NZ270626A - Cap, for a hub assembly, comprising access means with a one-way valve biased to a closed position - Google Patents

Description

27 0 6 2 6 PATENTS FORM NO. 5 Fee No. 4: $260.00 PATENTS ACT 1953 COMPLETE SPECIFICATION After Provisional „ No: 270626 n ; Dated: 3 March 1995 James & Wells Ref: 9897/4 LR '~Elj " ■ ' IMPROVEMENTS IN AND RELATING TO HUB ASSEMBLIES , • -• * I David Worsnop, a New Zealand citizen of 770 State Highway 1, Tamahere, Hamilton, New Zealand hereby declare the invention for which I pray that a patent may be granted to me, and the method by which it is to be performed to be particularly described in and by the following statement: 1 270626 TECHNICAL FIELD The present invention is directed to hub assemblies for wheels, and caps therefor. The present invention addresses problems with hub assemblies for use in wet and submersed conditions though will also find application 5 where other hub assemblies are used. The present invention shall also consider the use of fluid lubricants, such as oils, rather than greases and shall also consider methods for the administration and collection of same from hub assemblies.

BACKGROUND ART Existing hub assemblies for wheels generally comprise the hub or housing which contains the bearings and a shaft. In virtually all instances the chosen lubricant is a grease (as this addresses leakage problems), while a cap for the outer end of the hub is usually provided to allow repacking of the grease or replacement of other components.

However, there are several problems associated with the prior art. Firstly, grease is not the ideal lubricant for bearings. Grease will gradually be consumed due to the action of moving parts though, due to its non-fluid nature, the consumed grease is not replaced in the vicinity of the bearings. The result is the formation of a cavity within the plug of grease 20 which, unless removed, will ree.:lt in the bearings running without adequate lubrication.

The problem is intensified where hubs are to be submersed in water. This is common for boat trailers and most farm and agricultural machinery. During operation heat will build up causing air and fluid within the hub 25 assembly to expand and often vent through less than perfect seals to the outside. However when cooled (such as by the action of water in which it 2 270626 is submersed) the reverse occurs and water may be drawn into the hub assembly. Typically, due to the hydrophobic nature of grease, water finding its way into the hub assembly will migrate towards cavities, which are usually immediately surrounding the bearings. The result is 5 significantly decreased bearing lifetimes.

The art has tried to address this problem by applying a positive pressure to the grease at all times. Filler caps are available which may be filled with grease and contain a biased, sliding piston arrangement which continually forces grease into the hub assemblies. 'While most of these 10 work reasonably satisfactorily, the inward pressure may not be sufficient to remove all cavities within the grease, and neither does it address the unsatisfactory performance of grease under pressure as a bearing lubricant.

Furthermore, it requires the user to regularly inspect tht modified caps, 15 typically requiring removal from a hub assembly for inspection, if they are to continue working satisfactorily.

Where a grease nipple is not provided, the refilling of the caps with grease can be a messy operation as, apart from requiring removal of the modified cap from a hub assembly, the bias of the piston must often be overcome 20 while the cap is refilled and fitted to a hub assembly. As can be appreciated this is an operation more suited to the garage rather than performed at a remote location such as a boat ramp, where problems are usually diagnosed or encountered. The use of a grease nipple may not always be satisfactory in any event as there is no visual indication that all 25 voids have been filled with grease and also, pockets of pressurised air may prevent complete filling of the recess with grease. 3 270626 It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice.

Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example 5 only.

DISCLOSURE OF INVENTION According to one aspect of the present invention there is provided a cap for a hub assembly, said cap comprising: a body portion; - a connecting portion enabling a substantially fluid-tight connection to said hub assembly, and access means able to be closed in a fluid tight manner, and which allows fluid to be added or drained through said cap.

According to another aspect of the present invention there is provided a 15 cap, substantially as described above, which is transparent or translucent, or includes a window which is transparent or translucent.

According to another aspect of the present invention there is provided a cap, substantially as described above in which the body portion is of a plastics material.

