Description:FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10, rule 13)

“FUEL CAP ASSEMBLY”

JAY SWITCHES INDIA PVT. LTD.
an Indian Company,
of Plot no. 407, Phase 3, Udyog Vihar, Gurgaon,
Haryana, India, 122016.

The following specification particularly describes the invention and the manner in which it is to be performed.
Technical Field
The present invention relates to a fuel cap for a fuel tank of a motor vehicle. More particularly, the present invention relates to a fuel cap which can maintain the required air pressure within a fuel tank and avoid fuel spillage out of the fuel tank during the running of a motor vehicle.
Background
Fuel tank of a motor vehicle store fuel for running the engine. The fuel is mostly liquid such as diesel or petrol. The fuel tanks have an opening for filling of the fuel tank. Fuel caps are used to close this opening to prevent leakage of fuel when the fuel is not being filled. The fuel cap has to be configured to prevent fuel leakage when the vehicle is stationary, as well as vehicle is running.
Running of the vehicle may result in movement of the fuel within the fuel tank, which may result in pressure fluctuation as well as sloshing of the liquid fuel against the walls of the fuel tank as well as the fuel cap. In prior art fuel caps as described in the background section of patent application number 664/DEL/2010, the fuel caps used spring force to maintain sealing contact to prevent fuel leakage from the fuel filler neck of the fuel tank. The movement and sloshing of the fuel in the fuel tank may result in overcoming such spring force and loss of sealing contact, resulting in fuel leakage.
Indian Patent Application No. 664/DEL/2010 discloses preventing leakage by limiting the free space inside the locking projections by keeping the free space between 10-100% of the length of the main circular plate. However, such limiting of free space leads to blocking the axial movement of the locking member and may lead to tighter operation of the fuel cap while mounting or releasing the fuel cap on the fuel filler neck. Moreover, the solution proposed in the said patent application may result in the exertion of excessive pressure on the seal member resulting in a shorter life of the seal member requiring frequent repair. This may lead to an overall undesirable experience for a user of the fuel cap.
The present disclosure is directed to address one or more of the problems discussed above and other problems associated with the art.
Objects
An object of the present disclosure is to provide an improved fuel cap for a fuel tank of a motor vehicle which overcomes at least some of the problems faced by existing fuel caps while keeping a desirable user experience of operation of the fuel cap.
Another object of the present disclosure is to provide a fuel cap for the fuel tank of a motor vehicle which can maintain air tightness at an absolute air pressure of l.3 bar inside the fuel tank and does not allow air or fuel to escape.
Another object of the present disclosure is to provide for a fuel cap wherein the seal member is securely and rigidly fitted on the fuel filler neck once the fuel cap is secured on the fuel filler neck.
Summary
One or more shortcomings of conventional methods and systems are overcome, and additional advantages are provided through the present disclosure. Additional features and benefits are realized through the techniques of the present disclosure.
A fuel tank cap assembly for mounting on a fuel filler neck of a fuel tank of a vehicle is disclosed. The fuel cap assembly has a cylindrical body comprising a top portion, a middle portion and a bottom portion. The said top portion is separated from the middle portion by a circular portion and the said middle portion is separated from the bottom portion by a main circular plate. The main circular plate has a set of engagement projections. The fuel cap has a body cover encircling the middle portion of the cylindrical body. The said body cover has a cylindrical trunk portion and a circular plate located on a top end of the cylindrical trunk portion. The said circular plate is provided with a pair of anti-rotation projections on a bottom surface thereof. A turning handle is attached rigidly to the cylindrical body and angularly movable relative to the body cover. The turning handle is movable by a user between the securing start stage in which the fuel cap can be engaged on the fuel filler neck and a securing-finished stage in which the fuel cap is secured on the fuel filler neck. A circular seal member is accommodated by the bottom surface of the said circular plate of the body cover. A cylindrical locking member encases the cylindrical trunk portion of the body cover, and the cylindrical locking member mounted on the cylindrical body is angularly stationary and axially movable relative to the cylindrical body. A pair of locking projections are provided on an outside surface of the locking member. The locking projections are configured to engage the fuel filler neck to axially move the locking member relative to the cylindrical body. The locking member has an initial position corresponding to the securing start stage and a final position corresponding to the securing finished stage of the fuel cap. A pair of beams is provided on an inner surface of the locking projections, the pair of beams terminate at a predetermined distance from a bottom end of the locking projections. The engagement projections are engaged within the predetermined distance provided in the locking projections forming an initial gap between the beams and the engagement projections. The said predetermined distance is more than the length of the main circular plate separating the middle portion of the cylindrical body from the bottom portion of the cylindrical body. The beams abut the engagement projections to block the axially downward movement of the locking member relative to the cylindrical body when the locking member is in the final position.

In an aspect, each of the pair of locking projections has an inclined edge at its top portion that engages a set of locking ribs on a fuel filler neck, and an angle of inclination of the inclined edge is in the range of 16 degrees to 50 degrees.
In an embodiment, the thickness of the seal member is in the range of 4 mm to 8 mm.
In an embodiment, the thickness of the circular plate is in the range of 5 mm to 10 mm.
In an aspect, a fuel filler neck for a fuel tank is disclosed. The fuel filler neck has a neck extending from the fuel tank. The neck forms a conduit to connect the environment with the inner cavity of the fuel tank. The fuel filler neck further has a rim that is configured to abut a seal member of a fuel cap, and a pair of locking ribs positioned adjacent to the rim. The locking ribs are inclined relative to the axis of the fuel filler neck at an angle in the range of 2.5 to 10 degrees.
In an embodiment, the locking ribs extend axially downwards from a radially inner edge of the rim.
