FORM-2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2006
COMPLETE
Specification
(See Section 10 and Rule 13)
METHOD OF PLASTICIZATION OF VEHICULAR DOOR AND A PLASTICIZED VEHICULAR DOOR FORMED THEREOF
MAHINDRA AND MAHINDRA LTD.
an Indian Company
of Mahindra Towers, Worli,
Mumbai - 400 018, Maharashtra, India
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE NATURE OF THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED

FIELD OF THE DISCLOSURE
The present disclosure relates to the field of vehicular door.
Particularly, the present disclosure relates to the field of plasticization of the vehicular door for developing a plasticized vehicular door.
BACKGROUND
Vehicular doors are presently made of stamped steel sheets which are welded together and made robust by steel reinforcements. The extensive use of steel increases the weight of the door and hence weight of the vehicle. Further, the tail door of a vehicle, in particular, includes an inner panel and an outer panel bonded together at edges to define a space therebetween to enables mounting of auxiliary components. The fuel economy of the vehicle decreases with the increase in the weight of the vehicle. Hence, the overall weight of the vehicle is required to be reduced in order to achieve better fuel economy for meeting fuel economy standards to compensate for the higher fuel prices. The best method of reduction in the weight of the vehicle is carried out by reducing the weight of the vehicular door particularly the tail door.
Several attempts have been made to reduce the weight of vehicular doors.
Accordingly, United States Patent Number US6053562, United States Patent Number US7399022, United States Patent Number US4945682 and United States Patent Application Number US200600131926 disclose providing a tubular reinforcement between the inner panel and the outer panel to achieve additional structural rigidity. However, the tubular reinforcement does not enable substantial reduction in the weight of the vehicular door and hence the overall weight of the vehicle.

However, manufacturing a reduced weight vehicular door without providing the tubular metal reinforcement, as disclosed in United States Patent Number 7399022, results in failure to adequately seal the vehicular door to the body of the vehicle and thus increasing the chances of leakage for air and water into and out of the vehicle. The problem of improper sealing is accentuated in case of revolving type side opening door as the mounting and the latching arrangements at lower area and upper area of the vehicular door are not positively engaged with vehicle body.
Thus, there is felt a need for a vehicular door which enables reduction of the overall weight of a vehicle, while extending the requisite structural rigidity.
OBJECTS
Some of the objects of the system of the present disclosure, which at least one embodiment herein satisfies, are as follows:
An object of the present disclosure is to reduce the weight of vehicular doors.
Another object of the present disclosure is to enable increase in fuel efficiency.
Still another object of the present disclosure is to provide a rigid vehicular door besides weight reduction.
Yet another object of the present disclosure is to provide a vehicular door which is economical to manufacture.
Further another object of the present disclosure is to provide a light weight vehicular door having increased durability.
An added object of the present disclosure is to provide an improved sealing between the vehicular door and the vehicle body.

An additional object of the present disclosure is to compensate for an undesirable deformation of light weight vehicular door under critical environmental conditions.
Yet another object of the present disclosure is to provide a method for manufacturing a light weight vehicular door which is easy to implement while being efficient.
Other objects and advantages of the present disclosure will be more apparent from the following description when read in conjunction with the accompanying figures, which are not intended to limit the scope of the present disclosure.
SUMMARY
In accordance with the present disclosure there is provided a method of plasticization of a vehicular door mounted on a vehicle having a body defining a compartment, the vehicular door having an inner panel and an outer panel, the method comprising the following steps:
preparing a mould defining a cavity to complement a predetermined shape of the inner panel and the outer panel;
providing at least one air vent in the cavity;
preparing a core having a shape complementary to the cavity;
positioning a reinforcing mat of a predetermined thickness in the predetermined space within the cavity;
sandwiching the reinforcing mat between the cavity and the core by maintaining a predetermined gap between the core and the cavity at a parting surface of the mould;
injecting a resin material under high pressure into the cavity through at least one gate defined in the core to substantially wet the reinforcing mat to form a composite structure; and

