FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION (See section 10, rule 13)
1. Title of the invention: VEHICLE TIRE
2. Applicant(s)
NAME NATIONALITY ADDRESS
CEAT LIMITED Indian CEAT Ltd At: Get Muwala Po: Chandrapura Ta: Halol - 389 350 Dist: Panchmahal, Gujarat, 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.

TECHNICAL FIELD
[0001] The present subject matter relates, in general, to vehicle tires and,
particularly but not exclusively, to vehicle tires having treads.
BACKGROUND
[0002] Tires support the load of a vehicle and impact handling, drivability,
and safety of the vehicle. A tire has a crown or center region, a shoulder region, and beads on either side of the center region. The center region may be understood as an outer region of the tire formed along a complete circumference of the tire and spreads along a width of the tire, which contacts with a surface during rotation. The beads may be understood as edges of the tire. The beads contact with a wheel during the mounting of the tire. The shoulder region is a portion of the tire joining the center region and the beads of the tire.
[0003] Vulcanized and treated rubber that is applied on the center region
and shoulder region of the tire is called a tread of the tire. The tread is often carved in diverse configurations by way of tread blocks, tread grooves, tread voids, wear bar, and the like. The configuration of the tread affects contact and interaction of the tire with the road and thus affects traction of the vehicle and noise generated during the interaction of the tire with the road surface. Hence, the tread configuration has a crucial role in tire life, vehicle maneuvering, noise-free driving, safety, and ease of driving.
BRIEF DESCRIPTION OF DRAWINGS
[0004] The detailed description is described with reference to the
accompanying figures. The left-most digit(s) of a reference number identifies the figure in which the reference number first appears in the figures. The same

numbers are used throughout the drawings to reference like features and
components.
[0005] Figure 1 illustrates a perspective view of a tire, in accordance with
an implementation of the present subject matter;
[0006] Figure 2 illustrates an enlarged view of the tire depicting rubber
blocks provided in circumferential grooves of the tire, in accordance with an
implementation of the present subject matter; and
[0007] Figures 3A-3F illustrate an enlarged view of the circumferential
grooves of the tire depicting various shapes of protrusions in the rubber blocks
formed in the circumferential grooves of the tire, in accordance with an
implementation of the present subject matter.
DETAILED DESCRIPTION OF DRAWINGS
[0008] In vehicles, there are two major sources of noise generated during
the motion of a tire incorporated in a vehicle along a surface or road. One is a propulsion system of the vehicle, such as a combustion engine along with a power transmission shaft attached to it. Second, during the motion of the vehicle, tread region of the tire contacts with surface of the motion. Upon contact with the surface, ambient air gets trapped between the grooves of the tire and the surface. The trapping of the air and improper air channeling generates noise in the tire during motion. In the case of electric and hybrid vehicles, the propulsion system produces less noise, thus, less sound emission is expected from the tires which would otherwise appear accentuated. The presence of an electric motor in combination with a battery for e-vehicles tends to produce very low noise than a conventional internal combustion engine, so for a quiet ride for drivers and passengers, it is desirable to have a tire with lower noise as compared to the conventional tire.

[0009] Noise generated from tires significantly depends on tire tread
pattern design, tread compound, tire construction, or sidewall structure. For example, the tread pattern may contribute to tire-surface interaction noise through tread impact due to the interaction between tread blocks and the surface of the motion. In this context, tire design parameters are critical. Any deviation from any of them may lead to a trade-off in other performance parameters, which is not acceptable in some cases.
[0010] Since the tread patterns are responsible for the generation of major
noise in the tire, some tread patterns are designed with multiple longitudinal grooves to enhance air channeling during rolling to reduce such noise. However, the longitudinal grooves form a pipe in a region created by the tread blocks and the surface of the motion, which may cause noise emission at its resonance frequency. In some cases, as the speed of the vehicle increase, tread pitch frequency may coincide with the pipe resonance frequency, thereby generating excessive noise at that speed.
[0011] To avoid the tread pitch frequency from coinciding with the pipe
resonance frequency, tire manufacturers generally apply an optimized tread
pitch sequence and reduce the length of the tread blocks in the tire at the
shoulder and center regions. However, such an approach may impact the wear
appearance and handling of the tire compared with the conventional tire.
[0012] Thus, there exists a need for an improved tire that produces less
noise without deteriorating or marginally affecting other performance parameters.
[0013] To this end, the present subject matter provides a tire for a vehicle
that produces less noise during movement over a road surface, the tire may be modified to overcome the above-described problem associated with air channeling and consequent noise generation during motion of the vehicle on