The foregoing summary is illustrative only and is not intended to be limiting. In addition to the illustrative aspects, embodiments, and features described herein, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
Brief Description of the Drawings
The invention itself, together with further features and attended advantages, will become apparent from consideration of the following detailed description, taken in conjunction with the accompanying drawings. One or more embodiments of the present invention are now described, by way of example only, with reference to the accompanied drawings wherein like reference numerals represent like elements and in which:
FIG. 1 illustrates a top perspective view of a fuel cap in accordance with an embodiment of the present disclosure.
FIG. 2 illustrates a bottom perspective view of the fuel cap in accordance with an embodiment of the present disclosure.
FIG. 3 illustrates an exploded view of the fuel cap assembly in accordance with an embodiment of the present disclosure.
FIG. 4 illustrates a cross-section view of the fuel cap across line 4-4 of FIG. 18.
FIG. 5 illustrates the locking member of the fuel cap in upside down condition.
FIG. 6 illustrates a cross-sectional view of the fuel cap taken along a plane running through the pair of beams provided in the locking projection.
FIG. 7 illustrates a top perspective view of a fuel filler neck.
FIG. 8 illustrates a bottom perspective view of the fuel filler neck.
FIG. 9 illustrates a top view of the fuel filler neck.
FIG. 10 illustrates a cross-section of the fuel filler neck taken along line 10-10 of FIG. 9.
FIG. 11 illustrates a bottom perspective view of the fuel filler neck.
FIG. 12 illustrates a top view of the fuel filler neck.
FIG. 13 illustrates a cross-section of the fuel filler neck taken along the line 13-13 of FIG. 12.
FIG. 14 illustrates a cross section of the fuel cap and the fuel filler neck taken along the plane running through the pair of beams of the locking projection with the fuel cap in the securing start stage.
FIG. 15 illustrates a cross section of the fuel cap and the fuel filler neck taken along the plane running through the pair of beams of the locking projection with the fuel cap in the securing finished stage.
FIG. 16 illustrates a cross section of the fuel cap and the fuel filler neck taken along the plane running through the pair of beams of the locking projection with the fuel cap in the securing start stage.
FIG. 17 illustrates a cross section of the fuel cap and the fuel filler neck taken along the plane running through the pair of beams of the locking projection with the fuel cap in the securing finished stage.
FIG. 18 illustrates a top view of the fuel cap with different working angles of the fuel cap marked.
FIG. 19 illustrates a cross-section of the fuel cap with a thick gasket and the fuel filler neck along a plane running through the pair of beams of the fuel cap in the securing finished state.
Skilled artisans will appreciate that elements in the drawings are illustrated for simplicity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the drawings may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
Description
While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of examples in the drawings and will be described in detail below. It should be understood, however, that it is not intended to limit the invention to the particular forms disclosed, but on the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and the scope of the invention as defined by the appended claims.
The terms "comprises", "comprising”, or any other variations thereof, are intended to cover a nonexclusive inclusion, such that a setup, device that comprises a list of components does not include only those components but may include other components not expressly listed or inherent to such setup or device. In other words, one or more elements in a system or apparatus proceeded by "comprises ... a" does not, without more constraints, preclude the existence of other elements or additional elements in the system or apparatus.
FIG. 3 illustrates an exploded view of the components of the fuel cap assembly (100) in accordance with an embodiment of the present disclosure. The fuel cap assembly (100) is also referred to as ‘fuel cap (100)’. As shown, the components of the fuel cap (100) may include a lock assembly (102), a turning handle (140), an O-ring, a body cover (180), a seal member (200), a locking member (220), a seal ring (240), a spring (260), a cylindrical body (280), an actuator (400) and a breather valve assembly (500) (also referred to as breathe-in breathe-out assembly).
FIG. 1 illustrates a top perspective view and FIG. 2 illustrates a bottom perspective view of the fuel cap (100) in assembled condition. The turning handle (140) is a circular member forming the uppermost outer cover of the fuel cap (100). When the fuel cap (100) is secured on the fuel filler neck (600), the turning handle (140) typically remains exposed to the environment and covers the rest of the components of the fuel cap (100) and protects them from dust and other elements.
As shown in FIG. 1, the turning handle (140) is provided with a rectangular projection (142) running along the diameter of the turning handle (140). The rectangular projection (142) may be engaged by the hand and fingers of a user to grab and turn the turning handle (140) for opening or closing the fuel cap (100).
Further, the turning handle (140) is provided with a circular mouth (144) towards its bottom and a cylindrical opening (146) in the centre. The circular mouth (144) covers the peripheral edge of the circular plate (182) of the body cover (180). The cylindrical opening (146) is configured for receiving a top portion (282) of the cylindrical body (280), and to provide entry of a key into the lock assembly (102) for locking or unlocking the fuel cap (100) on the fuel filler neck (600). The turning handle (140) is affixed to the circular plate (182). The cylindrical opening (146) has a plurality of projections and recesses (148) on its inner surface thereof. These pluralities of projections and recesses (148) are complementary to the projections and recesses (286) present on the top portion (282) of the cylindrical body (280) and therefore are helpful in the tight fitment of the turning handle (140). The pluralities of projections and recesses (148, 286) prevent any relative angular movement of the cylindrical body (280) and the turning handle (140). Thus, when the turning handle (a 140) is rotated by a user, the cylindrical body (280) rotates along with the turning handle (140).

The top edge of this cylindrical opening (146) has a curved groove (150) to receive the O­ring (160). The O-ring (160) seals any gap between the top portion (282) of the cylindrical body (280), the lock assembly (102) and the top end of the cylindrical opening (146) to prevent dust and water from entering into the fuel cap (100) through such gaps.
