AU2015101986A4

AU2015101986A4 - Improved portable fuel container

Info

Publication number: AU2015101986A4
Application number: AU2015101986A
Authority: AU
Inventors: Colin Martin Haines
Original assignee: PQI Pty Ltd
Current assignee: PQI Pty Ltd
Priority date: 2014-05-19
Filing date: 2015-05-19
Publication date: 2020-09-24
Anticipated expiration: 2023-05-19
Also published as: EP3145829A1; AU2020204083A1; AU2022215166A1; WO2015176128A1; AU2015263851A1; EP3145829A4

Abstract

A portable fuel container, the fuel container including: a tank; a spout located on an upper part of the tank for permitting fluid to be placed into and poured from the tank; the spout having a sealing surface and an internal screw thread having more than one convolution of thread; a cap assembly for closing the spout; the cap assembly including a cap body, a plug body and a sealing element, the plug body including an external screw thread which can mesh with the screw thread of the spout; the cap body being mounted on the plug body for relative rotation via clutch means, the arrangement being such that a user can grip the cap body and rotate it in a first sense so that threads of the plug body and spout mesh whereby the sealing element is brought into sealing engagement with the sealing surface with a predetermined degree of compression and further rotation of the cap body causes operation of the clutch means so that the cap body rotates relative to the plug body whereby said predetermined degree of compression of the sealing element is maintained, and the clutch means is such that rotation of the cap body by the user a second sense, opposite to the first sense, enables the cap body and plug body to be rotated in unison for removal of the cap assembly from the spout; and wherein the cap assembly does not include a vent or pressure relief valve.

Description

IMPROVED PORTABLE FUEL CONTAINER

[0001] This invention relates to a portable fuel container.

[00021 More particularly, the invention relates to a portable fuel container which is provided with a novel spout and cap which is capable of providing a reliable sealing of the container and is able to withstand pressure and drop tests required for compliance with various standards relating to fuel tanks.

[0003] The invention is an improvement of the type of portable fuel container disclosed in Australian Innovation Patent No. 2012100678, the contents of which are incorporated herein by cross-reference.

[00041 The object of the invention is to provide modifications to the portable fuel container disclosed in the aforementioned patent in order to obtain improved performance.

[00051 According to the present invention there is provided a portable fuel container, the fuel container including: a tank; a spout located on an upper part of the tank for permitting fluid to be placed into and poured from the tank; the spout having a sealing surface and an internal screw thread having more than one convolution of thread; a cap assembly for closing the spout; the cap assembly including a cap body, a plug body and a sealing element, the plug body including an external screw thread which can mesh with the screw thread of the spout; the cap body being mounted on the plug body for relative rotation via clutch means, the arrangement being such that a user can grip the cap body and rotate it in a first sense so that threads of the plug body and spout mesh whereby the sealing element is brought into sealing engagement with the sealing surface with a predetermined degree of compression and further rotation of the cap body causes operation of the clutch means so that the cap body rotates relative to the plug body whereby said predetermined degree of compression of the sealing element is maintained, and the clutch means is such that rotation of the cap body by the user a second sense, opposite to the first sense, enables the cap body and plug body to be rotated in unison for removal of the cap assembly from the spout; and wherein the cap assembly does not include a vent or pressure relief valve.

[0006] The invention also provides a portable fuel container, the fuel container including: a tank; a spout located on an upper part of the tank for permitting fluid to be placed into or poured from the tank; the spout having a sealing surface and an internal screw thread having more than one convolution of thread; a lockable cap assembly for closing the spout; the cap assembly including a cap body, a plug body and a sealing element, the plug body including an external screw thread which can mesh with the screw threads of the spout; the cap body being mounted on the plug body for relative rotation via clutch means, the arrangement being such that a user can grip the cap body and rotate it in a first sense so that threads of the plug body and spout mesh whereby the sealing element is brought into sealing engagement with the sealing surface with a predetermined degree of compression and further rotation of the cap body causes operation of the clutch means so that the cap body rotates relative to the plug body whereby said predetermined degree of compression of the sealing element is maintained, and the clutch means is such that rotation of the cap body by the user a second sense, opposite to the first sense, enables the cap body and plug body to be rotated in unison for removal of the cap assembly from the spout, the clutch means including one or more resilient fingers which are engageable with ribs and rotate in unison until said predetermined degree of compression is reached

