comprises a light source, preferably a laser, and a particularly compensated prism unit, the laser and the prism unit being mounted on a common holder or base. The beam emitted from the laser is reflected 90.degree. by the prism unit, and although this unit is only approximately aligned with the laser the reflected beam will always form a right angle to the incident beam with an extreme accuracy, the deviation from 90.degree. being less than half an angular minute. The accuracy in reflexion independently of prism unit setting is attributed to the compensated prism unit, which comprises a quadrangular prism composed of two semi-quadrangular prisms, a reflecting surface being mounted, preferably in an adjustable position, adjacent one side of the prism.

Abstract: A wheel mirror calibrating device for checking and aligning mirrors used on motor vehicle wheel alignment equipment. The device comprises a portable unit comprising support and level members to align a rotatable horizontal shaft which supports a truncated triangular mirror support frame. The mirror support frame supports the wheel alignment mirror in the same manner as the rim of the wheel which would be aligned with the equipment. The frame has calibrated adjustment push screws for alignment of the mirror support pads to the zero position. An image is projected onto the mirror and reflected to a projection screen such that as the mirror is rotated the image must remain in the same position or the mirror needs alignment. Each mirror is individually adjustable by three screws on the back thereof for alignment of the mirror.

Abstract: An electro-optical apparatus for determining, during caster angle measurement procedures, when the front wheels of a vehicle have been turned into a first desired steering position oriented in one rotative direction from a "straight-ahead" position and have thereafter been turned to a second desired steering position oriented in the opposite rotative direction from the "straight-ahead" position. A multiple light beam projector and a photosensitive detector are mounted to a front wheel of the vehicle for rotation therewith, and a reflector is mounted to the rear wheel of the vehicle which is on the same side of the vehicle as the projector and detector. The projector rearwardly projects three directional beam patterns with each pattern consisting of sequentially emitted discrete beams which are projected at unique angles with respect to the plane of the front wheel.

Abstract: This invention relates generally to wheel alignment devices, and specifically to such a device in which accurate toe can be established even if the angular relationship of the device to a reference line, such as the horizontal, changes during the toeing procedure.

Abstract: An electro-optical wheel alignment system for vehicles includes a coaxially disposed radiant energy source and detector in which the source and detector are axially spaced apart and the source is physically small and provides a modulated output. The source and detector are adjustably disposed on the component of an automobile to be positioned in a predetermined attitude with respect to a reference device that is, in turn, positioned in a predetermined attitude with respect to the vehicle, such device comprising a radiant energy reflecting planar surface.

Abstract: An apparatus for measuring caster and camber in a motor vehicle including a mirror which is mountable on the respective hubs of the vehicle wheels and the normal to which is directed parallel to the wheel axles of the vehicles. A projector is disposed opposite the mirror and a projection surface is provided including a plurality of light-sensitive detectors for detecting images of horizontally-vertically oriented shutters disposed in the ray path of the projector reflected by the mirror. The improvement of the invention comprises the shutters comprising measuring edges of rotatable arms disposed in an object plane of the projector. The angles or rotation of the arms between a reference position and a position of the arms at which an image of one of the measuring edges reflected by the mirror onto at least one detector are used to measure the caster and camber angles of the wheels of the vehicle.

Abstract: A light projector mounted on a front wheel of a vehicle provides a pair of light beams. The first light beam is projected to a roof mirror mounted on an adjacent rear wheel and is reflected to a first target mounted with the projector on the front wheel of the vehicle. The toe angle of the front wheel relative to the axis of rotation of the rear wheel of said vehicle is calculated from signals which are developed by said first target. The second light beam is projected to a mirror mounted on the other front wheel and is reflected to a second target mounted adjacent to the projector to determine the total toe angle between the front wheels. The difference between the total toe angle and the measured individual toe angle of the front wheel upon which the projector is mounted is calculated to provide the individual toe angle of the other front wheel relative to said axis of rotation of the rear wheel of the vehicle.

Abstract: An apparatus and method for measuring toe in vehicle wheels. The apparatus ordinarily includes a pair of head units. Each of the head units is mounted upon one of the front wheels of the vehicle. Each head unit includes a projecting element for projecting a light beam generally laterally across the front of the vehicle and onto a target on the opposite head unit in determining front toe of the respective front wheels. Each head unit can also project a beam generally axially from the front wheel of the vehicle to a reflector on the adjacent rear wheel for determination of rear toe of the respective rear wheels. A metering device is connected operatively to signal generators on the head units for determining the toe in each front wheel in relation to a thrust-line reference calculated from the total rear toe of the vehicle.

Abstract: Wheel alignment apparatus for electrically indicating the alignment condition of a vehicle wheel in which there is sensing means, including an element adapted to be detachably secured to the wheel, for producing an electrical output dependent upon the extent of inclination of the wheel and an electrical display device having a movable member positioned in accordance with the electrical output of the sensing means. The sensing means is designed to selectively detect toe-in, camber, and caster.

Abstract: An optical wheel alignment instrument employs a pair of light weight units each housing a light source and optics including an adjustable mirror for directing a reticle image on a target screen of the other unit, and magnetic devices extend from the approximate centers of gravity of the units for mounting thereof to the hubs of the wheels to be aligned.

Abstract: To test the alignment of the front wheels of an automotive vehicle, the front wheels of the vehicle are driven onto a pair of spaced, parallel rollers, one of which is driven to effect rotation of the front wheels while the vehicle is standing motionless. The hubcaps are removed and a plane mirror is secured by a magnet to the hub of each front wheel. A laser beam is shone onto each mirror through a central hole in a chart. Means is provided for adjusting the the mirror angularly to tilt its plane relative to the axis of the associated spindle of the vehicle. Each mirror can be adjusted so that its plane is perfectly perpendicular to the axis of the spindle. Then the wheels can be accurately tested for toe, run-out and camber.

Abstract: A radiation sensor for determining a direction, relative to the sensor, in which a radiation source is located. A plurality of elongated radiation detectors are located in a base plane of the sensor. In a plane, disposed before the base plane of the sensor, slits, associated with each radiation detector, are positioned at an angle with respect to direction of elongation of the associated radiation detector. The slits provide planes of radiation which intersect each elongated radiation detector. A coordinate of the intersection of the radiation with the detector is provided by output signals from the detector. The coordinates of the intersection of the radiation with the elongated detectors can determine the location of the radiation source when more than two radiation detectors (of which two are non-parallel) are utilized, or a direction of the radiation source when two non-parallel radiation detectors are utilized.