Patent Description:
To uniformly distribute the payload caused by the amount of fuel carried on board, trucks may comprise a fuel supply system equipped with fuel tanks that are suspended on opposing sides of the centreline of the chassis. The fuel tanks can be arranged to form a system of fuel tanks, e.g. by a system of communicating vessels as described in <CIT>, so that the amount of fuel is evenly reduced on each side of the chassis. Simultaneously, the system can be more robust and maintenance friendly, by reducing the number of electronic components. For example, in such a fuel tank system it may suffice to provide only one of the fuel tanks with a common fuel level sensor, by having a common inlet port for receiving fuel, a common outlet port for dispensing fuel, while the fuel tanks are fluidly connected, e.g. by a common hose or duct, for allowing passage of fuel between tanks. Consequently, such a fuel tank system comprises different individual fuel tank configurations, e.g. a main fuel tank and an auxiliary fuel tank.

For manufacturability, however, each fuel tank may have an identical, hence generic design comprising orifices for mounting electronic components and for providing inlet or outlet ports. Depending on the configuration of an individual fuel tank, some orifices may be functional while others may be obsolete.

In particular, in a system of communicating vessels where a common fuel level sensor is employed in a main fuel tank, the orifice for mounting a second fuel level sensor in the auxiliary tank has consequently become obsolete. The obsolete orifice can e.g. be sealed, to prevent fuel leakage and/or ingress of contaminants into the fuel tank system. It is a challenge, however, to robustly prevent fuel thieves from removing the seal to steal fuel from the truck's fuel supply system.

In summary, the invention pertains to a truck, comprising a first fuel tank, a second fuel tank, and an injection mouldable sealer cap. The first fuel tank has a first orifice for housing a fuel level sensor for measuring a fuel level in a fuel supply system of the truck. The second fuel tank is arranged in fluid communication with the first fuel tank, and has a second orifice formed identically to the first orifice. The sealer cap is mountable to the second fuel tank for sealing the second orifice.

The injection mouldable sealer cap comprises a cover plate and a tubular insert. The cover plate is arranged for covering the second orifice. The tubular insert coaxially extends from the cover plate and is arranged for extending into the second orifice. The tubular insert comprises an outer wall provided with a locking arrangement that is engageable with an inner wall structure of the second fuel tank to clamp the cover plate, by applying a sealing force between the second fuel tank and the injection mouldable sealer cap.

The locking arrangement is lockable by a rotation of the injection mouldable sealer cap in a sealing direction. The cover plate comprises a top surface provided with a plurality of circular groove segments. The groove segments are dimensioned and positioned to minimize shrinkage or deformation of the sealer cap during the injection moulding process. Each groove segment of the plurality of groove segments provides a contact surface, substantially normal to the sealing direction, and the contact surface is accessible by a mounting tool for rotating the injection mouldable sealer cap in the sealing direction to apply the sealing force.

Each groove segment of the plurality of groove segments provides a bottom surface that extends against the sealing direction from the contact surface towards the top surface, wherein the bottom surface comprises an inclining wall section that inclines from a lower level inside the groove segment towards the top surface, for dislocating the mounting tool from the injection mouldable sealer cap when rotated against the sealing direction.

Accordingly, unauthorized individuals are only able to further secure the sealer cap to the second fuel tank, by driving the contact surfaces in the sealing direction, while the bottom surface prevents rotating the sealer cap against the sealing direction, to access the content of the fuel tank. The circular groove segments are dimensioned and positioned to define the geometry of the cover plate, to minimize shrinkage or deformation of the sealer cap during the injection moulding process.

To make the injection mouldable sealer cap compatible with dedicated mounting tools only, the contact surfaces can be at an offset to a midplane that intersects a centreline of the sealer cap.

The cover plate may comprise a bottom surface provided with a ring groove that encircles the tubular insert. In this way, an additional biasing or sealing element, such as an O-ring, can be applied between the injection mouldable sealer cap and the second fuel tank, to improve the sealing of the second orifice.

To further prevent unauthorized disassembly of the injection mouldable sealer cap, the cover plate may comprise an outer edge that is chamfered, so that conventional tools, such as wrenches or pliers, cannot easily engage with the cover plate. For similar reasons, the cover plate may comprise a circular contour.

The cover plate can comprise a protrusion that extends outward from the top surface, and the protrusion can provide an indicator for indicating a relative angle between the injection mouldable sealer cap and the second fuel tank along the sealing direction. By having the indicator extend from the top surface, the sealer cap is only compatible with specific mounting tools, e.g. a dedicated mounting tool that provides a clearance for the indicator when engaged with the sealer cap. As such, the risk of unauthorized disassembly of the injection mouldable sealer cap is further reduced. By indicating the relative angle between the sealer cap and the second fuel tank along the sealing direction, the protrusion can also provide a visual inspection means to verify whether the sealer cap is mounted properly, e.g. with a prescribed sealing force, so that the second fuel tank is securely sealed and the risk of fuel theft is minimized.