applying a compressive force on the core for compressing the composite structure between the core and the cavity.
Typically, the step of preparing the mould includes a step of extracting at least a portion of an existing vehicular door.
Typically, the step of preparing the core includes a step of extracting a resin mat adhesively bonded within the cavity to define a predetermined space therebetween corresponding to a desired thickness of the vehicular door.
Preferably, the step of providing at least one air vent includes the step of defining an inverted L-shaped groove.
Typically, the step of positioning includes a step of bonding the reinforcing mat to the cavity by application of adhesive.
Additionally, the step of applying a compressive force is stopped on attaining a predetermined thickness of the composite structure.
Preferably, in accordance with the method of the present disclosure, there is provided a plasticized vehicle door having an inner panel and an outer panel, wherein at least a portion of the inner panel and the outer panel are made of the composite structure as described herein above.
In accordance with the present disclosure there is provided a plasticized vehicular door for a vehicle having a body defining a compartment, the door having an interior surface and an exterior surface, the door comprising:
an inner panel defining a plurality of openings, the inner panel having at least one average concentration zone reinforced by at least one high concentration zone, the at least one average concentration zone and the at least one high concentration zone utilizing a composite structure having a predetermined composition;
at least one outer panel cooperating with at least a portion of the inner panel to form the exterior surface of the door;

a hinge reinforcement plate and a latch reinforcement plate adapted to be bonded to the inner panel, the hinge reinforcement plate being substantially parallel to the latch reinforcement plate, the hinge reinforcement plate and the latch reinforcement plate being substantially perpendicular to the inner panel and the outer panel; and
a seal leakage arrangement including at least two wire ropes adapted to discreetly cooperate with the latch reinforcement plate and the hinge reinforcement plate to sealingly press the inner panel against the body of the vehicle.
Typically, the plurality of openings is adapted to provide access paths for mounting and servicing of at least one auxiliary mechanism.
Additionally, at least one of the plurality of openings is adapted to include an window opening for positioning of a window glass.
Preferably, the plurality of openings are adapted to be covered by means of a trim pad, the trim pad being adapted to cooperate with the inner panel at the interior surface via at least one push pin.
Typically, the composite structure is formed by molding a resin and a woven glass mat, the at least one average concentration zone and the at least one high concentration zone being adapted to have variable concentration of the resin and the woven glass mat.
Typically, the inner panel is adhesively bonded to the outer panel.
Preferably, the at least one outer panel is positioned substantially below the window opening on the inner panel.
Additionally, the at least one outer panel is positioned substantially above the window opening on the inner panel.
Typically, the latch reinforcement plate and the hinge reinforcement plate are adapted to discreetly support a hinge mounting and a latch mounting, the hinge

reinforcement plate and the inner panel being adapted to define a predetermined cross-section, the pre-determined cross-section being selected from the group comprising arcuate shaped, D-shaped and C-shaped.
Typically, the latch reinforcement plate and the hinge reinforcement plate are adapted to be adhesively bonded to the inner panel, the window glass being adapted to be supported by the inner panel, the latch reinforcement plate and the hinge reinforcement plate.
Typically, the at least two wire ropes cooperates with the latch reinforcement plate and the hinge reinforcement plate through a corresponding bracket at one end and through a corresponding threaded rod at the other end, the corresponding threaded rod being tightened on the latch reinforcement plate and the hinge reinforcement plate to generate a predetermined tension on the wire rope, angularly displacing the door towards the vehicle body.
Preferably, the at least one outer panel and the inner panel has equal coefficient of thermal expansion.
Typically, the at least one outer panel and the inner panel are molded by an injection molding technique selected from the group consisting of reaction injection molding and structural reaction injection molding.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
The method of plasticization of vehicular door and a plasticized vehicular door formed thereof of the present disclosure will now be described with the help of accompanying drawings, in which:
Figure I illustrates an exploded view of a plasticized vehicular door in
accordance with the present disclosure;
Figure 2 and Figure 3 illustrate an inner panel of the plasticized vehicular door;

Figure 4 illustrates the inner panel cooperating with a latch reinforcement plate/ hinge reinforcement plate at a window opening area;
Figure 5 and Figure 6 illustrate the sectional view of the plasticized vehicular door panel along the line C-C and D-D respectively;
Figure 7 illustrates a wire rope arrangement for angular displacement of the plasticized vehicular door panel;
Figure 8 illustrates a flowchart illustrating the steps involved in plasticization of a vehicular door panel in accordance with the present disclosure;
Figure 9 illustrates cut-out portion of an existing door panel;
Figure 10 illustrates a mould prepared to complement to the shape of a portion of the vehicular door to be plasticized;
Figure 11 illustrates a mould and a core extracted from existing metal vehicular door;
Figure 12 illustrates a gate formed within the core;
Figure 13 illustrates an air gap formed within the mould; and
Figure 14 illustrates a compressive force applied to the core forming a composite structure.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS
A preferred embodiment of the method of plasticization of vehicular door and a vehicular door formed thereof of the present disclosure will now be described in detail with reference to the accompanying drawings. The preferred embodiment

