FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
The Patent Rules, 2003
Complete Specification
(See section 10 and rule 13)
A Tractor Wheel With Linear Adjustability Of Track Width And A Method Of Adjusting Track Width
Mahindra and Mahindra Limited
Indian company registered under the Indian Companies Act, 1956
Gateway Building, Apollo Bunder, Mumbai – 400001, Maharashtra, India
The following specification particularly describes the invention and the manner in which it is to be performed.

A TRACTOR WHEEL WITH LINEAR ADJUSTABILITY OF TRACK WIDTH AND A METHOD OF ADJUSTING TRACK WIDTH
FIELD OF INVENTION:
The present invention relates to wide range of adjustments of track width of a tractor within the adjustable limits and more particularly, it relates to adjustment of the track between the wheels of tractors by means of a double railed guider plate, slider plate and square headed bolt assembly.
BACKGROUND OF THE INVENTION:
Agricultural vehicles such as tractors are employed extensively for a variety of farm operations including cultivation of a range of crops. Agricultural vehicles such as tractors are provided with manually adjustable wheels in order to allow the track or track width – the spacing between the driven wheels of the tractor – may be adjusted to suit the requirement imposed by different applications. Crops are grown in differing widths of rows, for example, or different soil types may require specific tract widths. It is important that the tractor has the ability to vary its track width as a single machine may be used in differing requirements by adjusting the track width. This is important from achieving most effective crop growth and efficient land utilization.

Some tractors are equipped with a splined rear axle extending outwardly from the bearings sufficiently far to permit positioning of the wheel hub at various points and thereby varying the distance between the wheels. One of the disadvantages of this arrangement is that the axle must be very large in order to cope with the additional stress caused by the wheel hub to be out toward the end of the of the axle and away from the bearing.
Another method is to provide dished wheels that can be attached to the tractor with the concave surface in or out depending on the desired spacing. However, this necessitates complete removal of one or both rear wheels when a spacing change is required. Further, only a limited number of arrangements are possible – both concave surfaces facing outwardly or inwardly, or one facing in and the other out.
In some other manually adjustable wheels, a rim is detachably secured to a disc which in turn is secured to a hub situated at the end of a drive shaft. The conventional means for securing the rim to the disc comprise a plurality of lugs positioned circumferentially around the inner surface of the rim. The disc usually comprises a generally circular metal plate with a scalloped periphery. The apices of the scallops serve as elements that connect the disc with the rim.

In yet other arrangement, a disc is welded to the rim and the disc presents a polygonal shape, say octagonal, with four longer sides alternating with four shorter ones. The corners of the initially square disc are bent back and welded to the rim. Alternatively, the disc may be riveted to the rim. However in accordance with the EP Patent 0025677, such arrangements are unsuitable for high powered tractors and limited to lighter vehicles.
In all these arrangements, the procedure to change the tractor track width is extremely cumbersome and leads to waste of time and resources. The track width adjustment process typically involves Jacking-up the tractor, dismantling the tyre assembly from tractor, dismantling the disc from wheel rim, changing the disc to required position, assembling the wheel rim with tyre, tyre assembly with tractor. As this involves lifting of the entire tyre assembly, it is difficult for a single operator to manage. It also consumes lot of time which in turn reduces Farm Productivity due to down time of tractor.
There is therefore a need to provide adjustable wheels that do not require dismantling while adjusting the track width. There also a need to provide adjustable wheels that preferably do not require lifting during the track width adjustment process. There is therefore a need to provide wheels that are adjustable to provide any desired track width and which are easy to operate.

OBJECTS OF THE INVENTION:
One object of the present invention is to provide adjustable wheels that do not require dismantling while adjusting the track width.
Another object of the present invention is to provide adjustable wheels that preferably do not require lifting during the track width adjustment process.
A further object of the present invention is to provide wheels that are adjustable to provide any desired track width and which are easy to operate.
SUMMARY OF THE INVENTION
In one aspect of the invention it is intended to facilitate track width adjustment by means of a linearly adjustable Track Width mechanism provided on the tractor wheel. There is no dismantling of disc as with the conventional systems. Instead a railed guider plate is used which provides sliding movement of the rim-tyre assembly relative to the disc mounting provided on the tractor axle hub. The track width of a tractor can be thus be adjusted to any desirable value within the adjustable limits by changing offset of the wheel with respect to rim centre. Since sliding is employed instead of lifting in the present invention, a single user alone will be able to change the track widths of a tractor.