According to another aspect of the present invention there is provided a cap, substantially as described above which includes markings assisting the fluid level within the hub assembly to be gauged.

According to another aspect of the present invention there is provided a cap, substantially as described above in which the connection means 25 allows for connection to the hub assembly by at least one of the following 4 27 0 6 2 6 methods: by an interference fit; by a screw connection; by a bayonet connection; by a clipping arrangement, and by use of one or more separate connecting pieces.

According to a further aspect of the present invention there is provided a cap, substantially as described above, in combination with a hub assembly, and in which said hub assembly includes an inner oil-tight seal for the 10 hub.

According to a further aspect of the present invention there is provided a method for lubricating the bearings of a hub assembly comprising fitting said hub assembly with a cap, substantially as described above.

According to a further aspect of the present invention there is provided a 15 container for the administration of fluid for use within a cap with hub assembly combination substantially as described above, said container comprising a substantially flexible tube, one end of which comprises a compartment for fluid and closable access means allowing collection of fluid into said compartments; the second end of said container 20 comprising a compartment for holding fresh fluid and dispensing means to allow the administration of said fresh fluid.

Most embodiments of the present invention will comprise a cap able to be fitted to a hub assembly. The cap, while similar in some respects to caps of the prior art, does possess some differences. Firstly, the connection to 25 the hub is by a substantially fluid-tight connection - the fluid of choice typically being oil or another lubricant. This was not a consideration of the prior art as the non-fluid nature of grease did not require special oil tight t, / \) »J S. \J seals. This is also part of the problem contributing to the ingress of water into submersed hub assemblies. Less than adequate seals between the cap and hub would allow water to ingress under certain conditions.

The present invention may rely on several methods to provide this 5 substantially oil tight connection. Where an interference fit is relied upon (for the connection of the cap to a hub) the tolerances are generally quite tight and an adequate seal may be achieved providing manufacturing tolerances are within a satisfactory level. However, as different components may heat and expand at different rates, a perfect seal may 10 not always be maintained during conditions of extreme use.

Accordingly, in some embodiments, additional means may be relied upon to help seal the cap and hub. One method, depending upon the method of connection for the hub assembly, is to provide circumferential ribs about the substantially cylindrical portion of the cap interacting with the hub 15 assembly. Often a plurality of adjacent circumferential ribs will be provided, each of these providing a tight fit against the inner surface of the hub to which a cap is fitted. Each of these ribs may be of slightly larger diameter than the internal diameter of the hub. Depending upon the material from which the cap is constructed, these may deform slightly 20 to provide a tighter seal. As can be appreciated the chances of a lubricant finding its way past a series of tightly fitted ribs is quite remote. It is noted also that in some embodiments means is provided on the cap for draining, and refilling, with lubricant. For these embodiments the cap need rarely be removed - usually only for bearing removal and replacement. To 25 maintain a good fluid-tight seal between cap and hub, a new cap may be fitted. Where ribs deform (see above) to help provide a good seal, re-using a cap may give a less than ideal fluid-tight seal. 6 Other means which may be relied upon to improve sealing is the use of sealing washers and O-rings. These may be provided on a connecting portion of the cap (and act in a similar method to the aforesaid circumferential ribs), though may also be merely sandwiched between the 5 cap and end of the hub. Various arrangements of sealing washers and 0-rings may be used in conjunction with the present invention.

The cap will generally connect to the hub in some manner unless it has been integrally formed with the hub. However, even where the hub cap is not intended to be removed, it is likely that the cap portion will be 10 manufactured by a different process or in a different step to the hub and will be fitted as a separate unit. In most, if not all, cases the cap will include a connecting portion allowing it to be fitted to a hub. Any requirements for removal of the cap, or the lack of any such need, may influence the construction and design of this connecting. portion. 15 However, in many cases it is envisaged that the connecting portion will comprise a substantially cylindrical portion which will fit to the inside of the hub. Many hubs have been designed to accept a standard cap which is normally fitted to the hub in this manner. Accordingly, unless specific hubs are altered in design, ■- envisaged that most caps according to the 20 present invention will fit in U e manner of c nventional hub caps.

