IE42023B1

IE42023B1 - Wheel allignment measuring apparatus

Info

Publication number: IE42023B1
Application number: IE225575A
Authority: IE
Original assignee: Dunlop Ltd
Priority date: 1974-10-23
Filing date: 1975-10-16
Publication date: 1980-05-21
Also published as: NL7512368A; IT1044589B; AU8593575A; GB1526727A; FR2289885A1; BE834688A; DE2547564A1; IE42023L; FR2289885B1; DK476075A; AU507169B2; LU73630A1

Abstract

1526727 Vehicle wheel alignment apparatus DUNLOP Ltd 16 Oct 1975 [23 Oct 1974] 45790/74 Heading G1X An alignment measuring unit 10 comprises a support positionable in alignment with a wheel, an alignment sensing means and a locating means which selectively locates the sensing means in either of at least two positions relative to the support. A support tube 11, mounted on feet 12, carries adjustable probes 16 for contacting the wheel, and a mirror 17 lying in a vertical plane and rotatable about a spindle 19. A plate or cam 21, mounted for rotation with the mirror about the spindle 19, has two recesses 23 spaced 90 degrees apart about the spindle; the recesses are engaged by detent 29 of a spring loaded arm 24 to locate the mirror in positions either parallel or perpendicular to the tube 11. The unit is used with a complementary unit Fig. 4 (not shown) comprising a similar support tube, feet and probes but having a viewpiece (42) and a scale instead of the mirror. In use, to measure alignment of wheels on opposite sides of a vehicle, the mirror is set parallel to the tube 11, each unit is aligned with a respective wheel and the viewpiece is rotated until its sighting mark (44) coincides the image thereof seen in the mirror; for measurement of wheels on one side of the vehicle the mirror is set perpendicular to the tube 11 and the unit is aligned successively with the two wheels, readings being taken with the complementary unit positioned perpendicularly to the sides of the vehicle. Instead of the recessed plate 21, interfitting profiled plates Figs. 7-9 (not shown) can be used to locate the mirror. Alternatively or additionally to the mirror being mounted for location in two positions, the viewpiece may be similarly mounted.

Description

This invention relates to improved apparatus for use in measuring the alignment of two wheels and in particular to alignment measuring units suitable for measuring the alignment of two vehicle wheels located either on opposite sides or on a common side of a vehicle.

It hes been proposed hitherto to measure the alignment of two vehicle wheels located one each on opposite t sides of a vehicle by the use of two alignment measuring units each alignable with one of the pair of wheels. A first of said units has a vertical mirror secured thereto, and the second of said units has an optical view-piece pivoted thereon about a vertical axis, means being provided for indicating angular movement of the optical view-piece about said axis when the view-piece is pivoted to a position aueh that a sighting mark carried by the view-piece is reflected by the mirror back to the view-piece in alignment with a datum mark provided thereon.

When it is desired to measure the alignment of wheels on the same side of a vehicle it has been necessary for the mirror on the first unit to be able to reflect light in a direction parallel to the length of the vehicle, the second unit being free standing, i.e. away from the vehicle wheels, and aligned substantially perpendicular to the length of the vehicle. The second unit then acts as a reference relative to which the orientation of two wheels may be measured by successively positioning the first unit in alignment with the wheels, and the difference between the alignment readings obtained on the second unit for the first unit in said two 2.

Successive positions being the alignment measurement of the two vehicle wheels relative to one another. Adaptation of the apparatus described in the above paragraph has therefore been necessary and has been accomplished by removing the mirror from the first unit, securing a tubular tee piece adaptor to the first unit, and then securing the mirror to the tee piece adaptor.

According to the present invention an alignment measuring unit for measurement of wheel alignment comprises a support member for positioning in alignment with a wheel, a sensing component, and locating means comprising a recessed part to enable the sensing component to be selectively located relative to the support member in one of at least two positions determined by the locating means.

Preferahly retaining means is provided to retain the sensing component within predetermined limits of movement relative to the support member whilst the sensing component is moved between said at least two positions.

The locating means may comprise said retaining means, or the retaining means may be substantially independent of the locating means, and the locating means and/or retaining means may serve to clamp the sensing component relative to the support member.

Likewise, the retaining means may be integral with or independent of either the support member or the sensing component. Preferably the sensing component is pivotally mounted on the support member so that it may be rotated about a known axis when being moved between said at least two positions.

