FORM 2
THE PATENT ACT, 1970
(39 of 1970)
&
THE PATENTES RULES, 2005
COMPLETE SPECIFICATION
(See section 10, rule 13)
1. TITLE OF THE INVENTION
"Fuel Tank Door Assembly for Automotives"
2. APPLICANT(S)
(a) Name : MAHINDRA & MAHINDRA LIMITED
(b) Nationality : Indian Company registered under the provisions
of the Companies Act, 1956
(c) Address : R&D Center, Automotive Sector,
89, M.I.D.C., Satpur, NASHIK - 422 007 Maharashtra State, India
3. PREAMBLE OF THE DESCRIPTION
COMPLETE
The following specification particularly describes the invention and the manner
in which it is to be performed.
Fuel Tank Door Assembly for Automotives
FIELD OF THE INVENTION
The present invention relates to fuel tank of automotives, more particularly, the present invention relates to a fuel tank door assembly for automotives.
BACKGROUND OF THE INVENTION
Automobiles which are powered by petroleum or gaseous fuel have a fuel containment / storage system such as fuel tanks for storing the fuel therein, and a fuel tank door assembly such as fuel door or fuel lid is provided for covering the fuel tank. Typically, the fuel door is opened to provide access for fuel dispensing means such as spout of fuel gun to fill the fuel to fuel tank from external fuel reservoir. The fuel door, often, not only provides a cosmetic covering, but also the protective covering, which may be locked so as to provide protection against unauthorized access to the fuel tank.
Fuel door assemblies are known which are adapted for opening, for example, fuel door assemblies typically include a door side hinge leaf member and a body side hinge leaf member which are hingeably connected with each other using a hinge pin for defining a turnable mobility therebetween for carrying a fuel door between the closed and the opened position to enable the fuel filling operations thereof.
Fuel door assemblies are also known which are adopting a spring member for opening and closing the fuel door, for example, while enabling the opening action on the fuel door, after unlatching / unlocking the lock system mounted on the fuel door thereof, the fueJ door may then be opened, under the initial bias of a pop-up spring which moves the fuel door from a closed position to either a partially open position from which it may be manually moved to a fully opened position, or to a fully open position, similarly, while enabling the closing action on the fuel door

from either a partially open position or fully opened position of the fuel door to closed position, the effort / force need to be applied against resilient force of the pop-up spring.
Further, the art is also known to use a push-push system in which the fuel door is either moves to partially open position from which it may be manually moved to a fully opened position, or to a fully open position, if the flap is firstly pressed inwardly by hand and a locking means, which normally locks the flap, is in the unlocking position. The unlocking position is, for example, achieved by the actuation of the central locking of the automobile, alternatively, the locking means can also be unlocked by separate manual actuation, for example with the aid of a cable means, which is actuated via an actuation element in the interior of the automobile.
Different arts have different configurations of the fuel door assembly, based upon the desired operational characteristics, such as may be manually opened, remotely opened and/or have springs which provide for pop-up and full or partial opening. However, such fuel door is having inherent disadvantages such as:
1. Once unlocked, the fuel lid, not provided with spring member, does not give the indication of locking status and may remain free to oscillate between open-close position;
2. Once unlocked/unlatched, the fuel lid, provided with spring member, always remain either partially or fully open;
3. Accumulation of dust as, once unlocked / unlatched, the fuel lid remain in open condition;
4. In sliding door type vehicles the door, when slide to open, may damage the fuel door if not locked / latched.
Hence, need has been felt, in the view to negate the abovementioned shortcomings and inconveniences, to provide a opening-closing member assembly, in particular but not exclusive to fuel opening-closing member, which is adapted for use with a

spring member that provides the withstanding force to the opening and closing action of fuel opening-closing member upto designed degree of opening & closing action of fuel opening-closing member and thereafter assist by biasing force for further opening and closing motion so that delivering the better satisfaction level that the present day consumer are accustomed to.
OBJECTS OF THE INVENTION
An object of the present invention is to provide a fuel tank door assembly that open and close under its own bias force to meet the consumer delight yet providing safety as compared to sliding door type fuel tank door assembly vehicles.
Another object of the present invention is to provide a fuel tank door assembly that provide dust free or clean surrounding in nearby area of fuel tank door assembly even when a door member remain unlocked.
Still another object of the present invention is to provide a fuel tank door assembly that enables the fuel tank door to retain its closed position until sufficient force is applied to open it.
Yet another object of the present invention is to provide a fuel tank door assembly that enables the door member to open under its own bias force, once opened upto designed degree under external force.
Yet another object of the present invention is to provide a fuel tank door assembly that enables the door member to retain its opened position until sufficient force is applied to close it.