Some modifications to the connecting portion (circumferential ribs etc.) have already been mentioned. Other modifications may also be made. Some may be threaded and/or rely upon a screwing motion to enable the cap to be fitted to a hub. Bayonet, push-fit, and clipping arrangements are 25 among the possibilities. A complementary surface may not always be provided on the hub. It is possible that the connecting portion of the cap (or even the hub) is self tapping, or comprises a deformable material which will abrade or deform as it is screwed or inserted in (typically non7 27 0 6 2 6 removable embodiments). The use of adapters to convert conventional or unconventional hubs for use with various embodiments of the caps, according to the present invention, may also be relied upon.

Another characteristic of virtually all embodiments of the present 5 invention is the provision of access means to allow fluid to be added and/or drained through the cap. This allows the replacement or addition of lubricant without the removal of the hub cap. This can significantly improve the ease of lubricant addition or substitution. Compared with the prior art, this represents a significant advance as the operation can be 10 performed virtually anywhere without the need for special equipment. It enables such operations to be performed in remote positions and merely requires that the user penetrates, or removes closure means, for the aforesaid access means.

Typically the access means will comprise an aperture with some form of 15 closure device, or provision for the addition of such a closure device. The closure device will provide a substantially oil tight connection, though this may not always be a significant requirement according to the positioning of the access means. In some locations, the fluid level may never reach the access means, in wh'ch case there is less requirement for a fluid-tight 20 seal between the closure device and access means. However, such positioning of the access means may not always be suitable for subsequent draining of the hub assembly (where required) and in some embodiments several access means may be provided. One may be ideally positioned for drainage while another may be positioned to more easily allow for 25 lubricant and fluid addition.

One such example is where an access means for filling is provided substantially centrally on the body of the cap. In this position it is 8 27 0 6 2 6 generally accessible at all times, regardless of the rotational orientation of the cap. A valve-like member may be fitted for insertion of a lubricant. For instance the valve may be biased closed until a nozzle of a suitable dispensing device is inserted thereby allowing the lubricant to be 5 dispensed into the hub assembly. In many respects such operation is similar to the standard tyre valve.

The positioning need not be central, merely above the fluid level within a normal operating range. Generally the outer hub portion to which the cap is fitted, and thus the cap also, does not rotate during operation of the 10 hub assembly. Accordingly, when the cap is being fitted the user need only ensure that it is oriented in the correct manner so the filling access means is above the fluid level. Similarly if a separate drain access means is provided orientation is such that the drain is at or near the bottom of the fitted cap.

In this embodiment a second access means would normally be provided to act as a drainage device for the lubricant. This would generally be provided in a position such that, when the cap was rotated or fixed to a suitable orientation, it represented the lowest point on the cap. Providing the cap is fitted in this orientation, and as in most embodiments the cap 20 does not rotate during rotation of the wheel, the drainage port will always be at the lowermost point for drainage while the filling access means will always be in a readily accessible position. Even in embodiments where the cap rotates with rotation of the wheel, such an arrangement will often show some advantage, as when a substantially central filler access 25 means is provided, the filler access port is always positioned conveniently (and topping up will generally be the most often performed operation) even though the less frequent task of drainage may require some 9 270626 orientation (by rotation of the wheels) of the cap to position the drainage port in its lowermost position.

In other embodiments a single substantially centrally positioned access means may be provided, with the operation of drainage requiring the 5 insertion of a tube or nozzle through the access means to suck or syphon lubricant from inside the housing. In many instances, this arrangement may be acceptable. The inside of the filler cap may be modified to facilitate such operations. This may include the provision of internal conduits or guides, for an inserted tube/nozzle, to facilitate lubricant 10 removal. A trough or low point in the hub assembly, accessible to an inserted tube, and to which any fluid gravitates may also be provided.

A closure device for the one or more access means may take a variety of forms. While it may comprise a bung or plug insertable into an aperture, other devices are also possible. Threaded plugs may also be relied upon. 15 Valve arrangements may also be provided though these may be integral with or fitted permanently to the cap rather than being removable closure devices.

