FORM 2
THE PATENTS ACT, 1970
(39 OF 1970)
As amended by the Patents (Amendment) Act, 2005
&
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2006
COMPLETE SPECIFICATION
(See section 10 and rule 13)
TITLE OF THE INVENTION
Easy to mount and demount-light weight jointless any durable moulded wheel ballast for an agricultural vehicle
APPLICANTS
Mahindra & Mahindra Ltd, Gateway Building, Apollo Bunder Mumbai 400001
Maharashtra, India, an Indian Company
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the nature of this invention and the manner in which it is to be performed.

FIELD OF THE INVENTION
This invention relates to an easy to mount and demount, light weight, jointless and durable moulded wheel ballast for an agricultural vehicle.
This invention generally relates to ballasting or adding weight to wheels of agricultural vehicles such as tractors or construction equipments for adjusting or changing traction required for applications such as farming, haulage or puddling and particularly relates to adding weight to wheels of a tractor and more particularly relates to a wheel ballast having versatility in conveniently adjusting the weight of the wheel so as to suitably vary the tractive effort for smooth and effective operation of the tractor for different applications.
BACKGROUND OF THE INVENTION
In general, tractor is a vehicle which works in farm/ field based on traction which is the result of friction coefficient between tires of a vehicle and ground surface combined with the contact area of ground covered by tires ie foot print and weight of the ,vehicle tires pressing on the ground. Weight of the vehicle, type of drive wheel load-bearing area of ground surface and type of ground surface are the three important parameters of traction which determine the effective and smooth operation of the vehicle in field/farm for a particular application. Tractors are used with agricultural implements for farming and also for hauling a trailer or operating constructional equipments. The parameters of

traction as mentioned above differ with different applications. This necessitates the tractor to have some arrangement designed into it to vary traction or provision for ballasting with different amount of weight as desired.
Ballasting also becomes necessary since increasing size or width of the tires may not always be desirable or feasible for different farming operations. Besides the vehicle also needs to meet statutory requirements of respective territory. There exist other solutions in the field of design of weight of the tractor such as transferring of weight from the front end to the rear end of the vehicle (driving/ powered wheels), mounting or towing position of implements or increasing the tractor weight itself by increasing weight of some of its components.
Ballasting of tractor wheel is known to be used to increase traction of tractor suitable for farming or other operations and applications. Commonly used ballasting techniques include adding fluid like water to the rear wheels (tubes) of the vehicle, attaching additional weight to the rear wheels and, if required, to the front wheels. Adding fluid like water in tires requires special equipments or means for filling water and thereafter an air compressor to inflate the tires. Draining of fluid is also tedious and inconvenient to carry out in the field. In case of adding weight to the wheels, different sizes of weights are required. This increases the cost and does not provide flexibility to adjust the weight conveniently as per the requirement, as the weights need to be replaced with the appropriate ones every time wheel weight is to be changed.

Also mounting and removing of heavy wheel weights manually becomes quite tedious for
a single operator. Further to that, when tractor is operated in idle condition or some other
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applications not requiring additional ballasting, the unwanted extra weight added on the tractor results in additional load on its engine and thus adversely affects its performance and fuel consumption, besides extra wear of the other components of the tractor such as tires or brakes.
US 2780497 discloses a wheel weight which includes a hollow drum embodying inner and outer spaced circular walls having their outer peripheral edges connected by an
annular web providing a rim member. The rim member has an opening provided with a
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removable closure plate. The closure plate has a hole therein provided with a removable plug. The drum has a central opening therethrough for accommodation and reception of a tractor drive axle. The circular walls have aligned apertures and sleeves extending between them at circumferentially spaced points adapted to accommodate lug bolts. A plurality of L-shaped lugs are circumferentially secured at the rim member for removably connecting the drum to the rear wheel of the tractor via existing lug bolts.
The construction of the drum comprising an outer circular wall and an inner circular wall with the outer peripheral edges thereof connected by an annular peripheral rim member necessitates employment of very accurate and careful process techniques to join the walls with the annular member which otherwise may cause leakage problems when the drum is filled with water for ballasting the wheel weight and may reduce the reliability of the wheel weight. Further the closure plate provided on the rim member may also lead to

