AU690700B2

AU690700B2 - Tubeless tire assembly for two-wheel vehicles comprising a deformable, elastic, annular structure

Info

Publication number: AU690700B2
Application number: AU27268/95A
Authority: AU
Inventors: Philippe Bretey
Original assignee: Compagnie Generale des Etablissements Michelin SCA
Current assignee: Compagnie Generale des Etablissements Michelin SCA
Priority date: 1994-07-29
Filing date: 1995-07-28
Publication date: 1998-04-30
Anticipated expiration: 2015-07-28
Also published as: EP0695651A1; FR2723036A1; HU221151B1; HU9502171D0; KR960003995A; CZ195695A3; AU2726895A; JPH0858306A; CA2154419A1; HUT71878A

Description

MOWulaIo 2 Regulallon 3.2(2)

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Application Number: Lodged: Invention Title: TUBELESS TIRE ASSEMBLY FOR TWO-WHEEL VEHICLES COMPRISING A DEFORMABLE, ELASTIC, ANNULAR STRUCTURE e oes e eae

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The following statement is a full description of this invention, including the best method of performing it known to us BACKGROUND OF THE INVENTION The present invention relates to the field of tires for two-wheel vehicles and, more particularly, to the field of tires which are customarily mounted with an inner tube on wheels having spokes.

5 In such tires, the inflation pressure acts on the inner wall of said tire via an inner tube rather than directly. Upon travel over rough terrain containing sharp objects, the inner tube is frequently subjected to punctures, generally causing a spontaneous detachment of the tire from its rim and thus a loss of control in the steering of the vehicle.

Bursting of the inner tube results either from holes made by objects passing through both the tire and the inner tube or from a mechanism referred to as impact 15 pinching of the inner tube. In the latter case, under the i effect of a dynamic overload, for instance upon passing over an obstacle, the meridian section of the tire and that of the inner tube are violently and strongly crushed and pinched between, on the one hand, the ground or the obstacle and, on the other hand, the flanges of the rim. As a result of this pinching, the inner tube, which is subjected locally to substantial stresses, may tear, which then leads to instantaneous deflation of said tube and sudden flattening.

SUMMARY OF THE INVENTION The object of the present invention is to provide a solution which makes it possible to eliminate the risk of sudden flattening and which can be applied to a tire for two-wheel vehicles without making any change in the tire or wheel which are customarily used, said tire and the wheel on which it is mounted being of customary design. Another object of the present invextion is to permit travel without the tire coming off from the rim even in the event of the bursting by puncture of said tire, .".The object of the present invention is to propose S. 20 a process for transforming an assembly formed of a tire, an ee independent inner tube and a spoked wheel for a two-wheel vehicle, said wheel comprising a rim with two flanges and at least one hole for the passage of a valve, into an assembly Sin which the inflation air of the tire is in direct contact with the inner wall of said tire, said tire having beads intended to come into contact with the flanges of said rim, comprising the following steps: •o a) the well of the rim is made aiz-tight, except for the hole or holes for the passage of the valve or valves; b) one of the beads of the tire is put in place between the flanges of the rim; c) a deformable, elastic, continuous annular structure is introduced into the tire, said structure being of a smaller volume than the volume defined by the inside of the tire mounted on its rim and the well of the rim, and said structure, once in place, having an inside diameter less than the'outside diameter of the rim flanges, and an axial dimension, seen in radial section in stressfree condition, which is greater than the axial distance between the beads of the tire mounted on the rim; d) the second bead is placed on the rim in such a manner that the annular structure is located axially between the two beads of the tire and can thus move said beads of the tire axially apart so as to apply them against the flanges of the rim; e) the tire is then inflated to the desired pressure, using an inflation means provided for this purpose.

Stress-free condition, as used herein, is the condition of the annular structure when it is off the tire.

A structure is said to be elastic and deformable when it can deform under the action of a force and is capable of :V resuming its initial shape after the elimination of said force.

.Preferably, in order to facilitate the mounting of the tire, the continuous annular structure is an inflatable structure having inflation means, said structure occupying, in inflated condition, a volume less than the volume defined by the inside of the tire and the well of the rim, and said inflated structure having an inside diameter less than the outside diameter of the flanges of the rim and an axial dimension of radial section, in inflated condition free of any stress, which is greater than the axial distance between the beads of the tire mounted on the rim. This inflatable annular structure is put in place non-inflated in step c) of the process described above, said process being then continued by the following steps; the second bead is placed on the rim in such a manner that the inflatable annular structure is located axially between the two beads of the tire; the annular structure is inflated to a pressure sufficient to move the beads of the tire axially apart so as to place them in contact with the flanges of the rim; finally, the tire is inflated to the desired pressure.

