FORM 2
THE PATENT ACT 1970
[39 OF 1970]
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
[See Section 10 and Rule 13]
“INTEGRATING FUEL SUPPLY UNIT MOUNT RING TO FUEL TANK BODY”
Name and Address of the Applicant: TATA MOTORS LIMITED, Bombay House, 24 Homi Mody Street, Hutatma Chowk, Mumbai – 400001, Maharashtra, India.
Nationality: Indian
The following specification particularly describes the nature of the invention and the manner in which it is to be performed.

TECHNICAL FIELD
The present disclosure relates to joining two materials. More particularly, relates to a method of joining thermoplastic material by heating and pressing process resulting in a fusion bond.
BACKGROUND OF DISCLOSURE
In an automotive vehicle the kind of fuel used plays an important role. Different vehicles utilize different fuels and in turn return different performance values. The different kind of fuels ranges from Petrol, Diesel, hydrogen fuels, bio fuels etc and since these fuels are highly volatile in nature it is of great importance to prevent the fuels from vaporization due to the excess heat generated. This heat generation may cause a fuel fume build up within the tank and leads to vaporization of the fuel. This formation of a liquid fuel to a gas formation leads to various other problems like vapour lock. A vapour lock occurs when the liquid fuel changes its state from liquid to gas while still in the fuel delivery system. This disrupts the operation of the fuel pump, causing loss of feed pressure to the carburetor or fuel injection system, resulting in transient loss of power or complete stalling. Restarting the engine from this state may be difficult. In an automotive vehicle, fuel system plays an important role, it is a basic and prime means of running the engine but also on the other hand plays a major role contributing to the emission of the engine affecting the environment.
In conventional automotive systems, sheet metal fuel tanks are used the materials of sheet metal mainly being steel or aluminium. These sheet metals tanks were heavy and in the cases where the environmental temperature was high, the heat causes a rise in temperature within the sheet metal tank and may lead to possible formation of fumes within the tank leading to various problems as discussed above. Nowadays, the main concern in an automobile vehicle is to make it light, more fuel efficient and to cut down on the manufacturing cost in making a vehicle. Due to the advert technical advancement in technology and research the modern day vehicle fuel tanks are equipped with newer materials for their fuel tanks which leads to a number of advantages, one of the many advantages is the weight reduction in such tanks. The fuel tanks equipped in the vehicles nowadays are special grade thermoplastics which aids in weight reduction. Also, the main focus was to reduce the weight of the fuel tank, the focus was still on developing a safe part and also to control the evaporative emissions due to permeation and leakages.

Since, fossil fuels are depleting day by day and since fossil fuels are non-renewable resources they take millions of years to form and the reserves are being depleted much faster than the new ones are being formed. Hence there is a need to utilize the fossil fuels in a conserved and efficient manner; this invention was made to ensure that structural integrity of the peripheral parts of the fuel system with respect to the fuel tank was maintained. This in turn provided robustness to the fuel tank from a mechanical strength point of view and also from safety under extreme abuse conditions.
OBJECTS OF THE DISCLOSURE
An object of the present disclosure is to provide a foolproof solution during the manufacture of plastic/thermoplastic fuel tank with “in-situ” peripherals of the fuel system.
Another object of the present disclosure is to provide a weld joint, which is safe, homogeneous and leak proof, which can be achieved through simple, low cost and robust manufacturing process.
Another objective of the present disclosure is to provide an advanced design which helps in reducing evaporative emissions and provides better mechanical strength of joineries.
SUMMARY OF THE DISCLOSURE
The shortcomings of the prior art are overcome and additional advantages are provided through the provision as claimed in the present disclosure. Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.
In an embodiment of the disclosure, a method for joining thermoplastic materials comprising acts of: forming a ‘V’ shaped annular ring on a mating surface of a mounting flange wherein, the ‘V’ shaped annular ring provided on the mounting flange forms a first mating part; placing a second mating part of predetermined shape below the first mating part; heating the first mating part and the second mating part for a pre-determined time period forming a crest at the ‘V’ profile of the mounting flange and a trough on the second mating part; pressing for a predetermined time period the first mating part and the second mating part after aligning the ‘V’ profile with the trough to form a joint.

In an embodiment of the disclosure wherein, placing a heater intermediate to the first mating part and the second mating part for heating wherein the heater is provided with a trough formation on one side and a crest formation on the other side.
In an embodiment of the disclosure, the trough formation provided on one side of the heater heats comes in contact with the ‘V’ shaped annular ring of the mounting flange which in turn leads to a crest formation.
In an embodiment of the disclosure, the crest formation provided on the other side of the heater heats the second mating part forming a trough formation.
In an embodiment of the disclosure, the heater is removed after heating.
In an embodiment of the disclosure, the first mating part and the second mating part are heated by the heater at a temperature ranging from 120 ºC to 280 ºC, covering relevant thermoplastic materials (typical experimental temperature range: 160 °C to 190 °C).
In an embodiment of the disclosure, the first mating part and second mating part is pressed together at a predetermined pressure ranging from 1.6 kg/cm2 to 2 kg/cm2.
In an embodiment of the disclosure, the joint after pressing process is cooled at an elevated ambient temperature having temperature ranging from 40 ºC to 80 ºC.
In an embodiment of the disclosure, plurality of inserts is provided on the circumference of the mounting flange for fastening means.
In an embodiment of the disclosure, the second mating part is a fuel tank and the joint formed is a leak proof joint.
The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The novel features and characteristic of the disclosure are set forth in the appended claims. The disclosure itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description

