FORM 2
THE PATENTS ACT, 1970 (39 of 1970) & THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10, rule 13)
/. Title of the invention: VEHICLE TIRE
2. Applicants)
NAME NATIONALITY ADDRESS
CEAT LIMITED Indian CEAT Ltd At: Get Muwala Po: Chandrapura Ta: Halol, Dist: Panchmahal, Gujarat 389 350, India
3. Preamble to the description
COMPLETE SPECIFICATION
The following specification particularly describes the invention and the manner in which it
is to be performed.

FIELD OF INVENTION
[0001] The invention described herein, in general, relates to radial tires,
and in particular, relates to bead structure in the radial tires.
BACKGROUND
[0002] A tire is an assembly of numerous components such as tread,
body plies, beads, inner liners, fillers, etc. The tread makes direct contact
with the road, providing traction and handling characteristics. Surrounding
the tread are sidewalls that offer structural support and flexibility, extending
from the tread to the beads, which anchors the tire to a wheel rim of a
vehicle. Layers of reinforcing fabric, known as body ply, enhance strength,
while the inner liner acts as a barrier. The fillers, such as carbon black and
silica, are added to the rubber for specific properties. Additionally, certain
tires may include an abrasion gum strip (AGS). The AGS is generally
provided externally to the body ply on each of the sidewalls, running
vertically from a mid-region of the sidewalls to a position near the bead.
[0003] The AGS may be composed of a specialized rubber compound
with reinforcing materials. The AGS serves a protective role by shielding the sidewall from abrasion, cuts, and environmental factors. This contributes significantly to the tire's durability and longevity, ensuring consistent performance across various driving conditions. Beyond the functional benefits, the AGS may also enhance the tire's aesthetics. The AGS in the tire helps maintain the structural integrity of the sidewalls, safeguarding inner tire components and supporting stable handling and traction. Thus, whether in passenger vehicles, trucks, or off-road applications, the AGS plays an essential role in enhancing the overall performance and resilience of the tire throughout its lifespan.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] The detailed description is described with reference to the
accompanying figures. In the figures, the left-most digit(s) of a reference

number identifies the figure in which the reference number first appears.
The same numbers are used throughout the drawings to reference like
features and components.
[0005] Fig. 1 illustrates a cross-sectional view of a tire, in accordance with
an implementation of the present invention.
[0006] Fig. 2 illustrates positioning of a shear resistance gum strip on a
body ply of the tire, in accordance with an implementation of the present
invention.
[0007] Fig. 3 illustrates a scatter plot depicting impact of width of the
shear resistance gum strip on bead endurance of the tire, in accordance
with an implementation of the present invention.
DETAILED DESCRIPTION
[0008] Despite the careful design and construction of tires, issues may
arise that affect their performance and safety. One such issue is a separation between the Abrasion Gum Strip (AGS) and a body ply in a tire that may significantly impact tire performance and safety. This separation usually occurs in bead portion, where the tire engages with wheel rim of a vehicle. The separation issue manifests in interface between the AGS, which is positioned externally to the body ply along each sidewall portion, and the body ply, a part of the tire's internal structure.
[0009] Chafing and friction between the AGS and the wheel rim during
the tire's rotation and contact with a road surface may lead to the separation problem. This chafing may result from various factors, including driving conditions, tire inflation, and overall tire design. The separation between the AGS and the body ply compromises adhesion between these tire components. This compromised adhesion may lead to a range of performance issues, such as reduced stability, handling problems, and diminished overall tire integrity.
[0010] One of the critical consequences of separation is the potential for
air leaks and loss of tire pressure. The separation allows air to escape,