As soon as the inflation of the tire has been a o effected, the inflation of the inflatable annular structure can be resumed up to a pressure close to or even greater than the inflation pressure of said tire in order to press the beads of said tire with greater force against the 0 .flanges of the rim; thus, even in case of a decrease of pressure or.loss of inflation pressure in the tire, it is possible to eliminate the risk of the tire separating from the rim during travel.

-4- Another object of the present invention is to provide a kit for transforming an assembly formed of a tire intended to be mounted normally with an independent inner tube on a spoked wheel, said wheel having a rim with two flanges for two-wheel vehicles into an assembly comprising the same tire and the same rim, in which the inflation pressure of the tire is in direct contact with the inner wall of said tire, said tire having beads intended to come into contact with the flanges of said rim, the transformation kit comprising an elastic, deformable, annular structure, the'inside diameter of which, once in place, is less than the outside diameter of the flanges of the rim and the maximum axial dimension of the radial section of which, in stress-free condition, is at least slightly greater than the space available axially within the beads mounted on the rim, and a valve permitting the inflation of the tire.

The annular structure can be made, for instance, of material of elastic foam type of low density so as to permit a decrease in the weight of the tire assembly mounted 9* without inner tube on its wheel, as compared with the same assembly with inner tube. The annular structure is preferably continuous, so as to be able to place the beads of the tire against the flanges of the rim over the entire circumference of said flanges.

Furthermore, there is also proposed a transformation kit .n which the elastic, deformable, annular structure is an inflatable annular structure having means for inflating said structure independently of the inflation of the tire, the inner diameter of said inflated structure is less than the outer diameter of the rim flanges, and the maximum axial dimension of the radial section of said structure, in inflated state, free of any stress, is at least slightly greater than the space available axially within the beads mounted on the rim.

By inflated staze, free of any stress, there is understood a condition of the annular structure off the tire and subjected only to the forces exerted by an internal inflation pressure within said structure.

Said transformation kit may furthermore comprise, for instance, an air-tight ribbon intended to be wound on the well of the rim in circumferential direction, or an airtight, elastic continuous band intended to cover at least the width of the well of the rim in order to produce the tightness of said rim well.

DESCRIPTION OF THE DRAWINGS The figures of the accompanying drawings illustrate, in non-limitative manner, two embodiments of the reduction to practice of the invention and make it possible to understand its principle and advantages.

Fig. 1 is a radial section through a tire, for a two-wheel vehicle, mounted on a rim, which has been transformed in accordance with the invention; Fig. 2 shows a manner of mounting inflation means for the tire and of the annular structure, respectively, corresponding to the embodiment of Fig. Fig. 3 shows a second embodiment of the invention comprisng an elastic internal support; and o. Fig. 4 shows, in perspective view, another embodiment of an inflatable annular structure.

DESCRIPTION OF PREFERRED EMBODIMENTS Fig. 1 shows a tire 1 having two beads 4 resting against the flanges 21 of a mounting rim 2 and against the extensions 22 of said flanges located radially towards the outside and axially towards the inside of said flanges 21.

The rim 2 has a rim well 26 formed of two walls 24 and with holes 23 for the passage and fastening of the spokes as well as a hole for accommodating an inflation valve.

In a first manner of transformation, in accordance with the invention, of the tire 1 mounted on the rim 2, as shown in Fig. 1, holes are drilled through the walls 24 and of the rim well 26 for the insertion of an inflation valve 6 for an inflatable annular structure 3 shown diagrammatically in Fig. 2. Thereupon, the rim well 26 is sealed by placing an air-tight means 5 on said well; this operation can be carried out, for instance, by winding an air-tight ribbon 51 in one or more turns on the radially ".20 outer surface of the rim well 26 so as to produce the sealing of said rim well 26, in particular at the places of a the fastening holes 23 for the spokes of said rim. This ribbon is preferably reinforced in longitudinal direction by textile cords 52 in the present example so as to limit the deformation of said ribbon at the places of the fastening holes for the spokes and thus assure greater resistance to the tearing for said ribbon.

go* In order better to fit the shape of the rim well 26 and thus produce a better seal, it may be desirable to use an air-tight ribbon which has the characteristic of -j" being covered on the face thereof intended to come into contact with said rim well with a highly deformable material which can also adhere to said well.

