GB2160482A - Run-flat inserts for tyres - Google Patents

Abstract

An assembly of a split-rim wheel, a tyre and a run flat insert 13 is provided with means e.g. 14, 15 for positively locating and holding the tyre insert against adverse movements caused by centrifugal and other forces. <IMAGE>

Description

SPECIFICATION Run flat tyres, inserts and wheels The invention relates to wheel, tyres and inserts on motor vehicles that enable the effects of a puncture or other deflation to be overcome.

Basically, tyre inserts hereof comprise closed cell elastomeric material that, in normally inflated tyres, are substantially free of contact with the interior tyre wass, but, in a punctured or otherwise deflated tyre offers sufficient immediate support to the tyre side walls to prevent ruinous buckling there-of. and subsequently after being worked by repeated compression/expansion, expands substantially to fill the tyre cavity and support the tyre for a period of "get home" running pending repairs.

Extensive tests have demonstrated the efficiency of such supports, particularly in the form of seperablestrips installed as rings side-by-side within the tyre on the outer periphery of the wheel, to such extent as readily to afford some tens, even hundreds of miles of near normal running pending repair.

However being conscous of the fact that other closed-cell elastomeric materials must be available and!or capable of development that are or would be satisfactory and would have different compressions and expansion properties allowing inserts of lesser volume that previously proposed to be used.

It is proposed that the size and volume of the inserts will be related to these compression and expansion properties and should now only be governed by the minima of providing support for the tyre at least to the equivalent of non-damaging inflation (prior to thermal expansion of inserts) the free air volume of the insert will bear relation to the thermal expansibility of the insert material used ie- If the insert material expands 10% of its volume thermally when in use, then the free air volume of the same insert can be 10% less than the interior volume of the tyre. If the insert material expands 20% then the free air volume of the insert may be 20% less than the interior volume of the tyre, or may be 15% or 10% less if it is deemed advantageous to pressurise the tyre case, and so on and so forth.

The object of this invention is to simplify the fitting and servicing of these inserts and tyres also to positively locate the insert against centrifugal desplacement and/or provide a gas tight seal for the proposed seperable wheel.

Accordingly, it is proposed that a wheel be made that is seperatable so that a tyre fitted with an insert may be mounted on said wheel without the need of a so called fitting well. The wheel may be divided in two with each part having one tyre retaining rim and flange or orifice designed to clamp and hold in place a specially formed base on the insert when the wheel is fastened together.

The special base of the insert would hold all the insert rings together in their proper order i.e. right and left (outer and inner) for ease of handling and to prevent any radial displacement, but would leave the rings substantially free to perform their separate functions. The special base when clamped in this way should be of sufficient precision to allow a gas tight seal for the split wheel, perhaps even compressed to ensure this. Similarly a one piece insert may be fitted located and sealed in this way.

A second wheel design here described also fulfils the above requirements. A wheel with a detachable rim, the rim being locatable in dowels and screwed or bolted in position with a gas tight seal between. The base of the wheel having locating channels at intervals in which corresponding protrusions to the base of the insert are located.

For this wheel the insert is fitted into the tyre and both placed on the wheel with the rim removed. The insert protrusions are alligned with the channels in the wheel and the tyre slid over the wheel until the far rim is contacted. The detached rim and seal are positioned and secured.

P Alternatively the tyre itself, or in conjunction with the insert may be used as a seal or be made with a seal attached. Such wheels as described above have the advantage of allowing the use of a one piece ring insert that is substantially wider than it is high thus aliminating the tendency for a one piece insert to roll over and distort and break up.

This design of insert may be used advantageously with a wide wheel and low profile tyre as those now fitted to many high performance vehicles.

Specific implementation of these proposals will now be described by way of example, with reference to accompanying drawing, in which: Figure 1 Is a section through a wheel, and insert and a tyre showing a method of splitting and forming the wheel, providing an insert that gives location and resistance to lateral and radical forces and a gas tight seal for the wheel.

Figure 2 Is a view of a seperable wheel showing lateral locating channels, split hub retaining bolts and normal retaining bolts.

Figure 3 Shows a seperable wheel with lateral locating channels as in figure 2, combined with an anular channel along the seperable line of the wheel the latter for location and a gas tight seal when used with a correspondingly shaped insert.

Figure 4 Is a section through a wheel an insert and tyre showing a detachable rim to fasilitate and simplyfy fitting and servicing of inserts and tyres and showing the use of the tyre bead and insert as a gas tight seal.