Yet another object of the present invention is to provide a fuel tank door assembly that enables the door member to close under its own bias force, once closed upto predefined degree by external force.
Statement of the invention
According to present invention there is provided a fuel tank door assembly for fuel tank of an automobile for covering a fuel tank opening, the fuel tank door assembly comprising;
a door member for covering a lid of the fuel tank;
a first hinge member secured to the door member;
a second hinge member secured to the first hinge member with an aligning member therebetween and secured to the body of the automobile, wherein the aligning member is capable of aligning first hinge member with and the second hinge member;
a latching member configured on the second hinge member;
a holding bracket secured to the first hinge member, the holding bracket having bracket openings configured thereon; and
a spring member rotatably secured between the latching member and the holding bracket,
wherein the door member remains in closed condition until an external force acting thereon, to access the fuel tank opening, force is applied to partially swivel the door member around the second hinge member to open the door member, thereby stretching the spring member increasing torsional energy therein, and the remaining opening of the door member is enabled by releasing the torsional energy developed in the spring member, to close the door member for restricting access, force is applied to partially close the door member thereby developing torsional energy in the spring member and the remaining closing of the door member is enabled by releasing the torsional energy developed in the spring member.

Typically, wherein the door member comprises:
a flat member;
a first flange and a second flange configured on a first and a third side of the flat member;
a third flange configured a second side of the flat member; and
a notch configured on fourth side of the flat member, wherein the notch enables to operate the door member.
Typically, wherein the first hinge member comprising;
a flat surface provided with a opening thereon; wherein the flat surface is adapted to secured over the flat member of the door member;
a curved portion extending from the flat surface opposite to the notch of the door member;
a first flange member and a second flange member configured on opposite side of the flat surface, the flange member and a second flange member are adapted to secure with the first flange and the second flange of the door member;
a first journal member and a second journal member configured on a distal portion of the curved portion; and
a first journal opening and a second journal opening configured on respectively the first journal member and the second journal member,
wherein the first journal opening and the second journal opening enables to secure the aligning member therein along with the second hinge member thereon, thereby enabling swelling of the first hinge member.
Typically, wherein the second hinge member comprises:
a seating face;
a first side face and a second side face extending parallelly from a opposite side of the seating face;
a first trapezoidal end portion, a second trapezoidal end portion, extending towards each other from the first side face and the second side face respectively; and

a first opening and a second opening configured on the first side face and a second side face respectively to hingeably secure the second hinge member to the first hinge member with the aligning member therebetween,
wherein the latching member is configured from a cut portion of the seating face of the second hinge member.
Typically, wherein the holding bracket comprises:
a base surface;
a first member and a second member extending perpendicular from the base surface;
an opening configured on each of the first members and the second member respectively; and
fitting holes configured on the base surface to secure the holding bracket with the first hinge member.
Typically, the spring member comprises:
a bight portion;
a first side member, and a second side member extending from the bight portion and parallel to each other;
a first helical coil and a second helical coil configured on at an end portion of the first side member and the second side member respectively; and
a first catch arm and a second catch arm extending respectively form the first helical coil and the second helical coil,
wherein the bight portion rotatably secured between the latching member and the first second hinge member, the first catch arm and the first catch arm secured rotatably in each of the opening of the holding bracket.
Typically, further comprising a locking means for locking the door member with a side body portion of the automobile
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

Figure I shows a partial perspective view of an automobile illustrating a fuel tank door assembling thereon according to the present invention;
Figure 2 shows an exploded perspective view illustrating the fuel tank door assembly according to the present invention;
Figure 3 shows a perspective view illustrating the fuel tank door assembly in assembled condition according to the present invention;
Figure 4 illustrates a perspective view of a second hinge member of fuel tank door assembly of figure 2;
Figure 5 illustrates a spring member holding bracket of fuel tank door assembly of figure 2: and
Figure 6 illustrates a spring member of fuel tank door assembly figure 2.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS AND THE PREFERRED EMBODIMENT
The foregoing objects of the present invention are accomplished and the problems and shortcomings associated with the prior art, techniques and approaches are overcome by the present invention as described below in the preferred embodiment.
In accordance with the present invention the drawback as stated hereinabove have been overcome by providing a modified automobile fuel tank door assembly which is adapted for use with a spring member that provides withstanding force to the opening and closing action of the fuel tank door member upto designed degree