In another manner of transformation in accordance with the invention, it is possible to use the single valve hole of the rim, possibly after having enlarged its diameter, in order to pass through it both the inflation means for the tire 1 and the inflation means for the annular structure 3, using for instance,* a single valve having two independent inflation paths, one connected to the tire 1 and the other to the annular structure 3. An example of such a two-path valve is described in U,S. Patent 2,991,821.

At the locations of the inflation valves (or at the location, as the case may be, of a single valve), the ribbon 51 which effects the seal is pierced, and the inflation means 7 of the tire 1 is put in place, as shown in 20 Fig. 2. The holding in place and the sealing of the inflation means 7 and 6 of the tire 1 and of the annular structure 3 on the rim well 26 are assured in a known manner by the compressing elastic seals 71 and 61 around the bases of the valves.

5 After having mounted the first bead of the tire 1 on the rim 2, the annular structure 3 is put in place, possibly utilizing its deformation elasticity, between the flanges 21 of the rim 2 and in such a manner as to have the inflation means 6 of said structure 3 pass through the hole provide for this purpose in the rim well 26. Finally, provided for this purpose in the rim well 26. Finally, the i. ii second bead, in its turn, is put in place on the rim 2 in a known manner.

In the example described, the annular structure 3, which is positioned axially between the beads 4 of the tire 1, is made of an air-tight, elastic elastomeric material. The structure 3 is such that, in inflated condition, its inside diameter Dj is less than the outside diameter D, 1 of flanges 21 and such that the maximum axial dimension L, of its radial section in inflated condition, free of any stress, that is off the tire 1, is greater than the space L 4 available within the beads mounted on the rim and, in the present case, substantially equal to the axial distance L, 2 between the extensions 22 of the flanges 21.

The annular structure 3 is then inflated up to a pressure sufficient to move the-beads 4 of the tire 1 apart and bring them in contact at least with the extensions 22 of the flanges 21. It is then possible to inflate the tire 1 to the desired pressure in view of the fact that the seal is produced at the place of the rim well 26 by the air- 20 tight ribbon 51, and that the beads 4 of the tire are flattened against the extensions 22 of the flanges 21 of the rim 2. The pressure which acts in the annular structure 3, which is sufficient to produce the seal at the place of the rim flanges, is slight, however, and cannot prevent the 25 passage of the inflation air .of the tire 1 between the wall of said annular structure 3 and the inner wall of the tire 1 at the places where they are in contact. In the event that the outer wall of the annular structure 3 and the inner wall of the tire 1 are too smooth and thus create a seal at the place of their contact, making the inflation of the tire 1

I

difficult, it is then necessary to produce a few fine c ':oves on said walls by means, for instance, of a rasp, in order to facilitate the passage of the inflation air between the annular structure 3 and said tire 1.

In order to control the increase in the outside diameter D 5 of the inflatable annular structure 3 during its inflation and permit said structure to remain in place between the beads 4 of the tire 1, said structure may comprise means limiting the variation of said diameter D 5 These means may be formed of reinforcing textile cords 34 arranged in the circumferential direction and in the part of the section of the structure located furthest radially to the outside, as shown in Fig. 4.

In case of the winding of a ribbon 51 on the rim well 26, and in order to increase the air-tightness of the rim well, in particular, with the passage of time, it may be desirable that the annular structure 3 be dimensioned in such a manner that, once inflated, it exerts pressure forces on the different turns of the ribbon, as shown in Fig. 3.

20 By exerting pressure forces on the ribbon 51 which coverm the rim well, the annular structure 3 presses said ribbon 51 .e 9* against the rim well 26 and prevents it from moving away radially. One manner of obtaining this effect is to employ an inflatable annular structure 3 formed of at least two 25 superposed layers 31 and 32, each layer being formed of an .4« elastomeric material reinforced by textile reinforcements 33 arranged along an angle of between 25° and 500, measured in uninflated condition and with respect to the circumferential direction, the reinforcement of each layer being crossed :*30 with respect to the reinforcements of the adjacent layer or 99 I L -~II layers. The angles are measured in ac- -dance with the customary conventions used in the fiel. of tires. When this annular structure 3 is inflated, its inside diameter D) 4decreases, which makes possible, without additional external means, a correct positioning of said structure between the beads of the tire in order to produce the contact of said beads with the rim flanges 21. Another advantage related to said annular structure is the ability to exert pressure forces on the ribbon 51 arranged on the rim well in such a manner as to hold it in place.