leading to underinflation, which, if not addressed promptly, may result in
decreased fuel efficiency, uneven tire wear, and compromised vehicle
safety. If the separation issue persists, it may escalate to more severe
problems, including the risk of tire failure. A separated AGS may weaken
the overall tire structure, making it susceptible to blowouts or tread
separation, posing a significant safety hazard to the driver and passengers.
[0011] The separation problem poses notable safety concerns, as it may
affect the tire's ability to respond predictably to steering inputs and road
conditions. This may result in decreased vehicle control and an increased
risk of accidents, especially during high-speed or emergency maneuvers.
[0012] In summary, the separation problem between the AGS and the
body ply may affect the tire's performance, safety, and overall reliability.
[0013] The present invention addresses the separation issue for ensuring
optimal tire function and preventing potential safety hazards associated with tire failure.
[0014] According to an aspect of the present invention, a tire is provided
that includes a tread portion and a pair of sidewall portions arranged to extend circumferentially and continuously on either side of the tread portion. The tire includes one or more body plies forming the tread and sidewall portions. Each sidewall portion of the pair of sidewall portions includes a bead portion located at a distal lower end of the respective sidewall portion. The bead portion comprises a bead core therein. An abrasion gum strip is arranged radially along each of the sidewall portions and surrounds the bead core, wherein the abrasion gum strip (AGS) interfaces externally with an outermost body ply of the one or more body plies. A shear resistance gum (SRG) strip is disposed between the outermost body ply and the AGS, wherein the SRG strip is positioned above a heel of the tire.
[0015] According to other aspects of the present invention, the tire may
include one or more of the following features. The SRG strip may be positioned to initiate at a midpoint of the bead core and extend above an apex tip end of the tire. The SRG strip may be located above the heel of the

tire at a distance of 10 mm from a lowermost point of the tire. The SRG strip may be positioned at a distance of 4.5-7.5 mm from an edge of the outermost body ply. The SRG strip may have a thickness of 1.5 mm. The SRG strip may have a width of 60 mm.
[0016] By using the SRG strip in tire construction, the problem of
separation between the Abrasion Gum Strip (AGS) and the body ply may be effectively addressed. The SRG strip acts as a bonding agent between the body ply and the AGS, enhancing adhesion between the body ply and the AGS in the bead portion where separation usually occurs. This improved adhesion reduces the risk of separation between the body ply and the AGS during the tire operation. Also, by providing a layer of shear-resistant adhesive material, the SRG strip reduces friction and chafing between the AGS and the wheel rim. This reduction in abrasive forces minimizes the wear and tear on these components, reducing the likelihood of separation between the body ply and the AGS over the tire's lifespan. The SRG strip also contributes to the overall integrity of the tire by ensuring a secure and durable connection between the AGS and the body ply. This improvement in structural integrity enhances the tire's ability to withstand external forces and provides a more robust construction.
[0017] Thus, the use of the SRG strip solves the problem of separation
between the AGS and the body ply by enhancing adhesion, reducing
friction, and providing a protective layer. This addition of the SRG between
the body ply and the AGS improves the overall performance, safety, and
durability of the tire, addressing challenges associated with tire separation.
[0018] The above-mentioned implementations are further described
herein with reference to the accompanying figures. It should be noted that the description and figures relate to exemplary implementations and should not be construed as a limitation to the present invention. It is also to be understood that various arrangements may be devised that, although not explicitly described or shown herein, embody the principles of the present invention. Moreover, all statements herein reciting principles, aspects, and

embodiments of the present invention, as well as specific examples, are intended to encompass equivalents thereof.
[0019] Fig. 1 illustrates a cross-sectional view of a tire 100, in accordance
with an aspect of the present invention.
[0020] The tire 100 includes a tread portion 102. The tread portion 102 is
a part of the tire 100 that comes into direct contact with a road surface. The
tread portion 102 is designed to provide traction and resist wear, and its
design can vary depending on the specific requirements of tire 100, such as
whether it is intended for use on dry, wet, or snowy surfaces. Further, on
either side of the tread portion 102 are sidewall portions 104. The sidewall
portion 104 extends circumferentially and continuously on either side of the
tread portion 102. The sidewall portions 104 and the tread portion 102 are
typically formed from one or more body plies 106. The sidewall portions 104
provide lateral stability to the tire 100 and protects the body plies 106 from
damage. They also contribute to the tire's 100 overall strength and flexibility.
[0021] At a distal end of each sidewall portion 104 is a bead portion 108.
The bead portion 108 houses a bead core 110 within it. The bead portion 108 is designed to ensure a secure fit between the tire 100 and a rim wheel of the vehicle. The bead core 110 is typically made of high-strength steel, providing the rigidity that is necessary for this purpose.
[0022] Another component of the tire 100 is an abrasion gum strip (AGS)
112. The AGS 112 is arranged radially along sidewall portion 104 and surrounds the bead core 110. The AGS 112 interfaces externally with an outermost body ply of the one or more body plies 106 and serve to protect the tire 100 from abrasion damage, which may occur as a result of contact with the road surface or the wheel rim.
[0023] In addition to the above components, as shown in Fig. 1, the tire
100 also includes a shear resistance gum (SRG) strip 114. The SRG strip 114 is disposed between the outermost body ply and the AGS 112. The SRG strip 114 is positioned above a heel 116 of the tire 100. The heel 116 refers to a lower part of the sidewall portion 104 near the bead portion 108.