does not limit the scope and ambit of the disclosure. The description provided is purely by way of example and illustration.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The following description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
A plasticized vehicular door (10), shown in Figure 1, is mountable on a vehicle having a body defining a compartment. The plasticized vehicular door (10) includes an inner panel (12) and an outer panel (14) forming an interior surface and an exterior surface of the plasticized vehicular door (10). The inner panel (12) and the outer panel (14), having equal coefficient of thermal expansion, are

made of the composite structure formed by injection molding technique, typically reaction injection molding or structural reaction injection molding.
The inner panel (12), illustrated in Figure 2 and Figure 3, defines a plurality of openings (30) and a window opening (28). The plurality of openings (30) provides access to at least one auxiliary mechanism during mounting and servicing of the same. The window opening (28) enables positioning of a window glass (16). At least a portion of the outer panel (14) is positioned substantially below the window opening (28) defined in the inner panel (12) while at least a portion of the outer panel (14) is positioned substantially above the window opening (28). A trim pad (18) cooperates with the inner panel (12) via at least one push pin so as to cover the plurality of openings (22) mounting the at least one auxiliary mechanism at the interior surface.
The inner panel (12) has at least one average concentration zone (26) reinforced by at least one high concentration zone (24). The average concentration zone (26) and the high concentration zone (24) are formed of the composite structure obtained by injection molding a resin with a reinforcing mat. The concentration of the resin material and the reinforcing mat utilized in preparing the composite structure are varied depending on requirement for obtaining the average concentration zone (26) and the high concentration zone (24).
The inner panel (12) is adhesively bonded to the outer panel (14) along at least a portion while a portion of the inner panel (12) cooperates with the outer panel (14) through a hinge reinforcement plate (22) and a latch reinforcement plate (20) for supporting a hinge mounting and a latch mounting respectively. The hinge reinforcement plate (22) and the latch reinforcement plate (20) are adhesively bonded by an adhesive (B), illustrated in Figure 4, to the inner panel (12) and the outer panel (14). The cross-section along the dotted line A-A in Figure 3, at which the hinge reinforcement plate (22) and the latch reinforcement plate (20) are adhesively bonded to the inner panel (12) as

illustrated in Figure 4, defines a pre-determined profile, typically arcuate shaped, D-shaped or C-shaped. The cross-section along the dotted line C-C and D-D are illustrates in Figure 5 and Figure 6 respectively. The hinge reinforcement plate (22) and the latch reinforcement plate (20) are substantially parallel to each other while being substantially perpendicular to the inner panel (12) and the outer panel (14). The window glass (16) is supported by the inner panel (12), the latch reinforcement plate (20) and the hinge reinforcement plate (22).
A wire rope (32), illustrated in Figure 7, cooperates with the latch reinforcement plate (20) to sealingly press the inner panel (12) and hence the plasticized vehicular door (10) against the body of the vehicle to form a seal leakage arrangement. The wire rope (32) cooperates with the latch reinforcement plate (20) through a bracket (34) at one end and through a threaded rod (36) at the other end. The threaded rod (36) is tightened on the latch reinforcement plate (20) to generate a predetermined tension on the wire rope (32) causing angularly displacement of the plasticized vehicular door (10) towards the vehicle body along the arrow X. The distance (d) between the bracket (34) and the threaded rod (36) is variable depending on the predetermined tension on the wire rope (32). Similarly, a seal leakage arrangement is formed with the hinge reinforcement plate through a corresponding wire rope and bracket and a threaded rod to cause angular displacement of the door towards the vehicle body.
The inner panel (12) and the outer panel (14) of the plasticized vehicular door (10), illustrated in Figure 1, are plasticized by an injection moulding technique, preferably, Structural Reaction Injection Moulding. The steps involved in obtaining the inner panel (12) and the outer panel (14) of the plasticized vehicular door (10) are illustrated in Figure 6.

