WHEELS FOR LUGGAGE ITEMS

The present invention relates to wheels for luggage items, in particular to wheels not having a central hub. The wheels of the invention are particularly useful when applied to a trolley style case.

Trolley style cases comprise a compartment defined by an outer casing, and a pair of wheels secured to respective portions of the outer casing such that at least a portion of each wheel projects beyond the outer casing for rolling engagement with the ground. A handle is provided remote from the pair of wheels for manipulation of the case by a user.

In known arrangements, the wheels are mounted to the outer casing via respective axle shafts (or axle pins) that are themselves secured to the casing. In particular, the outer casing adjacent each wheel is provided with a substantially semicircular recess for housing an upper portion of each respective wheel. The respective axle shafts are secured to the outer casing at opposite sides of the recess. Alternatively, the respective recesses may be open on one side, with the associated axle shaft being secured to the other side of the recess only. Only a relatively small portion of the wheels projects beyond the outer casing. Such an arrangement minimises the overall outer dimensions of the case, which is an important consideration in the field of luggage design. For example, many airlines have defined maximum dimensions for luggage items that are allowed to be carried on to a plane. Thus, it is often desired to keep the overall outer dimensions of a luggage item within such defined limits.

However, whereas the above-mentioned wheel mounting arrangements minimise the impact that the provision of wheels has on the outer dimensions of a case (as compared to a case that does not have wheels), this is to the detriment of the storage space within the compartment, due to the pair of wheel-receiving recesses. Not only do these recesses reduce the volume within the compartment, they also make the compartment a more awkward shape.

A further problem associated with the above-mentioned prior art mounting arrangements is the relatively narrow distance between the points of contact of the wheels with the ground. The narrower the distance between the points of contact is, the more unstable the case.

An alternative prior art arrangement for mounting wheels to a luggage item is that employed by the typical shopping trolley. In such an arrangement, an axle interconnects a pair of wheels, and the axle is mounted to a compartment by brackets. Whereas this arrangement has the advantages that it does not alter the shape or dimensions of the compartment and also enables the distance between the wheels to be maximised to improve stability, a significant drawback is that the overall outer dimensions of the trolley are significantly affected by the provision of the wheels, axle and mounting brackets. Also, the axle is generally unprotected, thus increasing the risk of it being damaged.

In view of these problems with the prior art, it is an object of the present invention to minimise the impact that the provision of wheels has on the overall outer dimensions of a luggage item, whilst not relying on the use of recesses that reduce the volume and useful shape of a compartment of the luggage item. It is another objective of the present invention to maximise the distance between the wheels to improve the stability.

In accordance with the present invention, there is provided a luggage item comprising: a compartment defined by an outer casing; a first wheel assembly; and a second wheel assembly, each wheel assembly comprising: a body adapted to be secured to a respective portion of the outer casing; a hollow cylindrical inner support member secured to the body; an annular tyre; and

a bearing disposed between an outer surface of the inner support member and an inner surface of the tyre, such that the tyre is rotatable about the inner support member and hence with respect to the luggage item, wherein the portion of the outer casing to which the body of the first wheel assembly is secured is on a first side wall and the portion of the outer casing to which the body of the second wheel assembly is secured is on a second side wall opposite the first side wall, such that the wheel assemblies are secured at opposite sides of the outer casing in planes parallel to the respective side walls and with at least a portion of each tyre projecting beyond the outer casing for rolling engagement with the ground, wherein the compartment does not include any recesses into which the wheel assemblies protrude.

This addresses the above-mentioned objectives and overcomes the problems associated with the above-mentioned prior art arrangements, because the wheel assemblies do not include an axle shaft and there is therefore no need to secure an axle shaft to the outer casing of a luggage item. Instead, it is merely necessary to secure the body of each wheel assembly to the luggage item.

Whereas wheels having no axle shaft are known per se, these have generally been used for much larger-scale applications, such as on motorbikes, bicycles and cars. One particular example is the Osmos (RTM) wheel that is the subject of US Patent No. 5,248,019.

Preferably, the bearing is a roller bearing comprising an inner ring, an outer ring and a plurality of roller elements disposed therebetween, the inner ring being secured to the outer surface of the inner support member, and the outer ring being secured to the inner surface of the tyre.

Preferably, the inner support member has a stepped outer surface, such that the inner support member comprises a first portion at one end having an outer diameter that is relatively larger than that of a remaining portion, wherein the inner support member is secured to the body at the portion having the relatively smaller outer diameter, and

wherein the bearing encircles the portion with the relatively smaller outer diameter, at least a part of the bearing being retained between the portion with the relatively larger outer diameter and the body.

