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: TYRE MANUFACTURING
2. Applicant(s)
NAME NATIONALITY ADDRESS
CEAT LIMITED Indian RPG HOUSE, 463, Dr. Annie
Besant Road, Worli, Mumbai 400 007 Maharashtra, India

TECHNICALFIELD
[0001] The present subject matter relates, in general, to techniques for
manufacturing of tyres and, in particular, for embedding external devices in tyres.
BACKGROUND
[0002] Tyres play an important role in dynamics of a vehicle. Among other
things, they help providing lateral forces to the vehicle required for tracking, steering, traction and providing stability to the vehicle. Therefore, it becomes vital to monitor various properties of the tyres. For instance, an external device may be used for monitoring various properties of the tyre, such as inflation pressure, stress cycles, number of revolution, tyre temperature, and the like. Data from such devices may be extracted and can be used for improving further structure and stability of the tyres.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] The detailed description is described with reference to the
accompanying figures. In the figures, the left-most digit of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference the same elements.
[0004] Figs. 1a and 1b illustrate a cross-sectional view of a tyre, in
accordance with an example implementation of the present subject matter;
[0005] Fig. 2 illustrates a view of the tyre with an external device in the
cavity, in accordance with an example implementation of the present subject matter;
[0006] Fig. 3 illustrates an example method of creating a cavity in a tyre, in
accordance with an example implementation of the present subject matter.
[0007] Fig. 4 illustrates an example method of embedding an external
device in a tyre, in accordance with an example implementation of the present subject matter.

DETAILED DESCRIPTION
[0008] Generally, implants are provided inside the tyre for fixing the
external devices inside the tyre. The external devices can be fixed on to the implants for various purposes, such as tyre testing. The implants are generally bonded to an inside surface of the tyre. Conventional techniques for bonding the implants are implemented on a cured tyre, i.e., after the tyre has been made. One such technique is hot vulcanization, where a region where an implant is to be bonded is spot heated. Another technique is bonding by adhesives, where the implant is bonded to the inner surface of the tyre with an adhesive.
[0009] However, the conventional techniques are invasive and damaging to
the tyre. For instance, when the tyre is spot heated in case of hot vulcanization, the tyre body gets damaged and bonding between steel cords and rubber material is adversely affected. Further, adhesive bonding of the external devices provides inefficient bonding between the tyre and the external devices, hence, the implants gets displaced or removed, thereby, damaging the tyre and the external device mounted onto the tyre. Further, damage to the external devices leads to erroneous experimental readings.
[0010] Moreover, the methods of invasive treatment necessitate the cured
tyre to be transported back to manufacturing stations for performing rework on the cured tyre for attaching the external device, thereby, causing wastage of time and effort, hence, incurs additional costs.
[0011] According to an example implementation of the present subject
matter, techniques for creating a cavity in a tyre during curing process, are described. According to the process, during building of a tyre, a plurality of sheets first substrate is placed to a form a base layer. In an example, a first substrate, such as rubber, is placed onto one another to form a base layer on an inner side of a tyre. The first substrate is deposited such that the first substrate surrounds a block of material placed therein. In other words, the first substrate is deposited such that the plurality of sheets of the first material surrounds the block of the material and do not cover a top surface of the block of the material.

[0012] Once the plurality of sheets of the first substrate is depoisted, a
plurality of sheets of a second substrate is disposed over the base layer such that the plurality of sheets of the second substrate encloses a portion the block of material. In an example, the second substrate may be rubber. Thereafter, the tyre is transferred to a tyre curing machine for curing. After the curing, the block of the material is removed or extracted to obtain a cavity. This cavity is used for housing external devices, such as sensors, monitoring modules, and other electronic devices. In an example implementation, the cavity is formed in the tyre and is integral to the tyre itself without using any external adhesive.
[0013] The cavity is formed during tyre building and curing, and is
integrated to an inner surface or inner liner of the tyre. Therefore, need of additional processing methods is obviated for creating the cavity. In addition, no invasive techniques, such as spot heating, are required for creating the cavity integrated to the inside surface of the tyre. Therefore, bonding between steel cords and rubber material is not damaged. Further, no rework is required after the cavity is created, thus, not incurring any extra manufacturing cost and time for creating the cavity. In addition, the bonding of the integrated cavity is strong, since the cavity is made during the tyre curing process and, thus, cavity is strongly bonded and integral to the tyre.
[0014] It should be noted that the description and the 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 subject matter. Moreover, all statements herein reciting principles, aspects, and implementations of the present subject matter, as well as specific examples thereof, are intended to encompass equivalents thereof.
[0015] Fig. 1a illustrates a cross-sectional view of a tyre 100, in accordance
with an example implementation of the present subject matter. The tyre 100 includes a tread 102 having tread patterns 104. In operation, a plurality of sheets of