To determine the sealing force level, the locking arrangement may comprise a plurality of bayonet locking elements arranged around the circumference of the tubular insert. Each bayonet locking element of the plurality of bayonet locking elements can e.g. extend radially outward from the outer wall and may comprise a front section which in the sealing direction tapers from a lower level to a higher level, and a central section which is recessed with respect to the higher level. Accordingly, the taper of the front section and the height of the recessed central section can be adjusted to determine the sealing force and/or the releasing force.

<FIG> represents a truck <NUM>, illustrated by a chassis <NUM> comprising a pair of longitudinal chassis beams <NUM>, <NUM>, arranged along a driving direction of the truck <NUM>, and a cross member <NUM> extending in a lateral direction between the longitudinal chassis beams <NUM>, <NUM>. A first fuel tank <NUM> and a second fuel tank <NUM> are suspended to the chassis <NUM>, as part of a fuel supply system of the truck <NUM>. For example, as illustrated in <FIG>, the first fuel tank <NUM> can be suspended on one side of the chassis <NUM>, along longitudinal chassis beam <NUM>, e.g. as a main fuel tank. The second fuel tank <NUM> can be suspended on the other, opposing side of the chassis <NUM>, along longitudinal chassis beam <NUM>, e.g. as an auxiliary fuel tank. Alternatively, or additionally, the space between the longitudinal chassis beams <NUM>, <NUM> can be used for suspending one or more fuel tanks.

The first and second fuel tanks <NUM>, <NUM> are fluidly connected, e.g. by one or more intermediate hoses or ducts, such that fuel is able to flow between the first and second fuel tanks <NUM>, <NUM>, e.g. as in a system of communicating vessels. For example, when fuelling the truck <NUM>, fuel may be supplied to both tanks <NUM>, <NUM> through an inlet <NUM> e.g. provided on the first fuel tank <NUM>. Also, fuel is available from both tanks <NUM>, <NUM>, when dispensing fuel through an outlet e.g. provided on the first fuel tank <NUM>, to the engine of the truck <NUM>.

As shown in <FIG>, the first fuel tank <NUM> comprises a first orifice <NUM> for housing a fuel level sensor <NUM>. Accordingly, by having the first and second fuel tanks <NUM>, <NUM> arranged as communicating vessels, the fuel level sensor <NUM> can be used as a common fuel level sensor for measuring a common fuel level in the fuel supply system of the truck <NUM>.

The second fuel tank <NUM> is arranged in fluid communication with the first fuel tank <NUM>, e.g. via one or more intermediate hoses <NUM>. To facilitate manufacturability of the fuel supply system, the first and second fuel tanks <NUM>, <NUM> have an at least partially generic, or similar design, causing each fuel tank to have identical ports for accessing the fuel tanks and identical interfaces for connecting components thereto. Accordingly, the second fuel tank <NUM> comprises a second orifice <NUM> which is formed identically to the first orifice <NUM> of the first fuel tank <NUM>.

Since the fuel supply system is provided with a single, common fuel level sensor <NUM>, mounted to the first orifice <NUM> of the first fuel tank <NUM>, the second orifice <NUM> of the second fuel tank <NUM> is obsolete. Accordingly, a sealer cap <NUM> is mounted to the second fuel tank <NUM> for sealing the second orifice <NUM>. The sealer cap <NUM> is injection mouldable. Alternatively, the sealer cap <NUM> may be manufacturable by die casting or additive manufacturing.

As illustrated in <FIG>, the injection mouldable sealer cap <NUM> comprises a cover plate <NUM> arranged for covering the second orifice, and a tubular insert <NUM> that coaxially extends from the cover plate <NUM> and is arranged for extending into the second orifice. The tubular insert <NUM> comprises an outer wall <NUM> provided with a locking arrangement <NUM> that is engageable with an inner wall structure of the second fuel tank. For example, the locking arrangement <NUM> can comprise a threaded connection, a keyed connection, a bayonet connection, a snap-lock connection, a press-fit connection, or a magnetic connection.

By rotating the sealer cap in a sealing direction D, e.g. a clockwise direction, the locking arrangement <NUM> applies a sealing force between the second fuel tank and the sealer cap <NUM>, which sealing force seals or clamps the cover plate <NUM> to the exterior surface of the second fuel tank. Accordingly, the cover plate <NUM> circumferentially seals the second orifice with a specific, e.g. predefined, sealing force.

