GB2086317A - Wheel adaptor - Google Patents

Abstract

An adaptor, for enabling a spare wheel of a motor vehicle to be fitted to a trailer, especially a caravan, consists of a plate (10) with holes (11) to receive studs (13) on the trailer hub by which the adaptor is secured to the trailer; the vehicle wheel being secured to the adaptor by studs (12) mounted on the plate (10). The plate may alternatively have a plurality of holes arranged on different pitch circles for receiving bolts to secure different wheels to the adaptor. In another embodiment the holes for the trailer hub studs are provided in a first plate and studs for the vehicle wheel on a second plate secured to the first. <IMAGE>

Description

SPECIFICATION An adaptor for vehicle wheels The present invention relates to adaptors for vehicle wheels, such adaptors being for fitting wheels to axle drums.

When a vehicle is towing a trailer, especially a caravan, it is often the case that the drum axles of the vehicle and trailer are different in the number and spacing of the studs or bolts which are used to fix the wheel to an axle drum.

Thus, a spare wheel for the vehicle will be of no use as a spare wheel for the trailer if there is failure of a trailer wheel or puncture of a trailer tyre. The disadvantage of carrying a spare wheel for the trailer is the occupying of precious space in either the vehicle or trailer. Furthermore placing a spare wheel on a roof rack increases fuel consumption, or finally if as is commonly used a special rack used to secure spare wheel under the trailer, this may cause the low-slung trailer rack to bottom when going up a steep slope or result in trailer instability in some circumstances.

According to the invention there is provided a wheel adaptor comprising a plate arranged to be secured to a wheel by studs or bolts and means for securing the plate to a trailer axle drum. The means for securing the plate to a trailer in one embodiment comprises receiving holes in the plate which receive studs on the axle drum.

Thus the present invention will provide an adaptor which will dispense the need for a separate spare wheel for the trailer, because when the adaptor is fitted to the trailer axle drum the spare wheel of the towing vehicle can then be used as the replacement wheel.

However, in some circumstances the drum axle studs are nearly aligned with the receiving holes and therefore in a further embodiment the means for securing the plate in a trailer comprises a further plate which has holes in this further plate which receive studs on the axle drum and in this embodiment there are means for securing the two plates together.

Thus the invention provides wheel adaptors for adapting for example four stud trailer hubs to a wide range of wheel stud or bolt holes.

An embodiment of the present invention will now be described with reference to the accompanying drawings wherein: Figure 1 is a plan view of a wheel adaptor according to one embodiment of the invention, Figure 2 is a cross-section taken along the line A-A of Figure 1, Figure 3 is a plan view of a wheel adaptor according to a second embodiment of the invention comprising two plates, Figure 4 is a cross-section taken along the line B-B of Figure 3, Figure 5 is a cross-section taken along the line C-C of Figure 3, and Figure 6 is a plan view of a third embodiment of the invention.

In Figure 1 an adaptor 5 is shown which comprises a plate 10 on which are fixedly mounted outward facing splined bolts 12 for receiving adaptor wheel nuts (not shown), and in which plate are formed holes 11 for the receiving studs 1 3 of the trailer axle drum. The plate 10 is formed as an annular one inch (25mm) thick plate of mild steel.

Figure 2 shows more clearly one of the normally four receiving holes 11 which is at the bottom of a circular recess 8 having a side 1 5 and a bottom 1 6. This recess allows a trailer wheel nut 1 7 to screw down on a stud 1 3 which projects from the wheel hub (not shown) to secure the adaptor to the trailer hub.

The adaptor of Fig. 1 is for the case when a trailer axle drum or hub has four studs and the adaptor has four outward facing bolts at a reduced diameter to those on the trailer hub. This enables a different wheel, e.g. the towing vehicle wheel, to be secured to the wheel hub.

Figure 2 also shows a bolt 12 fixedly mounted on the plate 10 of the adaptor 5. The bolt 12 is securely fixed to the plate by means of a circular hole 6, and a recess 7 being an enlargement of hole 6 and large enough to accommodate the head 4 of the bolt. The bolt is splined at 1 8 adjacent the head which ensures the bolt once pressed into the plate is fixed to the plate. A variation of this first embodiment is when the vehicle wheel has inwardly facing wheel bolts instead of studs and nuts.

