WO2004077004A1

WO2004077004A1 - Apparatus and method for the static balancing of vehicle wheels

Info

Publication number: WO2004077004A1
Application number: PCT/EP2003/002109
Authority: WO
Inventors: Antonio Tosi
Original assignee: Star S.R.L.
Priority date: 2003-02-28
Filing date: 2003-02-28
Publication date: 2004-09-10
Also published as: AU2003214084A1; EP1639336A1

Abstract

An apparatus (10) for balancing the wheels of road vehicles, and particularly of motorcycles or similars, comprises a horizontal axle (12) free rotating on a supporting structure (14), said axle being apt to receive the wheel to be balanced. A bar (18), rotatably joined to said axle (12), consitues an angular referenceof the unbalance zone of the wheel, means for setting the reciprocal positions of said axle (12), said wheel (11) and said angular reference (18) being provided. The value of the balancing weights to install on the wheel rim is indicated by means (31) apt to measure the weight force due to the unbalancing of the wheel after that this one is joined with the bar (18) and rotated until positioning the bar in a horizontal position.

Description

APPARATUS AND METHOD FOR THE STATIC BALANCING OF

VEHICLE WHEELS. o o o o o o o

Technical field

This invention concerns an apparatus for the static balancing of road vehicle wheels, and specifically, wheels of two-wheelers, scooters or similar vehicles.

The invention refers also to a method for balancing wheels of vehicles.

Description of the prior art

As we know, in the field of servicing and repairing of wheels and tyres of road vehicles, machines and equipments apt to allow an easy balancing of the wheels are widely used.

In particular, the balancing machines allow an extremely quick and effective dynamic balancing, supplying the operator with exact data and instructions about position and size of specific weights to install on the wheel rim in order to counterbalance any detected unbalance.

The above machines are, for instance, widely used at the shops of substitution and repair of car tyres, as it is necessary to make the balancing of a wheel every time that its tyre is substituted or repaired.

Such requirement is obviously needed also as regards wheels of motorscooters, or similar two-wheeler or three-wheeler vehicles, but, in these cases, the balancing is done in a more rough and simple way, by using simple equipments and by empirically determining the unbalance amount to be corrected. In these cases, in fact, the effectiveness of the balancing depends strongly by the skill of the operator, that, according to its own experience, establishes the amount of the balancing weights to install on the wheel, by examining the oscillatory movement of the wheel when this one is in a condition of unstable equilibrium on a rotation axle.

Considering the lower number, and economic importance, of scooters, motorcycles or other two-wheelers in respect of cars, it is clearly inadequate to employ, also in the two-wheeler sector, the above cited dynamic balancing machines; but, anyway, it would be very appreciated the availability of equipments by which it is possible to work in a more sure and professional way than now, and which costs are lesser than those ones of the above machines.

Summary of the invention

This invention aims to provide an apparatus and a method for balancing the wheels of road vehicles, and, particularly, of motorcycles or similar, in such a way to achieve the above objects.

A further ai of the invention is to provide a wheel balancing apparatus having low dimensions and weight, so to be advantageously used in restrained working spaces and to be easily moved.

Such aims are attained by an apparatus for balancing the wheels of road vehicles, and particularly of motorcycles or similar, comprising:

- a horizontal axle free rotating on a supporting structure, said axle being apt to receive the wheel to be balanced;

- angular reference means of the unbalance zone of the wheel, said means preferably consisting of a bar rotatably joined to said axle;

- fixing means for setting the reciprocal positions of said axle, said wheel and said angular reference means;

- measuring means of the weight force due to the unbalance of the wheel, said measuring means being advantageously supported on said structure;

- a horizontal lever protruding from said bar, or an appendix, or other means apt to transfer to said measuring means said weight force proportional to the unbalance amount.

The fixing means dedicated to connect, each other, the wheel and the angular reference bar are formed, preferably, by L shaped arms, hinged at the ends of said bar and elastically pulled toward the centre of the wheel, in such a way to be firmly associated to the wheel by pressing on the external circumference of said wheel.

The fixing means may also be formed by threaded ring nuts placed on the rotation axle in a position useful to tighten the bar against a lateral surface of the wheel.

The measuring means of the weight force proportional to the unbalance amount of the wheel consist of load-cells and related electronics or of automatic mechanic or electric weighing machines.

The horizontal axle, free rotating on the supporting structure, may be cantilever supported or may be sustained at the superior ends of columns provided in said structure. A method for balancing vehicle wheels, according to the present invention, provides the step of:

- positioning the wheel on a horizontal axle free rotating on a supporting structure and provided with an angular reference bar, or equivalent means, hinged to said axle;

- deteiτnining, by gravity action, the unbalancing portion of the wheel;

- firmly connecting to said wheel the angular reference bar or equivalent means;

- rotating, by a prefixed angle, the mechanical assembly formed at the previous step;

- measuring the weight force due to the wheel unbalancing in the rotated position;

- installing on the wheel rim balancing weights, according to the value indicated by said measuring means.

