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: FLAP MOLDING DEVICE
2. Applicant(s)
NAME NATIONALITY ADDRESS
CEAT LIMITED Indian RPG HOUSE, 463, Dr. Annie Besant Road, Worli, Mumbai, Maharashtra 400030, 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 subject matter described herein, in general, relates to a tire flap, and
in particular, relates to a system for manufacturing the tire flap.
BACKGROUND
[0002] Many tires for large vehicles such as buses, heavy trucks, and tractors
are designed for use with a tube provided inside the tire with high internal pressure. The tube is a torus-shaped balloon generally made from an impermeable material such as soft, elastic synthetic rubber, to prevent air leakage. The tube is inflated with a valve and fits inside the casing of the tire. The inflated tube provides structural support and suspension, while the tire provides grip and protects the more fragile tube.
[0003] A tire flap is usually inserted in the tire to occupy the space between the
tube and steel rim that holds the tire on a wheel. The tire flaps are used to protect tubes from immense heat and pressure by avoiding direct contact with the steel rim and the output is that it adds life to tubes as well as tires. They also protect the tube from sharp areas on the inside of the wheel and getting sucked into the tire bead toe, therefore, preventing the tube from being punctured.
[0004] The tire flaps are generally manufactured separately from the tire.
Generally, the tire flaps are manufactured using a molding process.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] 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.
[0006] FIG. 1 shows a vertical cross-section view of a tire flap molding device,
according to an example of the present subject matter; and
[0007] FIG. 2 shows an enlarged schematic view of a circumferential groove of
the tire flap molding device, according to an example of the present subject matter.

DETAILED DESCRIPTION
[0008] The present invention relates to a tire flap molding device that may be
used to improve the process for manufacturing a tire flap (hereinafter flap), in accordance with the present subject matter.
[0009] The flaps are generally used to separate a tube from a tire bead and rim
for heavy-duty motor vehicles. The flaps help protect the tube from damage by the
rocking of the tire bead, abrasion with the rim, and to prevent the entry of foreign
material into the rim. Generally, they are a continuous band of solid rubber used in
tube tire assemblies for vehicles requiring high tire pressures. These flaps are made
of usually the same solid vulcanized rubber material as the tube and are intended to
solve the problem of fatigue stress cracks occurring in the tube where the tire
sidewall deflects somewhat under heavy loads. When a tire is not fitted with the
flaps they have a very high chance of experiencing blowouts or failure.
[0010] To manufacture such a flap, an un-vulcanized rubber or a flap material
that may be extruded into an appropriate shape and cut into a predetermined size is taken. Further, said flap material is arranged along a flap material receiving space that may be formed along the circumferential direction inside a tire flap molding device. Once the flap material is arranged, the tire flap molding device is pressed and passed through the compression molding under heating to vulcanize the flap material. These vulcanized flaps have excess flap material, generally known as "edge flash", which may require manual trimming by using hand trimming tools such as knives, scissors, razor blades, or skiving knives.
[0011] However, a foremost limitation of the manual trimming process is that
its effectiveness is highly dependent on the skills of an individual operator tasked with the manual trimming of the edge flash. As a result, the quality of delivered flap and consistency of results from one flap to another may vary widely, resulting in an uneven flap edge gauge and an uneven flap development length. Due to improper trimming of the edge flash from the flap by the operator, the final flap may get rejected at the quality control stage. Besides, the benefits to the manufacturer from doing so, i.e., trimming of edge flash using the hand trimming tool, would be vastly outweighed by the amount of time and money expended in the effort.

[0012] Also, in a manual trimming setup, an operator working in a facility that
manufactures flaps, on a daily basis, may be required to trim around 700 parts of flash edge from the molded flash using the hand trimming tool. Owing to monotonous activity and unworkability with safety gloves in hand, the operation of edge flash trimming with the hand trimming tool is usually done by bare hand. Use of the hand trimming tools, which are generally made of metal, maybe a safety concern for the operator during manual trimming with a bare hand. Also, continuous use of the hand trimming tool by the operator may create skin abrasion or other skin issues. This may affect the overall working capacity of the operator, resulting in a loss of productivity.
[0013] Therefore, described herein is a tire flap molding device by the use of
which, once the curing of the flap is done, the edge flash accumulated in the flap material receiving space of the molding device may be separated from the flap edges completely, making it possible to pull the edge flash away from the flap material receiving space without using any hand trimming tools.
[0014] An implementation of the present subject matter describes a tire flap
molding device to be used for forming and curing heat-curable moldable tire flaps.
The device comprises a lower mold section that includes a flap material receiving
space and a first recess. The molding device further comprises an upper mold
section that includes a top portion and a bottom portion. The bottom portion of the
upper mold section has a first protruding ridge and the top portion has a second
recess, wherein the first protruding ridge is adapted to couple with the
corresponding flap material receiving space in the lower mold section.
[0015] The molding device also comprises a central mold section that includes
a first annular flange and a second annular flange. The first annular flange is supported by the upper mold section against the second recess and the second annular flange is supported by the lower mold section against the first recess so as to retain the central mold section in a sealing position. The upper mold section, the lower mold section, and the central mold section in the sealing position together define a flap molding cavity, wherein the shape of the flap molding cavity matches with the final conformation to be given to a flap material.