The heel 116 is the part of the bead portion 108 that sits on the wheel rim. More specifically, the heel 116 may be understood as a portion of the tire 100 that is closest to the wheel rim when assembled. The heel 116 maintains a secure fit between the tire 100 and the wheel rim. Proper engagement of the heel 116 with the wheel rim is essential for maintaining tire pressure, stability, and overall tire performance.
[0024] In an aspect of the present invention, the SRG strip 114 may have
a thickness of 1.5 mm. This thickness of 1.5 mm of the SRG strip gauge has been identified based on the SRG strip 114 penetration in cross-section of the tire which is required for proper adhesion between the AGS 112 and the outermost body ply. In other aspects, the SRG strip 114 may have a width of 60 mm, or, in other words, the SRG strip 114 may extend 60 mm along the sidewall portion. In Fig. 1, the width of the SRG strip 114 is denoted by W.
[0025] Fig. 3 illustrates a scatter plot depicting a change in bead
endurance of the tire with respect to a varying width of the SRG strip 114 with respect to time, in accordance with an implementation of the present invention. The scatter plot of Fig. 3 and Table 1 below presents the results of the bead endurance report conducted by the inventors of the present invention, evaluating the impact of varying widths of the SRG strip 114 on the endurance of the bead of the tire 100 and improvement % in the bead endurance with respect to a regular tire.
Table 1

Bead Endurance Report
S.
No
. Trial iteration Value in Hrs. Improvemen t with
respect to conventiona
l tires in %
1. Conventional tire 1 (Without SRG strip) 47.2 -

2.
3. 4. 5. Conventional tire 2 (Without SRG strip) 48.2 -

SRG strip with 70 mm Width 52.2 10.6

SRG strip with 65 mm Width 56 18.6

SRG strip with 60 mm Width 61.1 29.4
[0026] The SRG strip 114 widths tested include 70 mm, 65 mm, and 60
mm. Bead endurance results indicated in the above table, respectively, at serial nos. 3, 4, and 5 represent specific measurement indicators in terms of improvement % in bead endurance obtained for each SRG strip width in multiple trials. The values in Table 1 offer insights into the influence of the width of the SRG strip 114 on the endurance of the bead, assisting in determining optimal configurations for enhanced tire performance and longevity. As can be seen from Table 1 and the scatter plot depicted in Fig. 3, the SRG strip 114 with 60 mm width achieved significantly improved endurance results. A series of experiments were conducted by the inventors to determine the impact of varying the widths of the SRG strip 114 on the endurance of the bead of the tire 100 and surprising results were obtained. The inventors found that the SRG strip 114 with 60mm width exhibits the highest improvement in the bead endurance of the tire 100 as per the aspect of the present invention. The inclusion of the SRG strip 114 in the construction of the tire 100 provides an additional layer of protection against bead separation, a common issue that can affect the performance and safety of tires.
[0027] According to another aspect of the present invention, the SRG
strip 114 may be located above the heel 116 of the tire 100 at a distance of 10 mm from a lowermost point of the tire 100. The SRG strip 114 ending position is based on the outermost body ply ending around 5mm from the heel 116 to support bead bundle comprised within the bead core 110. This results in the SRG strip 114 ending above 10mm from the heel 116. In yet other cases, the SRG strip 114 may be positioned at a distance of 4.5-7.5

