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: A CURING MOULD
2. Applicant(s)
NAME NATIONALITY ADDRESS
CEAT LIMITED Indian RPG HOUSE, 463, Dr. Annie Besant Road, Worli, Mumbai, Maharashtra 400 030, 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.

BACKGROUND
[0001] Tyres are a crucial component of an automobile. In an automobile,
a tyre may be responsible for a plurality of functions. A final manufactured tyre may be required to conform to a plurality of quality standards, which may be based on the manner in which the tyre has been manufactured. During tyre manufacturing, a plurality of different components may be designed and attached together to form a preliminary uncured tyre, which is referred to as green tyre. The processed green tyre, once obtained, may then be cured in a curing mould, as a final step for tyre manufacturing process. During curing, the green tyre may be placed in a bottom half mould, and a top half mould may be positioned against the bottom half mould. Upon positioning, the tyre may be subjected to the curing process.
BRIEF DESCRIPTION OF THE DRAWINGS
[0002] The following detailed description references the drawings,
wherein:
[0003] FIG. 1A is a diagram depicting a front view of an example curing
mould with an alignment mechanism, as per an implementation of the present
subject matter;
[0004] FIG. 1B is a diagram depicting a magnified view of an example
alignment cavity, to be used in the curing mould with alignment mechanism,
as per an implementation of the present subject matter;
[0005] FIG. 1C is a diagram depicting a magnified view of an example
bush and a guide pin in the alignment cavity, to be used in the curing mould
with alignment mechanism, as per an implementation of the present subject
matter;
[0006] FIG. 2 is a diagram depicting a top view of an example curing mould
with an alignment mechanism, as per an implementation of the present
subject matter;
[0007] FIG. 3A is a diagram depicting a cross sectional view of an example

bush to be used in the curing mould with an alignment mechanism, as per an implementation of the present subject matter; and
[0008] FIG. 3B is a diagram depicting a cross sectional view of an example
guiding pin to be used in the curing mould with an alignment mechanism, as per an implementation of the present subject matter.
[0009] Throughout the drawings, identical reference numbers designate
similar, but not necessarily identical elements. The figures are not necessarily to scale, and the size of some parts may be exaggerated to more clearly illustrate the example shown. Moreover, the drawings provide examples and/or implementations consistent with the description; however, the description is not limited to the examples and/or implementations provided in the drawings.
DETAILED DESCRIPTION
[0010] Vehicles have become an essential requirement for private
individuals as well as for commercial purposes. As would be generally understood, a tyre is one of the most essential and critical components of the vehicle. During vehicle operation, the tyre is the only source of contact between the vehicle and the road, owing to which, a plurality of dynamics of the vehicle operation may be controlled by the tyre. The tyres may be responsible for guiding and maintaining the alignment and movement of a vehicle while driving. In addition, the tyres contribute to the safety of the vehicle while carrying loads, and when the automobile is to be halted by application of brakes.
[0011] Owing to the complexity of roles performed by the tyres in a vehicle,
it may be crucial for tyre manufacturers to manufacture a tyre which may conform to the adequate quality parameters. The quality parameters of the final manufactured tyre may be based on the manner in which the tyre has been manufactured, i.e., the manner in which the tyre has been subjected to various processes involved in the tyre manufacturing. The quality parameters of the final manufactured tyre may also be based on the constructional