the road surface without any adverse effect on other performance parameters of the tire.
[0014] In accordance with an embodiment of the present subject matter, a
tire having a center tread region and a shoulder tread region on either side of the center tread region is disclosed. The tire includes one or more circumferential grooves along its center region. The tire further includes a plurality of rubber blocks that are located at different circumferential positions of each of the one or more circumferential grooves of the tire. Each of these rubber blocks includes one or more protrusions that extend from a bottom of each of the circumferential grooves toward its surface side.
[0015] Due to the presence of the rubber blocks in a space formed by the
circumferential grooves, resistance against the airflow in the circumferential
grooves is increased during rolling of the tire, whereby air pipe resonance
noise is more greatly reduced. Also, by breaking the whole pipe formed by the
longitudinal grooves in multiple segments, harmonics of the center and the
shoulder regions may be avoided. Hence, the tire generates reduced noise
including cabin noise and pass-by noise when rolled over a road surface.
[0016] Thus, the present subject matter discloses a tire with circumferential
grooves configuration that helps reduce pipe resonance noise without
degrading drainage performance or other performance parameters.
[0017] The above and other features, aspects, and advantages of the
subject matter will be better explained with regard to the following description and accompanying figures. It should be noted that the description and figures merely illustrate the principles of the present subject matter along with examples described herein and should not be construed as a limitation to the present subject matter. It is thus understood that various arrangements may be devised that, although not explicitly described or shown herein, embody the principles of the present disclosure. Moreover, all statements herein reciting

principles, aspects, and examples thereof, are intended to encompass equivalents thereof. Further, for the sake of simplicity, and without limitation, the same numbers are used throughout the drawings to reference like features and components.
[0018] Figure 1 illustrates schematics of a tire 100, in accordance with an
implementation of the present subject matter. In an implementation of the
present subject matter, the tire 100 has a center region 102 and a shoulder
region 104 on either side of the center region 102. More specifically, the tire
may have two shoulder regions 104 with a center region 102 between the two
shoulder regions 104. The center and the shoulder regions may include
different tread patterns as illustrated in Figure 1. The tire tread pattern may be
formed by a plurality of circumferential tread rows separated by one or more
circumferential grooves 106. The one or more circumferential grooves 106
may be disposed in the center region 102 of the tire 100 and understood as a
recess in tread portion of the tire 100 along a circumference of the tire 100.
[0019] In an implementation of the present subject matter, each of the
circumferential grooves 106 may include a plurality of rubber blocks 108. Each of the rubber blocks 108 may be located at different circumferential positions either at equal or varying distances in each of the circumferential grooves 106. The rubber block 108 makes the airflow generated during the rolling of the tire 100 pass through small gaps created by the rubber blocks 108 and move the airflow to the road surface that allows the occurrence of energy loss and reduction in sound pressure, thereby enabling the pipe resonance noise to be reduced.
[0020] Figure 2 illustrates an enlarged view of a portion of the tire 100
depicting the rubber block 108 in detail, according to an example implementation of the present subject matter. In an implementation of the present subject matter, the rubber block 108 includes one or more protrusions