leakage if the joint is not strong and precise to restrict water leakage once it is secured to the rim member. The drum construction and securing of the closure plate with the rim member need to be robust enough to be used with tractors supposed to be working in rough environmental conditions like farm/ field.
Addition of L-shaped lugs for mounting the drum with wheel rim increases the count of
parts in the wheel weight thereby leading to complexity in the manufacture and
increasing the cost. Improper joint of the L shaped lugs also may adversely affect
reliability of the wheel weight. Another major disadvantage of the wheel weight is that it
is mounted onto the wheel and protrudes beyond the outer surface of the tires thereby
increasing track width of the vehicle which may not be desirable or permissible as per the
statutory requirements or application itself. Another drawback of the wheel weight is the
position of the removable closure plate and plug on the periphery of the rim member,
which can force the operator to remove the drum from the rim of the whee] and support it
on drive axle for filling the drum with the desired material. This may not be convenient to
do every time and the operator will end up carrying the required tools for removing the
drum from the wheel. ,
US 1368535 discloses a tractor wheel by which traction force can be decreased or increased according to the demand with a ballast. The wheel comprises a hub, a rim. inner spokes connecting the rim to the hub. a ballast tank removably mounted between the rim and the hub and outer spokes removably connected outside of the ballast tank and connecting the rim and the hub. The ballast tank is located within the wheel itself.

Therefore, mounting or demounting of the ballast is very tedious and it may not be
possible to carry out the same by a single operator. Further the ballast tank is fabricated
and comprises joints. Therefore, it may suffer from leakage unless extreme care is
exercised at the manufacturing stage thereby reducing reliability. It also suffers from
some of the other disadvantages discussed earlier. Further, it comprises a large number of
i parts and joints between the related parts which makes the wheel construction very
complex and complicated.
US 2243380 discloses a wheel construction which includes a dished wheel disc, a weight
member having a surface complemental to the outer face of the wheel disc and in
continuous engagement therewith and means extending through the weight member for
detachably connecting the weight member of the wheel disc. The wheel disc is provided
with circumferentially spaced radial slots ands bolts passing through the slots for
detachably connecting the weight member to the wheel disc. Some of the drawbacks of
the wheel construction are inflexibility to adjust the wheel weight because of the fixed
weight of the weight member, heaviness of the weight member, inconvenience of
handling the weight member by single operator and high cost of manufacture.
tBecause of the problems and disadvantages of the prior art wheel ballasts as discussed above there remains the need to develop a wheel ballast which overcomes the drawbacks and shortcomings of the prior art wheel ballasts and the invention provides such a wheel ballast.

SUMMARY OF THE INVENTION
According to the invention there is provided an easy to mount and demount, light weight, jointless and durable moulded wheel ballast for an agricultural vehicle, the wheel ballast comprising a hollow cylindrical body defined by an inner circular face, an outer circular face spaced apart from the inner circular face and an annular web integrally formed with the outer peripheries of the inner annular face and outer annular face, the cylindrical body having a recess at the centre of the inner circular face thereof to accommodate the hub of a wheel of the vehicle, atleast one grip means to facilitate handling of the wheel ballast, wheel tire valve exposing means to facilitate access to the wheel tire valve, a feed opening provided with a leak tight closure, a plurality of vibration dampening mounting means for mounting the wheel ballast to the wheel and a plurality of spaced apart reliefs at the periphery of the inner circular face aligned with the wheel mounting bolts to avoid fouling with the wheel mounting bolts.
BRIEF DESCRIPTION OF THE DRAWINGS ACCOMPANYING THIS SPECIFICATION
In the drawings accompanying this specification:
Fig la is a front view or outer side view of a wheel ballast for an agricultural vehicle according to an embodiment of the invention without the leak tight closure for the feed opening thereof;