a first substrate is deposited to form a base layer 106 on the tyre 100. The plurality of sheets of first substrate surrounds a block of a material 108 placed therein. In an example, the block of material 108 may be placed there during deposition of the plurality of sheets of the first substrate. In an example, the first substrate is deposited such that the plurality of sheets of the first material surrounds the block of the material 108 and do not cover a top surface of the block of the material 108. Further, in an example, the plurality of sheets of the first substrate may be deposited on an inner liner of the tyre.
[0016] Further, plurality of sheets of a second substrate is deposited to form
a top layer 110. The plurality of sheets of the second substrate encloses a portion of the block of material 108 as shown in Fig. 1a. The plurality of sheets of the second substrate encloses a portion of the top surface of the block of material 108 such that a space 116 is left through which the block of the material 108 may be accessed. In other words, in the space 116, the second substrate is not deposited. After setting, the tyre 100 is cured to remove the block of material 108. The block of the material 108 is removed by pulling out the block of the material 108 through the space 116. The removal of the block of material 108 creates a cavity as will be described with reference to Figure 1b.
[0017] In an example, the first substrate and the second substrate may be
rubber while the block of material 108 may be made up of cellophane paper, plastic, Bakelite, metal, etc. Further, the thickness of the block of material 108 may be in range of 3-4 millimeters (mm). In an example, the shape of the block of the material 108 may be circular, hexagonal, pentagonal, etc.
[0018] Fig. 1b illustrates a cross-sectional view of a tyre 100, in accordance
with another example implementation of the present subject matter. The tyre 100 includes a tread 102 having tread patterns 104, a base layer 106 and a top layer 110. In an example implementation, a cavity 114 is integrally formed between the base layer 106 and the top layer 110, due to removal of the block of the material 108 during curing of the tyre 100.

[0019] As illustrated in Figure 1a, the block of material 108 may have a
thickness in range of 3-4mm, accordingly, in an example, the cavity 114 may have a depth of about 3 to 4 mm. Further another example, the cavity 114 may have different shapes such as circular, hexagonal, rectangular, pentagonal, triangular, circular, square corresponding to the shape of the block of the material 108 being used.
[0020] In an example implementation, the cavity 114 is utilized to house an
external device, such as device sensor, for monitoring properties of the tyre, such as inflation pressure, stress cycles, number of revolution, tyre temperature, and the like. In an example, the shape of cavity 114 may be created in accordance with the shape of the external device to be positioned in the cavity 114.
[0021] Fig. 2 illustrates a view of the tyre 100 with an external device 118
positioned in the cavity 114, in accordance with an example implementation of the present subject matter. In an example, the cavity 114 may have different shapes, such as circular, hexagonal, rectangular, and the like. In an example implementation, height of the external device 118 may in a range of about 10 to 25 mm. In operation, an external device 118 may be inserted from an inner side of the tyre 100 for securely housing the external device 118 inside the cavity 114. The external device 118 is affixed on the tyre without using a glue or any external means, thus, there is no quality degradation as no after treatment is required to create a cavity.
[0022] Fig. 3 describes a method 300 of obtaining a cavity on an inner
surface of the tyre 100, in accordance with an example implementation of the present subject matter. The order in which the method 300 is described is not intended to be construed as a limitation, and any number of the described method blocks may be combined in any order to implement the method 300, or an alternative method.
[0023] At block 302, a plurality of sheets of a first substrate is deposited to
form a base layer on a tyre. The plurality of sheets of the first substrate is deposited such that the plurality of the sheets of the first substrate surrounds a block of

