[001] This invention is related to in general agriculture tractor wheel more particularly, to a structural lug.
BACKGROUND/PRIOR ART OF THE INVENTION
[002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[003] Agricultural tractor with adjustable wheels are known to be provided in the market, wherein, the track i.e. the spacing between a pair of coaxial wheels of the tractor may be adjusted to suit its use in differing agricultural situations where for example differing widths of rows of crops have to be traversed by the tractor. Such known manually adjustable wheels usually comprise a rim detachably secured to a disc which is itself detachably secured to a rotary member such as a driveshaft. The means for detachably securing the rim to the disc usually comprises a plurality of lugs spaced apart circumferentially around the radially inner surface of the rim.
[004] Agriculture tractor vehicle often requires fastener/lug for the attachment of disc to a rim. However, it was observed in the existing lug/fastener design (twin shape) that there is a failure of lug/fastener design and also weld crack observed between the lug and rim. Therefore, the life of the wheel is less.
[005] Now, reference may be made to figure 1 regarding a known twin shaped lug/fastener employed for the attachment of disc to rim. However, it is associated with several drawbacks which can be listed hereinunder:-
- Failure of lug/fastener

- Weld crack between lug and rim
Shorter life span of wheel.
[006] Now, reference may be made to the following prior arts: -
[007] GB2341152A- A method of making a wheel for a vehicle in which the wheel includes a rim to receive a tyre, the rim having a.generally cylindrical portion; a plurality of lugs spaced apart around a radially inner surface of the generally cylindrical portion of the rim; 'a wheel disc for connection of the wheel to a hub of the vehicle, the wheel disc being adapted to be secured in the rim to the lugs by fastener means; the method being characterised in that the method includes providing the lugs by severing individual lugs from feedstockmaterial.
Drawback of prior art: As it can be seen in the figure 1 and 2, the lugs 30 each have a generally channel shape in cross section parts 39, and a pair of outwardly turned flanges 33 at the free ends of the channel sides 34. The channels parts 39 of the lugs 30 extend generally axially of the wheel 10 and the flanges 33 extend outwardly generally circumferentially. In the above lug design, occurance of failure is high due to lug crack or rim crack from the welding area.
However, in present invention the lug shape is tube type hollow rectilinear section. Due to this stresses are reduced where the lug is attached to the rim and the life of wheel is also increased.
[008] EP0808250B1- A wheel (10) comprising a rim (11), and a disc (15) by which the wheel (10) is attached to a hub, the disc (15) being attached to the rim (11) by means of generally axially extending fasteners (50) each of which passes through a respective opening (46, 47) of the disc (15) and is received in a respective generally axially extending passage (40, 41) of a connection member of the rim (11) , tolerances in the openings (46, 47) of the disc (15), and/or the passages (40, 41) of the connection member and the fasteners (50) permitting variation in the position of the disc (15) relative to the rim (11), characterised in that at least two indicating means (60b) are provided, the positions of which are fixed with respect to the rim

(11), and each indicating means (60b) may be aligned with a corresponding additional opening (60, 60a) in the disc (15).
Drawback of prior art: As it can be seen in the figure 1 and 2, each of the lugs 31 to 34 has a pair of passages 40 and 41. The passages comprising through openings in each of two limbs 42, 43 of the generally U-shaped lugs 31 to 34.
[009] However, in present invention the lug shape is tube type hollow rectilinear steel section. Due to this stresses are reduced where the lug is attached to the rim and the life of wheel is also increased.
[010] GB2263449B: Wheel for variable-gauge vehicles comprising an annular rim for reception of the tire and a central plate of generally polygonal form fixed to the inner part of the rim by means of double bolting of the corners to brackets welded to the rim and characterized in that each bracket is made up of a generally rectangular plate in the form of a double omega to identify in the central loop of each omega a seat for reception of one of two bolts for fastening of the central plate, the free ends and the central part between the omegas being welded below to the rim and between outer parts of the loops of each omega and areas welded to the rim there being moulded strengthening ribbings.
Thus, each bracket (12) is made up of a generally rectangular plate in the shape of a double omega to identify in the central loop of each omega a reception seat for one of two bolts (13, 14) for fastening of the central plate (15).
However, in present invention the lug is generally tube type hollow rectilinear steel section. Due to this, stresses are reduced where the lug is attached to the rim.
[011] US4643484A: A manually adjustable wheel for a vehicle, e.g., a tractor, comprising: a rim to receive a tyre; a plurality of channel-shaped fixing lugs spaced apart around the radially inner periphery of the rim, the lugs being arranged in pairs with the circumferential spacing between the lugs of each pair being less than the circumferential spacing between adjacent lugs of adjacent pairs, the lugs having