110-1, 110-2, 110-3. Each of the one or more protrusions 110-1, 110-2, 110-3
extends from a bottom 112 of the circumferential groove 106 toward a surface
side 114 of the circumferential groove 106. In an example embodiment of the
present subject matter, the protrusions 110-1, 110-2, 110-3 may be reinforced
in columns formed by the circumferential groove 106 in such a manner that
the height of each of the protrusions 110-1, 110-2, 110-3 lies in a range of 30%
to 100% as compared to a depth of the circumferential groove 106.
[0021] In the present example, the protrusions 110-1, 110-2, 110-3 in the
rubber block 108 are shown to be forming a U-shape, however, are not limited thereto. The protrusions 110-1, 110-2, 110-3 may be reinforced in the circumferential grooves 106 in other shapes as well, such as triangle shape, rectangular shape, T shape, etc.
[0022] For example, Figure 3A illustrates a first pattern 302 of the rubber
block 108 that is formed by a plurality of first protrusions 304 and second
protrusions 306 having the T shape and rectangular shape, respectively. Each
of the first protrusions 304 has a base whose dimension is defined by “F” and
a height whose dimension is denoted by “G”. The first protrusion 304 further
includes a top structure disposed over the base of first protrusion 304 and has
a predefined height whose dimension is denoted by “E”. Each of the second
protrusions 306 has a length and width denoted by “K” and “J”, respectively.
[0023] Similarly, Figure 3B illustrates a second pattern 308 of the rubber
block 108 that is formed by a plurality of third protrusions 304 each having a triangular shape. As shown in Figure 3B, each of the third protrusions 304 has a base and a height whose dimensions are denoted by “M” and “L”, respectively. Also, each of the adjacent third protrusions 304 are separated by a predefined distance whose dimension is denoted by “N”.
[0024] Figure 3C illustrates a third pattern 312 of the rubber block 108 that
is formed by a plurality of fourth protrusions 314 and fifth protrusions 316. Each

of the plurality of fourth protrusions 314 and fifth protrusions 316 have a
rectangular shape. As shown in Figure 3C, each of the plurality of fourth
protrusions 314 and fifth protrusions 316 has a width whose dimensions are
denoted by “D” and “B”, respectively. Further, a length of each of the plurality
of fourth protrusions 314 and fifth protrusions 316 is denoted by “C”.
[0025] Similarly, Figure 3D illustrates a fourth pattern 308 of the rubber
block 108 that is formed by a plurality of sixth protrusions 320 each having the T shape. As shown in Figure 3D, each of the sixth protrusions 320 has a base whose dimension is defined by “P”. Each of the sixth protrusion 320 further includes a top structure disposed over the base of sixth protrusion 320 and has a predefined height whose dimension is denoted by “R”. As shown in Figure 3D, each of the sixth protrusions 320 may be separated by another sixth protrusion 320 provided on its opposite side by a predefined horizontal distance denoted by “S”.
[0026] Further, Figure 3E illustrates a fifth pattern 322 of the rubber block
108 that is formed by a plurality of seventh protrusions 324 each having the U shape. As shown in Figure 3E, each of the seventh protrusions 324 has a base whose dimension is defined by “U”. Each of the seventh protrusion 324 further includes a shoulder portion having a predefined distance from its base which is denoted by “T”. As shown in Figure 3E, each of the seventh protrusions 324 may be separated by another seventh protrusion 324 provided on its opposite side by a predefined horizontal distance denoted by “S”.
[0027] Further, Figure 3F illustrates a sixth pattern 326 of the rubber block
108 that is formed by a plurality of eighth protrusions 328 each having the U shape. As shown in Figure 3F, while each of the eighth protrusions 328 is also U-shaped, it has a curved portion 328 that is protruded more towards a center of the circumferential groove 106 when compared with a curved portion 332 of the U-shaped seventh protrusion 324.

[0028] Each of the eighth protrusions 328 has a base whose dimension is
defined by “Y”. Each of the eighth protrusion 328 further includes a shoulder portion having a predefined distance from its base which is denoted by “N”. As shown in Figure 3F, each of the eighth protrusions 328 is separated diagonally by another eighth protrusion 328 provided on its opposite side by a predefined distance denoted by “AA”.
[0029] The table below provides dimensions for each of such protrusions
that are to be reinforced in the circumferential grooves 106.