features of the equipment used in tyre manufacturing.
[0012] Conventionally, rubber, along with other materials, may be used as
a raw material for manufacturing the tyres. A plurality of different components
may be designed and assembled together, using a variety of techniques which
involve both chemical and physical processes. For example, the raw materials
may be processed into different components to form a toroidal shaped
preliminary uncured tyre, which is also referred to as a green tyre.
[0013] Green tyre, once obtained, may then be cured when subjected to a
curing process in a curing press. As would be understood, curing may refer to a process of applying pressure and heat energy to the green tyre in a toroidal mould cavity in the curing mould of the curing press. The heat energy applied during curing process may enable chemical reactions between the rubber and other materials, to obtain its final shape. Further, tread pattern may also be imprinted on the obtained tyre during the curing process.
[0014] The curing mould of the curing press may be a toroidal mould cavity
to accommodate the green tyre. Specifically, the curing mould may include a bottom half mould and a top half mould. The green tyre may be accommodated in the bottom half mould, and the top half mould may be positioned against the bottom half mould.
[0015] The green tyre, upon being accommodated in the curing mould,
may then be subjected to various processes during in the curing process. For example, the green tyre may be imprinted with tread pattern and side wall letter engraving during the curing process. Thereafter, the top half mould may then be lifted up and opened to obtain the final manufactured tyre. The final tyre thus manufactured may have a parting line in the direction of rotation of the tyre and perpendicular to the axis of the tyre, indicative of the two half moulds used during the tyre manufacturing.
[0016] As would be understood, the constructional features of the bottom
half mould and the top half mould to form the toroidal mould cavity, affect the quality of the tyre to be manufactured. Therefore, it may be crucial to ensure proper accommodation of the green tyre in the curing mould. Further, it may

also be required to ensure that the tyre, while undergoing curing process, may be properly accommodated inside the curing mould and is not affected y external disturbances or factors.
[0017] However, the conventional approaches and the manner in which
the tyre is manufactured, and how the curing mould is operated, may result in the final tyre having surface projections, referred to as flash. During curing process, as described previously, the bottom half mould may be fixed and the top half mould may be positioned against the bottom half mould. Owing to the repeated opening and closing of the top half mould, the quality of the curing mould may tend to degrade.
[0018] Further, owing to the toroidal shaped half moulds, it may be the
case that the top half mould and the bottom half mould may get misaligned with respect to each other over a period of time or due to repeated use. The pressure exerted on the green tyre inside the curing mould may tend to displace the top half mould, thereby resulting in the misalignment of the two half moulds.
[0019] In such cases, the green tyre when cured in the curing mould, may
cause extrusion of the material from the green tyre through the opening of the bottom half mould and the top half mould, thereby resulting in formation of flash. Owing to the joining of the bottom half mould and the top half mould for the formation of toroidal mould cavity in the curing mould, the flash may tend to form along the parting line, thereby also hampering the tread pattern on the tyre. Not only this may result in the degradation of quality of the tyres, it may also result in the raw material used for manufacturing tyres getting wasted. Furthermore, the tyre manufactured in the misaligned curing mould may be unfit for use, owing to the misalignment in the final manufactured tyre along the parting line.
[0020] To this end, an improved curing mould with an alignment
mechanism is described.
[0021] As per an implementation of the present subject matter, the curing
mould may include a bottom half mould and a top half mould. The top half

mould may be positioned against the bottom half mould to form a toroidal
mould cavity. Specifically, the circumference of the top half mould may be
positioned against the circumference of the bottom half mould. The toroidal
mould cavity thus formed may include a parting line perpendicular to the axis
of the toroidal mould cavity, and is to accommodate a green tyre.
[0022] The bottom half mould may further include a first set of at least three
cavities extending orthogonally with respect to the bottom half mould and located in a proximity to a circumference of the bottom half mould. Each of the first set of cavities may accommodate a bush. In one example, each of the plurality of bushes may be a longitudinally extending cylindrical depression, and may include a bottom portion and a collared top portion. In a similar manner, the top half mould may further include a second set of at least three cavities extending orthogonally with respect to the top half mould and located in a proximity to a circumference of the top half mould.
[0023] In operation, the bottom half mould may be positioned against the
top half mould. Upon positioning, the second set of cavities are aligned with
the first set of cavities to form a set of alignment cavities. Since each of the
first set of cavities and the second set of cavities are positioned
circumferentially on the bottom half mould and top half mould, respectively,
the set of alignment cavities may also be positioned circumferentially on the
curing mould in an exactly similar manner. In one example, the alignment
cavities may be separated from each other by an angular distance in the range
of about 85º to 145º along the circumference of the curing mould.
[0024] The set of alignment cavities may accommodate a plurality of
guiding pins such that the plurality of guiding pins may be inserted into the set
of alignment cavities through the second set of cavities and fastened onto the
plurality of bushes accommodated in the first set of cavities. In one example,
each of the plurality of guiding pins may be a longitudinally extending
cylindrical protrusion, and may include a bottom portion and a collared top
portion.
[0025] As per another implementation of the present subject matter, the