of an illustrative embodiment when read in conjunction with the accompanying figures. One or more embodiments are now described, by way of example only, with reference to the accompanying figures wherein like reference numerals represent like elements and in which:
Figure 1 illustrates conventional joining process of thermoplastic materials with or without hot melt glue.
Figure 2 illustrates side view of the fuel tank body and mounting flange.
Figure 2A illustrates top view of the fuel tank body, mounting flange along with inserts.
Figure 3 illustrates cut section view of the fuel tank along with first and second mating parts.
Figure 4 illustrates cut section view of first mating part (Mounting flange) and second mating part (fuel tank).
Figure 5 illustrates cut section view of the first mating part and second mating part with a heater placed intermediate to them.
Figure 6 illustrates cut section view of the crest formation on the “V” profile and trough formation on the fuel tank body.
Figure 7 illustrates cut section view of the pressing process of the two mating parts.
Figure 8 illustrates cut section view of the mating parts during pre curing process.
Figure 9 illustrates magnified cut section view of the joint formed between the mounting flange and fuel tank with fused material flow.
The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION OF DISCLOSURE
The foregoing has broadly outlined the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. Additional features and advantages of the disclosure will be described hereinafter which form the subject of the claims of the disclosure. It should be appreciated by those

skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the disclosure as set forth in the appended claims. The novel features which are believed to be characteristic of the disclosure, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and make part of this disclosure.
Referring now to the drawings wherein the drawings are for the purpose of illustrating an exemplary embodiment of the disclosure only, and not for the purpose of limiting the same.
Figure 1 illustrates conventional joining process of thermoplastic materials with or without hot melt glue. A first mating part (3') which is nothing but a mounting flange (2') is placed over a second mating part (4') as shown in the figure. The second mating part (4') is a fuel tank (5') body placed below the first mating part (3'). In this conventional joining process of the mounting flange (2') with the fuel tank (5') wherein, the two parts are heated to high temperatures and pressed together for a brief period of time. The mounting flange (2') is provided with series of inserts (9') at the top portion. The point of contact of the first mating part (3') and the second mating part (4') are heated to very high temperatures (upto melting point temperatures). The semi liquid state of contact points are pressed together for a brief period of time until the joint is set. The formation of the joint can also be done by using a suitable filler material or glue to fix the two thermoplastic materials together to form a joint. This joint formed is not a strong joint and there are many finishing processes that have to be carried out to get a suitable end result. Another process of joining the thermoplastic materials is by ultra sonic welding, vibration welding of two parts which may or may not use hot melt glue in between the jointing members.
Figure 2 and 2A illustrates side view and top view of the fuel tank body and mounting flange. From the figure, a thermoplastic fuel tank body (5) is disclosed having a predetermined

shape, the fuel tank (5) has a top opening and the neck of the opening has a mounting flange (2) joined to it by the joining process disclosed in the instant disclosure. The mounting flange (2) fixed to the tank body (5) has a plurality of inserts (9) provided for fastening means.
Figure 3 illustrates top perspective view of the mounting flange with inserts. Figure shows a magnified perspective view of the fuel tank body (5) with a mounting flange (2) fixed to it.
Figure 4 illustrates cut section view of first mating part (Mounting flange) and second mating part (fuel tank). The first mating part (3) has a “V” shaped annular ring (1) at the bottom of the mounting flange (2) is provided all along the circumference of the mounting flange (2). The annular ring provided below is purposefully made to have a “V” profile. The “V” profile of the mounting flange (2) will make the line contact for the first mating part (3). The second mating part (4) is effectively a fuel tank body (5) placed right below the first mating pat (3). The axis of the through hole of the mounting flange (2) is in synchronization with the axis of the through hole of the fuel tank body (5). As shown in the figure, the “V” shaped annular ring having a “V” tip is in contact with the fuel tank body (5) of the second mating part (4).
Figure 5 illustrates cut section view of the first mating part (3) and second mating part (4) with a heater (10) placed intermediate to them. The heater (10) used in this joining process is an electrical heater having heating coils (11) along the entire length of the heater (10). The electric heater distributes the heat uniformly and consistent heating takes place. The top portion of the heater (10) has a trough shaped provision and the bottom portion of the heater (10) has a crest shaped provision. The trough shape comes in contact with the “V” profile annular ring (1) of the mounting flange (2). During the heating process the “V” profile of the mounting flange (2) melts and takes the shape of the trough provided on the top portion of the heater (10), this effectively forms a crest (6) formation on the “V” profile annular ring (1) changing its shape. The crest shape provided on the bottom of the heater (10) is in contact with the fuel tank body (5) which melts the material and forms a trough (7) formation on the fuel tank body (5). The crest and trough formation provided on the top and bottom of the heater is of the same dimension {i.e the crest provided at the bottom of the heater (10) has a dimension equal to that of the trough shape provided at the top of the heater (10), this forms a male and female part for mating it together and pressing to form a joint}.
Figure 6 illustrates cut section view of the crest (6) formation on the “V” profile and trough (7) formation on the fuel tank body (5). The first mating part (3) with a crest (6) formed at the