Preferably, the body includes an aperture in registration with an interior surface of the hollow inner support member. In addition to the above-mentioned functional advantages of the present invention over the prior art, a further advantage provided by the present invention is that it is aesthetically pleasing. Since there is no axle shaft, there is no associated hub on the wheel, and it is possible for the interior of the inner support member to be clear of mid- wheel constructional features. With no such mid-wheel structures, and with an aperture in the body in registration with the interior surface of the hollow inner support member, there is an unobstructed view through the wheel arrangement.

Preferably, the body comprises a moulded thermoplastic material.

Preferably, the wheel further comprises a dummy hub, adapted to be mounted so as to be coaxial with the inner support member. Further preferably, the dummy hub is mounted to the body. Even further preferably, the dummy hub is an integral part of the body. The provision of such a dummy hub feature can give the impression that the wheel is a standard wheel (i.e. having an axle shaft and associated hub, and a tyre surrounding an associated rim), but in which the tyre 'floats' around the central hub, because there is no mid-wheel structure between the hub and the rim. According to a preferred aspect, the dummy hub includes logo, the orientation of the logo being constant irrespective of a rotational position of the tyre. Such an arrangement provides the appearance that the central hub, which would normally be expected to be rotating with the tyre is stationary, even when the tyre is rotating. An attendant benefit is that any branding (i.e. logo) that is applied to the dummy hub remains at a constant orientation.

Preferably, the portion of the outer casing to which the body of the first wheel assembly is secured is at an interface between the first side wall and an adjacent bottom

wall, and the portion of the outer casing to which the body of the second wheel assembly is secured is at an interface between the second side wall and the adjacent bottom wall.

Further preferably, the body of each wheel assembly comprises a planar portion and a flange extending substantially perpendicularly with respect to the planar portion, the planar portion and the flange together defining an inner surface that is shaped to be contiguous with the respective portion of the outer casing to which it is secured, with the planar portion being secured to the side wall and with the flange being secured to the adjacent bottom wall.

Preferably, the bodies are secured to the outer casing by screws.

Preferably, the luggage item further includes reinforcing material at the portions of the outer casing to which the bodies are secured.

Preferably, the luggage item comprises a trolley style case, the case including a handle remote from the first and second wheel assemblies.

These and other aspects of the present invention will now be described, by way of example, with reference to the accompanying drawings in which:

Figure 1 is a perspective view of a wheel assembly applied to a portion of a luggage item according to the present invention;

Figure 2 is an elevation view of the wheel assembly of figure 1 ;

Figure 3 is a rear perspective view of the same wheel assembly;

Figures 4a to 4f comprise, respectively, bottom, rear, right, front, left and top views of a wheel assembly separated from the luggage item in accordance with the present invention;

Figure 5 is perspective view of the wheel assembly of figure 4;

Figures 6a to 6c are exploded perspective views of the wheel assembly of figure

5;

Figures 7a to 7c comprise respectively rear, top and front views of the wheel assembly separated from the luggage item of the present invention;

Figure 7d comprises a cross sectional view taken through the line A-A on figure 7c; and

Figure 8 corresponds to figure 1 , showing an alternative configuration for the wheel assembly.

As illustrated in the accompanying figures, a wheel assembly 10 comprises four basic elements: a body 12. an inner support member 14, a tyre 16, and a bearing 18 (seen in figures 6a to 6c and 7d).

The body 12 comprises a planar portion generally indicated at 60, with a generally arcuate flange 62 extending substantially perpendicularly therefrom, for a purpose to be described below. The planar portion 60 includes a circular aperture 64. The body 12 preferably comprises a moulded thermoplastic material.

The inner support member 14 is a generally hollow cylindrical shaped member having an inner surface 14a and an outer surface 14b. The outer surface is stepped, such that the inner support member 14 comprises a first portion 20 at one end having an outer diameter that is relatively larger than that of a remaining portion 22. This is best seen in figures 6a and 7d. The inner support member 14 is preferably comprised of moulded thermoplastic. Most preferably, the thermoplastic is treated to have a metallised appearance. It should be appreciated that the inner surface 14a need not be defined by a cylindrical shape.

The tyre 16 includes an inner surface 16a and an outer surface 16b. The inner surface 16a may define an annular channel. The tyre preferably comprises rubber.