Examples of such inflatable annular structures are found among so-called tubular tires.

If, in this configuration of the inflatable annular structure 3 resting on the means 5 covering the rim well 26, the outside diameter Ds'of said structure is made greater than the diameter D~ 1 of the flanges 21, then said structure 3 can also serve as internal support for the tire 1 in case of a loss of the inflation pressure of said tire 1.

Finally, if it is desired further to reduce the S risk of perforation by shock-pinching of the tire 1 itself, one can employ an inflatable annular structure 3, such as shown in Fig. 3, which is characterized by the fact that on the radially outer part of the outer wall of said structure there is arranged at least one element 8 of elastic, deformable material occupying in meridian section a large part of the space left free between said inflated annular structure 3 and the tire 1 in order to limit the flattening amplitude of said tire 1 when it is subjected to violent "30 shocks. Furthermore, in case of the bursting of the tire 1, -11- 1' m said arrangement makes it possible to assure satisfactory conditions of travel in deflated condition, it being understood that the annular structure 3 remains inflated and holds the beads 4 of said tire 1 in place against the flanges 21. In the example shown in Fig. 3, a continuous ring 8 of elastic foam of quasi-rectangular cross section is fastened by bonding radially on the outside of the annular structure 3, in such a manner that, once in place in the tire 1, said ring 8 is, for instance, in contact by its two radially inner -edges 8' and with the inner surface of the tire 1.

Fig. 4 shows a variant of the inflatable annular structure 3 made of elastomeric material and reinforced on the radially outer half of its radial section by textile reinforcement cords 34 oriented ,circumferentially, so as to limit the variation in the outside diameter of said structure during the inflation. Furthermore, this annular struccure 3 comprises, bonded on its outer surface, pads of elastic foam 81 forming sections of a ring, intended to serve as elastic support in case of travel of the tire underinflated or completely without inflation pressure.

.40 9* The transformation process described in the present specification makes it possible easily to obtain a mounted assembly which is intended for a two-v ,eel vehicle, 9* 2 *25 comprising a rim with sp.,es and a tire customarily provided 99 with an inner tube not requiring an inner tube in order to inflate said tire and thus imparting to said assembly better efficiency and better endurance with respect to travel over rough terrain by decreasing the risk of puncture by shock-

S'.

3 0 pinchi, without thereby increasing the weight of said *0:30 pinchidn, without thereby increasing the weight of said a 0 9icig -12assembly as compared with the customary mounting with inner tube.

One of the fields of application of the invention also concerns its use, in athletic competitions, on socalled all-terrain bikes for which the ease in mounting and the effectiveness during the race are particularly important factors.

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Claims

1. A process for transforming an assembly formed of a tire intended to be inflated by independent inner tube and a non air-tight spoked wheel for equipping a two-wheel vehicle, said wheel comprising a rim having a well between two flanges and at least one hole for a valve, in an assembly in which the inflation air of the tire is in direct contact with the inner wall of said tire, such tire having beads intended to come in contact with flanges of said rim, comprising the following steps: a) the well of the rim is made air-tight, except for the hole or holes for the valve or valves, by applying a sealing material around the well; b) one of the beads of the tire without an inner tube is put in place between the flanges of the rim; S• c) a deformable, elastic continuous annular structure is introduced :..into the tire, said structure having a volume less than the volume defined by the inside of the tire mounted on its rim and by the well of the rim, and said structure, S. once in place, having an inside diameter less than the outside diameter of the rim flanges and an axial dimension, seen in radial section in stress-free condition, greater than the axial distance between the beads of the tire mounted on the rim; d) the second bead is placed on the rim in such a manner that the annular structure is located axially between the two beads of the tire and can thus move said beads of the tire axially apart so as to apply them against the flanges of the rim and ensure air-tight contact of the beads of the tire with the flanges of the rim; e) the tire is then inflated to the desired pressure, using an inflation means provided for this purpose.

2. A process according to Claim 1, characterized by the fact that the continuous annular structure is an inflatable annular structure comprising an inflation means, said structure being inflated, after putting the second bead of the tire in place, to a pressure sufficient to move said beads axially apart and apply them against the flanges of the rim, before proceeding with the inflation of the tire to the desired pressure.

3. A process according to Claim 2, characterized by the fact that, after having inflated the tire to the desired pressure, the inflatable annular structure is again inflated to a pressure greater than the inflation pressure of the tire.