Another possibility is a sliding member which obscures a provided aperture or part. Sliding members may also be used in conjunction with 20 other closure means to prevent inadvertent release, or protect against contamination. Sliding may be linear or rotational. Biasing, clipping and/or locking functions may be provided to maintain the sliding member in a particular position (usually closed) Linking means may also be provided to link a removed closure device to 25 the cap so that it is not readily lost upon its removal. As can appreciated a wide range of closure devices, and valves, may be relied upon in various embodiments of the present invention. In most cases they 270626 will provide adequate sealing to prevent the loss of lubricant, and the ingress of dirt, moisture and contaminants - especially where submersion of the hub assembly is likely.

In many embodiments the cap will be a single piece. While closure 5 devices and seals may be formed separately, it is typical that the cap will substantially be a single piece unit. This may lend itself to manufacturing processes such as casting and moulding, and for a preferred embodiment of the present invention which is of a plastics material, this is the preferred method of manufacture. However, other 10 manufacturing techniques may also be relied upon.

Many embodiments of the present invention will also be modified by the provision of a window to allow the contents of a hub assembly to be gauged. Typically, this is configured and positioned to allow the viewing of lubricant within a normal operating range of levels. In some instances 15 the entire cap may be formed of a substantially transparent or translucent material, thereby negating any real need for a separate window portion to allow visibility into the interior of the hub assembly.

Modifying the cap to allow the interior of a hub assembly to be viewed can provide several significant and potentially realisable advantages over the 20 prior art. For instance, it allows the user to readily check the lubricant levels within the hub assembly. Some form of scale or graduations may be provided to assist the user in gauging such levels. Concentric rings or linear scales may be provided though other means are also possible. These scales may merely indicate minimum and maximum levels 25 though may also provide further information.

Another potentially realisable advantage is that it enables the user to determine the condition of the lubricant and also whether moisture or 11 270626 contaminants have gained entry into the hub assembly. This can provide the user with an early indication to drain and refill, or flush the interior of the hub assembly.

The use of a window or clear cover can also allow the use of lubricants 5 incorporating an indicator to indicate when certain conditions have occurred. These indicators may comprise colour or other visible changes when conditions such as lubricant breakdown, the presence of an unacceptable level of moisture, or other conditions arise. Such visible changes will be clearly observable through the window or clear cap.

In practice a cap, such as described above, can be substituted for currently provided hub caps though in some instances a hub may be specifically manufactured to co-operate with such a cap. In such instances improved connecting and sealing features may be introduced.

However, to fully maximise the potential of embodiments of the present 15 invention it is desirable to further modify existing hub assemblies so that they may take advantage of a fluid or oil lubricant. This will generally require the addition of an oil seal at the inner end of the hub assembly to prevent the leakage of oil. As grease does not present these problems, such seals are not normally provided on hub assemblies, though a grease 20 seal (with lesser sealing abilities) may be occasionally present.

In most instances no further modification of the hub assembly is required. The main requirement is that there is adequate sealing so that the oil is retained. The seal of the inner seal about the central hub shaft is not always required to be fluid tight as oil will very rarely reach this 25 position as it is above the normal oil level, and further, centrifugal force during operation will generally keep the oil away from this position. 12 27 0 6 26 However, in submersible applications, an adequate moisture seal will generally be required in this region, If available oil seals do not provide an adequate seal then the use of flexible boots and other sealing means may be considered for in this region.

In practice, little more is required other than the fitting of a cap substantially as described herein and the provision of adequate oil and moisture seals on the interior of the hub assembly. It is considered that such an arrangement can in many instances provide significant advantages over the art. It is not unreasonable to expect that the use of oil 10 rather than grease as a lubricant will, under normal conditions, extend the lifetime of many bearings by at least two times. The fluidity of the oil, as compared to grease, and the ability for it to wash moving components continually during operation, can help achieve this improved lifetime. Perhaps, more importantly, suitably chosen oils can displace moisture, 15 which may find its way into the system, away from critical parts. Further, in cases where water and contaminants are expected to enter, or do enter, the entire system may be readily emptied, optionally flushed, and refilled in substantially less time, and with better results, than grease based systems. This is especially important in situations where hub 20 assemblies are submersed for long periods, one such situation being the equipment used in rice paddies throughout Japan and Asia. Extensive problems are experienced for this type of machinery which rely upon grease based systems and for which considerable effort has been directed to solve the problems associated with rapid wear and seizure due to 25 moisture contamination.