first set of at least three cavities may comprise a plurality of bushes. In one example, the plurality of bushes may be coupled to the bottom half mould using any technique known to a person skilled in the art. In a similar manner, the second set of at least three cavities may comprise a plurality of guiding pins. In another example, the plurality of guiding pines may be coupled to the top half mould.
[0026] In operation, the top half mould may be positioned against the
bottom half mould. In such cases, upon positioning, the second set of cavities are aligned with the first set of cavities to form a set of alignment cavities. The alignment cavities may be such that that it may allow the plurality of guiding pins to be fastened onto the plurality of bushes, thereby aligning the top half mould with the bottom half mould.
[0027] As would be appreciated, the curing mould with the alignment
mechanism, as described in the approaches of the present subject matter, may provide for alignment of the top half mould with the bottom half mould. As a result, the top half mould may remain stationary with respect to the bottom half mould during the curing process, thereby eliminating the problems associated with misalignment of curing mould during curing process. The final tyre thus manufactured, may also be improved in terms of various quality parameters, and may have minimal flash at the parting line. Not only the appearance and overall quality of the tyre may be improved, but the raw material used for manufacturing the tyres may also be conserved. Furthermore, the use of at least three guiding pins and bush in the present subject matter may also restrict the movement and displacement of the top half mould in all four directions along a plane perpendicular to the axis of the top half mould.
[0028] These, and other aspects, are described herein with reference to
the accompanying FIGS. 1-3. It should be noted that the description and figures relate to certain example, and should not be construed as a limitation to the present subject matter. 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 subject matter. Moreover, all statements herein reciting principles, aspects, and embodiments of the present subject matter, as well as specific examples, are intended to encompass equivalents thereof.
[0029] FIG. 1A is a diagram depicting a front view of an example curing
mould with an alignment mechanism, as per an implementation of the present subject matter. The curing mould 100 may be a part of a curing press (not shown in FIG. 1) well known to a person skilled in the art. Along with the curing mould 100, the curing press may include a plurality of other components (not shown in FIG. 1 for the sake of clarity).
[0030] As described previously, a green tyre, after undergoing other steps
involved in a tyre manufacturing process, may be subjected to a curing process in a curing press as the final step for tyre manufacturing process. Specifically, curing may refer to a process of applying pressure and heat energy to a green tyre in a toroidal mould cavity in a curing mould, such as curing mould 100 of a curing press.
[0031] In the foregoing description, various components and structural
aspects of the curing mould 100 have been explained with respect to FIGS. 1-2. FIG. 2 is a diagram depicting a top view of an example curing mould, such as curing mould 100, with an alignment mechanism, as per an implementation of the present subject matter.
[0032] The curing mould 100 may include a bottom half mould 102 and a
top half mould 104. The bottom half mould 102 and the top half mould 104 may be a half toroidal shaped mould with a side wall of a thickness, such that the thickened side wall may define a circumference of the thickness of the bottom half mould 102 and the top half mould 104 (as depicted in FIG. 2). In one example, the thickness of the circumference of the bottom half mould 102 and the top half mould 104 is in the range of about 40 millimetres to 80 millimetres in a radial direction.
[0033] In another example, the curing mould 100 may be of a material
comprising forged steel. The use of forged steel to make the curing mould 100