First Pattern
302 Parameter W
8 W
8 W
8 W
8 W
8 W E F
3 M
6 B
2 Q
2 U
6 Z G J K

Dimension (mm)
1.5
1.5 2 3.5
Second Pattern
308 Parameter
L
N

Dimension (mm)
5
2
Third Pattern
312 Parameter
A
C D

Dimension (mm)
1
6 5
Fourth Pattern
318 Parameter
P
R S

Dimension (mm)
3
3 3
Fifth Pattern
322 Parameter
T
V X

Dimension (mm)
1.3
3.5 1.5
Parameter
Y
AA

Sixth
Pattern Dimension (mm)
326 8 5 2 1.5
[0030] In the above table, W signifies the width of the circumferential
groove without any rubber blocks disposed of in it. Also, the sixth pattern 326 is the same as the pattern of the rubber block 108 described in the present example.
[0031] In an example, the table given below indicates a noise level created
by each of the first pattern 302, the second pattern 308, the third pattern 312, the fourth pattern 318, fifth pattern 322, and the sixth pattern 326, respectively, at sample level:

Frequency Band: 1500-4000 Hz

Noise Level Measured (in dB)
Reference 100
First Pattern 302 90
Second Pattern 308 100
Third Pattern 312 87
Fourth Pattern 318 85
Fifth Pattern 322 86
Sixth Pattern 326 92
[0032] As a result of an example implementation of the present subject
matter, the tire incorporated in a vehicle, when rolled over a road surface along with the movement of the vehicle, produces significantly reduced in-cabin noise and pass-by noise respectively as compared to the conventional tires. Further, because of reduced noise, less vibration is produced resulting in a more comfortable ride for the passengers which is improved approximately by

5 %. However, there is no impact on the wear appearance of the tire when compared with the conventional tire.
[0033] Although implementations of a tire are described, it is to be
understood that the present subject matter is not necessarily limited to the specific features of the systems described herein. Rather, the specific features are disclosed as implementations for the tire.

I/We claim:
1. A tire (100) having a center region (102) and a shoulder region (104) on
either side of the center region (102), the tire (100) comprising:
one or more circumferential grooves (106) along the center region (102); and
a plurality of rubber blocks (108) located at different circumferential positions of each of the one or more circumferential grooves (106),
wherein each of the plurality of rubber blocks (108) comprises one or more protrusions (110-1, 110-2, 110-3) extending from a bottom (112) of the circumferential groove (106) toward a surface side of the circumferential groove.
2. The tire as claimed in claim 1, wherein each of the plurality of rubber blocks is positioned at equal distance from each other.
3. The tire as claimed in claim 1, wherein each of the plurality of rubber blocks is positioned at varying distances from each other.
4. The tire as claimed in claim 1, wherein a noise level of the tire (100) lies in a range of 80-100 dB.
5. The tire as claimed in claim 1, wherein a height of each of the one or more protrusions (110-1, 110-2, 110-3) lies in a range of 30-100% as compared to a depth of the one or more circumferential grooves (106).
6. The tire as claimed in claim 1, the height of each of the one or more protrusions (110-1, 110-2, 110-3), and the depth of the one or more circumferential grooves (106) are different.

7. The tire as claimed in claim 1, wherein each of the one or more protrusions (110-1, 110-2, 110-3) are formed in a U shape.
8. The tire as claimed in claim 1, wherein each of the one or more protrusions (110-1, 110-2, 110-3) are formed in a triangle shape.
9. The tire as claimed in claim 1, wherein each of the one or more protrusions (110-1, 110-2, 110-3) are formed in a rectangular shape.
10. The tire as claimed in claim 1, wherein each of the one or more protrusions (110-1, 110-2, 110-3) are formed in a T shape.