[0016] Further provided with the molding device is a circumferential groove that
collects excess flap material, wherein the circumferential groove is provided adjacent to a periphery of the flap molding cavity along walls of the upper mold section and the lower mold section, respectively.
[0017] With the above-disclosed subject matter, the edge flash trimming process
may be substantially automatized without requiring any hand trimming tools, thereby, providing a flap with an even flap edge gauge and flap development length. Also, the flap produced by the molding device of the present subject matter possesses a smooth finish and generates a paper-thin edge flash only at the circumferential groove which can easily be pulled out by the operator without having to use any hand trimming tool.
[0018] 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.
[0019] FIG. 1 is a cross-sectional view of a tire flap molding device 100, as per
implementation of the present subject matter. The flap molding device 100 device comprises an upper mold section 102, a lower mold section 104, and a central mold section 106. The lower mold section 104 comprises a flap material receiving space 124 and a first recess 126. The upper mold section 102 comprises a top portion 116 and a bottom portion 118. The bottom portion 118 comprises a first protruding ridge 120 and the top portion 116 comprises a second recess 122, wherein the first protruding ridge 120 is adapted to couple with the corresponding flap material receiving space 124 of the lower mold section 104.

[0020] The central mold section 106 comprises a first annular flange 128 and a
second annular flange 130. The first annular flange 128 is supported by the upper
mold section 102 against the second recess 122 and the second annular flange 130
is supported by the lower mold section 104 against the first recess 126 to retain the
central mold section 106 in a sealing position. The upper mold section 102, the
lower mold section 104, and the central mold section 106, in the sealing position,
together define a flap molding cavity 114, wherein the shape of the flap molding
cavity 114 matches with the final conformation to be given to a flap material.
[0021] In an example implementation of the present subject matter, the upper
mold section 102 is coupled to a movable plate 110 of a molding press (not illustrated) via lugs integrally formed thereon and the bolts. The lower mold section 104 is similarly mounted on a fixed plate 112 via lugs and bolts.
[0022] The flap molding device 100 further comprises a circumferential groove
108 that is to acts as a collection point for excess flap material or edge flash. The circumferential groove 108 is provided adjacent to a periphery of the flap molding cavity 114 along wall of the upper mold section 102.
[0023] In an example, unlike conventional flap molding devices which include
an edge flash collection point at the bottom of the mold as well, the present flap molding device 100 only comprises one edge flash collection point, i.e., circumferential groove 108. In the present invention, bottom half 138 of the flap molding device 100 may be sealed-off utilizing a sealing membrane 132. One of the advantageous features of the present molding device 100 is that no edge flash is generated at the bottom half 138 of the molding device 100, and hence, there is no need to trim the bottom edge flash. This minimizes the manual intervention in the post-vulcanization processing of a tire flap.
[0024] In another example, the flap material receiving space 124 in the lower
mold section 104 may have a flap material receiving capacity at least equal to the capacity of the completed flap molding cavity 114 when the upper mold section 102, the lower mold section 104, and the central mold section 106 are closed. In yet another example, when the molding press is in operation, the movable plate 110 is closed with respect to the fixed plate 112 and, during this process, a first interfacing

surface 134 of the bottom portion 118 of the upper mold section 102 may approach
for actual face-to-face contact with a second interfacing surface 136 of the lower
mold section 103, thereby, exerting extreme pressure against each other.
[0025] In another example, the sealing membrane 132 that is provided along the
bottom portion 118 of the upper mold section 102 may ensure an extremely tight fit with respect to the vertically disposed of an annular retaining surface 140 when the upper mold section 102, the lower mold section 104, and the central mold section 106 are closed. A similar sealing membrane (not illustrated) may be provided on the first annular flange 128 and the second annular flange 130 of the central mold section 106 to ensure a positive fit with their respective the second recess 122 and the first recess 126 on the upper mold section 102 and the lower mold section 104, respectively.
[0026] In an example implementation of the present subject matter, in order to
manufacture a tire flap using the flap molding device 100 of the present invention, first, an un-vulcanized flap material may be introduced into the flap material receiving space 124 between the upper mold section 102 and the lower mold section 104 directly adjacent to the flap molding cavity 114. Once the un-vulcanized flap material is placed into the flap material receiving space 124, the upper mold section 102, the lower mold section 104, and the central mold section 106 are combined by the closing of the molding press with the lowering of the movable plate 110. Once the flap molding device 100 is closed, the pressure may be applied by known means through the upper mold section 102, lower mold section 104, and central mold section 106 into the flap material for completion of the vulcanization process. After the vulcanization of the flap material is completed, all the three mold sections are separated, and the vulcanized tire flap is taken out.
[0027] As it may be understood, in the vulcanization process, there will usually
be a slight amount of excess flap material in the form of “flash,' which may be required to be trimmed off or removed from the vulcanized tire flap at the end of the vulcanizing process. To this end, the circumferential groove 108 is provided adjacent to the periphery of the mold flap molding cavity 114 in the wall of the upper mold section 102 to collect this paper-thin excess flap material.