The apparatus of the present invention is provided with specific devices and technical features in order to assure high reliability and functional capacity.

Brief description of the drawings

For better understanding, however, the above-mentioned advantages and the characteristics of the present invention, this will now be described by way of embodiment examples, with reference to the accompanying drawings, in which:

- figure 1 shows a perspective view of an apparatus according to the invention, in a particular using arrangement;

- figure 2 shows a side view of the apparatus of fig.l, in a different using arrangement;

- figure 3 shows a front view of the apparatus of fig.l, in another different using arrangement;

- figure 4 shows a perspective view of a different embodiment of the invention apparatus;

- figure 5 shows a view, in longitudinal section, of the apparatus of

4;

- figure 6 shows a detailed view in section, obtained through the section line VI-VI of fϊg.5;

- figure 7 shows a perspective view of the apparatus of fϊg.4, in an using arrangement corresponding to that one of fig.3;

- figure 8 shows a perspective view of a particular component of the apparatus of fig.4.

Description of the preferred embodiments of the invention

Referring first to fig-l, it is indicated with 10 an apparatus for the static balancing of wheels, 11, for motorcycles, scooters or similar.

The apparatus, 10, comprises an horizontal axle, 12, cantilever supported by a column 13, of a fixed structure, 14, said axle being free rotating in respect of said structure thanks to journal bearings placed between the axle itself and tubular supporting means, 15, positioned at the top of the column 13.

Spacers, 16, and conical bushes, 17, are placed on said axle, 12, for positioning the wheel on the axle.

A bar, 18, having rectangular section, is joined to the axle, 12, in such a way to free rotate in a vertical plane perpendicular to said axle. Two L shaped arms, 19, 20, are hinged at the ends of the above bar 18, said arms protruding towards the portion of the axle 12 on which the wheel is positioned. The L shaped arms, 19, 20, are exactly hinged to the bar, 18, in two points, 21, 22, placed on the median longitudinal line of said bar. The arms 19, 20, are pulled, by elastic means 23, 24, toward the centre of the wheel, 11, and are usually kept in the open position of fig.2 by means of two rest pins, 25, 26, shown in the same figure.

Said pins are passing through the bar 18; they are positioned in such a way to interfere with the movements of the arms 19, 20, around the respective hinge points 21, 22.

The above movements are allowed when the rest pins 25, 26, are cleared away from the interference positions, by pulling them on the opposite side of the bar, acting on their respective handling knobs, 27, 28.

A further horizontal pin, 29, is connected to the bar 18; said pin 29 is placed in such a position that, upon a clockwise rotation of said bar to the position of fig.3, the pin gets in contact with a load-cell, 30, that, in this embodiment of the invention, is used to determine the size of the wheel unbalancing.

Furthermore, said horizontal pin, 29, is used to assure the placing of the bar, 18, in vertical position; in fact, said pin can be fitted in a suitable seat, 40, of a rest bracket fixed to the structure of the machine 10, shown in fig.3.

The output signal of the load-cell, 30, is processed by an electronic unit,

31, dedicated to display the wheel unbalancing size. Said unit provides, further to the digital display 32, some buttons, 33, useful to select the diameter of the wheel to be balanced, and LEDs, 34, useful to indicate the selection we made.

In the embodiment of fig.4, instead of the load-cell, 30, and corresponding electronic unit, 31, an automatic weighing machine, 35, is used. A suitable rod, 37, can lean on the plate, 36, of said automatic balance, 35, said rod 37 being supported by a U-shaped element, 38, connected to the angular reference bar, 18', through screw means 39, as shown in fig.8.

Also this bar, 18', can be placed exactly in vertical position by using, in this case, a rest bracket, 41', fixed to a column, 43, of the structure 14'.

How we can see in fig.4, in this embodiment of the invention, the rotation axle, 12', is supported on two columns, 42, 43, of the structure

14' of the machine 10'. Also in this case, however, said axle is free rotating in respect of the supporting structure; in fact, the ends of the axle 12' are simply sustained by two pairs of adjacent gears, 44, 45, 44',

45', placed at the top of said columns 42, 43.

According to the connecting scheme of fig.6, said gears are free to rotate in both directions, each of them being fitted on a respective bearing 46,

47, 46', 47', fixed, through supporting rod, 48, 49, 48', 49, to said columns 42, 43.