-. 3

whereon one or more of the fingers resiliently deflect and pass over the ribs, a key operated locking mechanism which causes selective movement of the one or more fingers between extended and retracted positions such as when the cap assembly is mounted on the spout and said one or more fingers are in their retracted positions of rotation of the cap body in the first or second sense does not cause rotation of the plug body and wherein the said one or more fingers are in their extended positions, rotation of the cap body causes rotation of the plug body, subject to the operation of the clutch means, and wherein the cap assembly does not include a vent or pressure relief valve.

[0007] Preferably, the screw thread of the spout includes about 2.05 full convolutions of thread (excluding lead-in and lead-out portions of the thread).

[0008] Preferably, the cap body is made from high density polyethylene and more preferably is made from PRMO1 Lupolen 4261 AG.

[0009] Preferably further, the plug body is made from high density polyethylene and more preferably is made from RM006 Lupolen 4261 AG. This material is relatively elastic so that it can better conform to the complementary shape of the thread of the spout so as to provide a better grip therewith. This enhances the ability of the container to withstand pressure and drop tests.

[0010] Preferably further, the clutch means when a tightening torque of about 5Nm is applied to the cap body.

[0011] The invention also provides a cap assembly for a portable fuel container having a spout which permits fluid to be placed into or poured from the tank; the spout having a sealing surface and an internal screw thread having more than one convolution of thread; the assembly including the cap assembly including a cap body, a plug body and a sealing element, the plug body including an external screw thread which can mesh with the screw threads of the spout; the cap body being mounted on the plug body for relative rotation via clutch means, the arrangement being such that a user can grip the cap body and rotate it in a first sense so that threads of the plug body and spout mesh whereby the sealing element is brought into sealing engagement with the sealing surface with a predetermined degree of compression and further rotation of the cap body causes operation of the clutch means so that the cap body rotates relative to the plug body whereby said predetermined degree of compression of the sealing element is maintained, and the clutch means is such that rotation of the cap body by the user a second sense, opposite to the first sense, enables the cap body and plug body to be rotated in unison for removal of the cap assembly from the spout, characterised in that the cap assembly does not include a vent or pressure relief valve.

[00121 The portable fuel container may supply in combination with a pourer. In this case the pourer has a screw thread which can mesh with the screw thread of the spout after the cap assembly has been removed.

[00131 The invention will now be further described with reference to accompanying drawings, in which: Figure 1 is schematic side view of a fuel container constructed in accordance with the invention; Figure 2 is a plan view of a container; Figure 3 is an end view of the container; Figure 4A is a side view of the spout of the container of the invention; Figure 4B is an axial view of the spout; Figure 4C is a cross-sectional view along the line 4-4; Figure 4D is a cross-section through the spout and cap assembly; Figure 5 is a plan view of a plug body which forms part of the cap assembly;

Figure 6 is a side view of the plug body; Figure 7 is an underside view of the cap body which forms part of the cap assembly; Figures 8 and 9 are schematic views showing operation of the clutch mechanism of the cap assembly; Figure 10 is a fragmentary view of part of a lockable cap assembly with the cap in the locked position; Figure 11 is a similar view to Figure 10 but with the lock in the unlocked position; Figure 12 is a schematic plan view of the plug body of the lockable cap assembly; Figure 13 is a side view of a pourer which can be used with the container of the invention; Figure 14 is a schematic longitudinal cross-section along the line 14-14; and Figure 15 is an enlarged cross-sectional view of the proximal end of the pourer.

[0014] Figure 1 shows a jerry can 2 constructed in accordance with the invention. In the illustrated arrangement, it includes a 20 litre container 4 which is formed from pressed metal in the usual way. The container includes a handle assembly 6 welded to the top of the container 4. The top of the container 4 includes a spout 8 and cap assembly 10 of the invention.