The fuel cap (100) has the cylindrical body (280) (better shown in FIG. 3). The cylindrical body (280) has the top portion (282), a middle portion (288) and a bottom portion (290). The top portion (282) and the middle portion (288) are demarcated by a circular portion (292), and the middle and the bottom portion (290) are demarcated by a main circular plate (294). In other words, the circular portion (292) lies between the top portion (282) and the middle portion (288), and the main circular plate (294) is positioned between the middle portion (288) and the bottom portion (290) of the cylindrical body (280). The bottom portion (290) extends beyond the main circular plate (294).
The circular portion (292) has two clearances (296) that are spaced 180° symmetrical to each other. The top portion (282) of the cylindrical body (280) comprises a plurality of projections and recesses (286) that extend from the circular portion (292) to an uppermost end of the top portion (282). However, the clearances (296) continue as recesses till the top end of this top portion (282). The middle portion (288) has two projections which start from the left edges on the clearances (296) and run across its length to end at the lower end of the middle portion (288).
The main circular plate (294) is in the form of a flange extending in a plane perpendicular to the cylindrical axis (102) of the cylindrical body (280). The main circular plate (294) supports the spring (260) when the spring (260) is placed over the cylindrical body (280) between the locking member (220) and the cylindrical body (280). Further, the main circular plate (294) has a pair of engagement projections (300). The engagement projections (300) extend slightly outside the periphery of the circular portion of the main circular plate (294). In the embodiment as shown, two engagement projections (300) are provided that are positioned diametrically opposite to each other. The engagement projections (300) are configured to fit into locking projections (222) as explained later herein. The engagement projections (300) abut the beams (228) and bear load when the fuel cap (100) is secured on the fuel filler neck (600), discussed later herein. The engagement projections (300) may be made integrally as a part of the main circular plate (294). In an embodiment, the engagement projections (300) being a load bearing part, may be made thicker compared to the other portions of the main circular plate (294). The rest of the portion of the main circular plate (294) prevents dust or fuel from entering the fuel cap (100) from the bottom portion (290).
The main circular plate (294) may be made integrally as a part of the cylindrical body (280). The main circular plate (294) may have a length (l) measured along the cylindrical axis (102). The length of the main circular plate (294) may include the overall length of the main circular plate (294) that is functional, including any parts of the main circular plate (294).
The body cover (180) has a circular plate (182) and a trunk portion (184). The trunk portion (184) has a hollow cylindrical shape. The trunk portion (184) covers the middle portion (288) of the cylindrical body (280) when the fuel cap (100) is in the assembled state. The lower end of the trunk portion (184) rests on the main circular plate (294) when the fuel cap (100) is in assembled state. The cylindrical trunk portion (184) has two pair of ribs (186) on its inner surface thereof. The two pair of ribs (186) are spaced 180° symmetrical to each other. The clearances (296) are formed on the top portion (282) and circular portion (292) respectively of the cylindrical body (280) to allow the insertion of two pairs of ribs (186) for fitment of the body cover (180) onto the middle portion (288).
The circular plate (182) extends from the top end of the trunk portion (184) in a plane perpendicular to the cylindrical axis (102). The inner portion of this circular plate (182) is joined to a frustum surface (188) narrowing in diameter and finally meeting the trunk portion (184). The outside slope of this frustum like surface (188) comprises four steps (192) (see FIG. 4) spaced 90° symmetrical to each other.
The circular plate (182) has outer dimensions configured to fit into the circular mouth (144) of the turning handle (140) as shown in FIG. 2 and FIG. 4. In an embodiment, the circular plate (182) may be snap fitted with the turning handle (140) by inserting the circular plate (182) in the circular mouth (144). The seal member (200) is positioned below the circular plate (182) as shown in FIG. 2 and FIG. 4.
The circular plate (182) is further provided with anti-rotation projections (190). The anti-rotation projections (190) extend perpendicularly downwardly from the circular plate (182). When the fuel cap (100) is mounted on the fuel filler neck (600), the anti-rotation projections (190) engage the fuel filler neck (600) and prevent any relative angular movement between the fuel filler neck (600) and the body cover (180). Corresponding gaps (610) are provided in the fuel filler neck (600) for receiving the anti-rotation projections (190). In the embodiment as shown, the anti-rotation projections (190) are positioned angularly 180° apart on the circular plate (182).
The circular seal member (200) has two openings (202) which allow the anti-rotation projections (190) to pass through the openings (202) to prevent the seal member (200) from rotation relative to the circular plate (182) once the seal member (200) is positioned on the circular plate (182). The seal member (200) may have a diameter slightly less than the diameter of the circular plate (182). The diameter of the seal member (200) may correspond to the diameter of the fuel filler neck (600). The seal member (200) may seal any gap between the circular plate (182) and a rim (620) of the fuel filler neck (600) when the fuel cap (100) is mounted on the fuel filler neck (600). The circular plate (182) covers the fuel filler neck (600) and supports the seal member (200) against the fuel filler neck (600) when the fuel cap (100) is secured on the fuel filler neck (600).
The locking member (220) is a hollow cylindrical component. FIG. 5 illustrates a perspective view of the locking member (220) wherein the locking member (220) is shown upside down to better show the inner configuration of the locking member (220). The diameter of the locking member (220) is configured to receive the trunk portion (184) of the body cover (180). When the fuel cap (100) is in assembled condition, the locking member (220) 5 encases the cylindrical trunk portion (184) of the body cover (180). The top surface of the locking member (220) rests below the circular seal member (200). Further, the locking member (220) has a step (224) provided on the inside surface near a top edge of the locking member (220). This step (224) is configured to support a top end of the spring (260), while the lower end of the spring (260) rests on the main circular plate (294). The locking member (220) rests below the four steps (192) that may be spaced 90° symmetrical to each other on the outside slope of a frustum like surface (188) of the body cover (180).