[0028] In an example implementation of the present subject matter, once the
vulcanization is completed, the excess flap material gets accumulated in the circumferential groove 108 of the flap molding device 100 which may be easily pulled out by the operator with bare hands without using any hand trimming tool or requiring puncturing of the excess flap material.
[0029] FIG. 2 shows an enlarged schematic view of the circumferential groove
114 of the tire flap molding device 100, according to an example of the present subject matter. In an example, a distance of the circumferential groove 108 from the periphery of the flap molding cavity 114 may stand in a range of 0.3 to 0.8 mm. In another example, a radius of the circumferential groove 108 may start from 0.5 mm of flap edge and may lie in a range of 0.5 mm to 0.20 mm. In yet another example, the flap molding cavity 114 has an area that may have a fixed volume defined by molding surfaces of the upper mold section 102, the lower mold section 104, and the central mold section 106, simultaneously.
[0030] In yet another example, the shape of the circumferential groove 108 may
be semicircular. The semicircular shape of the circumferential groove 108 may have the advantage that the bulge of the semicircle is easy to hold and pull. Hence, the excess flap material that gets accumulated in the semicircular-shaped circumferential groove 108 would be easy to pull out.
[0031] In another example, molding surfaces of the upper mold section 102 and
the lower mold section 104 may be located so as to partially penetrate a molding surface of the central mold section 106. A person skilled in the art would understand that any molded product may be formed by the molding device 100 of the present invention that has a required shape matching with the shape of the molding device 100. It is conceivable that a tubular element of endless but rectangular form as distinguished from the annular type illustrated may be manufactured in the same manner.
[0032] The embodiments of this invention can be used in combination or
individually to form tire flaps by improved manufacturing processes and/or with improved performance features. The overall design of the molding device of the invention disclosed herein results in a combination being an improved process for

making, namely but not exclusively, tire flaps that may be used for preventing the
tube from any kind of damage as a result of getting into direct contact with the metal
rim.
[0033] Although implementations for improving the tire flap manufacturing
process are described, it is to be understood that the present subject matter is not
necessarily limited to the specific features described. Rather, the specific features
are disclosed as implementations.

I/We Claim:
1. A tire flap molding device (100) comprising:
a lower mold section (104) comprising a flap material receiving space (124) and a first recess (126);
an upper mold section (102) comprising a top portion (116) and a bottom portion (118), the bottom portion (118) comprising a first protruding ridge (120), and the top portion (116) comprising a second recess (122), wherein the first protruding ridge (120) is adapted to couple with the corresponding flap material receiving space (124) in the lower mold section (104);
a central mold section (106) comprising a first annular flange (128) and a second annular flange (130), the first annular flange (128) being supported by the upper mold section (102) against the second recess (122) and the second annular flange (130) being supported by the lower mold section (104) against the first recess (126) to retain the central mold section (106) in a sealing position,
wherein the upper mold section (102), lower mold section (104), and central mold section (106) in the sealing position together define a flap molding cavity (114), a shape of the flap molding cavity (114) matching the final conformation to be given to a flap material, and
a circumferential groove (108) to collect excess flap material, wherein the circumferential groove (108) is provided adjacent to a periphery of the flap molding cavity (114) along wall of the upper mold section (102).
2. The tire flap molding device (100) as claimed in claim 1, wherein circumferential groove (108) is semicircular.
3. The tire flap molding device (100) as claimed in claim 1, wherein the distance of the circumferential groove (108) from the periphery of the flap molding cavity (114) lies in a range of 0.3 to 0.8 mm.
4. The tire flap molding device (100) as claimed in claim 1, wherein the radius of the circumferential groove (108) lies in a range of 0.5 to 0.20 mm.

5. The tire flap molding device (100) as claimed in claim 1, wherein the flap molding cavity (114) has an area which has a fixed volume defined by molding surfaces of the upper mold section (102), the lower mold section (104), and the central mold section (106).
6. The tire flap molding device (100) as claimed in claim 1, wherein molding surfaces of the upper mold section (102) and the lower mold section (104) are located so as to partially penetrate a molding surface of the central mold section (106).
7. The tire flap molding device (100) as claimed in claim 1, wherein the upper mold section (102) along the bottom portion (118) comprises a sealing membrane (132), the sealing membrane 132 is to seal-off bottom half (138) of the tire flap molding device (100).