[0015] Figures 4A to 4C show more details of the spout 8 of the jerry can 2. The spout 8 is a hollow cylindrical tubular body welded to the top surface 12 of the container 4. The spout 8 includes an internal screw thread 14 which is preferably rolled into the sidewall of the spout. As shown in Figure 4A, the thread 14 includes a tapered lead-in portion 15 and a tapered lead-out portion 17. The thread 14 extends more than one convolution of the spout. In the illustrated arrangement, the thread 14 extends through 738° which is about 2.05 complete convolutions, excluding the lead-in and lead-out portions 15 and 17, as best seen in Figures 4A and 4B. The profile of the thread is preferably similar to that which is typically used in the filler spout of automotive fuel tanks. The pitch of the thread is preferably about 6.35mm. As can be seen in Figure 4C, the outer edge 16 of the spout is rolled down so that it is U-shaped in cross-section. This provides strength as well as the profile giving a generally annular sealing surface 18.

[00161 Figure 4D is a schematic cross-sectional view showing the cap assembly 10 mounted in the spout 8 so as to effectively seal the container.

[0017] The cap assembly 10 includes a cap body 20, plug body 22 and an O-ring 24. The plug body 22 includes a cylindrical skirt 26 formed with external threads 28 which mesh with the thread 14 of the spout 8. In the illustrated arrangement there are at least two full convolutions in the external threads 28. A user can close the container 4 by inserting the skirt portion 26 into the spout and rotating it (clockwise for a right-hand thread) in order to cause the threads 14 and 28 to mesh and move the assembly downwardly so that the O-ring 24 engages the sealing surface 18. Continued rotation of the cap body 20 will cause resilient compression to a pre-determined degree of the O-ring and then a clutch mechanism 30 (not shown in Figure 4B) will operate to prevent further rotation of the plug body 22 so that the correct degree of compression of the O-ring 24 is maintained. It is preferred that the clutch mechanism operates when the user applies a torque greater than about 5Nm. A torque of this magnitude produces the correct degree of compression of the O-ring 24 and also provides stronger tightening of the cap compared to the cap disclosed in the aforementioned patent. The O-ring 24 can be of circular cross-section as shown in the drawings or alternatively may include a circumferential slot so that it is generally C-shaped in cross-section. The cap assembly 10 can be removed by the user gripping the cap body and rotating it in a counter-clockwise direction. In this mode of operation the clutch mechanism 30 is such that the cap body 20 and plug body 22 always rotate in unison so that the cap assembly 10 can be removed.

[0018] Figures 5 to 9 illustrate schematically one arrangement for providing the clutch mechanism 30 in the cap assembly 10. In this arrangement, the plug body 22 includes an integral upper annular flange 31 upon which are formed three resilient fingers 32. The resilient fingers 32 are integrally formed by moulding with the plug body 22 and are resiliently flexible in a radial direction. Each of the fingers 32 includes an inclined face 34 which terminates in a radial face 36. The inner face of the fingers 32 include a part circular recess 38 which defines an integral hinge 40 which facilitates radial resilient flexing of the fingers 32. In the illustrated arrangement, the fingers 32 are located above the plane of the annular flange 31 of the plug body 22. Located adjacent to the fingers 32 are upstanding guide plates 42 which assist in maintaining axial alignment and rotation of the cap body 20 relative to the plug body 22.

[0019] As best seen in Figures 4B and 7, the cap body 20 is moulded so as to have a transverse gripping bar 50 on its upper surface 52. The cap body 20 includes a downturned flange 54 which has inwardly-directed resilient projections 53 which engage the underside of the annular flange 31 of the plug body 22 so that the plug body 22 is effectively interlocked with the cap body 20.

