Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60B—VEHICLE WHEELS; CASTORS; AXLES FOR WHEELS OR CASTORS; INCREASING WHEEL ADHESION
  • B60B15/00—Wheels or wheel attachments designed for increasing traction
  • B60B15/26—Auxiliary wheels or rings with traction-increasing surface attachable to the main wheel body
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60B—VEHICLE WHEELS; CASTORS; AXLES FOR WHEELS OR CASTORS; INCREASING WHEEL ADHESION
  • B60B11/00—Units comprising multiple wheels arranged side by side; Wheels having more than one rim or capable of carrying more than one tyre
  • B60B11/02—Units of separate wheels mounted for independent or coupled rotation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60B—VEHICLE WHEELS; CASTORS; AXLES FOR WHEELS OR CASTORS; INCREASING WHEEL ADHESION
  • B60B19/00—Wheels not otherwise provided for or having characteristics specified in one of the subgroups of this group
  • B60B19/06—Wheels not otherwise provided for or having characteristics specified in one of the subgroups of this group with compartments for fluid, packing or loading material; Buoyant wheels

Definitions

• This invention relates to wheel attachments and is concerned with adding support and traction for vehicles travelling on soft or muddy ground, or even for giving buoyancy.
• Rigid attachments have two main drawbacks. First, when they are not in use, they are bulky and awkward to store, and take up useful space in the vehicle. Generally, they cannot be left attached to the wheels for normal road use.
• the preferred configuration of a- rigid attachment is that of a large cog, with axially parallel ribs.
• this is not good on soft sand, where it tends simply to churn through the surface layer and throw sand about.
• a vehicle wheel attachment for increased support and traction comprising an inflatable bag, to be positioned co-axially with the wheel, characterised in that the bag is generally toroidal and a restraint is provided for connection to the wheel and to extend co- axially through the toroid to connect to the axial end remote from the wheel thereby to hold the bag, when inflated, firmly against the side of the wheel as an extension thereof.
• a torus or toroid is a ring- shaped body of circular or elliptical cross section.
• toroid and “toroidal” are used in this Specification, for convenience, in a wider sense to indicate a body of revolution generated by a closed curve rotated about a non-intersecting axis.
• the restraint may take various forms; it can be a rigid member, a flexible member, a 1 telescopic tube assembly, or it can be provided over the major part of its length by the inner wall of the toroid.
• a substantially rigid load spreading member for engaging the bag at the axial end remote from the wheel and to which the restraint connects. It will normally be of disc-like form, and it may be progressively more flexible towards its outer periphery.
• annular element may also be means for positively locating the bag against the wheel rim, and this may take the form of an annular element bonded to the bag for engagement with the wheel rim throughout its circumference. Also, there may be at least one further annular element for fitting to the first one to adapt the locating means to wheel rims of different sizes.
• the bag may have internal flexible but substantially inextensible restraints to stabilise it when inflated. There nay be sufficient of these to lessen the need for the load spreading member, and even to eliminate that altogether.
• the load spreading member may be adapted to be secured to the wheel to trap the bag between itself and the wheel.
• the bag can be left permanently attached, and inflated and deflated when required.
• the bag may be formed with a tread on its external surface, but this may not be appropriate for all uses. Therefore, there may be provided one or more flexible sleeves, each with different treads, and the selected one can be frictionally held surrounding the bag when the latter is inflated within it.
• connection of the restraint to the wheel is conveniently through a fitting secured to the wheel hub using nuts, studs or bolts by which the wheel itself is attached to the vehicle.
• Figure 1 is a perspective view, partly in ghost, of a vehicle wheel with an extra support attachment
• Figure 2 is a diagrammatic axial section of a wheel with such an attachment being stowed
• Figure 3 is a diagrammatic axial section of part of an alternative attachment
• Figure 4 is a diagrammatic axial section of part of another alternative attachment
• Figure 5 is a diagrammatic axial section of yet another alternative attachment.
• a vehicle wheel 1 has a pneumatic tyre 2 and is mounted on screw threaded studs through its hub 3, which is secured by nuts 4 tightened onto those studs in conventional fashion. But some of those studs serve as the means by which an anchorage 5 is fixed to the hub, for example as described in GB-B-2028239 and in WO87/04668 ,
• the anchorage is essentially a disc 6 with apertures around its periphery which register with alternate wheel studs, and with a central eye 7 on the side remote from the wheel.
• t ⁇ ut and bolt assemblies 8 fitted through those apertures secure onto the wheel studs.
• the extra support attachment itself is a toroidal inflatable bag 9. It is generally cylindrical but it has a narrow co-axial passage 10 which aligns witlT the wheel axis and through which extends a tension member 11 linked to the eye 7. Although shown as a rod, rigidity is not essential and it may take various different forms, as explained further below. At the outer end, remote from the wheel, this member 11 links to another eye 12 at the centre of a dished plate 13, convex towards the wheel.
• the radius of the plate is such that it spans the mouth of the passage 10 and substantially beyond that over the outer end of the bag to spread the load of the tension member 11, but its periphery is still well within the outer circumference of the bag when that is fully inflated. It may be bonded to the bag and effectively be part of it, or it may be an independent element. Preferably, it will be constructed so that towards its periphery it becomes increasingly flexible. This may be done by choice of materials and/or "feathering" it in thickness, and the purpose is to graduate the transition between flexible bag and rigid centre of the plate 13. The latter may be perforated to ensure that there is atmospheric pressure within the passage 10, but normally the wheel 1 has perforations which perform this function.