In this variation plate 10 does not have outward facing bolts 1 9 or recesses 7, but has a threaded wheel bolt receiving portion in the area of recess 7.

In Figure 3 a second embodiment of the invention is shown in which an adaptor 50 has five adaptor bolts 1 9 and four receiving holes 61 for the hub studs. In some cases the studs and receiving holes overlap and for this reason a further plate 20 is necessary. The further plate 20 is securely fitted to the plate 60 by means of bolts or screws 21 as more clearly shown in Figure 4.

The screw 21 shown in Figure 5 has a conventional screw driving groove 22. Figure 5 shows the case when the stud 1 3 of the trailer axle drum overlaps with the stud 1 9 of the adaptor, and the figure shows how the overlap problem is solved by the use of the second plate 20 which has the bolt 1 9 firmly placed inside the second plate in the same way as in Figure 2. The plates 60 and 20 forming the adaptor 50 are secured to the trailer hub by means of a nut 23 and a stud 13 as shown both in Figure 4 and Figure 5.

The thickness of the second plate 20 in Figure 4 is a inch (1 9mm) and is similar in shape to the other plate. However, in the case of wheel bolts where the bolts are only partly threaded, plate 20 will have to be thicker and suitably one-inch thick.

In Figure 6 a third embodiment of the invention is shown in which an adaptor 65 has four receiving holes 71 in the plate 70 for hub nuts 77.

In this plate there are a further twelve holes, in which there are three sets of four holes at a certain distance from the centre of the adaptor 65.

In this case there are a set of four holes 74 at a pitch circle diameter of 4w inches, a set of four holes 72 at a pitch circle diameter of 5-inches, and a set of four holes 73 at a pitch circle diameter 6-inches, the three sets corresponding to standard sizes of wheel attachment holes. The means for securing the wheel is by a set of four bolts.

In the case of wheel bolts being used the holes 72-74 are threaded.

The plates 10, 20, 60 and 70 of the adaptors can either be turned or pressed from sheet steel or made from other suitable metal or alloys, and if present the adaptors' studs are formed from hardened steel.

It will be appreciated that in use the adaptors shown can either be fitted before a journey and the trailer is then readily adapted in the case of a wheel failure or puncture for the easy replacement of a failed wheel by the vehicle's own spare wheel, or else the adaptor need only be carried so that in the event of a trailer wheel failure, the trailer wheel is removed, the adaptor placed on the trailer hub and then the vehicle spare wheel may be secured to the trailer. Furthermore the cost of an adaptor for a wheel is less than the cost of an extra spare wheel and wheel carrier rack for the trailer. Also the fuel consumption for the towing vehicle may be reduced by not needing to carry a spare wheel on a roof rack. Furthermore, the weight of the adaptor being less than a spare wheel, allows more load to be carried in the trailer.

Also use of an adaptor allows the tyres of vehicle and trailer to be moved from trailer to vehicle to even up the tyre wear. This decreases the chance of infrequently used trailer tyres failing.

Claims (7)

1. A wheel adaptor comprising a plate arranged to be secured to a wheel by studs or bolts and means for securing the plate to a trailer axle drum.

2. A wheel adaptor as claimed in Claim 1 in which the means for securing the plate to a trailer axle drum comprises receiving holes in the plate.

3. A wheel adaptor as claimed in Claim 1 in which the securing means comprises a further plate which has holes to receive axle drum studs or bolts, means being provided to secure the two plates together.

4. A wheel adaptor as claimed in any of the preceding claims in which a plurality of differently pitched vehicle wheel securing holes are provided between adjacent pairs of the axle drum securing means.

5. A wheel adaptor substantially as described with reference to Figures 1 and 2 of the accompanying drawings.

6. A wheel adaptor substantially as described with reference to Figures 3 to 5 of the accompanying drawings.

7. A wheel adaptor substantially as described with reference to Figure 6 of the accompanying drawings.