Figs 2a and 3a are isometric views of the wheel ballast of Fig la from the front side or outer side thereof without the leak tight closure for the feed opening thereof;
Fig 4a is a back side or inner side view of the wheel ballast of Fig la;
Fig 5a is an isometric view of the wheel ballast of Fig la from the back side or inner side thereof;
Fig 6a is a section along line XX in Fig 2a;
Fig 7a is an isometric view of a bush of the wheel ballast of Fig la;
Fig 8a is a sectional view of the bush of Fig 7a;
Fig 9a is a view of a mounting stud of the wheel ballast of Fig la;
Figs 10a and 11a are isometric views of a stud cap of the wheel ballast of Fig la from opposite sides thereof;
Fig 12a is a sectional view of the stud cap of Fig l0 or Fig 11a;

Fig 13a is a sectional view of the leak tight closure for the feed opening of the wheel ballast of Fig la including the associated metal insert;
Fig 14a is view of the outer end of the stepped outer diameter hollow tubular member of the leak tight closure of Fig 13a; and
Fig 15a is a fragmental sectional view of the ballast of Fig la mounted to a wheel.
DETAILED DESCRIPTION OF THE DRAWINGS ACCOMPANYING THIS SPECIFICATION
The wheel ballast 1 for the wheel of an agricultural vehicle as illustrated in Figs la to 15a of the drawings accompanying this specification comprises a hollow cylindrical body 3 defined by an inner circular face 4, an outer circular face 5 spaced apart from the inner circular face and an annular web 6 integrally formed with the outer peripheries of the inner circular face and outer circular face. Preferably the outer surface of the annular web is corrugated (corrugations marked 7) to give rigidity to the wheel ballast. The hollow space in the ballast is marked 8. The cylindrical body is formed with a recess 9 at the centre of the inner face 4 thereof matching with the wheel hub to accommodate the
wheel hub. The cylindrical body is also provided with a pair of diametrically opposite
i oblong notches 10 to provide a grip and facilitate handling of the wheel ballast. (Figs la,
2a, 3a, 6a, 13a and I5a). 12 is a dent at the outer periphery of the wheel ballast aligned
with the wheel tire valve (not shown) to provide access to the valve.

The wheel ballast comprises four equally spaced apart tapered mounting holes 13 extending across the entire width of the wheel ballast isolated from the hollow space 8 within the ballast (Fig 6a). The mounting holes are tapered from both the outer ends in the inner circular face and outer circular face of the cylindrical body towards the inner direction of the mounting holes (Figs 6a and 15a). As shown in Fig 15a the wheel ballast is easily mounted to the wheel 2 by introducing a pair of elastic bushes 14 (one of which is shown in Figs 7a and 8a) into each of the mounting holes from opposite sides thereof with the larger diameter portions of the bushes directed outwardly. A mounting stud 15 of Fig 9a is introduced through the bushes. Both the inner and outer ends of the stud are threaded and are marked 16 and 17. The outer end of each stud is mounted to the outer circular face 5 by engaging nut 18 and washers 19 on the outer end of the stud and tightening the nut against the washers and the outer circular face. The outer ends of the studs and the corresponding nuts and washers are covered with stud caps 20 shown in Figs 10a, 11a and 12a.
A stud cap comprises a cup shaped body and a metallic nut 21 at the open end thereof. The caps are introduced over the outer ends of the studs and the corresponding nuts and washers through the holes 21a in the nuts and tightened over the outer ends of the studs. The inner ends of the studs protrude out of the inner circular face 4 of the wheel ballast. The ballast 1 is aligned with the wheel 2 with the wheel hub located in the recess 9 at the inner circular face of the ballast. The protruding inner ends of the studs are engaged in corresponding mounting holes (not marked but can be seen in Fig 15a) in the wheel and are mounted to the wheel with nuts 22 and washers 23 engaged on the inner ends of the