may provide a smooth internal surface of the curing mould 100 and a good mould surface quality, thereby resulting in good serviceability of the curing mould 100 during curing process. However, it may be noted that the aforementioned example is only illustrative and should not be construed to limit the scope of the present subject matter. Any other material may also be used for making the curing mould 100 without deviating from the scope of the present subject matter.
[0034] Continuing with the present example, the bottom half mould 102
may further include a first set of at least three cavities 106 extending orthogonally with respect to the bottom half mould 102 and located in a proximity to a circumference of the bottom half mould 102 (as depicted in FIG. 1). In one example, each of the first set of cavities 106 may be a longitudinally extending cylindrical cavity.
[0035] Each of the first set of cavities 106 may accommodate bush 108.
In one example, each of the plurality of bushes 108 may be a longitudinally
extending cylindrical depression. In another example, each of the plurality of
bushes 108 may be coupled with the first set of cavities 106 on the bottom half
mould 102 with a bolt 110 and a washer 112 (as depicted in FIG. 1).
[0036] In a similar manner, the top half mould 104 may further include a
second set of at least three cavities 114 extending orthogonally with respect
to the top half mould 104 and located in a proximity to a circumference of the
top half mould 104 (as depicted in FIG. 1). In one example, each of the second
set of cavities 114 may be a longitudinally extending cylindrical cavity.
[0037] In operation, as per one implementation of the present subject
matter, a green tyre may be placed in the bottom half mould 102. Thereafter, the top half mould 104 may be positioned against the bottom half mould 102. Specifically, the circumference of the top half mould 104 may be positioned against the circumference of the bottom half mould 102 to form a toroidal mould cavity 116. The toroidal mould cavity 116 thus formed may include a parting line 118 perpendicular to the axis of the toroidal mould cavity 116, and is to accommodate the tyre.

[0038] Upon positioning, the second set of cavities 114 are aligned with
the first set of cavities 106 to form a set of alignment cavities 120. The same has been illustrated in FIG. 1B. FIG. 1B is a diagram depicting a magnified view of the alignment cavity 120.
[0039] Since each of the first set of cavities 106 and the second set of
cavities 114 are positioned circumferentially (as depicted in FIG. 2) on the bottom half mould 102 and the top half mould 104 respectively, the set of alignment cavities 120 may also be positioned circumferentially on the curing mould 100 in an exactly similar manner.
[0040] It may be noted that the curing mould 100 may include at least three
alignment cavities 120 as depicted in FIG. 2. In one example, the set of alignment cavities 120 may be at a distance of about 25 millimetres to 50 millimetres from the outer diameter of the curing mould 100 in a radially inward direction. In another example, the set of alignment cavities 120 may be separated from each other by an angular distance 202. The angular distance 202 may be in the range of about 85º to 145º along the circumference of the curing mould 100.
[0041] It may be further noted that although the present example has been
explained with respect to at least three alignment cavities 120, the same should not be construed to limit the scope of the present subject matter. More than three alignment cavities 120 may also be used in the curing mould 100 without deviating from the scope of the present subject matter.
[0042] Continuing with the present example, the set of alignment cavities
120 may then accommodate a plurality of guiding pins 122 such that the
plurality of guiding pins 122 may be inserted into the set of alignment cavities
120 through the second set of cavities 114 and fastened onto the plurality of
bushes 108 accommodated in the first set of cavities 106. The same has been
illustrated in FIG. 1C. FIG. 1C is a diagram depicting a magnified view of a
guide pin 122 inserted into the alignment cavity 120 and fastened onto a bush
108, as per an implementation of the present subject matter.
[0043] In one example, each of the plurality of guiding pins 122 may be a

longitudinally extending cylindrical protrusion. In another example, each of the plurality of guiding pins 122 may be coupled with the second set of cavities 114 on the top half mould 104 with a bolt 124 and a washer 126 (as depicted in FIG. 1).
[0044] As per another implementation of the present subject matter, the
first set of cavities 106 may comprise a plurality of bushes 108. In one example, the plurality of bushes 108 may be coupled to the bottom half mould 102 using a bolt 110 and a washer 112. However, it may be noted that the plurality of buses 108 may be coupled to the bottom half mould 102 using any technique known to a person skilled in the art without deviating from the scope of the present subject matter.
[0045] In a similar manner, the second set of cavities 114 may also
comprise a plurality of guiding pins 122. In one example, the guiding pins 122
may be coupled to the top half mould 104 using a bolt 124 and a washer 126.
However, any other technique known to a person skilled in the art may also
be used to couple the plurality of guiding pins 122 to the top half mould 104.
[0046] In operation, the top half mould 104 may be positioned against the
bottom half mould 102. In such cases, upon positioning, the second set of cavities 114 are aligned with the first set of cavities 106 to form a set of alignment cavities 120. The alignment cavities 120 may be such that it may allow the plurality of guiding pins 122 to be fastened onto the plurality of bushes 108, thereby aligning the top half mould 104 with the bottom half mould 102.
[0047] The manner in which the plurality of guiding pins 122 and bushes
108 are to cause the curing mould 100 to have an improved alignment, is explained in further details in conjunction with FIG. 3.
[0048] FIGS. 3A and 3B are diagrams depicting cross sectional views of
an example bush and guiding pin respectively to be used in the curing mould with an alignment mechanism, as per an implementation of the present subject matter. The bush may be a similar bush 108 and the guiding pin may be a similar guiding pin 122 as described in FIG. 1.