• the bag is bonded co-axially to an
• S /SCS annular plate 14 whose outer diameter is such that it fits snugly against the rim of the wheel around its whole circumference to be located thereby, and v/hich may be contoured for clearance over parts of the wheel radially within the rim. Its inner diameter, which may define the mouth of the inner end of the passage 10, is greater than the diameter of the anchorage disc 6. Indeed it may be very much greater, making the plate 14 virtually a ring. Also, since it may be desired to fit this extra support to wheels of different sizes, there may be a base ring of the minimum diameter required, to which may be fitted, simply by pressing for example, one or more larger rings which will locate against larger wheel rims.
• the bag will be of rubberised fabric or plasics material likely to have a very high co-efficient of friction with rubber, it may be possible to dispense with this locating plate or ring 14 and rely on the engagement of the inner end of the bag and the side wall of the tyre 2 to prevent mutual rotation.
• the anchorage 5 may be left virtually permanently in place on the wheel 1, and when the extra support is required the bag 9 is offered up to the wheel and the tension member 11 is threaded through the passage 10. If the plate 13 is separate from the bag the latter is folded in towards the wheel while the final attachment is made between the member 11 and the eye 12, but if the plate is part of the bag, the final attachment is made between the member 11 and the eye 7 with the bag folded towards the plate 13. Inflation can then commence, with the plate 14 guided to locate against the wheel rim as necessary. As pressure increases, the bag assumes its toroidal shape and the member 11 comes under tension.
• the actual working pressure will depend on the size of the attachment and the use to which it is to be put, but generally it will not be so much as that in the tyre 2.
• the aim is to achieve a large "footprint" which does entail the bag 9 flattening out to some extent where the load is imposed and acting like a linked track.
• SL/SCS There may also be diagonal braces 16 of similar material for stability. Alternatively, or in addition, there could be internal webs for this purpose, but perforated or fitted so that air can reach all compartments formed by them. It may also prove possible, with sufficient internal restraints and using the Figure 5 attachment described below, to dispense with the load spreading plate 13.
• a flexible member 11, of wire, cord or chain, for example, would be used, or possibly a telescopic tube assembly.
• On release of air pressure it would be necessary to nip the central portion of the bag inwards, as shown in Figure 2, to ensure that it was not proud of the tyre 2, and this can be done by one or more straps 17.
• FIG. 3 Another, neater arrangement is shown in Figure 3 where the member 11 is an assembly of telescopic tubes 20, the outer one being secured to the anchorage disc 6 around a central screw-threaded socket 21 and the innermost one to the plate 13, around a central hole 22.
• a bolt 23 can be introduced through the hole 22 and tightened into the socket 21, thus making the assembly secure.
• the wall of the passage 10 is extended at the inner end as a short cylindrical tube 26 separate from the main body of the bag which curves outwards at the inner mouth of the passage 10 as before.
• This tube is bonded or otherwise fixed to a disc 27 which is secured to the anchorage disc 6 by one or more bolts 28 accessible through the passage 10.
• a cover 29 which acts as a load spreading member in the same way as the plate 13. However, it is rather larger, and at its periphery it curves back towards the wheel.
• the bond between the bag and this cover terminates within this periphery, which is slightly larger than the wheel rim if a locating ring 14 is provided, but which may match that of the rim if not.
• the bag When the bag is deflated, it can be folded within the cover 29, without the use of straps, as the cover is pressed up against the wheel.
• the periphery of the cover may engage the side wall of the tyre 2, or the wheel" " rim, " and this completely conceals the bag, apart from what can be seen of the wall of the passage 10 through the centre of the cover.
• This form of cover may be used instead of the plate 13 in previous examples, and it will be understood that the shapes shown are only two examples of many possibilities.
• the plate 13 may be flat or convex in the opposite direction.
• the ground engaging surface of the bag will generally have some form of patterned tread.
• tread may not be appropriate for all uses of the bag.
• a basic bag adapted to receive outer sleeves, these having the treads.
• Such a sleeve indicated at 30 in Figure 5, can be fitted loosely before full inflation of the bag, but when that is complete the bag will have expanded tightly up against the inside of the sleeve, which will be held fast by friction and the double curved interface, the sleeve preferably being domed similarly to the basic bag.
• the air inlet (by which also the bag can be exhausted) will generally be at the outer end of the bag, clear of the plate 13, and inflation may be by any convenient or conventional means. Gas other than air could of course be used, for example in an emergency where a high pressure bottle is available. Also, where a catch arrangement such as that of Figure 4 is used, the wheel could be arranged to carry a small pressure bottle connected by a remotely controlled valve to the bag. The driver could then inflate the bag from his cab. If straps were used to hold the bag in, they would be weak enough to be snapped by this inflation, or their fasteners would be arranged to release.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Tires In General (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=10620120

Family Applications (1)

Country Status (4)

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Family Cites Families (5)

• 1987
  • 1987-07-06 GB GB878715797A patent/GB8715797D0/en active Pending
• 1988
  • 1988-07-06 WO PCT/GB1988/000531 patent/WO1989000112A1/en not_active Application Discontinuation
  • 1988-07-06 EP EP19880905951 patent/EP0365581A1/de not_active Withdrawn
  • 1988-07-06 AU AU19667/88A patent/AU1966788A/en not_active Abandoned

Non-Patent Citations (1)

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