studs and tightened against the wheel. The wheel ballast can be easily demounted or disengaged from the wheel by loosening and removing the nuts and washers from the respective studs. Spaced apart depressions 24 at the periphery of the inner circular face of the wheel ballast are aligned with the wheel mounting bolts 25a to provide space to accommodate the wheel mounting bolts and to help to avoid fouling with the wheel mounting bolts (Fig 15a).
The wheel ballast is also provided with a feed opening 25 at the periphery of the outer circular face 5 thereof (Fig 2a). A leak tight closure 26 for the feed opening is shown in Figs [3a and 14a. The closure comprises a stepped outer diameter holfow tubular member 27 having a larger outer diameter portion 28 and a smaller outer diameter portion 29 defined by a step 30. The larger outer diameter portion comprises threads 31 on the outer circumference thereof. The tubular member also comprises a closure member 32 extending across the entire inner diameter thereof. 33 is a sealing gasket, preferably an O-ring, located over the inner diameter portion of the tubular member against the step between the larger outer diameter portion and smaller outer diameter portion. 34 is a metal insert having threads 35 at the outer end inner surface thereof matching with the threads on the larger outer diameter portion of the tubular member. The metal insert also comprises a downwardly directed bent portion 36 projecting down from the inner end thereof and adapted to abut against the sealing gasket. The metal insert also comprises a circumferential groove 37 on the outer circumference thereof matching with the thickness of the periphery of the feed opening. The metal insert is push fitted in the feed

opening with the periphery of the feed opening engaged in the circumferential groove on the outer circumference of the metal insert.
In order to close the feed opening, the tubular member 27 is introduced in the metal insert
and turned in one direction and tightened in the metal insert with the threads in the metal
insert and on the tubular member in thread engagement until the sealing gasket abuts
against the downwardly directed bent portion of the metal insert. The closure member 32
in the tubular member completely closes the feed opening 25. The sealing gasket, thread
engagement between the tubular member and metal insert and fitment of the periphery of
the feed opening in the circumferential groove on the cover circumference of the collar
together provide a leak tight joint between the feed opening and the closure when the
feed opening is closed with the closure.
The feed opening is opened by turning the tubular member in the metal insert in the opposite direction and removing the tubular member from me metal insert. As shown in Fig 14a the outer end of the stepped outer diameter tubular member 27 is closed and formed with a T-shaped slot 38 to provide a grip and facilitate rotation of the tubular member in opposite directions.
The elastic bushes are made of elastic materials selected from polyvinyl chloride nitrile rubber. The stud caps are made of flexible materials selected from nylon-6. The wheel ballast of the invention is moulded or rotomoulded with any mouldable or rotomouldable and durable material. Preferably the mouldable or rotomouldable material is selected

from low or medium density polyethylene or crosslinked polyethylene. The cup shaped body of the stud caps is preferably made by moulding with flexible materials selected from polyvinyl chloride nitrile rubber.
As and when the weight of the wheel of an agricultural vehicle is to be increased the leak tight closure 26 is detached from the feed opening 25 and the required amount of a weight increasing material (not shown) is filled into the hollow empty space 8 in the wheel ballast through the feed opening. After this the feed opening is closed with the closure and the vehicle is operated. The weight increasing material that may be filled in the wheel ballast include granular material such as sand or liquid such as water or combination of both.
Because the wheel ballast of the invention is made by moulding or rotomoulding, it is possible to mass produce the wheel ballast so as to reduce the production cost and render the wheel ballast cost effective. It is also possible to achieve a jointless or seamless and integrated construction of the wheel ballast. As the wheel ballast is without joints probability of leakage of the material from the wheel ballast, especially liquid material is completely eliminated. As a result the reliability of the wheel ballast is increased. The wheel ballast is light weight and can be easily handled by one person. At the same time it is also mechanically strong and durable to bear the brunt of rough and tough field and farm conditions. Further the weight of the wheel ballast can be increased to the required amount by filling it with the required amount of material. Therefore, the wheel ballast is versatile to give required amount of weight by filling the required amount of material.