[0049] As described previously, the bottom half mould 102 and the top half
mould 104 (not shown in FIG. 3) may include a first set 106 and a second set
114 of cavities respectively (not shown in FIG. 3). In one example, the first set
of cavities 106 may accommodate a plurality of bushes 108. On the other
hand, the second set of cavities 114, may allow the plurality of guiding pins
122 to be inserted into the set of alignment cavities 120 and fastened onto the
plurality of bushes 108 accommodated in the first set of cavities 106.
[0050] In another example, as described previously, the second set of
cavities 114 may accommodate the plurality of guiding pins 122. In such cases, in operation, the top half mould 104 is positioned against the bottom half mould 102. Upon positioning, the second set of cavities 114 are aligned with the first set of cavities 106 to form a set of alignment cavities 120. The alignment cavities 120 may be such that it may allow the plurality of guiding pins 122 to be fastened onto the plurality of bushes 108.
[0051] Each of the plurality of bushes 108, as depicted in FIG. 3, may be
a longitudinally extending cylindrical depression. In such cases, the bush 108 may include a bottom portion 302 and a collared top portion 304. The bottom portion 302 may further include a threaded cavity 306. The threaded cavity 306 may accommodate a bolt and a washer (not shown in FIG. 3) to couple the bush 108 with one of the first set of cavities 106 in the bottom half mould 102. In another example, the outer surface of each of the plurality of bushes 108 and an inner surface of each of the first set of cavities 106 may be threaded, and may allow the bushes 108 to be coupled with the first set of cavities 106. In yet another example, the dimensions of each of the plurality of bushes 108 may be slightly smaller than the dimensions of the first set of cavities 106, so as to ensure smooth coupling and decoupling.
[0052] Continuing with the present example, the collared top portion 304
may accommodate one of the plurality of guiding pins 122, when the top half mould 104 is positioned against the bottom half mould 102. In operation, the collared portion 308 may ensure that the bush 108 may not pass through the first cavity 106.

[0053] In a similar manner, each of the plurality of guiding pins 122, as
depicted in FIG. 3, may be a longitudinally extending cylindrical protrusion. In
such cases, the guiding pin 122 may include a bottom portion 310 and a
collared top portion 312. The bottom portion 310 may be tapered to form a
conical frustum head, as depicted in FIG. 3. The conical frustum head of the
guiding pin 122 is to cause the guiding pin 122 to fasten onto the bush 108,
when the top half mould 104 is positioned against the bottom half mould 102.
[0054] Further, the collared top portion may include a threaded cavity 314.
The threaded cavity 314 may accommodate a bolt and a washer (not shown in FIG. 3) to couple the guiding pin 122 with one of the second set of cavities 114 in the top half mould 104. In another example, the outer surface of each of the plurality of guiding pins 122 and an inner surface of each of the second set of cavities 114 may be threaded, and may allow the guiding pins 122 to be coupled with the second set of cavities 114. In yet another example, the dimensions of each of the plurality of guiding pins 122 may be slightly smaller than the dimensions of the second set of cavities 114, so as to ensure smooth coupling and decoupling.
[0055] Continuing further, in operation, the collared portion 316 of the
guiding pin 122 may ensure that the guiding pin 122 may not pass through the second cavity 114. In another example, accommodation of the guiding pins 122 onto each of the plurality of bushes 108 and continuous use of the bush 108 and guiding pin 122 during curing process may tend to damage those surfaces that may repeatedly come into contact with each other. Therefore, to provide wear resistance properties, the inner surface of each of the plurality of bushes 108 and the outer surface of each of the plurality of guiding pins 122 may be treated with nitriding process.
[0056] Although examples for the present disclosure have been described
in language specific to structural features and/or methods, it should be understood that the appended claims are not necessarily limited to the specific features or methods described. Rather, the specific features and methods are disclosed and explained as examples of the present disclosure.