point of contact is brought close to the second mating part (4) having a trough (7) formed at the point of contact on the second mating part (4).
Figure 7 illustrates cut section view of the pressing process of the two mating parts. The first mating part (3) and the second mating part (4) are joined together at their mating points and pressed together for a brief time period under a predetermined pressure ranging from 1.6 kg/cm2 to 2 kg/cm2. The pressing process is done immediately soon after the heating process is finished. The temperature at which the pressing and heating process is carried out is very crucial and hence a perfectly strong joint is formed only at ambient temperatures. The pressure at which the first and second mating parts (3 and 4) are pressed is also crucial as excess pressure applied would lead to the melted part to seep out of the trough (7) formation. In the present disclosure, the pressure applied is just enough for the perfect joint.
Figure 8 illustrates cut section view of the mating parts during pre curing process. The mounting flange (2) firmly sits into the trough (7) of the fuel tank body (5). The joined parts have to be cooled at a temperature just above the ambient temperature ranging from 40 ºC to 80 ºC. The semi molten state of the mating parts is cured in such a way that the molecules of the thermoplastic materials fuse together and help in forming a stronger joint (8). The resulting joint (8) has more mechanical tensile and shear strength properties. The joint (8) has a homogenous weld penetration (12) and fused material flow (13) which gives a structurally rigid, leak-proof joint (8) making it a very safe aggregate assembly.
Figure 9 illustrates magnified cut section view of the joint (8) formed between the mounting flange and fuel tank with fused material flow (13). A magnified image of the joint (8) formed shows us the weld penetration (12) and the fused material flow (13). The joint (8) so formed is stronger than the strength of the base materials.
EQUIVALENTS
With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.
It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the

term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.”

In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.
While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.
REFERENCE NUMERALS

1 “V” shape annular ring
2 Mounting Flange
3 First mating part
4 Second mating part
5 Fuel tank body
6 Crest
7 Trough
8 Joint
9 Inserts
10 Heater
11 Heating Coils
12 Weld Penetration
13 Fused material flow
2' Mounting flange (Conventional method)
3' First mating part (Conventional method)

4' Second mating part (Conventional method)
5' Fuel tank body (Conventional method)
9' Inserts (Conventional method)

WE CLAIM:
1. A method for joining thermoplastic materials comprising acts of:
forming a ‘V’ shaped annular ring (1) on a mating surface of a mounting flange (2) wherein, the ‘V’ shaped annular ring (1) provided on the mounting flange (2) forms a first mating part (3);
placing a second mating part (4) of predetermined shape below the first mating part (3);
heating the first mating part (3) and the second mating part (4) for a pre-determined time period forming a crest (6) at the ‘V’ profile of the mounting flange (2) and a trough (7) on the second mating part (4);
pressing for a predetermined time period the first mating part (3) and the second mating part (4) after aligning the ‘V’ profile with the trough (7) to form a joint (8).
2. The method of joining a thermoplastic material as claimed in claim 1, wherein placing a heater (10) intermediate to the first mating part (3) and the second mating part (4) for heating wherein the heater (10) is provided with a trough (7) formation on one side and a crest (6) formation on the other side.
3. The method of joining a thermoplastic material as claimed in claim 1 and 2, wherein the “trough” profile (7) provided on one side of the heater plate, heats the ‘V’ shaped annular ring (1) of the mounting flange (2), which in turn leads to a contoured crest (6).
4. The method of joining a thermoplastic material as claimed in claim 1 and 2, wherein the “crest” profile (6) provided on the other side of the heater plate, heats up the surface of the second mating part (4), forming a trough (7).
5. The method of joining a thermoplastic material as claimed in claim 2, wherein the heater (10) is removed after the heating.
6. The method of joining a thermoplastic material as claimed in claim 1, wherein the first mating part (3) and the second mating part (4) are heated by the heater (10) at a temperature ranging from 120 ºC to 280 ºC.

7. The method of joining a thermoplastic material as claimed in claim 1, wherein the first mating part (3) and second mating part (4) is pressed together at a predetermined pressure ranging from 1.6 kg/cm2 to 2 kg/cm2.
8. The method of joining a thermoplastic material as claimed in claim 1, wherein the joint (8) after pressing process is cooled at an elevated ambient temperature having temperature ranging from 40 ºC to 80 ºC.
9. The method of joining a thermoplastic material as claimed in claim 1, wherein plurality of inserts (9) are provided on the circumference of the mounting flange (2) for fastening means.
10. The method of joining a thermoplastic material as claimed in claim 1, wherein the second mating part (4) is a fuel tank (5) and the joint (8) formed is a leak proof joint.
11. A fuel tank fabricated by a method as claimed in claim1.