flanges which overlie, and are welded to, the rim thus fixedly to secure the lugs to the rim; a disc of uniform thickness for connection to a hub of the vehicle; the disc having substantially the shape of a square with the corners cut off so that the disc has an irregular octagonal shape having four longer sides and four shorter sides arranged alternately around the periphery of the octagon and with each shorter side being juxtaposed against a pair of lugs; and bolt means detachably securing the disc to the lugs, the disc and lugs being arranged so that the disc may be selectively secured to the lugs in either of two positions, the bolt means being located along the shorter sides of the disc only and, at each of said shorter sides comprising two bolts with each bolt passing through the disc and through one of the lugs of a pair of lugs juxtaposed to said shorter side.
Thus, secured to the radially inner periphery of the rim are eight lugs 58 which are arranged in pairs with a circumferential spacing between the lugs of each pair being less than the circumferential spacing between adjacent lugs of adjacent pairs. These lugs are generally of top hat section and provide, referring to one of the lugs, a channel having sides 59, a base 60 and flanges 60a.
In comparison, in present invention the lug is generally of tube type rectilinear steel section used which is having more strength as compared to above mentioned patent because the surface area is more as compared to lug 58 and also the stresses are reduced in case of new improved lug design.
[012] DE837649C: Vehicle wheel, especially for agricultural vehicles, z. B. tractor, in which the wheel rim is connected by means of attached to the rim base wreath-shaped or U-shaped or similar intermediate members for the purpose of changing the track feasible with a radial flange of the wheel by parallel to the axis extending screws, characterized in that the intermediate links ( 2) with serving for centering the rim on the flange of the wheel body lugs (4, 14) are provided.
The above invention is based on the known attachment of the wheel rim to the wheel body by means of angled or U-shaped or similarly bent intermediate members

attached to the la wheel base, which are detachably connected to a radial flange of the wheel body by screws' extending parallel to the wheel axis.
In the proposed application, the lug is genarally tube type hollow rectilinear shaped section and attachment of lug to the wheel rim by means of welding. The welding acts as permanent fastener and whereas in the above mentioned patent in which screws are used which act as temporary fastener. Therefore, strength is more in present invention when tube lug is attached to wheel rim by means of welding.
[013] None of the above can fulfill the requirements of present invention, for which it is devised. Hence, the present invention introduces a structural lug for agriculture tractor wheel.
OBJECTS OF THE INVENTION
[014] An object of the invention is to propose a structural lug for agriculture tractor wheel which obviates shortcomings of prior art(s).
[015] Another object of the invention is to propose a structural lug for agriculture tractor wheel which is simple in construction.
[016] Still another object of the present invention is to provide a structural lug for agriculture tractor wheel which is durable.
[017] Yet another object of the present invention is to provide a structural lug for agriculture tractor wheel which provides more strength to the wheel and leads to overall stress reduction.
[018] These and other objects and advantages of the present invention will be apparent to those skilled in the art after a consideration of the following detailed description taken in conjunction with the accompanying drawings in which a preferred form of the present invention is illustrated.
SUMMARY OF THE INVENTION

[019] One or more drawbacks of conventional systems and process are overcome, and additional advantages are provided through the apparatus and a method as claimed in the present disclosure. Additional features and advantages are realized through the technicalities of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered to be part of the claimed disclosure.
[020] In accordance with the invention there is provided a manually adjustable wheel for a vehicle e.g. an agricultural tractor comprising a rim to receive a tire, the rim having at least one cylindrical portion; a plurality of lugs spaced apart around the radially inner surface of said cylindrical portion of the rim, the lug extending perpendicular to the rotary axis of the wheel and receiving a pair of circumferentially spaced apart bolts extending transversely across said lug, each lug extending circumferentially of the wheel rim and being attached by welding to said radially inner surface of a said cylindrical portion of the rim; and a wheel disc for connection to a hub of the vehicle.
[021] According to this invention, there is provided a structural lug for agriculture tractor wheel comprising a wheel rim with a plurality of circumferentially spaced apart lugs connected to the radially inner surface thereof, each of said lugs is secured to a disc at the variable offset of wheel by fastener including bolts extending transversely through said lug, wherein the lug is a hollow elongated member having rectilinear cross section, wherein the member comprises atleast four walls including a pair of upper and lower and left hand side and right hand side opposed walls; the upper and lower walls are curved in shape which run parallel to each other, the left hand side and right hand side walls are flat in profile which are disposed parallel to each other, wherein the side walls are provided with a pair of through holes in proximate to end thereof that two holes are disposed opposite to each other that a bolt can pass through the same for bolting with the disc while assembling the wheel.
[022] The lug is preferably made of high tensile steel.