As shown in FIG. 5, the locking member (220) on its outside surface has two locking projections (222) which are spaced 180° symmetrically to each other. These locking projections (222) extend from the outer surface and create corresponding hollow recesses on the inner surface of the locking member (220). The width of the locking projections (222) may be configured corresponding to the width of the anti-rotation projections (190) of the circular plate (182). As shown in FIG. 2, FIG. 4, and FIG. 6, the locking projections (222) lie just below the anti-rotation projections (190) when the fuel cap (100) is not mounted on the fuel filler neck (600) or in the securing start stage. The locking projections (222) have one vertical side longer than the other vertical side, thus making an inclined edge (226) at the top of the locking projections (222).
As shown in FIG. 3 and FIG. 5, the locking projections (222) are provided with a pair of beams (228) on their inner surface thereof. These beams (228) may extend axially from the top inclined edge (226) of the locking projections (222), and may terminate at a predetermined distance from a bottom end of the locking projection (222). The beams (228) may provide structural strength to the locking projections (222). Further, the main circular plate (294) is provided with a pair of engagement projections (300) that engage within the locking projections (222), as shown in FIG. 2, FIG. 4 and FIGs. 14-17. More particularly, these engagement projections (300) engage within the predetermined distance provided in the locking projections (222). The engagement projections (300) keep engaged with the locking projections (222) in the securing start stage as well as securing finished stage. This way the cylindrical body (280) engages the locking member (220) to move it angularly, and the locking member (220) rotates along with the cylindrical body (280). The beams (228) on the inner surface of the locking projections (222) restrict the axial movement of the locking member (220) relative to the cylindrical body (280) when the fuel cap (100) is in securing finished stage as explained later herein.
The seal ring (240) may have a rectangular cross section. The seal ring (240) is placed between the top surface of the main circular plate (294) and the lower end of the trunk portion (184). The lower end of the trunk portion (184) is provided with a step on its inner surface to accommodate the seal ring (240). The rectangular cross-section of the seal ring (240) may occupy all the space that is present in the step provided in the trunk portion (184). Moreover, a flange may be provided on the top and bottom surfaces of the seal ring (240) to create and maintain a better sealing contact. The flange may be either triangular, trapezoidal, circular, or rectangular in shape.
The spring (260) may be a coil spring (260). The diameter of the spring (260) may be configured to position the spring (260) between the trunk portion (184) and the locking member (220) when the fuel cap (100) is in assembled condition. The ends of the spring (260) are positioned between the top edge of the locking member (220) and the main circular plate (294). This placement of the spring (260) creates a biasing force that pushes the locking member (220) upwards against the main circular plate (294).
The breather valve assembly (500) is fitted in the bottom portion (290) of the cylindrical body (280). The bottom portion (290) of the cylindrical body (280) is exposed inside the fuel tank when the fuel cap (100) is mounted on the fuel filler neck (600). The breather valve assembly (500) has a valve assembly and an end cap (502) that secures the valve assembly in a cavity defined in the bottom portion (290) of the cylindrical body (280). The breather valve assembly (500) aids in venting out pressure inside the fuel tank, as well as regulating any negative pressure created inside the fuel tank as known in the art.
The following paragraphs explain in detail how these components are assembled together to form a unitary structure to form the fuel cap (100).
As shown in FIG. 4, the cylindrical body (280) forms the core of the fuel cap (100). All other components of the fuel cap (100) are assembled in or around it. The lock assembly (102) is housed inside the top portion (282) and middle portion (288) of the cylindrical body (280). The actuator (400) is placed below the lock assembly (102) in the middle portion (288) of the cylindrical body (280). The lock assembly (102) may be operated by a key to actuate the actuator (400) between the lock position and release position. There are two rectangular openings (302) on the lower part of the middle portion (288) which are positioned diametrically against each other and are 90° symmetrical to the two projections (298). These rectangular openings (302) allow the actuator (400) to project out in the locked condition while being drawn in in the release condition. When the actuator (400) projects out of the rectangular openings (302), the actuator (400) blocks the angular movement of the pair of ribs (186) relative to the cylindrical body (280) and thus prevents angular movement of the cylindrical body (280) relative to the body cover (180).
The locking member (220) with the spring (260) inside it, is placed over the middle portion (288) of the cylindrical body (280) with the engagement projections (300) aligned angularly with the locking projections (222). The body cover (180) is fitted onto the middle portion (288) of the cylindrical body (280). The pair of ribs (186) formed on the trunk portion (184) are passed through the clearances (296) to mount the body cover (180) on the middle portion (288) of the cylindrical body (280). Once the body cover (180) is fitted on the cylindrical body (280), the trunk portion (184) of the body cover (180) rests between the circular portion (292) and the main circular plate (294). In the assembled condition, the body cover (180) may not move axially relative to the cylindrical body (280), but may move angularly relative to the cylindrical body (280). The circular portion (292) of the cylindrical body (280) may block the axially upward movement of the pair of ribs (186), whereas the main circular plate (294) may block the axially downward movement of the pair of ribs (186) and the trunk portion (184) of the body cover (180). The height of the pair of ribs (186) or the trunk portion (184) may be corresponding to the height of the middle portion (288) for fitment of the body cover (180) onto the middle portion (288) of the cylindrical body (280).
The circular seal member (200) is mounted on the bottom surface of the circular plate (182) by insertion of the anti-rotation projections (190) into the rectangular openings (202) of the seal member (200). Further, the turning handle (140) is mounted on the cylindrical body (280) and the circular plate (182). The top portion (282) of the cylindrical body (280) is inserted into the cylindrical opening (146) provided at the centre of the turning handle (140). Simultaneously, the circular plate (182) of the body cover (180) is fitted into the circular mouth (144) of the turning handle (140).