To facilitate the introduction and removal of lubricant to a hub assembly according to the present invention, a modified container may be relied upon. Such a container will generally resemble a tube in nature though 13 270626 other configurations may be adopted which embody the general principles and desired characteristics described herein. In a preferred embodiment the container is substantially tube-like and separated into two compartments by a substantially central partition, seam, or divider. One 5 compartment is generally left empty and is designated for the collection of used lubricant. The neck or opening into this compartment may be modified to allow the ready collection of lubricant. For instance the opening to the compartment may comprise a substantially funnel-like arrangement enabling a stream of lubricant to be readily collected and 10 directed into the compartment. Closure means may then be provided to close this compartment so that the container may be disposed of or returned for recycling.

Other arrangements may also be relied upon. For instance a nozzle or probe insertable into the hub assembly may be provided so that the 15 lubricant may be drained or sucked (by squeezing of the flexible resilient container) for fluid collection. A syphoning arrangement may also be relied upon. Some embodiments may allow connection to access means of the filler cap so that a substantially oil tight seal is provided which can address the problems of accidental leakage or loss.

In a preferred embodiment means is provided to allow the container to be supported by the hub cap or hub assembly so that the container may merely be left in place while lubricant drainage is completed. This would enable the user to perform other tasks in the meantime.

The second portion of the container will generally comprise a 25 compartment with fresh fluid for insertion into the hub assembly once it has been drained. A nozzle or other dispensing means may be provided to enable the lubricant to be injected through access means in the cap. 14 270626 Where val"e means may be provided on the cap for filling, the nozzle or outlet of the second compartment may be suitably adapted to engage same. As can be appreciated a wide variety of methods of dispensing and connection may be relied upon.

While such containers may be adapted for specific or preferred use with the hub cap and hub assemblies of the present invention, it is also envisaged that they may find use in other areas. Many other pieces of equipment require the removal and replacement of lubricants such as oil etc.

BRIEF DESCRIPTION OF DRAWINGS Further aspects of the present invention will become apparent from the ensuing description which is given by way of example only and with reference to the accompanying drawings in which: Figure 1 is a side diagrammatic view of one embodiment of the present invention illustrating a hub cap and hub assembly, Figure 2 is a side diagrammatic view of an embodiment of a container suitable for use with the embodiment of Figure 1, and Figure 3 is a front diagrammatic view of an alternativ embodiment of a cap. 27 0 6 26 BEST MODES FOR CARRYING OUT THE INVENTION With reference to the drawings and by way of example only there is provided a cap (generally indicated by arrow 1) for a hub assembly (generally indicated by arrow 2), said cap 1 comprising a connecting 5 portion (generally indicated by arrow 3) providing a substantially oil tight connection to said hub 4 and access means (5, 6) allowing fluid to be added or drained through said cap 1.

In Figure 1 the cap 1 comprises a moulded body of one piece construction. While a variety of materials may be used, including metals, plastics 10 materials etc. the illustrated embodiment is moulded of clear polycarbonate plastic. This material is sufficiently strong and durable to withstand the rigours to which it is likely to be subjected and is resistant to attack from most lubricants. In addition, the polycarbonate material chosen is clear or translucent. This enables the level of fluid within the 15 hub assembly 2 to be ascertained.

The connecting portion 3 comprises a cylindrical portion configured to fit inside the end of the hub 4. A plurality of circumferential ribs 7 are provided on the cylindrical portion 8 to improve the grip and seal between the cap 1 and hub 4.

A sealing washer 9 is optionally provided to further guard against leakage of oil from the completed assembly.