The cover plate <NUM> comprises a top surface <NUM> that is provided with circular groove segments <NUM>, e.g. two or more circular groove segments <NUM>. <FIG> illustrates an embodiment in which the top surface <NUM> is provided with four circular groove segments <NUM>. Preferably, the circular groove segments <NUM> are coaxially aligned with the centreline of the sealer cap <NUM>. Each groove segment <NUM> provides a contact surface <NUM> which is substantially normal to the sealing direction D. The contact surfaces <NUM> can e.g. be accessible by a dedicated mounting tool for rotating the sealer cap <NUM> in the sealing direction D to apply the sealing force.

Each groove segment <NUM> further provides a bottom surface <NUM> that extends against the sealing direction D, from the contact surface <NUM> towards the top surface <NUM> of the cover plate <NUM>. The bottom surface <NUM> comprises an inclining wall section <NUM> that inclines from a lower level inside the groove segment <NUM> towards the top surface <NUM>. Accordingly, when a mounting tool is engaged with the groove segments <NUM> and rotated against the sealing direction D, e.g. to try to disassemble the sealer cap <NUM> from the second fuel tank <NUM>, the inclining wall sections <NUM> of the bottom surfaces <NUM> dislocate the mounting tool from the sealer cap <NUM>.

<FIG> and <FIG> illustrate a top view and section view of another or further embodiment of the sealer cap <NUM>, wherein the cover plate <NUM> has a circular contour. Additionally, or alternatively, the outer edge of the cover plate may be chamfered, rounded, or bevelled, sloping downwards from the top surface <NUM> towards the contour. Accordingly, it is difficult for conventional tools, such as pliers or wrenches, to engage with the edge or contour of the cover plate <NUM> and apply a torque in or against the sealing direction D, to assemble or disassemble the sealer cap <NUM>. Instead, the design of sealer cap <NUM> is compatible only with specific, e.g. dedicated, mounting tools which can interact with the groove segments <NUM> in the cover plate <NUM>.

As illustrated, the contact surfaces <NUM> can be arranged at an offset X to a midplane P that intersects the centreline of the sealer cap <NUM>. Thus, any mounting tool dedicated for the depicted embodiment is to be provided with correspondingly arranged protrusions for engaging with the contact surfaces <NUM> at an offset X to the midplane P.

<FIG> and <FIG> show that the cover plate <NUM> may additionally comprise an indicator <NUM> that extends outward from the top surface <NUM>, and that is arranged for indicating a relative angle between the sealer cap <NUM> and the second fuel tank along the sealing direction D. In this way, proper sealing of the second orifice of the second fuel tank is verifiable by visual inspection. Simultaneously, the outward extension of the indicator <NUM> further prevents engagement of conventional tools with the sealer cap <NUM>, because of the mounting tool clearance volume that is required around the indicator <NUM>.

The cross-sectional view depicted in <FIG> illustrates that the cover plate <NUM> may comprise a bottom surface provided with a ring groove <NUM> that encircles the tubular insert <NUM>. The ring groove <NUM> can e.g. be used for accommodating a biasing or sealing member, such as an O-ring, gasket, or washer.

As illustrated in <FIG>, the cover plate <NUM> can comprise a flange section <NUM>-<NUM> that radially extends beyond the outer wall <NUM> of the tubular insert <NUM>. By dimensioning of and relative positioning between the groove segments <NUM> and the ring groove <NUM>, the flange section <NUM>-<NUM> can be provided with inherent flexibility, e.g. in axial and/or radial direction of the sealer cap <NUM>, thereby improving the geometrical stability of the flange section <NUM>-<NUM> when the sealer cap <NUM> is manufactured in an injection moulding process. By defining the wall thickness t of the flange section <NUM>-<NUM>, the effects of material shrinkage on the geometrical properties of the sealer cap <NUM>, specifically the flange section <NUM>-<NUM>, can be minimized.

For example, the dimensions of the ring groove <NUM> can be considered as given, having an inner diameter d1 and outer diameter d2 and extending a depth z1 into the cover plate <NUM>, e.g. for accommodating a specific sealing member around the circumference of the second orifice of the second fuel tank. Subsequently, the groove segments <NUM> can be dimensioned to have an inner diameter d3, an outer diameter d4, and an extension depth z2 into the cover plate <NUM>, to define the wall thickness t along the flange section <NUM>-<NUM>. Alternatively, or additionally, the dimensions of the ring groove <NUM> can be adapted to the dimensions of the groove segments <NUM>.

<FIG> provides a side view of another or further embodiment of the sealer cap, comprising bayonet locking elements <NUM> arranged around the circumference of the tubular insert <NUM>. Each bayonet locking element <NUM> extends radially outward from the outer wall <NUM> of the tubular insert <NUM> and comprises a front section <NUM> which in the sealing direction D tapers from a lower level L to a higher level H, and a central section <NUM> which is recessed with respect to the higher level H.