Accordingly, a mould and a core are required to be prepared so as to allow casting of the inner panel (12) and the outer panel (14) therebetween. The mould is either prepared depending on a required predetermined shape of the inner panel (12) and the outer panel (14) to be cast or a predetermined shape of an existing metal vehicular door required to be plasticized. In the case wherein plasticization of an existing metal vehicular door is envisaged, a cut-out portion (38), shown in Figure 9, of the outer panel and the inner panel of the existing metal vehicular door are utilized for preparing the mould.
In accordance with one method of preparing the mould and the core for plasticization of an existing metal vehicular door, a plastic tape (46) is adhesively bonded to one side of the cut-out portion (38) of the outer panel and/or the inner panel of the existing metal vehicular door. The combined thickness of the cut-out portion (38) and the plastic tape (46) correspond to a requisite thickness (D) of the outer panel and the inner panel of the existing metal vehicular door. The required mould (42) and the core (48), illustrated in Figure 11, are extracted from the cut-out portion (38) and the plastic tape (46) respectively. On preparing of the mould (42) and the core (48), the cut-out portion (38) and the plastic tape (46) are removed from the mould (42) so as to define a space having the requisite thickness (D) of the outer panel and the inner panel of the existing metal vehicular door.
In accordance with another method of preparing a mould and a core for plasticization of the existing metal vehicular door, firstly a mould (42), illustrated in Figure 10 and Figure 11, is extracted from the cut-out portion (38) of the outer panel and/or the inner panel of the existing metal vehicular door to define a cavity (44) therein. A plastic tape (46), illustrated in Figure 10, having a thickness equal to the requisite thickness (D) of the outer panel (12) and the inner panel (14), is adhesively bonded to the cavity (44). The plastic tape (46) is deformed to complement the shape of the outer panel (12) and the

inner panel (14). The core (48), illustrated in Figure 11, is extracted from the plastic tape (46) so as to complement the shape of the outer panel (14) and the inner panel (12). On preparing the core (48), the plastic tape (46) is removed from between the core (48) and the cavity (44) of the mould (42) to define a casting space with the requisite thickness (D).
The core (48) defines at least one gate (50), illustrated in Figure 12, to allow for passage of resin within the casting space in the cavity (44) with the requisite thickness (D). An air vent (52), illustrated in Figure 13, is defined within the mould (42) to enable venting out of trapped gas/air during the process of casting the plasticized vehicular door (10). The air vent (52), typically L-shaped, are formed along the parting portion between the mould (42) and the core (48).
Figure 14 illustrates the process of plasticization utilizing the technique of Structural Reaction Injection Moulding. On preparing the mould (42), a reinforcing mat (22), illustrated in Figure 12, is placed within the cavity (44) of the mould (42). Thereafter, the core (48) is positioned within the mould (42) so as to sandwich the reinforcing mat (22), typically a woven glass mat, between the cavity (44) and the core (48). The reinforcing mat (22) covers a portion of the requisite thickness (D) of the casting space defined between the core (48) and the cavity (44) of the mould (42) by maintaining a gap between the parting surface of core (48) and cavity (44). A resin material, under high pressure, is injected within the casting space through the gate (50). The resin material is allowed to substantially wet the reinforcing mat (22) so as to form a composite structure having a shape and thickness corresponding to that of the inner panel (12) and the outer panel (14). A compressive force (F) is applied on the core (48) so as to compress the composite material between the core (48) and the cavity (44) and thus close the gap between parting surfaces of core (48) and cavity (44). The compressive force (F) on the core (48), enables venting out of gases/air bubbles remaining within composite structure due to gas trapping thus

preventing presence of weak points on the composite structure, The application of the compressive force (F) is terminated on attaining the predetermined thickness of the composite structure corresponding to that of the inner panel (12) and/or the outer panel (14). Thus, a plasticized inner panel (12) and outer panel (14) of the plasticized vehicular door (10), illustrated in Figure 1 are formed.
TECHNICAL ADVANCEMENTS
The technical advancements offered by the present disclosure include the realization of:
• reduced weight of vehicular doors;
• increased fuel efficiency;
• providing a rigid vehicular door;
• a light weight vehicular door having increased durability;
• an improved sealing between the vehicular door and the vehicle body;
• preventing undesirable deformation of light weight vehicular door under critical environmental conditions;
• a light weight vehicular door which is economical to manufacture; and
• a method for manufacturing a light weight vehicular door which is easy to implement while being efficient.
Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

The use of the expression "at least" or "at least one" suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.
The numerical values given of various physical parameters, dimensions and quantities are only approximate values and it is envisaged that the values higher or lower than the numerical value assigned to the physical parameters, dimensions and quantities fall within the scope of the disclosure unless there is a statement in the specification to the contrary.
Wherever a range of values is specified, a value up to 10% below and above the lowest and highest numerical value respectively, of the specified range, is included in the scope of the disclosure.
The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

