GB2324769A

GB2324769A - Wheel balancing apparatus.

Info

Publication number: GB2324769A
Application number: GB9708331A
Authority: GB
Inventors: Douglas Garrington; David Reynolds
Original assignee: SP Tyres UK Ltd
Current assignee: Dunlop Tyres Ltd
Priority date: 1997-04-25
Filing date: 1997-04-25
Publication date: 1998-11-04
Also published as: GB9708331D0

Abstract

A wheel balancing apparatus comprises a support frame 21 and independent first and second rotatable chucks 22a, b for engaging each side of the rotational centre portion of a wheelrim. The first chuck 22a is in a fixed axial position with respect to the support frame and the second chuck is aligned axially with the first chuck and movable axially with respect to the support frame both towards and away from the first chuck. Axial movement may be caused by a pneumatic reciprocating cylinder (25 Fig. 3) operated by a foot pedal.

Description

WHEEL BALANCING APPARATUS The present invention relates to apparatus for balancing wheel assemblies of a tyre and wheelrim and particularly but not exclusively to a portable apparatus such as might be transported and used at motorsport events.

Conventionally such transportable balance machines have been relatively simple and robustly engineered machines to withstand the rigours of use.

In a prior art portable wheel balancing apparatus 1 shown in Figure 1 the wheel assembly 2 to be balanced is assembled onto a rotatable shaft 3 mounted in support bearings 4 held in a support frame 5.

The procedure for balancing a wheel assembly using this prior art apparatus 1 comprises firstly sliding one of a pair of conventional twist-locking tapered chucks 5a onto the shaft 3 and locking it a pre-set distance from one end of the shaft. The other end of the shaft 3 is then passed through the centre of the wheel assembly and the second of the pair of chucks 5b is than put onto the open end of the shaft. This second chuck Sb is slid up to the wheel assembly and locked onto the shaft so that the wheel assembly is held tightly between the first and second chucks 5a and 5b respectively.

The shaft 3 with the wheel assembly mounted on it is then taken to the support frame 5 and placed onto the shaft support bearings 4 as shown. The wheel assembly can now be spun by hand in order to check its balance.

After the balance check has been completed the wheel assembly and shaft are dismounted from the support frame 5 and then the wheel assembly is removed from the shaft carrying out in reverse the previously described operations.

The above-described balancing procedure requires much manual effort and ideally requires two people to operate and is thus labour intensive and time consuming.

Accordingly it is an object of the present invention to provide a balancing apparatus which can be used by a single operator and is more efficient.

According to the present invention a wheel balancing apparatus comprises a support frame and independent first and second rotatable chucks for engaging each side of the rotational centre portion of a wheelrim characterised by the first chuck being in a fixed axial position with respect to the support frame and the second chuck being aligned axially with the first chuck and movable axially with respect to the support frame both towards and away from the first chuck.

Further aspects of the invention will become apparent from the following description by way of example only of one embodiment of the invention in conjunction with the following diagrams in which: Figure 1 is a sectional front elevation of a wheel balancing apparatus according to the prior art; Figure 2 is a front elevation of a wheel balancing apparatus according to the present invention; Figure 3 is a plane view of the apparatus of Figure 2 taken in the direction of arrow P; and Figure 4 is a side elevation of the apparatus of Figures 2 and 3 taken in the direction of arrow E.

A wheel balancing apparatus according to the present invention and shown in Figures 2-4 comprises a support base and frame 21 holding two independent tapered chucks 22a and 22b mounted at the ends of circular shafts 27a and 27b respectively. The chucks are mutually aligned along the axial centreline CIL of the apparatus and are rotatable in planes perpendicular to the axial centreline CIL via the circular shafts being mounted in bearing housings 23 and 24.

The axial position of the first chuck 22a is fixed with respect to the support frame 21 whilst the axial position of the second chuck 22b is variable along the centreline C/L. Thus this second chuck is movable towards and away from the first chuck whilst remaining aligned with it.

Movement of the second chuck 22b is provided by means of a pneumatically reciprocating cylinder 25 fixed attached to the support frame 21 and the piston 26 of which is fixed attached to the free end of the circular shaft 27b which is slidable through the bearing housing 24. Operation of the pneumatic reciprocating cylinder 26 by means of for example a foot pedal (not shown) thus causes the second chuck to move towards or away from the first chuck 22a for mounting and dismounting a wheel assembly.

The apparatus of Figures 2-4 may be further provided with means, for example a movable platform or a pair of rollers, for raising and lowering the wheel assembly in order to facilitate mounting and dismounting the wheel assembly from the apparatus.

Claims

1. A wheel balancing apparatus comprising a support from and independent first and second rotatable chucks for engaging each side of the rotational centre portion of a wheelrim is characterised by the first chuck being in a fixed axial position with respect to the support frame and the second chuck being aligned axially with the first chuck and movable axially with respect to the support frame both towards and away from the first chuck.

2. A wheel balancing apparatus according to claim 1, characterised by moving means for moving the second chuck relative to the first chuck.

3. A wheel balancing apparatus according to claim 2, characterised in that the moving means comprises pneumatic or hydraulic means.

4. A wheel balancing apparatus according to either of claims 2 or 3, characterised in that the moving means is operated by a foot pedal.

5. A wheel balancing apparatus according to any of claims 1 to 4, characterised in that the support frame comprises means for raising and lowering a wheel assembly perpendicularly to the axial direction of movement of the second chuck.