[0020] It will be seen that the inner side of the flange 54 is provided with a plurality of ribs 56. Each of the ribs has a radial face 58 and a sloping face 60. The ribs 56 cooperate with the fingers 32 to form a clutch mechanism, as will be described. When a user grips the cap body 20 by the gripping bar 50 and rotates it clockwise, the threads 14 and 28 will engage so as to cause sealing engagement of the O-ring 24 with the sealing surface 18. If the user continues to rotate the cap body 20, compression of the O-ring 24 will occur and resistance to further tightening will increase. At this point, the ribs 56 will engage the sloping face 60 of the fingers, as diagrammatically shown in Figure 8. Further rotation will cause resilient deflection of the finger 32 and continued rotation will cause deflection of the fingers to the point where there is relative rotation between the fingers 32 and the rib 56 in engagement therewith (the rib moving anti-clockwise as shown in the underside view of Figure 8). When a predetermined level of compression of the O-ring 24 occurs, the rib 56 will disengage the finger 32 as seen in Figure 9 and the finger 32 will resume its non deflected shape. Further rotation of the cap body 20 in the same sense will cause the finger 32 to engage the next rib but it will deflect the finger and slide over it. In this way the user cannot over-tighten the cap assembly and the correct sealing engagement occurs between the O-ring 24 and the sealing surface 18. When the cap is rotated in an anti-clockwise direction for removal of the cap assembly from the spout 8 the radial face 58 of the ribs will engage the radial face 36 of the finger 32 so that rotation of the cap body 20 (clockwise as shown in Figure 9) will cause counter-clockwise rotation of the plug body 22 by virtue of the engagement of the faces 36 and 58 for removal of the cap assembly 10 from the spout 8.

[0021] Prototypes of the cap assembly 10 have been constructed and tested and the prototypes comply with Australian Standard AS2906.2001. A 20 litre prototype jerry can performed satisfactorily when subjected to a 1200 mm drop test. The can was also capable of withstanding internal pressures of 6.5 bar. In one drop test, the cap body 20 separated from the plug body 22 but the plug body 22 remained firmly engaged in the spout and no leakage occurred.

[0022] It will be appreciated that the cap assembly 10 can be readily formed by injection moulding of the cap body 20 and plug body 22. The O-ring 24 can be of any suitable type of elastomeric material which is resistant to petrol or diesel. The preferred materials for the components are as follows: (i) cap body 20 PRM01 Lupolen 4261 AG; (ii) plug body 22 RM006 Lupolen 4261 AG; and (iii) O-ring 24 Specification: ASTM D2000 M4BK 704 A24 EF21 Zi to Z8

[0023] It has been found that the particular type of high density polyethylene for the cap body 20 specified above provides good strength and impact resistance. The high density polyethylene for the plug body 22 provides good strength with some degree of elasticity which enables the threads of the body 22 to better conform to the complementary thread 14 of the spout so as to provide enhanced grip therewith.

[0024] It is also possible to provide an alternative arrangement which has a key locking feature to prevent unauthorised removal of a cap assembly from the spout 8. Figures 10, 11 and 12 schematically illustrate one arrangement of this type and the same reference numerals have been used to denotes parts which are the same as or corresponding to those of the earlier embodiment. In this arrangement, locking cap assembly 68 has a cap body which includes a locking mechanism 70 which projects downwardly from the underside of the cap body 20. The locking mechanism 70 need not be described in detail because it can be the same as or similar to those which are sometimes used on caps for automotive fuel tanks. It is important to note however that an automotive fuel tank cap cannot be used as a cap for a fuel container because they are normally vented and/or include pressure relief valves. The locking mechanism 70 includes a retractable resilient finger 72. The resilient finger 72 can be operated by a key mechanism in a manner which is known and need not be described. Figure 10 shows the resilient finger 72 in its retracted position. In this position, the finger is in use located within a circle 74 shown in broken lines in Figure 12. In this mode, unauthorised users attempting to rotate the cap body 20 cannot rotate the plug body 22 because the retractable finger 72 will lie within the circle 74 and will not engage the inwardly projecting ribs 76 which are formed on the inner side of the annular flange 31. When authorised opening or closing of the assembly 68 is required, the user uses a key (not shown) to move the finger 72 to its extended position (as shown in Figure 11). In this mode, the finger 72 will engage one of the ribs 76 so that rotation of the cap body 20 will cause corresponding rotation of the plug body 22. When however the required closure compression has been applied to the O-ring 24, the finger 72 will resiliently retract against the action of the spring 80 so as to slide over the ribs 76. It will be seen that the leading edge 78 of the finger 72 is sloped and profile of the ribs 76 is rounded to facilitate this movement. As can also been seen in Figure 11, the finger 72 is biased into its extended position by means of a compression spring 80.