In the embodiment of Figure 1, two access means (5,6) are provided. The first access means 5 is located substantially centrally with respect to the cap 1 and comprises a one way valve member allowing access to the 25 inside of a hub assembly but sealing against fluid exiting from same. 16 270626 Many such valve members are known though a simple valve comprising a spring biasing a seal against a seat may be relied upon. The bias of the spring may be sufficient to prevent normal contaminants from entering the device so that only an applied force, such as from a nozzle inserted 5 into the valve member, may overcome this resistance. An additional cap or locking member (such as the one which unlocks when a nozzle is inserted) may be provided to further guard against the ingress of contaminants. This arrangement would allow a user to readily fill or top up a hub assembly without the need for any tools. This relatively centrally 10 location of the inlet means 5 ensures that it is readily accessible regardless of the rotational orientation of the cap 1, and also avoids it being in a position where it can interfere with the gauging of the fluid level inside the hub assembly 2.

The second access means 6 comprises a downward body portion having 15 an aperture into which a threaded plug 10 can be inserted. This arrangement allows ready draining of the fluid from a hub assembly 2 when required.

In practice, an inner oil seal 11 will often be required to prevent fluid from exiting or leaking from the inside of the hub assembly. Such seals are 20 commonly available for use in many hub assemblies or may be suitably manufactured.

Other modifications may include the provision of a gauge or scale 12 on the cap 1.

Figure 3 illustrates an alternative embodiment of a cap 40. A central 25 access means 41 is provided, as is a second optional access means 42. When provided, this (42) will act primarily as a drain plug. 17 27 0 6 2 6 The central access means 41 comprises a rotationally sliding cover portion 44 to cover aperture 43. A pin 45 secures the cover 44 to the cap 40 and allows rotation to expose or seal the aperture 43. A resilient material may be provided (not visible) on the rear of the cover portion 44 to provide a 5 good seal. Another possibility is an annular groove (not shown) about aperture 43 to locate a sealing washer or O-ring.

Provided on the cover 44 are ribs 46 to assist a user sliding the cover in and out of position. A tab 47 interacts with a receiving portion 48 on a semi-annular retaining flange assembly 49. This assembly 49 helps 10 locate the cover in a closed position, and maintain a downward pressure against the face of the cap and provided sealing means.

Figure 2 illustrates a container for use in the administration and collection of fluid lubricant, and is suitable for use with the embodiment of Figure 1. The container 20 is a flexible tube similar to the flexible tubes 15 often used for storing many lubricants and oil additives. A central seam 21 divides the container into 2 compartments 22, 23.

The first compartment 22 is used for collecting used fluid. A threaded cap 24 is provided to close the access means 25 when the compartment 22 is filled with collected fluid. Connected to the cap 24 is a threaded funnel 26 20 which can be used to gather a stream of fluid (such as is drained from a drain hole 6). A loop 27 connected to the body of the container 20 enables the container 20 to be hooked over a hub cap 1, or the hub assembly 2, to allow the waste fluid to be collected by funnel 26 and directed into the compartment 22.

The alternate end of the container 20 contains fresh fluid and comprises a nozzle 28 connected to the outlet means 29. Closure means 30 for the nozzle assembly 28 may be provided though a disk of material positioned 18 270626 over the end of the outlet 29 before nozzle 28 is screwed on, could also be relied upon. The nozzle 28 will find use in filling the embodiment of Figure 1, where it is inserted into the valve 5 against the biased sealing member and the tube squeezed to insert fluid into the cap. This arrangement may also find use in other embodiments where the filling means for the cap may merely comprise an aperture.

Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof as defined in the appended claims. 19

Claims (22)

WHAT I CLAIM IS: /

1. A cap for a hub assembly, said cap comprising: a body portion, said body portion being of substantially one piece construction of a transparent or translucent material; a connecting portion enabling a substantially fluid-tight connection to said hub assembly, said connecting portion allowing for connection to the hub assembly by at least one of the following methods: by an interference fit, by a screw interaction of the cap with the hub assembly, by a bayonet connection of the cap with the hub assembly, or by a clipping arrangement between the cap and hub assembly, each said method being without the need for separate fastening members, and a first access means comprising a one-way valve arrangement biased to a closed position, said bias being sufficient to prevent the ingress of external material during the normal intended use of the hub assembly, and the arrangement being such that said bias can be overcome to allow for the insertion of lubricant into the hub assembly.