[023] The lug, one surface of which can be welded to rim inner surface by metal inert gas welding and other surface is bolted to the disc of wheel, in which the surface is having curvature corresponding to that of disc outer surface and rim inner surface respectively.
[024] Besides metal inert gas welding any other type of welding can be adopted, which is suitable for the present invention.
[025] The wheel rim can be selected from single well configuration/double well configuration/triple well configuration.
[026] Method of manufacturing the structural lug for agriculture tractor wheel comprising steps of>
- cutting of rectilinear hollow section into required length, standardization of hollow section,
- bending of hollow section, wherein the bending has to be matched with the rim inner diameter,
drilling/ punching/ piercing/ machining of mounting holes on hollow section of lug, wherein the holes are used to attach the disc to the lug by nut and bolt arrangement,
- deburring on lug to avoid generation of sharp edges while manufacturing.
[027] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.
[028] It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined to form a further embodiment of the disclosure.

[029] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[030] The illustrated embodiments of the subject matter will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. The following description is intended only by way of example, and simply illustrates certain selected embodiments of devices, systems, and processes that are consistent with the subject matter as claimed herein, wherein: -
Figure 1 shows: Shape of lug/fastener of prior art.
Figure 2 shows: A structural lug for agriculture tractor wheel according to
present invention.
Figure 3 shows: Sectional view of present invention.
Figure 4 shows: Disc secured to rim of agricultural tractor wheel in accordance with present invention.
[031] The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAIL DESCRIPTION OF THE PRESENT INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS OF PREFERRED EMBODIMENTS
[032] While the embodiments of the disclosure are subject to various modifications and alternative forms, specific embodiment thereof have been shown

by way of example in the figures and will be described below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the scope of the disclosure.
[033] The present invention makes a disclosure regarding an invention pertaining to a structural lug for agriculture tractor wheel.
[034] Now, reference may be made to figure 2 structural lug (100) of the instant invention.
[035] Now, referring to Figure 3, wherein a wheel includes a wheel rim (101) with a plurality of circumferentially spaced apart lugs (100) connected to the radially inner surface thereof. Here, each of said lugs is secured to a disc (102) at the variable offset of wheel by fastener such as bolts extending transversely through said lug.
[036] The wheel rim (101) can be selected from single well configuration/double well configuration/triple well configuration.
[037] The disc (102) has a central planer portion mounted on a drive shaft of tractor, wherein the drive shaft acts as axle. The disc can be having octagonal shape/square/rectangular shape.
[038] Thus, the disc is having four longer sides and four shorter sides provided alternatively to each other.
[039] Each shorter side of the disc is provided in connection to said lug (100). Each of the shorter sides of the disc is secured by a pair of circumferentially spaced apart lugs to the wheel rim. The lugs themselves being welded to the radially inner surface of the rim.
[040] The lug (100) constitutes a hollow structure forming a tubular member formed by four walls. Said walls (100A, 100B, 100C, 100D) include a pair of upper and lower and Left Hand Side and Right Hand Side opposed walls (100A, 100B);

(100C, lOOD). The upper and lower walls (100A, 100B) are curved in shape which run parallel to each other.
[041] The Left Hand Side and Right Hand Side walls (100C, 100D) are flat in profile which are disposed parallel to each other.
[042] Thus, the lug comprises an elongated member. Here, the side walls (100C, 100D) are provided with a pair of through holes (Hi, H2) in proximate to end thereof such that two holes (Hi, H2) are aligned to each other. So that a bolt can pass through the same for bolting with the disc while assembling the wheel.
[043] Here, in this particular embodiment, the cross section of the lug (100) is square. However, according to another embodiment of present invention, the cross section of the lug (100) can be rectangle. Thus, the cross section of said lug (100) is rectilinear in profile.
[044] The material of the lug (100) is preferably high tensile steel without restricting the scope of the invention to the same. Thus, other materials readily apparent to a person skilled in the art are understood to be within purview of invention.
[045] Now, referring to figure 3 and 4, the lug (100), one surface (100B) of which is welded to the rim inner surface i.e. it is secured to well portion of the wheel rim. The welding can be metal inert gas (MIG) type without limiting ambit of the invention to the same. The surface (100B) is having a curvature corresponding to that of rim inner surface.
[046] The other surface (100A) of lug (100) is provided intact with the outer circumferential surface of the disc as best seen in figure 4. Also disc can be mounted on either side of the lug (100C or 100D).
Lug manufacturing process:
• Cutting of rectangular/square structural section into required length,