mm from an edge of the outermost body ply 106.
[0028] Referring to Fig. 1, the positioning of the SRG strip 114 in relation
to the bead core 110 and end of apex tip 118 of the tire 100 is illustrated. It is known that the ending of the SRG strip 114 is a very critical point since this is a flexible zone above the wheel rim. If the AGS 112 and the SRG strip 114 end together, it would make a valley point that may be prone to stress formation by design itself. As would be understood, this may impact 29.4% of bead durability. Therefore, in an example implementation of the present subject matter, the SRG strip 114 may be positioned to initiate at a midpoint of the bead core 110 and extend above the apex tip end of the tire 100. The advantage of ending the SRG strip 114 above the apex tip 118 end of the tire 110 is to avoid stress formation at the SRG strip's 114 termination point. By extending the SRG strip 114 beyond the apex tip 118 end, stress concentrations or points of weakness that may arise from abrupt endings are reduced. This helps ensure a more gradual transition and distribution of forces along the apex tip 118, contributing to enhanced durability and reducing the likelihood of localized stress-related issues.
[0029] It is to be understood that the positioning of the SRG strip 114 as
described above are merely examples and that other positioning of the SRG
strip 114 may be possible without departing from the scope of the present
disclosure. For instance, the SRG strip 114 may be positioned at different
points along the bead core 110 or at different distances from the lowermost
point of the tire 100, depending on the specific sizes of the tire 100.
[0030] In an example embodiment of the present invention, the SRG strip
114 may be composed of a low heat generating compound having a tan delta value lower than that of compound which is used for forming the AGS 112. This composition of the SRG strip 114 may provide an additional layer of protection against bead separation, particularly in the bead portion 108 of the tire 100, which is a common area for bead separation to occur. The composition of SRG strip 114 in this manner may enhance the adhesion between the components of tire 100, thereby reducing the risk of bead

separation.
[0031] In some aspects of the present invention, the low heat resistance
compound of the SRG strip 114 may be selected based on its ability to withstand the heat generated during the operation of tire 100. This may be particularly beneficial in high-speed applications, where the heat generated by the friction between tire 100 and the road surface can be substantial. The low heat generating compound of the SRG strip 114 may also contribute to the overall durability of the tire 100, as it may be less likely to degrade or break down under low heat conditions compared to other types of compounds. In an example, volume of the compound of the SRG strip 114 may be 249840 mm3 per tire.
[0032] In an example, the SRG strip 114 may have a 300% modulus
ranging from 16 to 20 MPa. Further, the SRG strip 114 may have a minimum elongation at a break of 330%, exhibiting flexibility and durability under varying stress conditions. Furthermore, in an example, hardness of the SRG strip 114, measured on the Shore A scale, may lie within a range of 74 to 80, indicating a suitable balance between rigidity and pliability. The SRG strip's 114 tensile stress at break may be set at a minimum of 2.2 MPa. These properties collectively position the SRG strip 114 as a robust and adaptable component, effectively addressing the separation challenges between tire components.
[0033] In other cases, the SRG strip 114 may be applied to the body ply
106 using a ply cutter. This process variation may allow for precise and consistent application of the SRG strip 114 to the body ply 106, which may in turn enhance the overall quality and performance of tire 100. The use of a ply cutter for the application of SRG strip 114 may also contribute to the efficiency of the tire manufacturing process, as it may allow for the rapid and automated application of the SRG strip 114 to a large number of the body plies 106.
[0034] Fig. 2 illustrates positioning of the SRG strip 114 on the body ply
106 of the 100, in accordance with an aspect of the present invention.

