GB2214879A

GB2214879A - Apparatus for testing vehicle suspension linkages

Info

Publication number: GB2214879A
Application number: GB8803790A
Authority: GB
Inventors: Thomas Rothwell
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-02-18
Filing date: 1988-02-18
Publication date: 1989-09-13
Anticipated expiration: 2008-02-18
Also published as: GB8803790D0; GB2214879B

Abstract

Test apparatus (10) for testing the roadworthiness of a vehicle comprises upper and lower plates (11, 12). Roller bearings (15) are interposed between the plates (11, 12), and may be attached to the upper plate (11), so that the upper plate (11) can move over the surface of the lower plate (12) when a vehicle road wheel is supported on the upper plate (11). Movement of the upper plate (11) relative to the lower plate (12) can be effected by movement of a handle (23) connected to the plate via links (20, 21). The apparatus facilitates easy detection of knocks due to play in suspension and steering joints. <IMAGE>

Description

TEST APPARATUS This invention relates to test apparatus, and in particular to apparatus for use in testing the roadworthiness of a motor vehicle.

In the United Kingdom, as in many other countries, motor vehicles of a certain age are required by law to be tested for roadworthiness, and such vehicles may not be used on a public road unless they meet the statutory requirements in that regard. Various aspects of roadworthiness are tested, for example braking efficiency, working of the lighting systems, working of windscreen cleaning equipment, condition of bodywork and structural members, and the like. In addition, the degree of wear of the vehicle suspension and steering joints is tested, and it is in relation to the testing of those joints for wear that this invention is particularly concerned.

If the vehicle is stood on the ground on its road wheels, the suspension in particular is in its conventional operative configuration However, it is not possible effectively by hand to move the wheels relative to the vehicle to put any degree of strain on the suspension and steering joints and check them for excessive wear and play.

If the vehicle is jacked up, using the conventional jacking points, to support the vehicle body, the suspension units move, due to the weight of the otherwise unsupported wheels, into an unconventional inoperative configuration such that normally mutually contacting joint surfaces do not contact each other and movement of the wheels relative to the vehicle body does not give a representative test of the amount of wear and play present in the joints when thesuspension units are in their conventional operative configuration. In practice, the joints, when the suspension units are in this unconventional inoperative configuration, tend to be excessively tight such that relative movement of the wheel and vehicle body is not possible.If the vehicle is supported by placing a jack or jacks under the axle or axles of the vehicle, the weight of the vehicle body is transmitted through the suspension and steering joints. In consequence it is again not possible by hand to effectively move the wheels relative to the body and test the joints in a proper and effective manner.

To overcome the above problems, it is conventional to use greased plate" test apparatus. Such apparatus comprises a pair of plates which are placed in face to face disposition with a quantity of grease between them so that one plate can move relative to and in a direction parallel with the other plate. The apparatus is placed on the ground and the vehicle is positioned with one of its road wheels on the uppermost plate of the apparatus.

With the vehicle thus supported on its road wheels the suspension units are in their conventional operative position. Due to the reduced friction between the two plates of the test apparatus, and the ability of the upper plate to move relative to the lower plate, the wheel which is supported thereby can be moved by hand relative to the vehicle body. In this way the suspension and steering joints can be tested whilst the vehicle is in its normal operative configuration. However, unless the vehicle wheel is located substantially at the level of the tester's shoulders, an effective force cannot easily be applied to the wheel to perform the test.In addition, unless two people perform the test together, it is difficult to observe each of the joints concerned whilst applying a force to the wheel with the object of creating relative movement between the parts of the joints if wear thereof has occurred. Also, although lateral forces can be applied to the wheel it is difficult to apply effective fore and aft forces to the wheel to test the joints under such loadings.

It is an object of the present invention to provide a test apparatus the use of which avoids, or overcomes to a substantial extent, the abovementioned disadvantages.

The invention provides test apparatus comprising upper and lower plates in spaced face-to-face disposition with rolling bearing means located between said plates whereby said upper plate is movable relative to and in a direction parallel with the plane of said lower plate.

The rolling bearing means may comprise a plurality of rolling bearings, and said bearings may be secured to one of said plates. The bearings may be secured to said upper plate, and may be symmetrically disposed on the surface of said upper plate. Eighteen bearings may be provided. Each rolling bearing may comprise a ball rotatably retained in but extending outwardly of, a housing, which housing may be secured to, or be formed integrally with, said upper plate.

The apparatus may also comprise a linkage connecting the upper and lower plates, and allowing said relative movement therebetween, and said linkage may comprise handle means operative to move the upper plate relative to the lower plate. The handle means may be detachable from part of said linkage. The apparatus may comprise two linkages connecting the upper and lower plates and allowing said relative movement therebetween in two mutually perpendicular directions, and two said linkages may comprise common handle means.

The invention will now be described with reference to the accompanying drawing in which: Fig. 1 is a plan view of a first embodiment, Fig. 2 is a front elevation of-the embodiment of Fig. 1, and Fig 3 is a plan view of a second embodiment.

Referring now to Figures 1 and 2 there is shown a test apparatus 10 comprising an upper plate 11 and a lower plate 12. The plates 11,12 may be of steel, in which case the upper plate 11 has nine symmetrically disposed bearing housings 13 welded thereto on its under surface 14 which is in face-to-face disposition with the lower plate 12. Alternatively the upper plate 11 at least, or both plates 11,12, may be die cast, for example in zinc aluminium, in which case the housings 13 may be formed integrally with the plate 11. Held rotatably captive in each housing 13 is a rolling member 15. In this embodiment, in which movement of the upper plate 11 relative to the lower plate 13 in one direction only is provided for, as shown by arrow B in Fig. 2, the rolling members 15 may be balls, as shown in Fig. 1, or may be cylindrical rollers.