of opening and closing action of the fuel opening-closing member and thereafter assist by biasing force for further opening and closing motion of the fuel opening-closing member.
For the better understanding of this invention, reference would now be made to the embodiment illustrated in greater depth in the accompanying figures and description herein below, further, in the following figures, the same reference numerals are used to identify the same components in various views/figures.
Referring now to Figure J a schematic partial perspective view of an automotive vehicle (100) employing the present invention depicting, generally the external appearance of the automotive vehicle (100) specifically a four wheel automotive is illustrated, showing a side body portion (200), and a fuel tank door assembly (herein after referred as "door assembly (01)"). The door assembly (01) includes a door member (20), a first hinge member (40), a second hinge member (30), a latching member (36), a holding bracket (50), and an aligning member (15).
Referring now to figures 2 and 3, an exploded view and an assembly view of the door assembly (200) are illustrated. For the purpose of explanation, the door assembly (01) is mounted operatively on a rear portion of the side body panel (200) of the automotive (100). For example, the door assembly (01) is configured in an approximately rectangular O-letter shape, and swivelably supported on the side panel (200), in such a manner that an outer surface of the door member (20) in closed position is aligned with the side panel (200), thereby providing a continues appearance.
The door member (20) includes a flat member (19), a first flange (17), a second flange (18), a third flange (16) and a notch (20). The first flange (17) and the second flange (18) are configured on a first side (20c) and a third side (20d) of the flat member (19). The first side (20c) and the third side (20d) are opposite to each other. The first flanges (17) and the second flanges (18) are substantially

perpendicular to a flat surface (19). The third flange (16) is configured on a second side (20b) of the flat member (19). The third flange (16) is inclined with respect to the flat member (19). The notch (20z) is configured on a fourth side (20a) of the flat member (19). The notch (20z) enables to hold the door member (20) for opening and closing thereof.
Referring again to figure 2, the first hinge member (40) is secured to the door member (20) by means of welding or other means which may be obvious to a person skilled in the art. The first hinge member (40) includes a flat surface (41), a curved portion (42), a first flange member (49). a second flange member (49), a first journal member (45), a second journal member (not shown), and first journal opening (45o) and a second journal opening (not shown). The curved portion (42) is extending from the flat surface (41). In an embodiment, the curve portion (42) is in shape of reverse 4U' as shown in figure 2.
The curved portion (42) includes a first stand face (43a) extending approximately perpendicular from an end portion (42a) of the flat surface (41), a base member (43b) extending approximately perpendicular from an end portion (not numbered) of the first stand face (43a), and the second stand face (43c) extending approximately perpendicular from an end portion (not shown) of the base member (43b) and parallel to the first stand face (43a). The first journal member (45) and the second journal member are configure on the second stand face (43c) approximately perpendicular to a surface of the second stand face (43c) and extending towards the first stand face (43a). The first journal member (45) is provided with a first journal opening (45o). Similarly, the second journal member is provided with the second journal opening.
The first flange member (49) and the second flange member (48) are configured on opposite sides of the flat surface (41) approximately perpendicular thereof. The flat surface (41) of the first hinge member (40) is secured with the flat member (19) of the door member (20). The first flange member (49) is secured with the

first flange (17) of the door member (20). Similarly, the second flange member (48) is secured with the second flange (18) of the door member (20). In an embodiment, the flat surface (41) is provided with a cut portion for reduction in weight.
Referring now to figure 4, a perspective view of the second hinge member (30) in accordance with the present invention is illustrated. The second hinge member (30) includes a seating face (31), a first side face (33), a second side face (34), a first trapezoidal end portion (35a), a second trapezoidal end portion (35b), a first opening (33a) and a second opening (34a). The first side face (33) and the second side face (34) are extending approximately perpendicularly from the seating face (31). The first trapezoidal end portion (35a) and the second trapezoidal end portion (35b) are extending from the first side face (33) and the second side face (34) towards each other. The first opening (33a) and the second opening (34a) is configured on the first side face (33) and the second side face (34) respectively to hingeably secure the second hinge member (30) to the first hinge member (40) with the aligning member (15) therebetween. Further, the latching member (36) is configured from a cut portion of the seating face (31) of the second hinge member (30).
Referring now to figure 5, a perspective view of the holding bracket (50) in accordance with the present invention is illustrated. The holding bracket (50) includes a base surface (51), a first member (52), a second member (53), openings (52o & 53o) and fitting holes (51o). The first member (52) and the second member (53) extend approximately perpendicularly from the base surface (51). The opening (52o) is configured on the first member (52), and the opening (53o) configured on the second member (53). Further, the fitting holes (510) are configured on the base surface (51) of the holding bracket (50) to enable securing of the holding bracket (50) with the first hinge member (30). Specifically, the holding bracket (50) is secured to the second stand face (43c) of the first hinge member (40) with the first member (52), the second member (53) and the first