Particularly when the sensing component is pivotally mounted, the locating means may comprise a cam formed with at least two recesses at positions related to said at least two positions at which the sensing component is to be selectively locatable relative to the support member, and a locating arm provided with a detent for engaging with the cam recesses, the cam and arm attached one each to either the support member or the sensing component. Preferably the arm and cam are spring-loaded relative to one another so that the detent may be firmly retained in position'in one of the cam recesses.

As one alternative to the use of a cam and arm, the locating means may comprise a profiled block and a eomplementarily-shaped cap member selectively locatable relative to the block in two or more positions predetermined by the shape of the block. The block may be of symmetrical or non-symmetrical shape.

The sensing component may serve as receiving, transmitting or reflecting means. The sensing component may be light receiving means such as a mirror, a view-piece, or an optical lens, or may be means for receiving, reflecting, or transmitting other forms of electromagnetic waves such as ultraviolet or infra-red frequency electromagnetic waves, or other waves such as sound waves.

The apparatus may be used for measuring the 4. alignment of two or more vehicle wheels and particularly when intended for this use the support member may be so formed as to be locatable in a stable position on a substantially horizontal surface. The sensing component may be mounted to be rotatable about an axis which preferably extends vertically' though optionally it may be rotatable about an axis angled relative to the vertical axis and the horizontal plane.

The invention also provides a wheel alignment measuring apparatus comprising two wheel alignment measuring unite at least one of which is a unit in accordance with the present invention.

Three embodiments of the invention will now be described by way of example, with reference to the accompanying drawings, in which: FIGURE 1 is a plan view of the first unit of a measuring apparatus in accordance with the present invention; FIGURE 2 is a side elevationview of the first unit shown in Figure 1; FIGURE 3 is an end view of the first unit shown in Figure 1; FIGURE 4 is a plan view of a second unit of the apparatus in accordance with the present invention; FIGURE 5 is a side elevation view of the second unit shown in Figure 4; FIGURE 6 is an end view of the second unit shown in.

Figure 4; .

FIGURE 7 is a perspective view of the locating block of locating means of another measuring apparatus in accordance with the present invention; FIGURE 8 is a sectional view of locating means incorporating the locating block shown in Figure 7, and FIGURE 9 is a perspective view of the locating block of yet another measuring apparatus in accordance with the present invention.

In a first embodiment of the invention, illustrated in Figures 1-6, an optical vehicle wheel alignment measuring· apparatus comprises two separate alignment measuring units 10 each comprising a robust tubular support rod 11 maintained above ground level in a stable position and in a substantially horizontal plane by means of support feet 12. Two identical support arms 13, 14 are mounted on each support rod 11 and are maintained in spaced relationship by a straight spacing bar 15. In combination with the support rod 11 the spacing bar 15 serves to ensure that the two arms 13, 14 are constrained to lie in a common plane parallel with the length of the support rod. Two identical probe members 16 are mounted on each of the support arms and are adjustable in spacing and height from the ground by means of horizontal spaced apart slots in the arms 13, 14 and locking nuts so as to be capable of contacting a tyre or wheel at the required spaced positions e.g. on the tyre mid-sidewall or wheel rim flange.

A first of the units, shown in Figures 1 to 3, is 6. provided with a mirror 17 which is supported by the support rod 11 to lie in a substantially vertical plane. The mirror is secured to a backing frame 18 provided with a spindle 19 by which the frame is pivotally mounted on a carriage 20 itself slidably and rotatably mounted on the support rod 11. The backing frame is also provided with a mirror guard frame a.. The backing frame has arm portions 18b extending around the support carriage 20 in the form of a fork and thereby serves as retaining means to restrict movement of the mirror relative to the support carriage 20 in the direction of the length of the epindle and prevent separation of the mirror and support rod 11. A cam in the form of a quadrant plate is secured to the support carriage 20 with its centre of curvature in tiie apex region 22 lying coincident with the axis of the spindle 19. Two recesses 23 are formed in the curved outer surface of the quadrant plate at positions which subtend an angle of 90° at the centre of curvature of the plate. A locking arm 24 is pivotally secured about a spindle 25 attached to the mirror backing plate 18 and lies in the same plane as the quadrant plate 21. The locking arm is spring-loaded by means of a leaf spring 26 which reacts against a stop 27 provided on the backing plate, and is formed with a detent portion 29 which is urged against the quadrant plate 21 and held in position in one of the two recesses 23 under the action of the spring. An outer portion 30 of the locking arm serves as a small handle to which finger pressure may be applied to lift the detent clear of a recess against the action of the spring pressure and enable the mirror to be rotated through 90°.