[0025] It will be appreciated that in all embodiments of the invention, the assembly does not include a vent or pressure relief valve for relieving the internal pressure within the container 4.

[0026] A prototype of the container has been constructed and tested. It has been found to perform satisfactorily in a drop test of 1.8 metres and an internal pressure test of at least 250Kpa.

[0027] It is also possible to provide a pourer (not shown) which is provided with a base portion which is similar in shape to the plug body 22 so that it can be screw threaded into the spout 8. The pourer can be provided with an internal vent tube which vents the airspace at the top of the container 4 during pouring. The base part of the pourer can be provided with a projection or the like (not shown) which corresponds with a complementary projection (not shown) formed on the spout 8 so as to ensure that the vent tube is open to the top of the tank rather than at a level below the top of the fuel being poured from the spout 8. In an alternative optional embodiment, the spout 8 could be formed with a projection to control the position of the pourer when it is mounted on the spout 8 so that the vent tube is in an upward position so as to minimise fuel entering the venttube.

[0028] Figures 13 to 15 illustrate one form of pourer 90 which can be used with the jerry can 2 of the invention. In the axial cross-sectional view shown in Figure 15, the cross-section is taken slightly off said relative to the centre line of the pourer. The pourer includes a proximal end body 92, flexible tube 94 and pourer tip 96. In the illustrated arrangement, the proximal end body 92 is formed in two parts, as best seen in Figure 15. More particularly, the proximal end body 92 includes a moulded portion 98 and a hollow metallic coupling portion 97. The moulded portion 98 is preferably moulded from the same plastics material as the cap body 20 and includes external threads 100 which are preferably the same as the external threads 28 of the plug body 22. The moulded portion 98 includes a recess for receipt of an O-ring 102 which functions in a similar way to the 0 ring 24, that is to say it engages the sealing surface 18 of the spout when the pourer is mounted on the container 4 by meshing of the threads 100 with the internal screw thread 14 of the spout 8.

[0029] In the illustrated arrangement, the moulded portion 98 includes a one-way valve 104 to permit air to pass therethrough to enter the interior of the container as fuel is poured therefrom. In the illustrated arrangement, the one-way valve includes a cylindrical valve chamber 106 formed into the moulded portion 98 and communicates with an air passage 108 which communicates with the hollow interior of the moulded portion 98, as shown in

Figure 15. A valve ball 110 is loosely fit within the valve chamber 106 but held captive therein by means of a valve seat 112. In the illustrated arrangement, the valve seat 112 is preferably moulded from plastics material and press fit into the end of the valve chamber 106. The valve seat includes an internal bore 114 and the ball 110 can engage the inner face of the bore so as to form a seal therewith. This prevents fuel from the tank escaping through the bore 114 of the valve. A fine mesh 116 which spans an air port at the distal end of the bore 114 of the one-way valve. The function of the mesh 116 is to substantially prevent any splashes of fuel being discharged from the bore 114 when a user initially commences to pour fuel from the jerry can through the pourer. In the preferred form of the invention, the mesh 116 is heat welded into the body of the valve seat 112 which is in turn press-fit into the open end of the valve chamber 106. The mesh 116 is preferably made from brass or stainless steel wire and is relatively fine having an opening percentage of about 30%. The wire may have a diameter of 0.2286mm and an opening size of 0.28mm (50 x 50 per 2.55mm). Alternatively, the mesh could be a fine mesh of synthetic material such as nylon or the like which would facilitate heat welding of it to the moulded portion 98.

[0030] The moulded portion 98 is moulded with an internal bore 120 into which the hollow connecting portion 97 is press fit, as shown in Figure 15. The connecting portion 97 includes a distal portion 122 of narrower diameter and the proximal end of the tube 94 is mounted onto the portion 122. The hollow connecting portion 97 has a flare 123 at its proximal end. Preferably the portion 97 is retained in the moulded portion 98 by means of a press fit.