I/We Claim:
1. A curing mould comprising:
a bottom half mould comprising a first set of at least three cavities extending orthogonally with respect to the bottom half mould and located in proximity to a circumference of the bottom half mould, wherein each of the first set of cavities is to accommodate a bush; and
a top half mould comprising a second set of at least three cavities extending orthogonally with respect to the top half mould and located in proximity to a circumference of the top half mould, wherein the top half mould is to be positioned against the bottom half mould, and upon positioning, is to form:
a set of at least three alignment cavities formed by aligning
each of the first set of cavities with the respective second set of
cavities, wherein the alignment cavities are separated by an angular
distance in the range of about 85º to 145º.
2. The curing mould as claimed in claim 1, wherein the set of alignment cavities is to accommodate a plurality of guiding pins such that the plurality of guiding pins is to be inserted into the set of alignment cavities through the second set of cavities and fastened onto the plurality of bushes accommodated in the first set of cavities.
3. The curing mould as claimed in claim 1, wherein the top half mould and the bottom half mould are a half toroidal shaped mould with a side wall of a thickness, such that the thickened side wall is to define a circumference of a thickness of the bottom half mould and the top half mould.
4. The curing mould as claimed in claim 1, wherein the circumference of the top half mould is to be positioned against the circumference of the

bottom half mould to form a toroidal mould cavity with a parting line, wherein the parting line is perpendicular to axis of the toroidal mould cavity.
5. The curing mould as claimed in claim 3, wherein the thickness of the circumference of the bottom half mould and the top half mould is in the range of about 40 millimetres to 80 millimetres in a radial direction.
6. The curing mould as claimed in claim 1, wherein the first set of cavities and the second set of cavities on the bottom half mould and the top half mould, respectively, are at a distance of about 25 millimetres to 50 millimetres from outer diameter of the curing mould in a radially inward direction.
7. The curing mould as claimed in claim 1, wherein the curing mould is of a material comprising forged steel.
8. A curing mould comprising:
a bottom half mould comprising a first set of at least three cavities extending orthogonally with respect to the bottom half mould and located in proximity to a circumference of the bottom half mould, wherein each of the first set of cavities further comprises a bush;
a top half mould comprising a second set of at least three cavities extending orthogonally with respect to the top half mould and located in proximity to a circumference of the top half mould, wherein each of the second set of cavities further comprises a guiding pin, and wherein the top half mould is to be positioned against the bottom half mould, and upon positioning, is to form:
a set of at least three alignment cavities formed by aligning each of the first set of cavities with the respective second set of cavities, wherein the set of alignment cavities is to allow the plurality of guiding pins to be fastened onto the plurality of bushes.

9. The curing mould as claimed in claim 8, wherein each of the plurality
of bushes is a longitudinally extending cylindrical depression, and wherein
each of the plurality of bushes comprises:
a bottom portion comprising a threaded cavity, wherein the threaded cavity is to accommodate a bolt and a washer to couple the bush with one of the first set of cavities in the bottom half mould; and
a collared top portion, wherein the collared top portion is to accommodate one of the plurality of guiding pins.
10. The curing mould as claimed in claim 8, wherein each of the plurality
of guiding pins is a longitudinally extending cylindrical protrusion, and
wherein each of the plurality of guiding pins comprises:
a bottom portion, wherein the bottom portion is tapered to form a conical frustum head, and wherein the conical frustum head is to cause the guiding pin to fasten onto one of the plurality of bushes; and
a collared top portion comprising a threaded cavity, wherein the cavity is to accommodate a bolt and a washer to couple the guiding pin with one of the second set of cavities on the top half mould.