The trunk portion (184) of the body cover (180) is encompassed by the coiled spring (260). Whereas the coiled spring (260) is encased inside the locking member (220). More precisely, the coiled spring (260) rests between an upper surface of the main circular plate (294) and a lower surface of a step (224) provided on the inside surface near the top edge of the locking member (220). The coiled spring (260) biases the cylindrical body (280) to move axially downwards relative to the locking member (220). The biasing force thus created by the spring (260) aids in making and maintaining the sealing contact between the seal member (200) and the fuel filler neck (600), better explained later in this description.
A breathe-in breathe-out assembly (500) is housed within the lower portion of the cylindrical body (280).
FIGs. 7-13 illustrate the fuel filler neck (600). More particularly, FIG. 7 illustrate a top perspective view of the fuel filler neck (600), and FIGs. 8-13 illustrate the portion of the fuel filler neck (600) that is relevant for securing and working of the fuel cap (100) in accordance with an embodiment of the present disclosure. As shown, the fuel filler neck (600) has a neck (630) that is connected to the fuel tank. The fuel filler neck (600) further defines a filler opening (640) through which fuel may be filled inside the fuel tank. The neck (630) acts as a conduit to carry fuel from the filler opening (640) to the inner cavity of the fuel tank.
The fuel filler neck (600) has a rim (620) on its top portion. The rim (620) extends radially inwards from an upper outer periphery of the neck (630). The seal member (200) of the fuel cap (100) abuts the rim (620) to make a sealing contact for sealing the filler opening (640).
A pair of locking ribs (650) extend axially downwards from the inner edge of the rim (620). The locking ribs (650) are oriented facing downwards along the cylindrical axis (102). It is pertinent to note that FIG. 8 and FIG. 11 illustrate a bottom perspective view of the fuel filler neck (600) to better illustrate the construction and configuration of the locking ribs (650). The locking ribs (650) may be made integral with the fuel filler neck (600). The locking ribs (650) have a start point (652) at which the locking projections (222) engage the locking ribs (650) and an end point (654) at which the locking projections (222) reach when the fuel cap (100) is secured on the fuel filler neck (600). FIGs. 8-10 illustrate a fuel filler neck (600) with a smaller angle of taper of the locking ribs (650), whereas FIGs. 11-13 illustrate a fuel filler neck (600) with the angle of taper comparatively higher. Either of the fuel filler necks (600) may be utilized for practising the present disclosure as described later herein.
Stopping projections (656) are provided at the end point (654) to block or stop any further angular movement of the locking projections (222) on the locking ribs (650). The stopping projections (656) are in the form of rectangular extensions from the locking ribs (650) that extend axially downward along the cylindrical axis (102).
The fuel filler neck (600) has two gaps (610) that are placed 180° apart. Each gap (610) is positioned between a start point (652) of one locking rib (650) and the end point (654) of the other locking rib. The anti-rotation projections (190) are received in these gaps (610) to block the relative angular movement of the body cover (180) with respect to the fuel filler neck (600) when the fuel cap (100) is rotated over the fuel filler neck (600) to secure the fuel cap (100) on the fuel filler neck (600).
The fuel cap (100) is secured on the fuel filler neck (600) by inserting the locking projections (222) and the anti-rotation projections (190) through the gap (610) on the fuel filler neck (600). The locking projections (222) crawl under the locking ribs (650) and engage with the locking ribs (650).
As shown in FIG. 9, FIG. 12, FIG. 11 and FIG. 14 the lower edge of the locking ribs (650) are tapered relative to the cylindrical axis (102) of the fuel filler neck (600). In other words, the lower edge of the locking ribs (650) lies in a plane that is inclined at a non-orthogonal angle with respect to the cylindrical axis (102). When the fuel cap (100) is secured on the fuel filler neck (600), the inclined edge (226) of the locking projections (222) crawl under these tapered locking ribs (650) and move the locking member (220) axially downwards relative to the fuel filler neck (600) and the cylindrical body (280).
The position of the locking member (220) relative to the cylindrical body (280) when the fuel cap (100) is in securing start state may be referred to as the initial position of the locking member (220), and the position of the locking member (220) relative to the cylindrical body (280) when the fuel cap (100) is in securing finished state may be referred to as the final position of the locking member (220).
The axially downward movement of the locking member (220) compresses the spring (260), and increases the biasing force that the spring (260) exerts on the main circular plate (294), thus pushing the cylindrical body (280) along with the body cover (180) downwards. This presses the seal member (200) between the fuel filler neck (600) and the circular plate (182) to seal the gap therebetween.
The locking ribs (650) of the fuel filler neck (600) have the start point (652) at which the locking projections (222) start engaging the locking ribs (650), and an end point (654) where the locking projections (222) rest when the fuel cap (100) is in the secured condition on the fuel filler neck (600). When the turning handle (140) is rotated and the locking projections (222) reach the end point (654), the locking member (220) moves axially downward to compress the spring (260) and consequently increases the pressure exerted by the circular plate (182) on the seal member (200) against the rim (620) of the fuel filler neck (600).
At the securing-start stage, as illustrated in FIG. 14 and FIG. 16, the anti-rotation projections (190) extending downwards from the circular plate (182) of the body cover (180) are in line with the locking projections (222) provided on the locking member (220). The fuel cap (100) when inserted into the fuel filler neck (600) allows anti-rotation projections (190) and the locking projections (222) to enter into the fuel filler neck (600) via the gaps (610) provided between the locking ribs (650) in the fuel filler neck (600). The fuel cap (100) is inserted into the fuel filler neck (600) until the seal member (200) abuts the rim (620) of the fuel filler neck (600).