We claim:
1. A method of plasticization of a vehicular door mounted on a vehicle having
a body defining a compartment, the vehicular door having an inner panel
and an outer panel, said method comprising the following steps:
preparing a mould defining a cavity to complement a predetermined shape of the inner panel and the outer panel;
providing at least one air vent in said cavity;
preparing a core having a shape complementary to said cavity;
positioning a reinforcing mat of a predetermined thickness in the predetermined space within said cavity;
sandwiching said reinforcing mat between said cavity and said core;
injecting a resin material under high pressure into said cavity through at least one gate defined in said core to substantially wet said reinforcing mat to form a composite structure; and
applying a compressive force on said core for compressing said composite structure between said core and said cavity.
2. The method as claimed in claimed 1, wherein the step of preparing said mould includes a step of extracting at least a portion of an existing vehicular door.
3. The method as claimed in claimed 1, wherein the step of preparing said core includes a step of extracting a resin mat adhesively bonded within said cavity to define a predetermined space therebetween corresponding to a desired thickness of the vehicular door.
4. The method as claimed in claimed 1, wherein the step of providing at least one air vent includes the step of defining an inverted L-shaped groove.

5. The method as claimed in claimed 1, wherein the step of positioning includes a step of bonding said reinforcing mat to said cavity by application of adhesive.
6. The method as claimed in claimed 1, wherein the step of applying a compressive force is stopped on attaining a predetermined thickness of said composite structure.

7. A plasticized vehicle door having an inner panel and an outer panel, at least a portion of said inner panel and outer panel being made of composite structure as claimed in claim 1.
8. A plasticized vehicular door for a vehicle having a body defining a compartment, said door having an interior surface and an exterior surface, said door comprising:
an inner panel defining a plurality of openings, said inner panel having at least one average concentration zone reinforced by at least one high concentration zone, said at least one average concentration zone and said at least one high concentration zone utilizing a composite structure having a predetermined composition;
at least one outer panel cooperating with at least a portion of said inner panel to form the exterior surface of said door;
a hinge reinforcement plate and a latch reinforcement plate adapted to be bonded to said inner panel, said hinge reinforcement plate being substantially parallel to said latch reinforcement plate, said hinge reinforcement plate and said latch reinforcement plate being substantially perpendicular to said inner panel and said outer panel; and
a seal leakage arrangement including at least wire rope adapted to discreetly cooperate with said latch reinforcement plate and said hinge reinforcement plate to sealingly press said inner panel against the body of the vehicle.

9. The door as claimed in claim 7 and claim 8, wherein said plurality of openings is adapted to provide access paths for mounting and servicing of at least one auxiliary mechanism.
10. The door as claimed in claim 7 and claim 8, wherein said plurality of openings is adapted to include an window opening for positioning of a window glass.
11. The door as claimed in claim 7 and claim 8, wherein said plurality of openings are adapted to be covered by means of a trim pad, said trim pad being adapted to cooperate with said inner panel at the interior surface via at least one push pin.
12. The door as claimed in claim 7 and claim 8, wherein said composite structure is formed by molding a resin and a woven glass mat, said at least one average concentration zone and said at least one high concentration zone being adapted to have variable concentration of said resin and said woven glass mat.
13. The door as claimed in claim 7 and claim 8, wherein said inner panel is adhesively bonded to said outer panel.
14. The door as claimed in claim 7 and claim 8, wherein said at least one outer panel is positioned substantially below said window opening on said inner panel.
15. The door as claimed in claim 7 and claim 8, wherein said at least one outer panel is positioned substantially above said window opening on said inner panel.
16. The door as claimed in claim 7 and claim 8, wherein said latch reinforcement plate and said hinge reinforcement plate are adapted to discreetly support a hinge mounting and a latch mounting, said hinge reinforcement plate and said inner panel being adapted to define a pre-

determined cross-section, said pre-determined cross-section being selected from the group comprising arcuate shaped, D-shaped and C-shaped.
17. The door as claimed in claim 7 and claim 8, wherein said latch reinforcement plate and said hinge reinforcement plate are adapted to be adhesively bonded to said inner panel, said window glass being adapted to be supported by said inner panel, said latch reinforcement plate and said hinge reinforcement plate.
18. The door as claimed in claim 7 and claim 8, wherein said at least two wire ropes cooperates with said latch reinforcement plate and the hinge reinforcement plate through a corresponding bracket at one end and through a corresponding threaded rod at the other end, said corresponding threaded rod being tightened on said latch reinforcement plate and the hinge reinforcement plate to generate a predetermined tension on said wire rope, angularly displacing said door towards the vehicle body.
19. The door as claimed in claim 7 and claim 8, wherein said at least one outer panel and said inner panel has equal coefficient of thermal expansion.
20. The door as claimed in claim 7 and claim 8, wherein said at least one outer panel and said inner panel are molded by an injection molding technique selected from the group consisting of reaction injection molding and structural reaction injection molding.