[0031] The flexible tube 94 preferably has a diameter of about 25mm and is about 150mm to 180mm in length. The flexible tubular portion 94 is preferably made from helically wound metallic strip formed in a manner which is known in the art and need not be described in detail.

[0032] The pourer tip 96 is preferably press fit onto the distal end of the flexible tube 94 again by means of press fit. It includes a pourer at its end so as to permit fuel to be poured therefrom, in the usual way. In the illustrated arrangement, a filter element 130 is mounted in the tube 94 adjacent to the tip 96, as best seen in Figure 14. The mesh size of the filter element 130 is preferably relative fine bt not as fine as the mesh 116. Typically the filter element has a 400 micron mesh size. It can be made from wire and/or synthetic material.

[00331 In a further refinement of the pourer, the moulded portion 98 can be moulded with a projection (not shown) diametrically opposite to the one-way valve 104. In this way a user can grip the projection and the one-way valve 104 so that it functions analogously to the transverse gripping bar 50 of the cap assembly 10. In this arrangement, the user can tighten the pourer 90 on the spout 8 without danger of his or her fingers being caught between the pourer and the spout and/or container 4.

[0034] Many modifications will be apparent to those skilled in the art without departing from the spirit and scope of the invention.

[00351 LIST OF PARTS

jerry can 2 litre container 4 handle assembly 6 spout 8 cap assembly 10 top surface 12 internal screw thread 14 lead-in portion 15 outer edge 16 lead-out portion 17 sealing surface 18 capbody 20 plug body 22 -ring 24 cylindrical skirt 26 externalthreads 28 clutch mechanism 30 annular flange 31 three resilient fingers 32 inclined face 34 radial face of the fingers 36 part-circular recess 38 integral hinge 40 guide plates 42 transverse gripping bar 50 upper surface 52 projections 53 downturned flange 54 plurality of ribs 56 radial face of the ribs 58 sloping face 60 locking cap assembly 68 locking mechanism 70 retractable resilient finger 72 circle 74 ribs 76 leading edge 78 compression spring 80 pourer 90 proximal end body 92 flexible tube 94 pourer tip 96 moulded portion 98 hollow metallic coupling portion 97 external threads 100 O-ring 102 one-way valve 104 cylindrical valve -chamber 106 air passage 108 valve ball 110 valve seat 112 internal bore 114 fine mesh 116 internal bore 120 distal portion 122 flare 123 filter element 130

Claims

CLAIMS:

1. A portable fuel container, the fuel container including: a tank; a spout located on an upper part of the tank for permitting fluid to be placed into and poured from the tank; the spout having a sealing surface and an internal screw thread having more than one convolution of thread; a cap assembly for closing the spout; the cap assembly including a cap body, a plug body and a sealing element, the plug body including an external screw thread which can mesh with the screw thread of the spout; the cap body being mounted on the plug body for relative rotation via clutch means, the arrangement being such that a user can grip the cap body and rotate it in a first sense so that threads of the plug body and spout mesh whereby the sealing element is brought into sealing engagement with the sealing surface with a predetermined degree of compression and further rotation of the cap body causes operation of the clutch means so that the cap body rotates relative to the plug body whereby said predetermined degree of compression of the sealing element is maintained, and the clutch means is such that rotation of the cap body by the user a second sense, opposite to the first sense, enables the cap body and plug body to be rotated in unison for removal of the cap assembly from the spout; and wherein the cap assembly does not include a vent or pressure relief valve.