2. A cap as claimed in claim 1 which includes a second access means allowing for draining of fluid from within the hub assembly.

3. A cap as claimed in either claim 1 or claim 2 in which, when the cap is fitted to a hub assembly, allows the fluid level within the hub assembly to be viewed, at least within a normal operating range. Of M.Z. jlNTELi .... 20 \ 7 0 wU 0 < I RECEJ.VED. 270 62 u

4. A cap as claimed in any one of the preceding clnims in which tht bo dy portion is of a plastics material.

5. A cap as claimed in claim 4 in which the plastics material is a polycarbonate plastics material.

6. A cap as claimed in any one of the preceding claims which includes markings assisting the fluid level within the hub assembly to be gauged.

7. A cap as claimed in any one of the preceding claims, in which the connection portion includes one or more cap sealing means to maintain a substantially fluid-tight connection between said cap and hub assembly.

8. A cap as claimed in claim 7 in which a said cap sealing means comprises a resilient washer or O-ring.

9. A cap as claimed in claim 2, or any one of claims 3 through 8 when dependent upon claim 2, in which said second access means comprises an aperture in combination with a closure device.

10. A cap as claimed in claim 9 in which said closure device comprises at least one of: a threaded plug; a bayonet plug; a clip-fit plug; a deformable, or partially deformable, plug, and a closure device which slides over said aperture to close same.

11. A cap as claimed as claimed in claim 2, or any one of claims 3 through 10 when dependent upon claim 2, in which said second access means is positioned proud of the main portion of the cap bop^TELliCTUAL^nurcRliV OFWt t 2 3 jul 1998 received 21 # 270626

12, A cap as claimed in claim 2, or any one of claims 3 through 8 when dependent upon claim 2, in which said second access means for the removal of fluid is positioned such that said cap when fitted is, or can be, oriented such that said second access means is positioned at or near the bottom of the cap's body.

13, A cap as claimed in any one of the preceding claims in which the first access means is located substantially axially with respect to the cap when fitted to the hub assembly.

14, A cap as claimed in any one of the preceding claims in which there is included a cover for the first access means to prevent foreign matter entering the vicinity of said first access means.

15, A hub assembly when fitted with a cap as claimed in any one of the preceding claims.

16, A hub assembly with cap combination, as claimed in claim 15, wherein the hub assembly includes ail inner oil-tight seal.

17, A method for lubricating the bearings of a hub assembly comprising " fitting said hub assembly with a cap as claimed in any one of claims 1 through 14.

18, A method for lubricating the bearings of a hub assembly, as claimed in claim 16, comprising fitting an inner oil-tight seal on the alternate side of the hub's bearings to the cap.

19, A method for introducing lubricant into a hub assembly combined with a cap as claimed in any of claims 1 through 14, said method comprising insertion of the dispensing means of a container into the first access means of the cap; IwtutcrUAL PHmmvomT I OF N.Z. ' 22 j 23 JUL 1933 RECehti-I 270626 said container characterised by comprising a substantially flexible tube, one end of which comprises a compartment for fluid and closable access means allowing collection of fluid into said compartments; the second end of said container comprising a compartment for holding fresh fluid and dispensing means to allow the administration of said fresh fluid, and in which said dispensing means comprises a spout or nozzle configured to be insertable within the first access means on said hub cap.

20. A cap for a hub assembly, substantially as described herein with reference to the accompanying drawings.

21. A cap with hub assembly combination, substantially as described herein with reference to the accompanying drawings.

22. A method of introducing lubricant into a cap with hub assembly combination, substantially as described herein with reference to the accompanying drawings. DAVID WORSNOP by his Attorneys