4. A kit for the transformation of an assembly formed of a tire intended to be mounted with and inflated by an independent inner tube on a non air-tight spoked wheel for two-wheel vehicles, said wheel having a rim with a well between two flanges, into an assembly in which the inflation air of the tire is in directed contact with the inner wall of said tire, said tire comprising beads intended to come into contact with flanges of said kit, comprising a deformable, elastic annular structure the inside diameter D3 of which structure, once in place, is less than the outside diameter D21 of the flanges of the rim, and the axial dimension L3 of the radial section of which structure is, in stress-free condition, at least slightly greater than the axial space L4 available between the beads mounted on the rim to ensure air-tight contact of the beads of the tire with jthe flanges of the rim, a valve permitting the inflation of the tire and a sealing material to be applied around the well to make the well air-tight.

5. A transformation kit according to Claim 4, characterized by the fact that the annular structure is an inflatable structure comprising means permitting the inflation of said structure independently of the inflation of the tire, said inflated structure having an inside diameter less than the outside diameter of the flanges of the rim, and an axial dimension of its radial section, in inflated, stress-free condition, at least slightly greater than the axial space between the beads mounted on the rim.

6. A transformation kit according to Claim 5, characterized by the fact that the sealing material used to make the well of the rim air-tight is formed by an air- tight ribbon adapted to be wound on said rim well. 16

7. A transformation kit according to Claim 6, characterized by the fact that the air-tight ribbon is reinforced by textile cords in the longitudinal direction of said ribbon.

8. A transformation kit according to Claim 7, characterized by the fact that the air-tight ribbon is covered, on the face thereof intended to come into contact with the rim well, with a highly deformable material which can adhere to said well.

9. A transformation kit according to Claim 5, characterized by the fact that S the annular structure comprises means for limiting the variation of the outside S diameter of said structure under the effect of an inflation pressure.

10. A transformation kit according to Claim 9, characterized by the fact that the means for limiting the variation of the outside diameter of the annular structure are formed of reinforcement cords arranged in the circumferential direction and in the part of the section of the structure located furthest radially to the outside. S

11. A transformation kit according to Claim 6, characterized by the fact that the annular structure is dimensioned so that, once put in place and inflated, it exerts a force on the ribbon to press it against said rim well.

12. A transformation kit according to Claim 11, characterized by the fact that the annular structure is formed of at least two superposed layers, each layer being composed of an elastomeric material reinforced by textile reinforcements arranged along an angle of between 250 and 500, measured with respect to the circumferential direction in non-inflated condition, the reinforcements of each layer being crossed with respect to the reinforcements of the adjacent layer or layers.

13. A transformation kit according to Claim 5, characterized by the fact that the annular structure, once in place and inflated, has an outside diameter greater than the outside diameter of the flanges of the rim.

14. A transformation kit according to Claim 5, characterized by the fact that on the radially outer part of the outer wall of the inflatable annular structure there is arranged at least one element of elastic deformable material occupying in meridian section a large part of the space between said inflatable annular structure and the tire so as to limit the amount of flattening amplitude of said tire when it is deflated and subjected to a load.

A transformation kit according to Claim 5 for an assembly in which the rim cello toi .has a well between the flanges and in which the kit comprises furthermore an air-tight elastic continuous band intended to cover at least the width of the well :i rim.

16. A transformation kit according to Claim 5, characterized by the fact that the inflation means of the inflatable annular structure and the valve of the tire S. use the same valve hole in the rim.

17. A transformation kit according to Claim 16, characterized by the fact that the inflation means are formed of a single valve having two independent paths for the inflation, on the one hand, of thetire and, on the other hand, of the annular structure, said valve being provided with means necessary to produce the seal with the rim well. DATED this 4th day of February, 1998. COMPAGNIE GENERALE DES ETABLISSEMENTS MICHELIN MICHELIN CIE WATERMARK PATENT TRADEMARK ATTORNEYS 290 BURWOOD ROAD HAWTHORN VICTORIA 3122 AUSTRALIA DOC

18 AU2726895.WPC SKP/SJM/ML P ABSTRACT OP THE DISCLOSURE The invention relates to a process which makes it possible to transform a tire for a two-wheel vehicle, which is customarily mounted with inner tube on an air-tight rim, into a tire assembly in which the inflation pressure acts directly on the inner wall of said tire. It also concerns the kit comprising the different elements necessary for effecting said transformation. 0 00 0. o o 0 00 0 e0 0 6870