The central section <NUM> is e.g. recessed between <NUM> and <NUM> millimetre with respect to the higher level H. Accordingly, when the sealer cap <NUM> is rotated in the sealing direction, the sealing force is initially increased to a maximum sealing force level, by the inner wall structure of the second fuel tank engaging with the tapered front section <NUM>, and then decreased to a predefined sealing force level as the inner wall structure is locked, or secured, on the recessed central section <NUM>. The force difference between the maximum sealing force level and the predefined sealing force level can e.g. be accommodated by inherent elasticity of the sealer cap <NUM>, such as of the cover plate <NUM>, tubular insert <NUM> or locking arrangement <NUM>. Alternatively, or additionally, an extendible section can be provided between the sealer cap <NUM> and the second fuel tank, e.g. by a biasing or sealing member, arranged for extending or shortening to compensate for the force difference.

<FIG> illustrate top and bottom isometric views, respectively, of an example of a sealer cap <NUM> as described herein. The sealer cap <NUM> is an injection mouldable part, e.g. made of polyoxymethylene (POM), or any other type of formable polymer or metal.

It is thus believed that the operation and construction of the present invention will be apparent from the foregoing description and drawings appended thereto. For the purpose of clarity and a concise description features are described herein as part of the same or separate embodiments, however, it will be appreciated that the scope of the invention, defined by the appended claims, may include embodiments having combinations of all or some of the features described.

The invention applies not only to automotive applications where the sealer cap is used for automotive purposes, but also to other technical, industrial or agricultural applications where a sealer cap is used. It will be clear to the skilled person that the invention is not limited to any embodiment herein described and that modifications are possible which may be considered within the scope of the appended claims. Also kinematic inversions are considered inherently disclosed and can be within the scope of the invention. In the claims, any reference signs shall not be construed as limiting the claim.

The terms 'comprising' and 'including' when used in this description or the appended claims should not be construed in an exclusive or exhaustive sense but rather in an inclusive sense. Thus expression as 'including' or 'comprising' as used herein does not exclude the presence of other elements, additional structure or additional acts or steps in addition to those listed. Furthermore, the words 'a' and 'an' shall not be construed as limited to 'only one', but instead are used to mean `at least one', and do not exclude a plurality.

Claim 1:
A truck (<NUM>), comprising:
- a first fuel tank (<NUM>), comprising a first orifice (<NUM>) for housing a fuel level sensor (<NUM>) for measuring a fuel level in a fuel supply system of the truck;
- a second fuel tank (<NUM>), arranged in fluid communication with the first fuel tank (<NUM>), and comprising a second orifice (<NUM>) formed identically to the first orifice (<NUM>); and
- an injection mouldable sealer cap (<NUM>), mountable to the second fuel tank (<NUM>) for sealing the second orifice (<NUM>), wherein the injection mouldable sealer cap (<NUM>) comprises:
∘ a cover plate (<NUM>), arranged for covering the second orifice (<NUM>); characterized by
∘ a tubular insert (<NUM>), coaxially extending from the cover plate (<NUM>) and arranged for extending into the second orifice (<NUM>), wherein the tubular insert (<NUM>) comprises an outer wall (<NUM>) provided with a locking arrangement (<NUM>) that is engageable with an inner wall structure of the second fuel tank (<NUM>) to clamp the cover plate (<NUM>), by applying a sealing force between the second fuel tank (<NUM>) and the injection mouldable sealer cap (<NUM>);
wherein the locking arrangement (<NUM>) is lockable by a rotation of the injection mouldable sealer cap (<NUM>) in a sealing direction (D); wherein the cover plate (<NUM>) comprises a top surface (<NUM>) provided with a plurality of circular groove segments (<NUM>); wherein each groove segment (<NUM>) of the plurality of groove segments provides a contact surface (<NUM>), substantially normal to the sealing direction (D), wherein the contact surface (<NUM>) is accessible by a mounting tool for rotating the injection mouldable sealer cap (<NUM>) in the sealing direction (D) to apply the sealing force; and
wherein each groove segment (<NUM>) of the plurality of groove segments provides a bottom surface (<NUM>) that extends against the sealing direction (D) from the contact surface (<NUM>) towards the top surface (<NUM>), wherein the bottom surface (<NUM>) comprises an inclining wall section (<NUM>) that inclines from a lower level inside the groove segment (<NUM>) towards the top surface (<NUM>), for dislocating the mounting tool from the injection mouldable sealer cap (<NUM>) when rotated against the sealing direction (D).