The second measuring unit, illustrated in Figures to 6 of the accompanying drawings, has slidably and rotatably mounted on the support arm 11 thereof a support carriage 40 formed with an arm portion 41 extending longitudinally in the direction of the length of the support rod 11. An optical view-piece 42 is pivotally mounted about a spindle 43 on the carriage 41 and comprises a sighting mark 44, inclined mirror 45, datum mark (not shown), and an optical eye piece 46, In addition the optical view-piece is provided with a pointer arm 47 secured thereto and having at its end furthest from the spindle 43 a combined reference line and magnifying glass 48 which lies over a scale 49 secured to the end of the carriage arm 41, in use of the apparatus to measure the alignment of two vehicle wheels disposed one each on opposite sides of a vehicle the probes 16 of the two alignment measuring units are set at the required spacing and height, in particular, for example, that appropriate for the measurement of the toe-in angle of the pair of wheels, and the two units are then positioned in alignment with the respective wheels.

With the mirror 17 lying parallel with the length of the. support rod 11 of the first uhit, and substantially opposite the optical view-piece of the second unit, the optical view25 piece is rotated about its spindle 43 so that the sighting mark as reflected in the mirror 17 appears through the eyepiece 46 to be in alignment with the datum mark of the viewt piece. The alignment of two wheels may thenbe measured on 8. the scale 49.

When it is desired to measure the alignment of two wheels lying on the same side of a vehicle the first unit is converted by operation of the locating arm 24 as described above to rotate the mirror 17 through an angle of 90°. The second unit is then positioned to lie with its support arm 11 in a direction substantially perpendicular to the length of the vehicle and with the first unit in alignment with one of the vehicle wheels a reading is taken on the scale 49.

The first unit is then brought into alignment with a second of the vehicle wheels and a further reading taken on the scale 49. As described earlier the difference between the two readings on the scale 49 is a measure of the alignment of the two wheels.

• In a second embodiment of the invention, illustrated in Figures 7 and 8 of the accompanying drawings, first and second measuring units are constructed substantially as described in respect of the first embodiment of the invention except that the locating means provided in the first embodiment of the invention by the cam and spring-loaded locating arm are replaced by a locating block 60 of cruciform cross-sectional shape and tapered along its length, and a cap member 61 of complementary shape to that of the block 60.

.The block 60 is mounted on a support arm carriage (not shown) and a cap member 61 is secured to the backing member of a mirror carried by the first unit. A rod 52 screw-threaded in position on the block 60 extends centrally and axially therefrom and serves as a spindle about which the cap member 9. may be rotated when being moved between positions at right angles to one another. An upper portion 63 of the rod 62 is screw-threaded and carries a wing nut 64 which may be screwed downwards to securely clamp the cap member 61 against the block 60. A head portion 65 is formed at the end of the screwed portion 63 and limits upward movement of the wing nut 64 so that the cap member is retained within a predetermined range of movement relative to the block 60.

To adjust the position of a mirror carried by the cap member the wing hut is unscrewed upwards against the head portion 65, the cap member lifted upwards with its upper surface against the wing nut and then rotated through 90° and lowered onto the shaped block. The wing nut 64 is then screwed downwards to clamp the cap member and block firmly relative to one another.

In a third embodiment of the invention, illustrated in Figure 9 of the accompanying drawings, first and second measuring units are again constructed substantially as described in respect of the first embodiment of the invention except that the locating means is provided by a profiled plate 70. The plate 70 is formed with four symmetrically disposed and radially extending ribs 71 which may he engaged by a complementarily shaped cap member (not shown) in a similar manner to that described above in respect of the second embodiment of the invention. The plate 70 is formed centrally with an aperture 72 through which a spindle may extend to act as a pivot for the cap member.

The provision of a mirror which is readily movable . between predetermined positions reduces the time taken to convert alignment measuring apparatus from being suitable for measuring alignment of wheels on opposite sides of a vehicle to being suitable for measuring alignment of wheels on a common side of a vehicle, and the invention removes the need to provide previously used special adaptors which involved extra cost and a need to avoid loss or mis-laying.

Whilst in the embodiments of the invention described above it is only a vertical mirror which has been mounted so as to be readily movable between two predetermined positions, alternatively or additionally the optical viewpiece may be similarly mounted.