material, such as the block of the material 108. The block of material may be placed there during deposition of the plurality of the sheets of the first substrate. In an example, the plurality of sheets of a first substrate may be deposited on an inner liner of the tyre. In an example, the base layer may be similar to the base layer 106. Further, in an example, the first substrate may be rubber.
[0024] At block 304, a plurality of sheets of a second material is deposited
over the plurality of sheets of the first substrate such that the plurality of the layer of the second substrate encloses a portion of the block of the material. In an example implementation, the second substrate may be rubber.
[0025] Fig. 4 describes a method 400 of embedding an external device is a
tyre, in accordance with an example implementation of the present subject matter. The order in which the method 400 is described is not intended to be construed as a limitation, and any number of the described method blocks may be combined in any order to implement the method 400, or an alternative method.
[0026] At block 402, a plurality of sheets of a first material is deposited to
form a base layer on a tyre. The plurality of sheets of the first substrate is deposited such that the plurality of the sheets of the first substrate surrounds a block of material, such as the block of the material 108. The block of material may be placed there during deposition of the plurality of the sheets of the first substrate. In an example, the plurality of sheets of the first substrate may be deposited on an inner liner of the tyre. In an example, the first material may be rubber. Further, in an example, the thickness of the block of the second material may be in range of 3-4 mm.
[0027] At block 404, a plurality of sheets of third material is deposited over
the plurality of sheets of the first material such that the plurality of sheets of the third material encloses a portion of the block of the second material. In an example, the third material may be rubber.
[0028] The method then proceeds at block 406 where the block of the
second material is removed to create a cavity, such as the cavity 114.

[0029] At block 408, an external deice, such as sensor is embedded in the
cavity.
[0030] In an example, the cavity may be shaped in accordance with the
shape of the external device. For example, if the external device is circular, a circular block of second material may be used to create a circular cavity. Thus, a rectangular, pentagonal, square, block of second material may be used in accordance with the shape of the external device to be embedded.
[0031] Further, various materials may be utilized for constituting the
layers of the tyre. For example, a rubber composition of butyl-rubber may be used. In addition, the block of the second material may be made of a material which does not stick to said inner set of layers and the layer of the third material. Though, the use of cellophane paper is described, other materials with similar properties may be used, in accordance with the implementations of the present subject matter.
[0032] Although implementations of the process for creating a cavity on
an inner surface of the tyre and embedding an external device in the cavity as per the present subject matter have been described in a language specific to structural features and/or applications, it is to be understood that the present subject matter is not limited to the specific features or applications described. Rather, the specific features and applications are disclosed as exemplary implementations.

I/We Claim:
1. A method of manufacturing a tyre (100) comprising:
depositing a plurality of sheets of a first substrate to form a base layer on the tyre (100) wherein the plurality of sheets of a first substrate surrounds a block of a material (108); and
depositing a plurality of sheets of a second substrate over the plurality of sheets of the first substrate such that the plurality of sheets of the second substrate encloses a portion of the block of the material (108).
2. The method as claimed in claim 1, wherein plurality of sheets of the second substrate encloses a portion of the top surface block of the material.
3. The method as claimed in claim 1, wherein the method further comprises removing the block of material (108) to create a cavity (114).
4. The method as claimed in claim 1, wherein the material may be a cellophane paper, plastic, Bakelite, metal.
5. The method as claimed in claim 1, wherein the material has a thickness in range of 3-4 mm.
6. The method as claimed in claim 3 further comprising positioning an external device (118) in the cavity (114).
7. The method as claimed in claim 1, wherein the shape of the block of the material (108) may be at least one of rectangular, hexagonal, pentagonal, triangular, circular, square.

8. A method of embedding an external device (118) in a tyre (100), the method
comprising:
depositing a plurality of sheets of a first material to form a base layer on the tyre (100) wherein the plurality of sheets of a first substrate surrounds a block of a second material (108);
depositing a plurality of sheets of a third material over the plurality of sheets of the first material such that the plurality of the layer of the third material encloses a portion of the block of the second material (108);
removing the block of the second material (108) to create a cavity (114); and
embedding an external device (118) in the cavity (114).
9. The method as claimed in claim 8, wherein plurality of sheets of the second substrate encloses a portion of the top surface block of the material
10. The method as claimed in claim 8, wherein the second material may be a cellophane paper.
11. The method as claimed in claim 8, wherein a thickness of the second material is in range of 3-4 mm.
12. The method as claimed in claim 8, wherein the method further comprises shaping the cavity (114) according to the shape of the external device (118).