Attached to, or formed integrally with, the upper and lower plates 11,12 are pairs of respective lugs 16,17.

In the lugs 16 is rotatably mounted a spindle 18 and in the lugs 17 is rotatably mounted a spindle 19. Fixedly secured to spindles 18 and 19 are respective pairs of links 20,21 which are pivotally attached to each other, at their ends opposed to those attached to spindles 18,19, by means of a third spindle 22. A handle 23 is attached to one end of spindle 19c Alternatively one end, or both ends, of spindle 19 is formed with a square or hexagonal socket to receive a correspondingly shaped socket wrench which serves as handle 23. By moving handle 23 in the direction of arrow A, Fig. 2, the upper plate 11 will move relative to the lower plate 12 in the direction of arrow B. Stops 24 may be provided on the lower plate 12 to limit the amount of movement of the upper plate 11 if desired. Although fixed stops are shown positionally, adjustable stops may be provided.

By means of the invention the testing of a motor vehicle in respect of wear of joints in the suspension and steering systems is facilitated. If the vehicle is driven so that one of the road wheels 25 is supported on the upper plate 11 with the axle of such wheel perpendicular to the spindles 18,19,22, movement of the handle 23 will cause a lateral force to be applied to the wheel 25 as the upper plate 11 moves in the direction of arrow B. The dimensioning of the handle 23 and links 20,21 may be such that a considerable lateral force can be applied quite readily to the wheel, for example some 10 to 15 times that which can be applied by hand to the wheel 25. In addition, it is possible for one person to operate the handle 23 and visually inspect the joints of the steering and suspension units of the vehicle at the same time, thereby being able to observe any movement in those joints and have an impression of the force required to produce such movement.

Referring now to Fig. 3 there is shown a test apparatus 30 which is generally similar to the apparatus 10 of Figs. 1 and 2, and corresponding parts are identified by means of corresponding reference numerals. However, in this case, the upper plate 11 is arranged for movement relative to lower plate 12 in two mutually perpendicular directions as shown by arrows B and C. The linkage 18,19,20,21,22 facilitating movement in the direction of arrow B is as described in relation to the previous embodiment, and there is a corresponding linkage 38,39,40,41,42 facilitating movement in the direction of arrow C. The spindle 39 is rotatably received in lugs 37 attached to or formed integrally with the lower plate 12 and the spindle 38 is rotatably received in lugs 36 attached to or formed integrally with the upper plate 11.

The handle 23 is connected to a ball 31 which is connected by further linkages 32,33 to spindles 19,39 respectively. The ball 31 is rotatably held captive in a housing 34 which has mutually perpendicular slots 35 therein through which linkages 32,33 extend. The handle 23 may be moved in either of the two perpendicular directions to cause movement of the plate 11 in the corresponding direction. For example, movement of the handle 23 in the direction of arrow A of Fig. 2 will cause rotation of spindle 19 and movement of the upper plate 11 in the direction of arrow B as previously described. The spindles 38,39 can slide in their respective mounting lugs 36,37 and the linkage 33 can pivot to accommodate such movement of upper plate 11.Similarly, movement of the handle 23 in a direction perpendicular to arrow A will cause movement of upper plate 11 in the direction of arrow C which is accommodated by sliding of spindles 18,19 in lugs 16,17 and pivoting of linkage 32. By this means lateral or fore and aft forces can readily be applied to the wheel 25 so as to enable a more thorough check on the condition of the joints of the suspension and steering mechanisms of the motor vehicle to be made than was possible by the previous methods.

Although reference has been made to the checking of suspension and steering joints, the apparatus is equally suitable for testing the suspension joints of rear wheels, particularly in the case of the embodiment of Fig. 3 whereby fore and aft forces can be applied to trailing arm linkages and the like. Although nine bearings are shown in Fig. 1, any number of bearings may be provided as desired, in particular more bearings, for example eighteen or nineteen, may be provided for use of the apparatus with relatively heavy vehicles.

Claims

1. Test apparatus comprising upper and lower plates in spaced face-to-face disposition with rolling bearing means located between said plates whereby said upper plate is movable relative to and in a direction parallel with the plane of said lower plate.

2. Test apparatus according to claim 1 wherein said rolling bearing means comprises a plurality of rolling bearings.

3. Test apparatus according to claim 2 wherein said rolling bearings are secured to one of said plates.

4. Test apparatus according to claim 3 wherein said rolling bearings are secured to said upper plate.

5 Test apparatus according to claim 4 wherein said rolling bearings are symmetrically disposed on the surface of said upper plate.

6. Test apparatus according to any of claims 2 to 5 wherein each said rolling bearing comprises a ball rotatably retained in, but extending outwardly of, a housing.

7. Test apparatus according to claim 6 wherein said housing is secured to said upper plate.

8. Test apparatus according to any of claims 1 to 7 when said upper and lower plates are connected by a linkage.

9. Test apparatus according to claim 8 wherein said linkage comprises a handle means operative to move the upper plate relative to the lower plate.

10. Test apparatus according to claim 9 wherein the handle means is detachable from part of said linkage.

11. Test apparatus according to any one of claims 8 to 10 wherein linkages connect said upper and lower plates allowing relative movement therebetween in two mutually perpendicular directions.

12. Test apparatus according to claim 11 wherein said two linkages comprise common handle means.

13. Test apparatus substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

14. Test apparatus according to any one of claims 1 to 13 when used to test a motor vehicle, the motor vehicle being positioned with a road wheel thereof supported on the said upper plate.