With reference to figure 7d, the bearing 18 is a roller bearing comprising an inner ring 30, an outer ring 32 and a plurality of roller elements 34 disposed therebetween, as is well known in the field of roller bearings. Preferably, a standard roller bearing element is used.

The assembly of the wheel assembly 10 is illustrated in figures 6a to 6c. A first step is to secure the tyre 16 on the bearing 18. This is preferably achieved by over- moulding the tyre 16 about the outer ring 32 of the bearing (figure 6b). The tyre is thus secured to the outer ring 32 by friction. Where the tyre includes an annular channel, the outer ring 32 of the bearing is received in the channel. This enhances the securement between the tyre 16 and the bearing 18.

The next step is to mount the assembled bearing and tyre onto the body 12. The assembled bearing and tyre are placed on the body 12 and the inner support member 14 is then inserted through the centre of the bearing (defined by an inner surface 30a of the inner ring 30) to be secured to the body 12.

The portion 22 of the inner support member 14 having the relatively smaller outer diameter is secured to the body 12. One means for attaching these elements comprises mounting screws 40, which may be disposed at intervals around the circumference of the inner support member 14, passing through the planar portion 60 of the body 12 and into the inner support member 14 at its narrower portion 22. This is best illustrated in figure 4b and 7a. Optionally, the body 12 includes an annular boss 66, as seen in figures 6a to 6c, on which the inner support member 14 is secured. In that case, the mounting screws 40 pass through the boss 66 and into the narrower portion 22 of the inner support member 14. The aperture 64 of the body 12 is substantially in registration with the inner surface 14a of the inner support member. Thus, where the body includes an annular boss 66, this surrounds the aperture 64. The provision of the boss 66 assists in the step of mounting the assembled bearing 18 and tyre 16 to the body,

because the inner surface 30a of the inner ring 20 of the bearing 18 encircles the boss 66. This helps to hold the bearing and tyre assembly to the body whilst the inner support member 14 is inserted and secured into place.

Once the inner support member 14 has been secured in place, the inner ring 30 of the roller bearing 18 encircles the outer surface 14b of the portion 22 of the inner support member having the relatively smaller outer diameter. The inner ring 30 is hence retained between the planar portion 60 of the body 12 and the portion 20 of the inner support member 14 having the relatively larger outer diameter. As discussed above, the outer ring 32 of the roller bearing 18 is disposed within and secured to the inner surface 16a in the tyre 16. In this manner, the tyre 16 is rotatable about the inner support member 14 by virtue of relative movement between the inner ring 30 and the outer ring 32.

The wheel assembly 10 further includes a dummy hub 50 that is mounted to be co-axial with the inner support member 14. The dummy hub 50 gives the impression that the wheel is an otherwise standard wheel, but in which the tyre and associated rim is

'floating ^' about the hub (where an axle shaft would be expected). Whereas in prior art wheels the central hub would rotate as the tyre rotates, the dummy hub 50 of the present invention remains fixed. Thus, a logo included on an end face 52 of the dummy hub remains at a constant orientation, irrespective of a rotational position of the tyre 16. For example, a logo may be provided on the end face 52 such that it is always in a substantially upright and legible position when the wheel 10 is in use.

The dummy hub 50 may take any shape. It is preferable for the dummy hub 50 to have a substantially circular cross-section (in a plane perpendicular to the axis of the inner support member 14), which need not be constant along the length of the dummy hub 50. The dummy hub 50 may either partially or fully extend to the inner surface 14a of the inner support member 14 to thereby to partially or fully fill the space defined by the inner surface 14a of the inner support member. Thus, according to one aspect, the dummy hub 50 may comprise a cylinder having an outer diameter that substantially matches the diameter of the inner surface 14a of the inner support member 14.

Preferably, the dummy hub 50 is mounted to the body 12. Most preferably, the dummy hub 50 is an intregal part of the body 12, for example extending from the generally arcuate flange 62. It will be appreciated that the dummy hub 50 could comprise a separate element from the body 12, but that this would lead to the wheel assembly having an increased number of parts, and also requiring an additional step to mount the dummy hub in position.

The wheel assembly 10 is particularly suited for use as one of a pair of wheel assemblies on a luggage item 100. The luggage item 100 comprises an outer casing 102 which defines an interior compartment. A first wheel assembly 10 is secured to a portion of the outer casing 102 at an interface between a first side wall 104 and an adjacent bottom wall 106. In position, the planar portion 60 of the body 12 lies flush with and is secured to the first side wall 104, and the generally arcuate flange 62 of the body 12 lies flush with and is secured to the bottom wall 106, which has an arcuate profile (as best illustrated in figure 2). Thus, the planar portion 60 and the generally arcuate flange 62 together define an inner surface that is shaped to be contiguous with the portion of the outer casing 102 to which it is to be secured.