This helps to control the wheel weight according to the traction force as required. As a result, there is no need to unnecessarily increase the engine power to carry unwanted or unrequired amount of wheel weight. This in turn reduces fuel consumption fciy the engine and wastage of fuel and increases the fuel efficiency of the engine. This also reduces the . wear and tear to the wheel and wheel tire of the vehicle.
Besides making light weight, the moulded construction of the wheel ballast also helps to control the dimensions of the wheel ballast accurately and make it compact and closely match the wheel outer diameter. Further the recess 9 at the inner circular face 4 of the wheel ballast helps to accommodate the wheel hub. As a result, the wheel ballast does not increase the width of the wheel and the vehicle beyond the required limits and it is possible to maintain the vehicle width within permissible limits.
The mould construction of the wheel ballast improves the aesthetic look and appearance of the wheel ballast. Covering of the outer ends of the mounting studs 15 with stud caps 20 also improves the aesthetic appearance and look of the ballast. Because of the moulded construction of the wheel ballast, complexity of construction of the wheel ballast is reduced and the construction is very much simplified.
The tapered geometry of the mounting holes 13 and bushes 14 and provision of two bushes in the mounting holes over the mounting studs 15 from opposite directions with the larger diameter portions of the bushes directed outwardly help to dampen the vibrations of the wheel getting transmitted to the wheel ballast. Besides dampening the

vibrations, the disconnect provided by the space 39 (Fig 15a) between the bushes also helps to break the continuivity of the vibrations getting transmitted from the wheel.
Mounting of the wheel ballast to the wheel 2 with the mounting studs 15 and nuts 19 and 22 demounting of the wheel ballast from the wheel by loosening and removing the mounting studs and nuts is very easy to carried out even by an unskilled person. Therefore, the mounting and demounting of the wheel ballast is very easy and convenient to carry out. Another main advantage of the invention is that mounting of the wheel ballast to the wheel and demounting of the wheel ballast from the wheel can be carried out without disturbing the wheef mounting at ail. The depressions 24 in the ballast provide enough clearance to handle the wheel mounting bolts (not shown) without disturbing or fouling with the wheel ballast. Provision of the feed opening 25 at the periphery of the outer circular face 5 makes it easy to access the feed opening. The leak tight closure 26 for the feed opening further improves the reliability of the ballast. The dent 12 at the outer periphery of the wheel ballast helps to access the wheel tire valve in the mounted condition of the ballast without disturbing the ballast. The entire construction of the wheel ballast is thus user friendly.
The above embodiment of the invention is by way of example and should not be construed and understood to be limiting the scope of the invention. The grip means
comprising oblong notches for handling the wheel ballast can be of a different
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construction or configuration. There can be one or more than two grip means. The recess at the centre of the inner circular face is optional. The geometry of the recess at the centre

of the inner circular face can be different. The wheel tire valve exposing means can be of a different construction or configuration besides being a dent. The vibration dampening mounting means comprising the mounting holes, bushes and mounting studs can be of a different construction or configuration. The outer surface of the annular web need not be corrugated. The leak tight closure can be of a different construction or configuration. The stud caps can be of a different construction or configuration. The geometry of the depressions (reliefs) to avoid fouling with the wheel mounting bolts can be different. Such variations in the construction or configuration of the wheel ballast are obvious to a person skilled in the art and are to be construed and understood to be within the scope of the invention.