LIST OF FIGURES:
Figure 1 shows fixed settings for a typical conventional adjustable wheel
Figure 2 shows brief steps involved in track width adjustment
Figure 3 shows a perspective view of the wheel rim incorporating the present
invention.
Figure 4 shows a close-up of the L-bracket attachment to the disc and the rim.
Figure 5 shows details of the L-Bracket, the guider plate and the square neck bolt
LIST OF PARTS:
1. Track width 8. Bolt with square neck
2. Axle 9. First round hole
3. Rim 10. Second round hole
4. Internal surface of the rim 11. Slot
5. Disc 12. Base
6. Guider plate 13. Square neck
7. L- Bracket
DETAILED DESCRIPTION OF THE INVENTION:
Figure 1 shows fixed settings that are possible with typical conventional adjustable tyres. It is easily understood that eight settings are possible. This is achieved by positioning the disc by facing ‘inside’ or ‘outside’ with respect to the

axle, and by positioning the disc towards the inside or outside of the wheel rim. The figure shows how the settings between 48” to 76” are achieved.
Figure 2 shows the brief steps involved in adjusting the track width in the conventional tractors. For turning the disc or the wheel, the wheel need to be dismantled, lifted and removed from the axle, turned and refitted.
Figure 3 shows a perspective view of the wheel rim incorporating the present invention. It shows a disc attached to a wheel rim. The disc is a standalone element which is fixed to the wheel rim with the help of L-brackets. The L-brackets have provisions for attaching to the wheel rim as well as the disc. The wheel rims are provided with guider plates which have at least one slit in which fixing elements such as screws may slide adjustably into a position.
One arm of the L-bracket may be fitted to the disc by the means of welding or nuts/bolts, or riveting, or any other suitable means. The other arm of the L-bracket may be fitted to the wheel rim by the means of a nut and bolt arrangement wherein the bolt may slide in any position along the slit provided in the guider plate.

The guider plates in turn may be fitted to the wheel rim by the means of any suitable methods such as welding, screw-fitting, riveting, or any other suitable method.
Figure 4 shows a close-up of the L-bracket attachment to the disc and the rim. It will be easily understood from this figure how the L-bracket may be positioned virtually anywhere along the slit.
In an alternative arrangement, a plurality of slits is provided on the guider plate. This allows more secure attachment of the L-Bracket to the wheel rim by eliminating or greatly reducing the possibility of disc tilting during the sliding movement of the disc during the track width adjustment operation. To strengthen the L-bracket connection with the rim further, depending upon the usage/application and tractor Configuration, i.e. the HP or gross weight of the tractor, more than two slits may be provided.
The guider plates are positioned with equal spacing between any two adjacent plates.
One of the drawbacks of the conventional adjustable track width systems is that they often deploy discs that are integrally provided with the connecting elements to connect them with the rims. The connecting elements and the area of the disc in

their vicinity are high stress areas and frequently experience failure. In the present invention, the provision of a standalone L-bracket ensures that the disc itself is free from undue stress. In the event of a failure of a joint, it is the L-bracket that needs replacing rather than the entire disc. The present invention provides the L-bracket which is of load bearing type making it a more substantial element than equivalent elements used in conventional systems. L-Bracket Disc thickness may increase or decrease in proportion to load acting on L-Bracket. It may possible that desired load can be met with higher thickness of L-bracket alone keeping Disc thickness on lower side thereby having commercial advantage on Design Proposal. However, the costs associated with these are minimal compared with the costs involved in replacing the entire discs.
As a further advantage, the present system provides a positive lock between the rim/tyre assembly and the disc while still facilitating easy sliding of the assembly with no change in disc position. This is achieved by provision of a square neck bolt and also providing a clearance between guider plate slot and square neck bolt in such a manner so as to arrest tilting of disc during rim-tyre assembly sliding during track adjustment.
Operation of the invention:
Adjustment of the track width is carried out by a single operator and in an easy manner. The wheel needing adjustment is jacked up to allow its free movement.

The screws or other fastenings that secure the L-bracket to the guider plate are loosened. The wheel is adjusted by loosening it and sliding it along the axle and bringing it to a position where the desired track width is achieved. The guider plate and the square neck bolts make it possible that the wheel remains in position while refastening the bolts. Bolts are refastened to secure the wheel in new position. Similar operation is carried out on the other wheel is necessary.
Based on the foregoing discussion it is evident that the present invention has the following embodiments:
1. A tractor wheel with linear adjustability of track width comprising:
- a wheel rim to which a disc is attached, said disc being a standalone
element which is fixed to said wheel rim with the help of a plurality of L-
brackets, said L-brackets having provisions for attaching itself to the wheel
rim as well as said disc;
- a plurality of guider plates which are fixedly attached to said wheel rim,
said guider plates having at least one slit in which fixing elements such as
screws slide adjustably into a position.
2. A tractor wheel with linear adjustability of track width as described in
embodiment no. 1 wherein the means of fixing said guider plates to said
wheel rim are welding, screw-fitting, riveting, or any combination thereof,
or any other suitable means.