Once the fuel cap (100) is inserted into the fuel filler neck (600), the first end (230) of the inclined edge (226) of the locking projections (222), which is positioned axially lower as compared to the second end (232), is positioned adjacent to the start point (652) of the locking ribs (650), so that when the locking projections (222) move angularly, the start point (652) engages the inclined edge (226) near the first end (230). Also, at the securing-start stage, each pair of ribs (186) provided on the inner surface of the trunk portion (184) of the body cover (180) lies between the right edge of the projection (298) and the left edge of the rectangular opening (302) of the middle portion (288) of the cylindrical body (280).
To secure the fuel cap (100) on the fuel filler neck (600), as the turning handle (140) is rotated from the securing start stage towards the securing finished state, the circular plate (182) remains angularly stationary with respect to the fuel filler neck (600), and the cylindrical body (280) rotates along with the turning handle (140). As the engagement projections (300) on the main circular plate (294) engage the locking member (220), the locking member (220) also rotates along with the cylindrical body (280) and the turning handle (140). Therefore, while the circular plate (182) along with the seal member (200) remain angularly stationary relative to the fuel filler neck (600), the locking projections (222) move angularly and the inclined edge (226) of the locking projections (222) abut and rub against the locking ribs (650) and move the locking member (220) downwards due to the tapered configuration of the locking ribs (650) which acts as a ramp. As the locking member (220) moves axially downwards, the coil spring (260) positioned between the lower surface of the step (224) provided near the upper edge of the locking member (220) and the upper surface of the main circular plate (294) provided on the cylindrical body (280) thereof, is compressed. The coil spring (260) placed between the locking member (220) and the main circular plate (294) biases the cylindrical body (280) downwards and thus urges the circular plate (182) along with the circular seal member (200) to press against the mouth of the fuel filler neck (600) to make the sealing contact.
Referring to FIG. 6, when the fuel cap (100) is away from the fuel filler neck (600) or when the fuel cap (100) is in securing start stage. The engagement projections (300) lie at a distance from the beams (228) provided on the inner surface of the locking projections (222). This distance is referred to as the initial gap (P). However, it is desirable that at the securing finished stage, after the fuel cap (100) is secured on the fuel filler neck (600), the cylindrical body (280) does not move relative to the fuel filler neck (600). To ensure this, it is desirable that during the movement of the fuel cap (100) from the securing start stage to the securing finished state, the locking member (220) moves axially downwards relative to the cylindrical body (280) to eliminate the initial gap (P) and the beams (228) abut the engagement projections (300) once when fuel cap (100) reaches the securing finished state.
In the fuel cap (100) in accordance with the present disclosure, at the securing finished stage, as shown in FIG. 15 and FIG. 17, the beams (228) provided on the inner surface of the locking projections (222) abut the engagement projections (300) to block any further axial movement of the cylindrical body (280). The locking ribs (650) of the fuel filler neck (600) block the axial upward movement of the locking projections (222) and the beams (228) provided on the inner surface of the locking projections (222) block the axial upward movement of the engagement projections (300). As the engagement projections (300) are an integral part of the main circular plate (294) and the cylindrical body (280), the upward axial movement of the whole cylindrical body (280) is blocked. Further, as the body cover (180) does not move axially relative to the cylindrical body (280), the axial upward movement of the circular plate (182) and the seal member (200) is also blocked relative to the fuel filler neck (600). This ensures that the seal member (200) is kept tightly abutting the rim (620) and the sealing contact is maintained rigidly until the fuel cap (100) is unlocked and moved to the securing start stage.
The axial downward movement of the locking member (220) is caused because of the tapered or inclined configuration of the locking ribs (650) and the inclined edge (226) of the locking projections (222). The amount of axial movement of the locking member (220) depends on the angle of inclination of the locking ribs (650) as well as the angle of inclination of the inclined edge (226) of the locking projections (222). The amount of axial movement may also depend on the overall height of the inclined edge and the locking ribs (650). A greater angle of inclination may lead to a greater axial height of the inclined edge or the locking ribs, which may be directly proportional to the axial movement of the locking member.
In prior art fuel caps, at the secure finished stage, there remained an axial gap (P) (also referred to as the ‘initial gap’) between the beams (228) and the engagement projections (300), due to which the engagement projections (300) had room to move axially within the locking projections (222), which led to the loss of sealing contact due to pressure fluctuations and sloshing of fuel in the fuel tank, resulting in the leakage of fuel from the fuel tank.
In the fuel cap (100) in accordance with the present disclosure, the angle of inclination of the locking ribs (650) and/or the inclined edge (226) of the locking projections (222) cause sufficient downward movement of the locking member (220) to eliminate the initial gap (P) and achieve abutment of the beams (228) with the engagement projections (300) at the final position of the locking member (220) or at the securing finished stage. In particular, the overall angle of the taper is configured to achieve the axial movement of the beams (228) of the locking member (220) to abut the engagement projections (300) when the locking member (220) is in the final position. It may be noted that such effect may be achieved by either configuration of the angle of inclination of the inclined edge (226), or the angle of inclination of the locking ribs (650), or by a combined configuration of the angle of inclination of the locking ribs (650) and the inclined edge (226) of the locking projections (222).
For example, at the securing start edge, when the locking projections (222) start engaging the locking ribs (650), the first end (230) of the inclined edge (226) engages the start point (652) of the locking ribs (650). As the locking projections (222) move further angularly, the second end (232) of the inclined edge (226) moves towards the start point (652). In such instance, the angle of the inclination of the inclined edge (226) may result in the initial axial movement of the locking member (220). After the second end (232) abuts the start point (652) of the locking ribs (650), further angular movement of the locking projections (222) towards the end point (654) results in further axial downward movement of the locking member (220) due to the tapered configuration of the locking ribs (650).