The angular reference bar, 18', may be fastened to axle, 12', by tightening a threaded bush, 50, placed on a side of the bar 18', to a hub, 51, placed on the other side of the bar, said hub being joined to die axle, 12', through screw means, 52.

To he hub, 51, is also joined, through a connecting pin, 53, a spacer, 54, to which is, in its turn, joined, through one more pin, 55, a locating bush,

56, of the wheel, 11'.

The wheel, 11', fitted to the bush, 56, is free to rotate integral to the axle,

12' and is firmly connected to said axle through a hub, 57, which gets in contact with wheel and force it to press the spacer, 54. The position of the hub, 57, on the axle. 12', can be lightly varied thanks to the fact that is joined by thread to a bush, 58, which can be fastened in different positions of the axle through spring pins, 59.

Exacfiy, according to fig.5, said spring pins are able to fasten the bush 58 in three different positions corresponding to the points of fastening shown with 60, 61, 62, and relating to the kind of wheel rim to be fitted on the axle 12'.

Finally a, pin apt to fix the position of the axle 12' while acting on the means, 57, for fastening the wheel 11' to the axle itself, is shown with 63.

^"When not in use, the pin 63, as we can see in fig.5, fits in a special cavity,

64, provided in the fixed structure 14'.

The above described apparatus operates as follows.

With reference to the embodiment shown in figures 1 and 2 the wheel,

11, is inserted in the axle, 12, by pressing together the spacers 16 and the conical bushes 17, while the L shaped arms, 19, 20, are in the open position of fig.2.

In such configuration the wheel, free to rotate, if unbalanced swings, thanks to the gravity, around the axle, coming to a stop when its stable equilibrium point is vertically positioned with respect to the axle, underneath the axle itself. Then, the angular reference bar, 18, is made integral to the wheel, just clearing away, through the handling knobs, 27, 28, the rest pins 25, 26, from the interference positions with the arms 19, 20, so allowing them to close on the wheel 11.

Afterwards, the assembly including the wheel 11 and the bar 18, is clockwise rotated, in this embodiment of an angle of 270°, until the bar gets a horizontal position; in such configuration the pin, 29, transversally joined to said bar, lean on the load cell, 30, which then transmits a signal, proportional to the entity of the unbalancing, to an electronic unit, 31 which displays the wheel unbalancing size. The exact amount of the unbalancing is shown on the display of the device 31 which is previously set, according to the diameter of the wheel, through the selection buttons 33. Said display so indicates the proper amount of the weight to apply on the wheel rim at the point diametrically opposite with respect of the point of contact with the end of the angular reference bar where the transversal pin 29 is.

Referring to the embodiment of fig.4 and followings, the positioning of the wheel 11' in the axle 12' takes place while this one is deprived of the hub 57 and of the threaded bush 58; then said elements are inserted on said axle by fastening the bush 58 in correspondence to one of the fastening points 60, 61, 62 and by rotating the hub 57 since it gets in contact with the wheel, 11^*, and force it to press the spacer, 54, so that the wheel becomes integral to the axle 12', while the bar 18' is free to rotate. The assembly so created is then fitted upon the columns 42, 43, of the fixed structure 14', in the configuration shown in fig.4.

Also in this embodiment the wheel stop swinging around the axle in the position in which its stable equilibrium point is vertically positioned with respect to the axle, underneath the axle itself.

In such condition, acting on the bush 50, the bar 18' is made integral to the axle 12^* taking care of the vertical position of the bar ensured by the contact with the rest bracket 41'.

Afterwards, the axle 12' is clockwise rotated, in this embodiment of an angle of 90°, until the bar 18', integral to said axle 12', gets a horizontal position; in such configuration, the suitable rod, 37, transversally joined to one end of the bar, can lean on the plate, 36, of the device measuring weights, 35, which, in this case, is an automatic balance. Then, said device, previously set up to ignore the weight of the suitable rod and of the supporting U-shaped element, 38, exactly indicates the size of the balancing weight to apply on the wheel rim.

The above described balancing activity come highly simplified with respect to the empirical methods used so far and it also assures precision and reliability of the results.

It is clear that such advantages are still safe even in case of some modifications and changes to the above described embodiments.

Different kinds of spacers or conical bushes 16, 17, 54, could be used, as for example the spacer 54' of fig.8, could be used to increase the versatility of the above described apparatus.

Besides the clear usage advantages, the apparatus of the invention is very cheap with respect to the balancing machines normally employed in the four wheels sector, so involving a clear and main advantage in the specific field where it has to be applied.

We have also to notice that the apparatus has very little global dimensions, both in length, in height and in width, so that it can be used even upon workshop tables.

The apparatus results also very light weighted, so that it can be easily moved, just using suitable boxes, to be used in different places.

Further changes to the above described embodiments can concern the shape of the resting means and the shape of the fixed supporting structure.