Any suitable means for securing the body 12 to the outer casing 102 may be used. For example, the body 12 may be secured to the outer casing 102 by mounting screws (not shown). Alternatively, the body 12 may be secured to the outer casing by adhesive.

A second wheel assembly is mounted to the luggage item 100 in an identical fashion at an interface between a second side wall (not shown) and the adjacent bottom wall 106.

The wheel assemblies 10 are mounted to the luggage item 100 such that at least a portion of each tyre 16 projects beyond the outer casing 102 for rolling engagement with the ground.

The luggage item 100 includes reinforcing material 108 at the portions of the outer casing 102 to which the bodies 12 of the wheel assemblies 10 are secured.

Since each wheel assembly 10 is mounted directly to the outer casing 102 by means of a body 12 which includes an inner surface that is designed to be contiguous with the portion of the outer casing to which the wheel is to be secured, it is not necessary for the outer casing 102 to include recessed portions for receiving each wheel assembly 10. The arrangement means that it is not necessary to encroach into the internal space of the compartment, thus maximising the usable space for packing items within the compartment. In the prior art, it has been necessary to include relatively large brackets within the compartment in order to support the axle shaft of each wheel. It has also previously been necessary to cut or make holes in the outer casing in order to secure the supporting brackets to the outer casing. Since no such step is necessary with the present invention, labour costs are reduced, assembly is simplified and production speed can be increased.

Another benefit of this arrangement is that there is no restriction on the type of material that the outer casing 102 is constructed of. The outer casing 102 can therefore comprise, but is not restricted to soft-sided, hard-sided or vacuum-formed ABS. polycarbonate or EVA products.

Moreover, since the wheel assemblies 10 of the present invention are secured directly to the outer casing 102 with no recesses in the outer casing, the tyres 16 can have a larger outer diameter than previously practical (since the recesses would have had to be correspondingly larger to accommodate the increased diameter tyres, hence further encroaching into the compartment space). Larger diameter tyres provide a smoother rolling action than smaller diameter tyres.

The arrangement also enables the tyres 16 of the first and second wheels to be spaced apart from one another by a maximum distance, thus maximising the stability of the luggage item 100.

Hence, in comparison to wheel assemblies of the prior art (as applied to luggage items), the invention enables the wheel assemblies 10 to be made more compact, lighter, stronger and of fewer parts, and for their assembly (including attachment to the outer casing 102) to be more efficient.

The luggage item preferably comprises a trolley style case, including a handle (not shown) remote from the first and second wheel assemblies.

An alternative means for mounting the inner support member 14 to the body 12 is illustrated in figure 8. Instead of the use of mounting screws, in this embodiment the body 12 comprises a first main portion 12a and a second portion 12b. The second portion comprises a substantially semi-circular bracket that can be secured to the main portion 12a, which itself includes a substantially semi-circular portion. By passing fixing screws (not shown) through mounting holes 70. the bracket 12b together with the semi-circular portion of the main part 12a encircles the narrower portion 22 of the inner support member 14, thus securing the inner support member 14 to the body 12.

The present invention has been described above purely by way of example. It should be noted that modifications in detail may be made within the scope of the invention. For example, whereas the body 12 of the wheel assembly 10 has been described as including a generally arcuate flange 62. it should be noted that the shape of the flange 62 is chosen so as to be contiguous with the bottom surface 106 of the outer casing 102 of the luggage item 100 to which the body 12 is to be mounted. Thus, the shape of the flange 62 will depend upon the contour of the bottom wall 106. Moreover, it is not necessary for the outer casing to comprise well-defined side and bottom walls. Any shaped outer casing 102 may be used, with the sole consideration being that the planar portion 60 and the flange 62 define an inner surface of the body 12 that is contiguous with the portion of the casing 102 to which the body 12 is to be secured, without requiring recesses to be defined in the outer casing 102. Also, it is not necessary for the outer casing 102 to include reinforcement material 108, particularly if the outer casing is already of sufficient strength to support the mounting of the pair of wheel assemblies. Furthermore, the bearing 18 does not have to be a roller bearing. Any

suitable bearing element, such as a plain bearing could instead be used, provided that it enabled relative rotation between the tyre 16 and the body 12, and could encircle and be secured in place by the inner support member 14, as would be appreciated by a person skilled in the art.