Where vehicle wheel alignment measuring apparatus comprises two units which are each provided with means for rotating either a mirror or optical view-piece through a predetermined angle there results the particular advantage that when measuring the alignment of two wheels lying on the same side of a vehicle it is necessary to take only one alignment reading. Instead of having to use the second unit as a reference relative to which the position of a first unit is measured when in successive positions against two vehicle wheels, if both the mirror of a second unit and the optical view-piece and associated pointer arm of a first unit are both rotated through an angle of 90° relative to their support arms it is necessary only to place the two units in alignment one each with the respective wheels and take one alignment reading.

Whilst the embodiments of the invention and 11. 0 '4$ variations thereof have been described specifically in respect of alignment sensing components of an optical kind it is to be appreciated that the inventive concepts embodied therein may be applied also to other forms of alignment measuring units and apparatus.

Claims

CLAIMS 1. An alignment measuring unit for the measurement of wheel alignment comprising a support member for positioning in alignment with a wheel, a sensing component^ and locating 5 means comprising a recessed part to enable the sensing component to be selectively located relative to the support member in one of at least two positions determined by the locating means.
2. An alignment measuring unit according to claim 1 10 comprising retaining means provided to retain the sensing component within predetermined limits of movement relative to the support member whilst the sensing component is moved between said at least two positions, 3. An alignment measuring unit according to claim 1 or IS 2 wherein the locating means comprises said retaining means and serves to clamp the sensing component relative to the support member. 4. An alignment measuring unit according to claim 1 or 2 wherein the retaining means is substantially independent of 20 the locating means and serves to clamp the sensing component relative to the support member. 5. An alignment measuring unit according to any one of claims 1 to 4 wherein the retaining means is integral with the support member or the sensing component. 2i> 6. An alignment measuring unit according to any one of claims 1 to 4 wherein the retaining means is independent of either the support member or the sensing component. 7 · An alignment measuring unit according to any one of the preceding claims wherein the sensing component is pivotally mounted on the support member so that it may be rotated about a known axis when being moved between said at least two positions. J. An alignment measuring unit according to claim 7 wherein the locating yeans comprises a cam formed with recesses at positions related to said at least two positions at which the sensing component is to be selectively locatable relative to the support member, and a locating arm provided with a detent for engaging with the cam recesses, the cam and arm being attached one each to either the support member or the sensing component. g. An alignment measuring unit according to claim 8 wherein the arm and cam are sping-loaded relative to one another so that the detent may be firmly retained in position in one of the cam recesses. 6. 10. An alignment measuring unit according to claim 9 wherein the cam is in the form of a quadrant plate having a curved outer surface formed with two recesses at positions which subtend an angle of 90° at the centre of curvature of the plate, Said centre lying at the axis of rotation of the support member. 7. 11. An alignment measuring unit according to claim 7 wherein the locating means comprises a profiled block and a complementarily-shaped cap member selectively Iocatable relative to the block in at least two positions predetermined by the shape of the block. 8. 12. An alignment measuring unit according to any one of the preceding claims wherein the sensing component comprises a view-piece. 5 9. 13. An alignment measuring unit according to any one of the preceding claims wherein the sensing component comprises an optical lens. 10. 14. An alignment measuring unit according to any one of the preceding claims wherein the sensing component comprises 10 a sighting mark. 11. 15. An alignment measuring unit according to any one of the preceding claims wherein the sensing component comprises a mirror. 12. 16. An alignment measuring unit according to any one of 15 the preceding claims wherein the sensing component comprises a datum mark. 13. 17. A wheel alignment measuring apparatus comprising two wheel alignment measuring units at least one of which is a unit according to any one of the preceding claims. 20 * * * * 25 14. 20 18 · An alignment measuring unit according to claim 11 wherein the locating means comprises a profiled block and a compleroentarily-shaped cap member substantially as described herein with reference to and as illustrated in Figures 7 and 8 of the accompanying drawings. 15. 25 19. An alignment measuring unit according to claim 11 wherein the locating means comprises a profiled block substantially as described herein with reference to and as 42033 illustrated in Figure 9 of the accompanying drawings. 20. An alignment measuring unit substantially as described herein with reference to and as illustrated in Figures 1-3 of the accompanying drawings. b 21. An alignment measuring apparatus substantially as described herein with reference to and as illustrated in Figures 1-6 of the accompanying drawings.