Figure 5 Is a section through a wheel and an insert and tyre showing a detachable rim with provision for locating the insert and using same as a gas tight seal, for the two parts of the wheel.

In figure 1, a vehicle wheel 10, fitted with a tyre 15 and an insert 13, has an integral side of the rim 11 a and a detachable side of the rim 11 b which is attached and detached by means of studs or bolts and nuts 12.

The base of the rim has a shaped depression 15 with shoulders 17a, 17b. The insert or inserts 13 have a base 14 to which they are attached or formed. This base 14 is located in the depression 15 and when the two parts of the rim 11a and 11b are drawn together using fastenings 12 the base becomes encaptured or located and advantageously slightly compressed to give resistance to displacement and to form a gas tight seal.

In figure 2, a wheel 10 has an integral part of the rim 11a (detachable rim or other half of wheel not shown) the base of the rim has lateral channels 15 for locating corresponding lateral protrusions 14 formed on the base of the insert 13. The studs 12 are for locating and fastening the remaining rim or half of the wheel.

Figure 3a shows a complete wheel of similar design to figure 2 in which 11a and 11b are corresponding halves of the rim with lateral channels 15 and an anular channel 18 within which the two parts of the rim mate.

Turning to figure 3b a complete wheel has lateral locating channels 15 as in figure 2 and a detachable rim 11 b which is located and fastened on studs 12.

In figure 4, a wheel 10 has an integral rim 11a and a detachable rim 11 b. This detachable rim has its inner face contoured at 19 to form a good fit with the similarly contoured mating surface on the wheel, thus ensuring centralisation and alignment of the detachable rim and wheel. The rim 11b is further located and secured by the bolts, screws or studs 12. The tyre 16 has beads 20a and 20b these beads have inward facing protrusions which correspond to similarly shaped indentations in the inset 13 so that when the tyre and insert are mounted on the wheel and the detachable rim is attached and drawn up. the tyre bead protrusions enter the indentations or channels in the insert thus clamping the insert against desplacement and forming a gas tight seal. It is noted that normally shaped tyre beads will give a gas tight seal if the insert base is slightly compressed between the tyre beads, and said insert is appropriate shaped and of sufficient precision fit.

In figure 5, a wheel 10 has an integral rim 11a and detachable rim 11b. These rims have shoulders 17a and 17b which support the tyre beads but stand above the base of the wheel 21. The insert 13 has channels of slots which allow the entry of the shoulders 17a and 17b thus holding or clamping the insert and forming a gas tight seal.

It is further envisaged that all splitable wheels described herein may be provided with an additional gas tight seal either as an additional seal or to enable the use of the wheel and tyre omitting the insert or using an insert that is located as described in this invention but not self sealing.

Claims (5)

1. Wheels for pneumatic tyres that are separable, with means for holding tyre inserts against desplacement by adverse forces.

2. Wheels for pneumatic tyres that are seperable with inward facing protrusions to the base of the rim for positively holding an appropriate shaped insert.

3. Wheels for pneumatic tyres that are seperable with an anular channel for holding inserts against displacement.

4. Wheels for pneumatic tyres that are seperable with channels running axially between the beads of the rim for holding inserts against desplacement.

5. Inserts for pneumatic tyres as in claim 1 in which the clamping construction is dimentioned to ensure a gas tight seal.

5. Wheels for pneumatic tyres with detachable rims wherein the rims have shoulders to support the tyre beads and enter appropriately dimensioned channels or slots in an insert to hold insert against displacement.

6. Pneumatic tyres with inward facing protrusions to the bead area for the purpose of holding inserts with corresponding indentations or channels against adverse displacement and improving gas tight seal.

7. Inserts for pneumatic tyres which are formed with appropriately shaped protrusions, channels, slots grooves etc. to enable them to be held against adverse displacement when used in conjunction with claims 1,2,3,4,5,6.

8. Inserts for pneumatic tyres as in claim 7, that also provide a gas tight seal.

9. Pneumatic tyre inserts and wheels substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings and any permutation of the same.

Amendments to the claims have been filed, and have the following effect: (a) Claims 1 to 3, 7 & 8 above have been deleted or textually amended.

(b) New or textually amended claims have been filed as follows: Claims 1 & 5 on attached sheet (c) Claims 4, 5, 6 & 9 above have been re-numbered as 2, 3, 4 & 6 and their appendancies corrected.

1. Inserts for pneumatic tyres of the closed cell foam rubber or plastics type which are formed with appropriately shaped protrusions, channels, slots or depressions which enable them to be held against displacement be adverse forces.