3. A tractor wheel with linear adjustability of track width as described in embodiment nos. 1 and 2 wherein said L-bracket may be positioned anywhere along the slit.
4. A tractor wheel with linear adjustability of track width as described in embodiment nos. 1 to 3 wherein said guider plate has position-markings on it along said slit to enable accurate positioning of said L-bracket at desired positions matching across all other guider plates of said wheel rim.
5. A tractor wheel with linear adjustability of track width as described in embodiment nos. 1 to 4 wherein said position-markings on said guider plate are achieved with one or more ways from options comprising engraving, embossing, painting, inking, stickers, labels or any combination thereof.
6. A tractor wheel with linear adjustability of track as described in embodiment nos. 1 to 5 wherein the number of said slits is greater than 1.
7. A tractor wheel with linear adjustability of track width as described in embodiment nos. 1 to 6 wherein said guider plates are positioned with equal spacing between any two adjacent plates.
8. A tractor wheel with linear adjustability of track width as described in embodiment nos. 1 to 7 wherein said L-bracket which is of load bearing type.
9. A tractor wheel with linear adjustability of track width as described in embodiment nos. 1 to 8 wherein the means of fitting said guider plate to

said wheel rim is a square neck bolt wherein a clearance is provided between said guider plate slot and said square neck bolt, said clearance being sufficient to arrest tilting of disc during rim-tyre assembly sliding during track adjustment. 10. A method of adjusting track width adjustment of the track width, said method involving the steps of:
- jacking up the tractor wheel as constructed in accordance with any of
embodiments 1 to 9 and needing adjustment to allow its free movement,
- loosening the screws or other fastenings means that secure said L-bracket to said guider plate,
- adjusting said wheel by loosening it and sliding it along the wheel axle and bringing it to a position where the desired track width is achieved,
- confirming consistency of position adjustment for all the guider plates with ,matching markings
- refastening the fastening to secure said wheel in new position
- performing all preceding steps on the other wheel if necessary.
While the above description contains much specificity, these should not be construed as limitation in the scope of the invention, but rather as an exemplification of the preferred embodiments thereof. It must be realized that modifications and variations are possible based on the disclosure given above without departing from the spirit and scope of the invention. Accordingly, the

scope of the invention should be determined not by the embodiments illustrated, but by the appended claims and their legal equivalents.

Claims:
1. A tractor wheel with linear adjustability of track width comprising:
- a wheel rim to which a disc is attached, said disc being a standalone
element which is fixed to said wheel rim with the help of a plurality of L-
brackets, said L-brackets having provisions for attaching itself to the wheel
rim as well as said disc;
- a plurality of guider plates which are fixedly attached to said wheel rim,
said guider plates having at least one slit in which fixing elements such as
screws slide adjustably into a position.
2. A tractor wheel with linear adjustability of track width as claimed in claim 1 wherein the means of fixing said guider plates to said wheel rim are welding, screw-fitting, riveting, or any combination thereof, or any other suitable means.
3. A tractor wheel with linear adjustability of track width as claimed in claims 1 and 2 wherein said L-bracket may be positioned anywhere along the slit.
4. A tractor wheel with linear adjustability of track width as claimed in claims 1 to 3 wherein said guider plate has position-markings on it along said slit to enable accurate positioning of said L-bracket at desired positions matching across all other guider plates of said wheel rim.
5. A tractor wheel with linear adjustability of track width as claimed in claims 1 to 4 wherein said position-markings on said guider plate are

achieved with one or more ways from options comprising engraving, embossing, painting, inking, stickers, labels or any combination thereof.
6. A tractor wheel with linear adjustability of track width as claimed in claims 1 to 5 wherein the number of said slits is greater than 1.
7. A tractor wheel with linear adjustability of track width as claimed in claims 1 to 6 wherein said guider plates are positioned with equal spacing between any two adjacent plates.
8. A tractor wheel with linear adjustability of track width as claimed in claims 1 to 7 wherein said L-bracket which is of load bearing type.
9. A tractor wheel with linear adjustability of track width as claimed in claims 1 to 8 wherein the means of fitting said guider plate to said wheel rim is a square neck bolt wherein a clearance is provided between said guider plate slot and said square neck bolt, said clearance being sufficient to arrest tilting of disc during rim-tyre assembly sliding during track adjustment.
10. A method of adjusting track width adjustment of the track width, said method involving the steps of:
- jacking up the tractor wheel as constructed in accordance with any of
claims 1 to 9 and needing adjustment to allow its free movement,
- loosening the screws or other fastenings means that secure said L-bracket
to said guider plate,

- adjusting said wheel by loosening it and sliding it along the wheel axle and bringing it to a position where the desired track width is achieved,
- confirming consistency of position adjustment for all the guider plates with ,matching markings
- refastening the fastening to secure said wheel in new position
- performing all preceding steps on the other wheel if necessary.