In case of a higher angle of inclination of the inclined edge (226), the height of the anti-rotation projections (190) may be adjusted to achieve proper engagement of the locking ribs (650) with the locking projections (222).
FIG. 14 and FIG. 15 illustrate an embodiment, wherein the angle of inclination of the locking ribs (650) is adjusted to achieve the abutment of beams (228) with the engagement projections (300) at the secure finished stage. FIG. 14 and FIG. 15 illustrate the cross-sectional view along a plane running through the two beams (228) in the locking projection (222). FIG. 14 illustrates the fuel cap (100) in the securing start stage and FIG. 15 illustrates the fuel cap (100) in the secure-finished stage. As shown in FIG. 14, the lower end of the beams (228) abuts the top surface of the engagement projections (300) to block the further axial upward movement of the cylindrical body (280) and the body cover (180).
In conventional fuel filler necks, the angle of inclination of the locking ribs (650) relative to the cylindrical axis (102) of the fuel filler neck is in the range of 1 - 2 degrees. In the fuel filler neck (600) of the fuel tank in accordance with an embodiment of the present disclosure, the angle of taper of the locking ribs (650) may be in the range of 2.5 to 10 degrees. Preferably, in an embodiment, the angle of taper of the locking ribs (650) may be in the range of 3-6 degrees.
FIG. 16 and FIG. 17 illustrate an embodiment, wherein the angle of inclination of the top edge of the locking projections (222) is adjusted to achieve the abutment of beams (228) with the engagement projections (300) at the secure finished stage. FIG. 16 and FIG. 17 illustrate the cross-sectional view along a plane running through the two beams (228) in the locking projection (222). FIG. 16 illustrates the fuel cap (100) in the securing start stage and FIG. 17 illustrates the fuel cap (100) in the secure-finished stage. As shown in FIG. 17, the lower end of the beams (228) abut the top surface of the engagement projections (300) to block the further axial upward movement of the cylindrical body (280) and the body cover (180).
It may be noted that the angle of inclination of the inclined edge (226) in the conventional fuel caps is about 15 degrees. In the fuel cap (100) in accordance with an embodiment of the present disclosure, the angle of inclination of the top edge may be 16-50º. Preferably, in an embodiment the angle of inclination of 18-25 degrees.
At the secure finished stage, due to the angular movement of the cylindrical body (280), the position of the pair of ribs (186) present on the inner surface of the body cover (180) is now changed and they lie between the left edge of the other projection (298) and right edge of the rectangular opening (302). This stage is known as securing finished stage of the fuel cap (100) as illustrated in FIG. 15 and FIG. 17. Thereafter, a key is inserted inside the lock provided in the fuel cap (100). The rotation of the lock levers by the key, allows the actuator (400) to project out of one of the rectangular openings (302) provided on a middle portion (288) of the cylindrical body (280) of the fuel cap (100). Thus, this movement of the actuator (400), out of one of the openings (302) makes one of the pair of ribs (186) now lie between the right edge of the actuator (400) and the left edge of the projection (298), causing the fuel cap (100) to be securely locked to the fuel filler neck (600).
In the lock position, a person would not be able to rotate the fuel cap (100) in an anti-clockwise direction without unlocking it with the key. Thus, the operation of the fuel cap (100) starting from the securing­ started stage to the lock position not only tightly secures the fuel cap (100) to the mouth or rim (620) of the fuel filler neck (600) but also makes it impossible to open the fuel cap (100) without unlocking it.
FIG. 18 illustrates the angular movement of the fuel cap (100) at different stages of securing the operation of the fuel cap (100) 1 onto a fuel filler neck (600). As shown, stage A illustrates the angular movement wherein the locking member (220) may move axially due to the angle of inclination of the top edge of the locking projections (222). Stage A may have a range of 45-55°. Stage B illustrates the angular movement of the fuel cap (100) in which the locking member (220) may move axially due to the angle of inclination of the locking ribs (650). Stage B may have a range of 100-120°. Stage C illustrates the angular movement wherein the beams (228) may abut and engage the engagement projections (300). Stage C may have a range of 20-50°.
It is pertinent to note that the abutment of the beams (228) with the engagement projection takes place only at the final stage. Therefore, when we consider the turning force required for securing the fuel cap (100), at stage A and a substantial portion of stage B, the turning handle (140) has to be rotated only while overcoming the resistance generated by the spring (260) force, whereas, in the final stage C, the turning handle (140) has to be rotated against the resistance generated by the spring (260) force, as well as the elastic compression of the seal member (200). Hence, it is to be noted that the substantial angular movement of the turning handle (140) can be achieved smoothly and only at the last final stage the cap has to be rotated with slightly greater force. The advantage of such a configuration is that the user experiences overall smooth operation as well as perceives tighter fitment of the fuel cap (100) as the last stage C requires slightly greater force. This way overall experience and satisfaction of the user with the fuel cap (100) is drastically improved.
In another embodiment, the abutment of the beams (228) with the engagement projections (300) on the main circular plate (294) may be achieved by increasing the thickness of the seal member (200) or the circular plate (182). More particularly, the thickness of the circular plate (182) or the seal member (200) may be extended towards the bottom. This increase in thickness will move the initial position of the locking member (220) downwards, and thus with a smaller amount of axial movement of the locking member (220), the abutment of the beams (228) with the engagement projections (300) may be achieved. The phrase thickness is used to refer to the dimension of the seal member (200) or the circular plate (182) along the cylindrical axis of the fuel cap. An example of such a fuel cap (100) assembly with a thicker seal member (200) is illustrated in FIG. 19.