Even" the material used to make the apparatus, or just some components, can change according to costs or making requirements.

The angular reference means indicating the unbalancing zone, which in the described embodiments is the free rotating bar, can change; for example, pliers or clamps can be used, which could be applied directly on the wheel near the unbalancing zone and, obviously, in this case, the previous set up of the measuring means is made also considering the weight of the said pliers or clamps.

The measuring means too may be different with respect to the above described; in fact, dynamometers or other kinds of balances could be used; they may also be placed in a different position on the fixed structure of the apparatus.

Referring to the operating ways, we can also notice that the rotation of the assembly following the localisation of the unbalancing zone, can be performed according to different, but still predefined, angles; in fact, angles differing from the 90° or 270° angles above described could be chosen, simply considering a correction factor to rightly characterize the weight force and the amount of the weight to apply on the wheel. This operation can obviously be automatically performed by the measuring means.

The above said changes to the described embodiments and many other can take place within the limits of the invention as defined by the following claims.

Claims

1- Apparatus for the balancing of road vehicles wheels, characterized in that it comprises:

- at least one horizontal axle (12) free rotating on a supporting structure (14), said axle being apt to receive the wheel (11) to be balanced;

- angular reference means of the unbalance zone of the wheel, said means preferably consisting of a bar (18) rotatably joined to said axle (12);

- fixing means for setting the reciprocal positions of said axle (12), said wheel (11) and said bar (18) or other angular reference means;

- measuring means (30, 31) of the weight force due to the unbalance of the wheel, said measuring means being advantageously supported on said structure;

- a horizontal lever (29) protruding from said bar (18), or an appendix, or other means apt to transfer to said measuring means said weight force proportional to the unbalance amount.

2- Apparatus according to the previous claim characterized in that said horizontal axle (12) is cantilever supported at the superior end of a column (13) provided in said fixed structure (14).

3- Apparatus according to claim 1 or 2 characterized in that said fixing means dedicated to connect, each other, the wheel (11) and the angular reference bar (18) are formed by L shaped arms (19, 20) hinged at the ends of said bar and elastically pulled toward the centre of the wheel (11), in such a way to be firmly associated to the wheel by pressing on the external circumference of said wheel.

4- Apparatus according to the previous claims characterized in that said measuring means of the weight force proportional to the unbalance amount of the wheel consist of load-cells (30) and related electronics (31), said electronics (31) being settable according to the diameter of the wheel (11), through suited selection buttons (33).

5- Apparatus (10') according to claim 1 characterized in that said horizontal axle (12') is free rotatably sustained at the superior ends of two lateral columns, (42, 43) of said fixed structure (14').

6- Apparatus (10') according to the previous claim characterized in that said fixing means consist of bushes or hubs (50, 52, 57) integral to the horizontal axle (12') and apt to fix the wheel (IT) and the reference bar (18') on said axle (12').

7- Apparatus according to claim 5 or 6 characterized in that said measuring means consist of automatic weighing machines (35) placed at the superior end of one (43) of said lateral columns, said weight force proportional to the amount of the wheel unbalancing being transmitted to said measuring means through a suitable rod (37) transversally joined to said bar (18').

8- Apparatus according to the previous claim characterized in that said measuring means (35) are previously set so that they directly show the size of weight to install on said wheel (11') in order to balance it.

9- Apparatus according to claim 1 characterized in that said angular reference means of the unbalancing zone of the wheel consist of pliers or clamps to apply on the wheel near said unbalancing zone. 10- Method for the balancing of road vehicle wheels, characterized in that it comprises:

- positioning the wheel on a horizontal axle free rotating on columns of a supporting fixed structure;

- determining, by gravity action, the unbalancing zone of the wheel;

- firmly connecting to said wheel an angular reference bar pivoting around said axle or equivalent angular reference means of the unbalancing zone;

- transmitting the weight force, caused by the unbalancing with the angular position imposed to the wheel, to measuring means placed on top of one of the columns of said fixed structure;

11- Method according to the previous claim characterized in that the predefined angle of rotation of the mechanical assembly formed by the wheel and the angular reference means is a 270° angle.

12- Method according to claim 10 or 11 characterized in that said measuring means consist of load-cells or automatic weighing machines and they are placed at the superior end of one of said columns of the fixed structure.

13- Method according to the previous claim characterized in that a horizontal pin, transversally joined to said reference bar, transmits the weight force caused by the unbalancing of the wheel to said measuring means.

14- Method according to one of the claims from 10 to 13 characterized in that said measuring means are previously set to ignore the weight of the suitable rod, the weight of the relating means of connection to said reference bar, or the weight of angular reference means unbalanced with respect to the horizontal free rotating axle.