We claim:
1) An easy to mount and demount, light weight, jointless and durable moulded wheel ballast for an agricultural vehicle, the wheel ballast comprising a hollow cylindrical body defined by an inner circular face, an outer circular face spaced apart from the inner circular face and an annular web integrally formed with the outer peripheries of the inner annular face and outer annular face, the cylindrical body having a recess at the centre of the inner circular face thereof to accommodate the hub of a wheel of the vehicle, atleast one grip means to facilitate handling of the wheel ballast, wheel tire valve exposing means to facilitate access to the wheel tire valve, a feed opening provided with a leak tight closure, a plurality of vibration dampening mounting means for mounting the wheel ballast to the wheel and a plurality of spaced apart reliefs at the periphery of the inner circular face aligned with the wheel mounting bolts to avoid fouling with the wheel mounting bolts.
2) The wheel ballast as claimed in claim 1, which is moulded with mouldable and durable material selected from low or medium density polyethylene or crosslinked polyethylene.
3) The wheel ballast as claimed in claim 1, which is rotomould with rotomouldable and durable material selected from low or medium density polyethylene or Crosslinked polyethylene.

4) The wheel ballast as claimed in any one of claims 1 to 3, which comprises a pair of grip means, each grip means comprising an oblong notch provided at the outer circular face of the wheel ballast diametrically opposite to each other.
5) The wheel ballast as claimed in any one of claims 1 to 4, wherein the tire valve exposing means comprises a dent at the outer periphery of the wheel ballast aligned with the wheel tire valve to provide access to the tire valve.
6) The wheel ballast as claimed in any one of claims 1 to 5, wherein the mounting means comprises a plurality of mounting holes extending across the entire width of the ballast isolated from the hollow space within the ballast and equally spaced part from one another, the mounting holes being tapered from both the outer ends in the inner circular face and outer circular face of the cylindrical body towards the inner direction of the mounting holes, a pair of tapered elastic bushes one engaged in a mounting hole through the outer circular face and the other engaged in the said mounting hole through the inner circular face, a mounting stud engaged through each pair of bushes in each of the mounting holes, the mounting stud being threaded at the ends thereof, the outer end of the mounting stud being mounted to the outer circular face with nut and washers tightened on the outer end of the mounting stud against the outer circular face, the inner end of the mounting stud protruding out of the inner circular face and being engaged in a corresponding mounting hole in the wheel and being mounted to the wheel with nut and washers tightened on the inner end of the mounting stud against the

wheel, the nuts and washers at the outer ends of the mounting studs being covered with stud caps.
7) The wheel ballast as claimed in claim 6. wherein the bushes are made of elastic material selected from polyvinyl chloride nitrile rubber.
8) The wheel ballast as claimed in claim 6 or 7, wherein the stud caps each comprises a cup shaped body and a metallic nut at the open end thereof.
9) The wheel ballast as claimed in claim 8. wherein the cup shaped body is made of flexible material selected from nylon-6.
10) The wheel ballast as claimed in anyone of claims 1 to 9, wherein the feed opening is provided at the periphery of the outer circular face and wherein the feed opening comprises a metal insert located therein' and having threads at the outer end inner surface thereof and a downwardly directed bent portion projecting down from the inner end thereof and wherein the leak tight closure for the feed opening comprises a stepped outer diameter hollow tubular member disposed in the metal insert and having a larger outer diameter portion and a smaller outer diameter portion defined by a step and a closure member extending across the entire inner diameter of the hollow tubular member, the larger outer diameter portion having threads on the outer circumference thereof matching with the threads at the outer end inner surface of the metal insert and being adapted to be in thread engagement with the outer end inner surface of the metal insert and a sealing gasket located

over the smaller outer diameter portion against the step between the larger outer diameter portion and smaller outer diameter portion and adapted to abut against the downwardly directed bent portion projecting down from the inner end of the metal insert, the outer end of the larger outer diameter portion of the tubular member being closed and formed with a T-shaped slot to provide a grip.
1 l)The wheel ballast as claimed in claim 10, wherein the sealing gasket is an O-ring.
12) The wheel ballast as claimed in any one of claims 1 to 11, wherein the outer surface of the annular web of the cylindrical body is corrugareb.
13) The wheel ballast as claimed in any one of claims 1 to 12 wherein the reliefs are depressions.