• Standardization of hollow section
• Bending of hollow section, wherein the bending has to be matched with the Rim ID (The rim ID is the inner diameter of the rim where the lug is welded),
• drilling/punching/piercing/machining of mounting holes (these holes are used to attach the disc to the lug by means of nut and bolt arrangement) on hollow section of structural lug,
• Deburring on lug to avoid generation of sharp edges while manufacturing.
[047] The disc and rim can be painted as a single unit.
[048] The lugs of a wheel constructed in accordance with the invention are sufficiently strong to accommodate the compressive forces as well as radial forces imparted thereto when the wheel disc is bolted to the lugs.
[049] It is found also that the attachment of the disc to each lug by two bolts, together with the fact that each lug is welded to the rim in a circumferential direction, minimizes the problems of air leakage which can be occasioned in known wheels by fatigue crack propagation from the weld sites. Thus a wheel constructed in accordance with the invention may be utilized with both tubed and tubeless tyres.
[050] Advantageous features
• More strength to the wheel
• Overall stress reduction
• Longer life span of wheel

[051] Test Result:
When vehicle is subjected to maximum tyre load/ overload during finite element analysis for the lug design as per figure 1. It has been observed lug failure during RFT (radial fatigue test).
When finite element analysis is conducted on new design as per figure 2, it has been observed during RFT (radial fatigue test) that the stresses are reduced up to 40-50 % as compared to previous design.
Note:
1. Length, Width and thickness of structural section of lug can be variable.
2. When lug is attached to REVI by means of welding. The welding can be continuous or equidistant.
3. Lug can be of square/ rectangular cross section.
[052] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases, it will be recognized that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.
[053] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all groups used in the appended claims.

[054] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particulars claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should typically be interpreted to mean "at least one" or "one or more"); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogues to "at least one of A, B and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to "at least one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but

not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B".
[055] The above description does not provide specific details of manufacture or design of the various components. Those of skill in the art are familiar with such details, and unless departures from those techniques are set out, techniques, known, related art or later developed designs and materials should be employed. Those in the art are capable of choosing suitable manufacturing and design details.
[056] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. It will be appreciated that several of the above-disclosed and other features and frnctions, or alternatives thereof, may be combined into other systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may subsequently be made by those skilled in the art without departing from the scope of the present disclosure as encompassed by the following claims.
[057] The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.
[058] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are

not intended to be limiting, with the true scope and spirit being indicated by the following claims.

WE CLAIM

1.A structural lug for agriculture tractor wheel comprising a wheel rim (101) with a plurality of circumferentially spaced apart lugs (100) connected to the radially inner surface thereof, each of said lugs is secured to a disc (102) at the variable offset of wheel by fastener including bolts extending transversely through said lug, wherein the lug (100) is a hollow elongated member (100) having rectilinear cross section, wherein the member (100) comprises atleast four walls (100A, 100B, 100C, 100D) including a pair of upper and lower and left hand side and right hand side opposed walls [(100A, 100B);(100C, 100D)]; the upper and lower walls (100A, 100B)are curved in shape which run parallel to each other, the left hand side and right hand side walls (100C, 100D) are flat in profile which are disposed parallel to each other, wherein the side walls (100C, 100D) are provided with a pair of through holes (Hi, H2) in proximate to end thereof that two holes (Hi, H2) are disposed opposite to each other that a bolt can pass through the same for bolting with the disc while assembling the wheel.
2. The hollow lug/fastener for agriculture tractor wheel as claimed in claim 1, wherein the lug (100) is preferably made of high tensile steel.
3. The hollow lug/fastener for agriculture tractor wheel as claimed in claim 1 or 2, wherein the lug (100), one surface (100B) of which is welded to rim inner surface and other surface (100A) is bolted to the disc (102) of wheel, in which the surface (100A, 100B) is having curvature corresponding to that of disc (102) outer surface and rim inner surface respectively.
4. The hollow lug/fastener for agriculture tractor wheel as claimed in claims 1-3, wherein the wheel rim (101) can be selected from single well configuration/double well configuration/triple well configuration.

5. Method of manufacturing the hollow lug/fastener for agriculture tractor wheel comprising steps of>
- cutting of rectilinear hollow section into required length, standardization of hollow section,
- bending of hollow section, wherein the bending has to be matched with the rim inner diameter,
drilling/punching/piercing/machining of mounting holes on hollow section of lug, wherein the holes are used to attach the disc to the lug by nut and bolt arrangement,
- deburring on lug to avoid generation of sharp edges while manufacturing.