journal member (45) and the second journal member are extending in opposite duration.
Referring now to figure 6, a perspective view of the spring member (10) includes a bight portion (14), a first side member (13a), a second side member (13b), a first helical coil (11), a second helical coil (12), a first catch arm (07) and a second catch arm (08). The first side member (13a) and a second side member (13b) are extending perpendicular from the bight portion (14). The first helical coil (11) is configured on an end portion opposite to the bight portion on the first side member (13a). Similarly, the second helical coil (12) is configured on an end portion opposite to the bight portion on the second side member (13b). The first catch arm (07) is extending from the first helical coil (11). Similarly, the second catch arm (08) is extending from the second helical coil (12).
Further, the bight portion (14) is rotatably secured between the latching member (36) and the first second hinge member (30). More particularly, the bight portion (14) is rotatably secured between the latching member (36) (as shown in Fig 4) and the seating face (31) of the first second hinge member (30). The first catch arm (07) and the first catch arm (08) secured rotatably in each of the openings (52o and 53o) of the holding bracket.
The door assembly (01) also includes a locking means (70) to rigidly lock the door member (20) with the side body portion (200) of the automobile (100). After unlocking the locking means (70) the door member (20) tends to move in the direction 'F' (refer figure 3) at the same time the withstanding force of the spring member (10) exerts opposing force to the motion of the door member (20), this opposing force enables to keep the door member (20) in closed position even when the locking means (70) is in unlocked condition, thereby area near to fuel inlet opening is always maintained clean.

Further, when applied force on the notch (20z) increases and surpasses the withstanding force, the first hinge member (40) along with the door member (20) start rotating about the axis defined by the first opening (33a) and the second opening (33b) of the first side faces (33) and the second side faces (34) of the second hinge member (30), urging each of the first and second catch arms (07 and 08) of the spring member (10) to displace in outwardly direction of the openings (52o and 53o) on the first member (52), a second member (53), of the holding bracket (50) as indicated by the arrow 'SF' [please refer Figure 4] during this process torsional energy get stored in the first and second helical coils (11 and 12) of the spring member (10). So long operator keeps on applying force on the door member (20), the door member (20) continues to rotate about the axis defined by the first opening (33a) and the second opening (34a) on the first and second side faces (33 and 34) of the second hinge member (30).
When the door member (20) is rotating, the axis formed by the openings (52o and 53o) of the holding bracket (50) also start rotating about the axis defined by the first and second openings (33a and 34a), and as the first and second catch arms (07 and 08) are received by the openings (52o and 53o), there exist a force on the first and second helical coils (11 and 12) of the spring member (10) that tends to shift the first and second helical coils (11 and 12) away from the seating face (31) of the second hinge member (30). Subsequently, a stage reaches when the axis passing through the openings (52o and 53o) on the spring holding bracket (50) and the axis defined by the first opening (33a) and the second opening (34a) on the first and second side faces (33 and 34) of the second hinge member (30) and the bight portion (10) of the spring member (14) become coplanar, at this stage the resilient helical coils (11 and 12) of the spring member (10) releases all the stored torsional energy to regain its original shape and urge the first and second catch arms (07and 08) of the spring member (10) to move back in inwardly direction through the openings (52o and 53o) of the holding bracket (50) as indicated by the arrow 'SR'. Thus, when the first and second helical coils (11 and 12) releases

torsional energy, it assists further opening motion of the door member (20), this gives positive feel to the operator and contributes towards customer delight.
Similarly, while closing of the door member (20) from open position, the operator applies force and the door member (20) tends to move in the direction indicated by arrow 'R' [please refer Figure 3] and at the same time the withstanding force of the spring member (10) exerts opposing force to the motion of the door member (20). As the applied force increases and surpasses the withstanding force, the first hinge member (40) along with the door member (20) start rotating about the axis defined by the first and second openings (33a) and (34a) on the first and second side faces (33 and 34) of the second hinge member (30) urging each of the first and second catch arms (07 and 08) of the spring member (10) to displace in outwardly direction through the openings (52o and 53o) on the journal members (52) and (53) of the spring member holding bracket (50) as indicated by the arrow 'SF' [please refer Figure 4] thereby storing torsional energy in the helical coils (11) and (12) of the spring member (10) and the door member (20) continues to rotate about the axis defined by the journaling openings (33a) and (34a) on the side faces (33) and (34) of the second hinge member (30).
When the door member (20) is rotating, the axis formed by the journaling openings (52o) and (53o) of the spring member holding bracket (50) also starts rotating about the axis defined by the journaling openings (33a) and (34a), and as the catch arms (07) and (08) are received by journaling openings (52o) and (53o) there exist a force on the helical coils (11) and (12) of the spring member (10) that tends to shift the helical coils (11) and (12) towards seating face (31) of the second hinge member (30), and subsequently a stage reaches when the axis passing through journaling openings (52o) and (53o) on the spring holding bracket (50) and the axis defined by the journaling openings (33a) and (34a) on the side faces (33) and (34) of the second hinge member (30) and the bight portion (10) of the spring member (14) become coplanar, at this stage the resilient helical coils (11) and (12) of the spring member (10) releases all the stored torsional energy to