Herein the body ply 106 may be understood as the outermost body ply with which the SRG strip 114 interfaces externally once assembled.
[0035] In an example embodiment of the present invention, in some
cases, the shear resistance gum (SRG) strip 114 may be applied to the body ply 106 using a ply cutter. This process variation may allow for precise and consistent application of the SRG strip 114 to the body ply 106, which may in turn enhance the overall quality and performance of the tire 100. The use of the ply cutter for the application of the SRG strip 114 may also contribute to the efficiency of the tire manufacturing process, as it may allow for the rapid and automated application of the SRG strip 114 to a large number of the body plies 106.
[0036] In some aspects of the present invention, the ply cutter may be
modified to apply the SRG strip 114 to the body ply 106. This modification may involve adjusting the positioning of the ply cutter to ensure that the SRG strip 114 is applied at the correct location on the body ply 106. For instance, as shown in Fig. 2, the SRG strip 114 may be applied to the body ply 106 at a distance of 4.5-7.5 mm from the edge of the body ply 106. The edge of the body ply 106 is shown as E in Fig. 2. The positioning of the SRG strip 114 in this manner may enhance the adhesion between the AGS 112 and the body ply 106 of the tire 100, thereby reducing the risk of bead separation.
[0037] It is to be understood that the process of applying the SRG strip
114 to the body ply 106 using the ply cutter and the specific positioning of
the SRG strip 114 as described above are merely examples and that other
methods of applying the SRG strip 114 and other positioning of the SRG
strip 114 may be possible without departing from the scope of the present
disclosure. For instance, the SRG strip 114 may be applied to the body ply
106 using different types of equipment or techniques, or it may be positioned
at different points along the body ply 106, depending on specific types of
the tire 100.
[0038] Thus, by incorporating the SRG strip 114 between the body ply

106 and the AGS 112, bead endurance capacity of the tire 100 may be improved significantly. Firstly, the SRG strip 114 enhances the adhesion between the body ply 106 and the AGS 112, effectively addressing the prevalent issue of separation, particularly in the bead area where chafing occurs. By introducing a shear-resistant adhesive material, the SRG strip 114 minimizes wear and tear in the bead region, extending the tire's lifespan and promoting overall durability. Additionally, the SRG strip 114 aids in maintaining consistent tire performance by preventing air leaks that could result from separation. This contributes to sustained tire pressure, optimizing fuel efficiency, and ensuring safe and reliable operation. In summary, the SRG strip 114 serves as a crucial solution to separation challenges, providing advantages such as enhanced adhesion, reduced friction-related wear, prolonged tire lifespan, and consistent performance, ultimately promoting safety and reliability in tire operation.
[0039] Although implementations have been described in a language
specific to structural features and/or methods, it is to be understood that the appended claims are not necessarily limited to the specific features or methods described.

I/We Claims:
1. A tire (100) comprising:
a tread portion (102);
a pair of sidewall portions (104) arranged to extend circumferentially and continuously on either side of the tread portion, wherein one or more body plies (106) form the tread portion (102) and the sidewall portions (104); each of the pair of sidewall portions (104) comprising:
a bead portion (108) located at a distal lower end of the sidewall portion (104), the bead portion (108) having a bead core (110) therein;
an abrasion gum strip (112) arranged radially along the sidewall portion (104) and surrounding the bead core (110),
wherein the abrasion gum strip (112) interfaces externally with an outermost body ply of the one or more body plies (106);
a shear resistance gum (SRG) strip (114) disposed between the outermost body ply and the abrasion gum strip (112),
wherein the SRG strip (114) is positioned above a heel (116) of the tire.
2. The tire (100) of claim 1, wherein the SRG strip (114) is positioned to
initiate at a midpoint of the bead core (110).
3. The tire (100) of claim 1, wherein the SRG strip (114) extends above
end of an apex tip (118) of the tire (100).
4. The tire (100) of claim 1, wherein the SRG strip (114) is located above the heel (116) of the tire at a distance of 10 mm from a lowermost point of the tire (100).
5. The tire (100) of claim 1, wherein the SRG strip (114) is positioned at a distance of 4.5-7.5 mm from an edge of the outermost body ply.

6. The tire (100) of claim 1, wherein the SRG strip (114) has a thickness of 1.5 mm.
7. The tire (100) of claim 1, wherein the SRG strip (114) has a width (W) of 60 mm.