IE43949B1

IE43949B1 - Safety tyre and wheel rim assembly

Info

Publication number: IE43949B1
Application number: IE212776A
Authority: IE
Original assignee: Dunlop Ltd
Priority date: 1975-09-26
Filing date: 1976-09-24
Publication date: 1981-07-01
Also published as: FR2325525A1; IT1075857B; JPS5912482B2; CA1041413A; LU75844A1; FR2325525B1; DE2643117A1; JPS5243202A; SE7610512L; SE428664B; FI762724A; IE43949L; AU1801076A

Abstract

FOR CASE DM 5620/5625 Cognate A safety tyre and wheel rim assembly having a safety support member comprising a plurality of arcuate segments of rigid material coupled together at their ends and mounted in a channelshaped bearing ring mounted on the wheel rim wherein the bearing ring is located against both tyre beads to retain them in position.

Description

This invention relates to safety tyre and wheel rim assemblies incorporating an annular safety support member intended to become load-carrying if the tyre becomes deflated.

Such safety support members are described, for example, in British Specification No. 1,375,415. The support member may, for example, be of rigid plastics or metal such as aluminium alloy and is preferably formed by interconnected segments.

According to the present invention a safety tyre and wheel rim assembly comprises a pneumatic tyre having a tread, sidewalls and beads, a wheel rim having a pair of bead seats and being without a well; an annular safety support member to act as load carrying member in the event of tyre deflation; a bearing ring having a channel shape in cross-section and which is mounted on the wheel rim, in the channel of which the support member is rotatably mounted; and locating means integral with, or separate from and engaging, the bearing ring and contacting both tyre beads to locate the bearing ring axially of the assembly and retain the tyre beads in position. The safety support member conveniently comprises a plurality of arcuate segments of rigid material coupled together by means of coupling portions at their ends. -243949 The pneumatic tyre in the assembly may be of the tubeless type and of either crossply or radial construction.

The bearing ring may be divided about a circumfereutial pane within the smaller external bearing diameter so that the bearing ring may be assembled onto a preassembled or partly pre-assembled support member. The bearing ring may also comprise two or more segments for interconnection in the same manner as the support member. Preferably the segments are the same in length and numbers as the segments of the support member.

The locating means may, for example, be integral shoulders provided either side of the bearing ring or may be separate spacer rings, and they may be of resilient material,for example rub'.'ir7and be r^id or ’•’'Hude vo’’ds. TW'’ locating means should be sufficiently hard to prevent bead dislodgement.

A low friction coating may be applied to the channel of the bearing ring, for example a P.T.F.E. coating, or alternatively a lubricant may be applied on assembly. A low friction material may also be provided at the surface of the support member which will contact the deflated tyre.

A degree of resilience in the event of tyre deflation may be provided by means of including a layer or layers of resilient material on the outer periphery of the safety support member or on the inner surface of the tyre.

The invention is particularly suited to applications in the field of truck and military vehicle tyre and wheel rim assemblies in which the wheel rim has no well and may have a removable flange ring or be of the split-rim type.

Thus the wheel rim may be of the kind having a 15° taper on the bead seats* in which case the locating means successfully prevent bead dislodgement.

There is now described, by way of example and with reference to the accompanying diagrammatic drawings, two embodiments of the invention. In the drawings:Figure 1 is a part cross-section of the first embodiment, the rim being of the detachable flange type; and Figure 2 is a part cross-section of the second embodiment, the rim being a split rim.

The tyre and wheel rim assembly shown in Figure 1 comprises a wheel rim with -3439 4® a main part 1 having a first bead-retaining flange 2, a bead seat 3 and a locking ring groove 4. A detachable flange 5 having a bead seat 5 is engaged with the main rim part 1 and is retained in said engagement by means of a locking ring 7, A sealing ring 8 is provided between the main rim part 1 and the detachable flange 5.

A tubeless tyre 9 is located on the bead seats 3 and 6.

A bearing ring 10 is fitted between the tyre beads 11 and 12. The bearing ring 10 comprises two halves 13 and 14 which abut to form the channel-shape cross-section of the ring 10. Abutment shoulders 15 provided on the two halves 13 and 14 contact the tyre beads 1£ and II and retain them against the flanges 2 and 5.

The bottom surface 16 of the channel of the bearing ring 10 has a layer 17 of P.T.F.E. attached to it and an annular safety support member 18 is mounted within the channel so that it runs upon the P.T.F.E. bearing layer 17.

The annular safety support member is as described in British Patent No, 1,375,415.

The embodiment shown in Figure 2 comprises a split wheel rim formed by two rim parts 19 and 20 held together by bolts 21 in conventional manner. A bearing ring 22 is located centrally on the rim and a pair of separate spacer rings 23 and 24 are provided one either side of the bearing ring 22 to provide location for the ring and to retain the tyre beads 25 and 26 against their respective flanges. The spacer rings are of rubber and are maintained under a degree of pre-compression by the assembly.

The bearing ring 22 is of channel section extending around the rim and the annular support member 27 may take any of the previously mentioned forms.

Claims

1. A safety tyre and wheel rim assembly comprising: a pneumatic tyre having a tread, sidewalls and beads, a wheel rim having a pair of bead seats and being without a well; an annular safety support member to act as a load-carrying member in the event of tyre deflation; a bearing ring having a channel shape in cross section and which is mounted on the wheel rim in the channel of which the support member is rotatably mounted; and locating means integral with, or separate from and engaging, the bearing ring and contacting both tyre beads to locate the bearing ring“axially of the assembly and retain the tyre beads in position.

2. A safety tyre and wheel rim assembly ..ccordi.'j to cl. ! m 1 w 1 ?! ? 4 r t u bearing ring comprises two annular parts divided by a circumferential plane.

3. A safety tyre and wheel rim assembly according to claim 1 or 2 wherein the bearing rim comprises two or more arcuate parts interconnected end-to-end.

4. A safety tyre and wheel rim assembly according to any one of claims 1-3 wherein the locating means comprise shoulder portions one either side of and integral with the bearing ring to contact the tyre beads.

5. A safety tyre and wheel rim assembly according to any one of claims 1-3 wherein the locating means comprises a pair of spacer rings one either side of the bearing ring.

6. A safety tyre and wheel rim assembly according to claim 5 wherein the spacer rings are of resilient material.

7. A safety tyre and wheel rim assembly according to claim 6 wherein the resilient spacer rings are of rubber.

8. A safety tyre and wheel rim assembly according to any one of claims 1-7 wherein a coating of low friction material is provided between the bearing ring and the support member.

9. A safety tyre and wheel rim assembly according to claim 8 wherein the coating comprises a P.T.F.E. layer on the bearing ring.

10. A safety tyre and wheel assembly, according to any of the preceding claims, in which the annular safety support member comprises a plurality of arcuate -54 3 9 4 9 parts of rigid material coupled together by means of coupling portions at their ends.

11. A safety tyre and wheel rim assembly constructed and arranged substantially as described herein and illustrated in figure 1 of the accompanying drawings.

12. A safety tyre and wheel rim assembly constructed and arranged substantially as described herein and illustrated in Figure 2 of the accompanying drawings.