regain its original shape and urge catch arms (07) and (08) of the spring member (10) to move back in inwardly direction of the journaling openings (52o) and (53o) of the spring member holding bracket (50) as indicated by the arrow 'SR\ Thus, when helical coils (11) and (12) release the torsional energy, assist further remaining closing motion of the door member (20), this gives positive feel to the operator and contributes towards customer delight.
While considerable emphasis has been placed herein on the particular features of this invention, it will be appreciated that various modifications can be made, and that many changes can be made in the preferred embodiments without departing from the principles of the invention. These and other modifications in the nature of the invention or the preferred embodiments will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

We Claim:
1. A fuel tank door assembly for fuel tank of an automobile for covering a fuel tank opening, the fuel tank door assembly comprising;
a door member for covering a lid of the fuel tank;
a first hinge member secured to the door member;
a second hinge member secured to the first hinge member with an aligning member therebetween and secured to the body of the automobile, wherein the aligning member is capable of aligning first hinge member with and the second hinge member;
a latching member configured on the second hinge member;
a holding bracket secured to the first hinge member, the holding bracket having bracket openings configured thereon; and
a spring member rotatably secured between the latching member and the holding bracket,
wherein the door member remains in closed condition until an external force acting thereon, to access the fuel tank opening, force is applied to partially swivel the door member around the second hinge member to open the door member, thereby stretching the spring member increasing torsional energy therein, and the remaining opening of the door member is enabled by releasing the torsional energy developed in the spring member, to close the door member for restricting access, force is applied to partially close the door member thereby developing torsional energy in the spring member and the remaining closing of the door member is enabled by releasing the torsional energy developed in the spring member.
2. The fuel tank door assembly as claimed in claim 1, wherein the door member comprises:
a flat member;
a first flange and a second flange configured on a first and a third side of the flat member;

a third flange configured a second side of the flat member; and a notch configured on fourth side of the flat member, wherein the notch enables to operate the door member.
3. The fuel tank door assembly as claimed in claims 1, wherein the first hinge member comprising;
a flat surface provided with a opening thereon; wherein the flat surface is adapted to secured over the flat member of the door member;
a curved portion extending from the flat surface opposite to the notch of the door member;
a first flange member and a second flange member configured on opposite side of the flat surface, the flange member and a second flange member are adapted to secure with the first flange and the second flange of the door member;
a first journal member and a second journal member configured on a distal portion of the curved portion; and
a first journal opening and a second journal opening configured on respectively the first journal member and the second journal member,
wherein the first journal opening and the second journal opening enables to secure the aligning member therein along with the second hinge member thereon, thereby enabling swelling of the first hinge member.
4. The fuel tank door assembly as claimed in claim 1, wherein the second hinge member comprises:
a seating face;
a first side face and a second side face extending parallelly from a opposite side of the seating face;
a first trapezoidal end portion, a second trapezoidal end portion, extending towards each other from the first side face and the second side face respectively; and

a first opening and a second opening configured on the first side face and a second side face respectively to hingeably secure the second hinge member to the first hinge member with the aligning member therebetween,
wherein the latching member is configured from a cut portion of the seating face of the second hinge member.
5. The fuel tank door assembly as claimed in claim 1, wherein the holding
bracket comprises:
a base surface;
a first member and a second member extending perpendicular from the base surface;
an opening configured on each of the first members and the second member respectively; and
fitting holes configured on the base surface to secure the holding bracket with the first hinge member.
6. The fuel tank door assembly as claimed in claim 1, the spring member
comprises:
a bight portion;
a first side member, and a second side member extending from the bight portion and parallel to each other;
a first helical coil and a second helical coil configured on at an end portion of the first side member and the second side member respectively; and
a first catch arm and a second catch arm extending respectively form the first helical coil and the second helical coil,
wherein the bight portion rotatably secured between the latching member and the first second hinge member, the first catch arm and the first catch arm secured rotatably in each of the opening of the holding bracket.

7. The fuel tank door assembly as claimed in claim 1, further comprising a locking means for locking the door member with a side body portion of the automobile.