FIG. 19 illustrates a cross-section of the fuel cap (100) and the fuel filler neck (600) along a plane running through the pair of beams (228) of the fuel cap (100) in the securing finished state. FIG. 19 illustrates a thicker seal member (200) used for achieving abutment of the beams (228) with the engagement projections (300) of the main circular plate (294). It may be understood that the thickness of both, the circular plate (182) and the seal member (200), may be increased in part to achieve the abutment of the beams (228) with the engagement projections (300). In an embodiment, the thickness (or length) of the circular plate (182) may be 5-10 mm. In an embodiment, the thickness (or length) of the seal member (200) may be 4-10 mm. Yet, in an embodiment, the thickness of the seal member (200) may be 5-8 mm.
In the fuel cap (100) as disclosed herein, once the fuel cap (100) is secured on the fuel filler neck (600), the sealing contact is rigidly maintained by blocking any axial movement of the circular plate (182) with respect to the fuel filler neck (600). Therefore, loss of sealing contact can not take place even if the pressure inside the fuel tank overcomes the biasing force of the spring (260). Therefore, the fuel cap (100) of the present disclosure prevents any leakage of the fuel due to loss of sealing contact between the circular plate (182) and the fuel filler neck (600).
Further, the fuel cap (100) as disclosed herein may be made using minimal changes in the components of the overall assembly. Moreover, a greater degree of freedom of design is available for the implementation of the present disclosure. For example, the present disclosure can be practised either by making modifications in the fuel filler neck (600), the fuel cap (100), or both. Yet in an embodiment, modifications may be made in the circular plate or the seal member, or partly in both. Yet in an embodiment, any of the combinations of various modifications as disclosed herein may be deployed for achieving abutment of the seal member (200) with the rim. The fuel cap (100) as disclosed also helps in saving fuel by preventing leakage of the fuel.
The fuel cap (100) as disclosed in the present disclosure may be tested using the test setup as disclosed in patent application number 664/DEL/2010.
The foregoing detailed description has described only a few of the many possible implementations of the present invention. Thus, the detailed description is given only by way of illustration and nothing contained in this section should be construed to limit the scope of the invention.
, Claims:We claim:
1. A fuel tank cap assembly for mounting on a fuel filler neck (600) of a fuel tank of a vehicle, the fuel cap assembly (100) comprising:
a cylindrical body (280) comprising a top portion (282), a middle portion (288) and a bottom portion (290), the said top portion (282) being separated from the middle portion (288) by a circular portion (292) and the said middle portion (288) being separated from the bottom portion (290) by a main circular plate (294), the main circular plate (294) comprising a set of engagement projections (300);
a body cover (180) encircling the middle portion (288) of the cylindrical body (280), the said body cover (180) comprising a cylindrical trunk portion (184) and a circular plate (182) located on a top end of the cylindrical trunk portion (184), the said circular plate (182) being provided with a pair of anti-rotation projections (190) on a bottom surface thereof;
a turning handle (140) being attached rigidly to the cylindrical body (280) and affixed angularly movable relative to the body cover (180), the turning handle (140) movable by a user between the securing start stage in which the fuel cap (100) can be engaged on the fuel filler neck (600) and a securing-finished stage in which the fuel cap (100) is secured on the fuel filler neck (600);
a circular seal member (200) accommodated by the bottom surface of the said circular plate (182) of the body cover (180); and
a cylindrical locking member (220) encasing the cylindrical trunk portion (184) of the body cover (180), the cylindrical locking member (220) mounted on the cylindrical body (280) angularly stationary and axially movable relative to the cylindrical body (280);
a pair of locking projections (222) on an outside surface of the locking member (220), the locking projections (222) configured to engage the fuel filler neck (600) to axially move the locking member (220) relative to the cylindrical body (280), the locking member (220) having an initial position corresponding to the securing start stage and a final position corresponding to the securing finished stage of the fuel cap (100);
a pair of beams (228) on an inner surface of the locking projections (222), the pair of beams (228) terminate at a predetermined distance from a bottom end of the locking projections (222), the engagement projections (300) engaged within the predetermined distance provided in the locking projections (222) forming an initial gap (P) between the beams (228) and the engagement projections (300), the said predetermined distance being more than the length of the main circular plate (294) separating the middle portion (288) of the cylindrical body (280) from the bottom portion (290) of the cylindrical body (280);
characterized in that,
the beams (228) abut the engagement projections (300) to block the axially downward movement of the locking member (220) relative to the cylindrical body (280) when the locking member (220) is in the final position.

2. The fuel cap assembly (100) as claimed in claim 1, wherein each of the pair of locking projections (222) has an inclined edge (226) at its top portion that engages a set of locking ribs (650) on a fuel filler neck (600), and an angle of inclination of the inclined edge (226) is in the range of 16-50º.
3. The fuel cap assembly (100) as claimed in claim 1, wherein the thickness of the seal member (200) is in the range of 4 mm to 8 mm.
4. The fuel cap assembly (100) as claimed in claim 1, wherein the thickness of the circular plate (182) is in the range of 5 mm to 10 mm.
5. A fuel filler neck (600) for a fuel tank comprising:
a neck (630) extending from the fuel tank, the neck (630) forming a conduit to connect the environment with the inner cavity of the fuel tank;
a rim (620) configured to abut a seal member (200) of a fuel cap (100);
a pair of locking ribs (650) positioned adjacent to the rim (620);
wherein the locking ribs (650) are inclined relative to the axis (102) of the fuel filler neck (600) at an angle in the range of 2.5 to 5 degrees.
6. The fuel filler neck (600) as claimed in claim 5, wherein the locking ribs (650) extend axially downwards from a radially inner edge of the rim (620).
Dated this 30th day of June 2023
GAURAV CHOUBEY
Of Choubey & Co.
Agent for the Applicant
IN/PA/2369