2. A portable fuel container, the fuel container including: a tank; a spout located on an upper part of the tank for permitting fluid to be placed into or poured from the tank; the spout having a sealing surface and an internal screw thread having more than one convolution of thread; a lockable cap assembly for closing the spout; the cap assembly including a cap body, a plug body and a sealing element, the plug body including an external screw thread which can mesh with the screw threads of the spout; the cap body being mounted on the plug body for relative rotation via clutch means, the arrangement being such that a user can grip the cap body and rotate it in a first sense so that threads of the plug body and spout mesh whereby the sealing element is brought into sealing engagement with the sealing surface with a predetermined degree of compression and further rotation of the cap body causes operation of the clutch means so that the cap body rotates relative to the plug body whereby said predetermined degree of compression of the sealing element is maintained, and the clutch means is such that rotation of the cap body by the user a second sense, opposite to the first sense, enables the cap body and plug body to be rotated in unison for removal of the cap assembly from the spout, the clutch means including one or more resilient fingers which are engageable with ribs and rotate in unison until said predetermined degree of compression is reached whereon some one or more of the fingers resiliently deflect and pass over the ribs, a key operated locking mechanism which causes selective movement of the one or more fingers between extended and retracted positions such as when the cap assembly is mounted on the spout and said one or more fingers are in their retracted positions of rotation of the cap body in the first or second sense does not cause rotation of the plug body and wherein the said one or more fingers are in their extended positions, rotation of the cap body causes rotation of the plug body, subject to the operation of the clutch means, and wherein the cap assembly does not include a vent or pressure relief valve.

3. A cap assembly for a portable fuel container having a spout which permits fluid to be placed into or poured from the tank; the spout having a sealing surface and an internal screw thread having more than one convolution of thread; the assembly including the cap assembly including a cap body, a plug body and a sealing element, the plug body including an external screw thread which can mesh with the screw threads of the spout; the cap body being mounted on the plug body for relative rotation via clutch means, the arrangement being such that a user can grip the cap body and rotate it in a first sense so that threads of the plug body and spout mesh whereby the sealing element is brought into sealing engagement with the sealing surface with a predetermined degree of compression and further rotation of the cap body causes operation of the clutch means so that the cap body rotates relative to the plug body whereby said predetermined degree of compression of the sealing element is maintained, and the clutch means is such that rotation of the cap body by the user a second sense, opposite to the first sense, enables the cap body and plug body to be rotated in unison for removal of the cap assembly from the spout, characterised in that the cap assembly does not include a vent or pressure relief valve.

4. A container as claimed in claim 1 or 2, wherein there are at least two full convolutions of thread on the spout.

5. A container as claimed in claim 4, wherein there are about 2.05 convolutions of thread.

6. A container as claimed in claim 4 or 5, wherein there are about two full convolutions of thread on the plug body.

7. A container as claimed in any preceding claim, wherein the clutch means operates when a torque of about 5Nm is applied to the cap body.

8. A container as claimed in any preceding claim, wherein the cap body and plug body are made from high density polyethylene.

9. A container as claimed in claim 8, wherein the cap body is made from PRM1 Lupolen 4261 AG.

10. A container as claimed in claim 8 or 9, wherein the plug body is made from RM006 Lupolen 4261 AG.

11. A portable fuel container as claimed in any preceding claim in combination with a pourer having a pourer screw thread which can mesh with the screw thread of the spout.

12. A portable fuel container as claim in claim 11, wherein the pourer includes: a pourer body upon which said pourer screw thread is located; a flexible tube which extends from the pourer body; and a pourer tip.

13. A portable fuel container as claimed in claim 12, wherein the pourer body includes first and second portions, the first portion being moulded from plastics material and includes said pourer screw thread, the second portion being a hollow metal tube, one end of which is sealingly coupled to the first portion and the other end of which projects from the first portion and has a proximal end to which the flexible tube is attached.

14. A portable fuel container as claimed in claim 13 including a pourer tip located at a distal end of the flexible tube.

15. A portable fuel container as claimed in any one of claims 11 to 14, wherein there are at least two full convolutions in the pourer thread.

16. A portable fuel container as claimed in claim 13, wherein a one-way valve is located in said first portion to permit air to flow therethrough as fuel is emptied from the tank.

17. A portable fuel container as claimed in claim 16, wherein the one-way valve includes a valve chamber, valve ball and valve seat, the valve ball being constrained for loose movement within the valve chamber and to sealingly engage the valve seat when fuel is poured from the tank.

18. A portable fuel container as claimed in claim 17, wherein the one-way valve includes an inlet port which includes a fine mesh which operates to prevent initial splashes of fuel entering the valve chamber from escaping through said port.