TECHNOLOGICAL FIELD

The present disclosure concerns tires suitable for use in wheels with relatively narrow profiles, such as wheels of bicycles, motorcycles, wheelchairs, etc.

BACKGROUND ART

References considered to be relevant as background to the presently disclosed subject matter are listed below:

- GB 191009830

- GB 191107930

- DE 2157076

- GB 940062

- WO 2017/085709

Acknowledgement of the above references herein is not to be inferred as meaning that these are in any way relevant to the patentability of the presently disclosed subject matter.

BACKGROUND

Tires are essential interfaces between wheels and the ground. They have a sealed compartment filled with a gas, typically compressed air. Most tires are provided with an inlet valve for introducing pressurized gas and supplementing gas lost through use.

WO 2017/085709 discloses a tire with a sealed compartment. It has a circumferential tire body with a compartment that is defined between a tire base and a circumferential ground-bearing portion. The tire of WO 2017/085709 has also two flanking portions integral with tire body generally parallel one to the other. GENERAL DESCRIPTION

Provided by this disclosure is a tire for fitting around a wheel's rim. The tire of this disclosure is particularly, although not exclusively, useful for wheels with relatively narrow profiles, such as wheels of bicycles, motorcycles, wheelchairs, etc.

The tire has a circumferential tire body with a circumferential sealed compartment that is defined between a circumferential tire base and a circumferential ground-bearing portion. All of the tire's elements are integrally formed (namely formed as a single unit out of elastomeric material, e.g. extruded, cast, molded or otherwise formed elastomeric material). The tire's base has an outer face that is configured for engagement with the rim of the wheel such that said base's outer face is in contact with the rim's outer face. In use, the tire's base is in tight contact {e.g. connected or adhered) with and bears against the wheel's rim. In other words, substantially the entire surface of the base's outer face is in contact with the outer face of the rim when the tire is fitted onto the wheel and during use thereof. In order to provide such tight contact, the base's outer face has a complementary shape to that of the rim's outer face. For example, where the rim is flat, namely is generally tangential, the base will also be flat, and where the rim is concave, the base's outer face will have a complementary convex shape.

One or more circumferential internal walls are formed within the circumferential compartment, each internal wall extending between opposite wall sections of the sealed compartment. In other words, each of the one or more walls extends between sections of walls that are oppositely oriented, for example, between a wall section of the tire base and a wall section of the ground-bearing wall. The one or more internal walls are integral with the base and the ground-bearing portion. Such internal walls divide that tire's sealed compartment into circumferential sub-compartments.

In some configurations, the tire may comprise two or more circumferential internal walls. The two or more internal walls may be substantially parallel to one another. Alternatively, two or more of the walls may be angled with respect to one another, such that two or more of said circumferential internal walls cross one another. In one typical example, two crossing internal walls may be substantially normal to one another. In other configurations, the circumferential internal wall is at least one first circumferential wall, which is generally radially oriented. The first wall extends between the tire base and the circumferential ground-bearing portion, and is integral with the base and the ground-bearing portion. Such a radial circumferential wall divides that tire's sealed compartment into circumferential sub-compartments. By an embodiment of this disclosure, there is one such radial wall within said compartment. Such a single radial wall extends perpendicular to the base, between an apex of the ground-bearing portion and the base of the tire, and divides the sealed compartments into two circumferential, typically mirror symmetric, sub-compartments. By other embodiments, there may be two or more such radial circumferential walls.

In case the internal wall is a radial wall, the wall may deform from its generally radial orientation as a result of the force bearing radially thereon. To avoid or minimize such deformation, provided by embodiments of this disclosure, is at least one second circumferential wall formed within the sealed compartment and being integral with said at least the first radial wall and with said circumferential ground-bearing portion, the second wall being orientated substantially normal to said at least one first wall and parallel to the tire's base.

By one typical (albeit not exclusive) embodiment, there is one such second wall within a compartment, crossing the first radial wall and extending between opposite lateral segments of the ground-bearing portions of the tire. Such second wall can also be viewed as two second walls formed in the same plane, one of each side of said first wall - namely extending each to a lateral segment of the tire (the lateral segments being opposite one another). The at least one second wall divides the compartment into further circumferential sub-compartments.

The one or more internal walls are typically solid or complete (i.e. without perforations) and hence gas-tight; and accordingly divides the compartment into sealed sub-compartments. In other embodiments, at least one of the circumferential walls may comprise perforations to allow gas passage between the sub-compartments during application of mechanical load onto the tire (e.g. during riding).

The tire is made of an elastomeric material, such as vulcanized rubber. The sealed compartment may be filled with a gas (e.g. air), optionally pressurized, or a shock-absorbing material or an elastomeric material softer than the tire material. As the compartment is deforming (due to its filling with gas or a softer material), the circumferential sealed compartment may function as a shock absorber when a rider rides a vehicle (such as a bicycle) over a bumpy surface. When filled with non- compressed air or another elastomeric material, the tire functions as a non-pneumatic, tubeless (and/or airless) tire, thereby circumventing the need to maintain a suitable air- pressure in the tire and/or risking a flat-tire.

The circumferential internal wall(s) provides support for the circumferential ground-bearing portion and undergoes a load-related, typically radially-directed, compression. This compression dampens the impact exerted on the tire during use, resulting in a smoother ride.

The internal walls have typically a thickness between 10% and 75% of the wall thickness of the circumferential ground-bearing portion. In some embodiments, the thickness is between 20% and 50% of that of the circumferential ground-bearing portion.

In other embodiments, the first wall has a thickness between 10% and 75% of the wall thickness of the circumferential ground-bearing portion. In some embodiments, the thickness is between 20% and 50% of that of the circumferential ground-bearing portion. The at least one second circumferential wall may have a thickness similar to that of said first circumferential radial wall, although in order to fulfil its function, it may also have a thickness smaller than that of said first circumferential radial wall.

The tire may comprise two flanking portions integral with the tire body, the two flanking portions being generally parallel to one another. These flanking portions, which may be of the kind disclosed in WO 2017/085709, embrace the peripheral portion of the wheel on which the tire is fitted. These flanking portions may, for example, serve as a braking surface.

Also provided by this disclosure is a wheel comprising a tire of the kind described below.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to better understand the subject matter that is disclosed herein and to exemplify how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

Fig. 1 shows a schematic illustration of a bicycle fitted with a wheel having a tire of this disclosure.

Fig. 2 is a perspective cross-sectional view of a section of the tire of this disclosure fitted on the wheel's rim.

Fig. 3A is a cross-section of the tire section of Fig. 2; and

Fig. 3B shows the tire of Fig. 3A during load support.

Figs. 4A-4C are schematic cross-sectional views of other embodiments of the tire of this disclosure.

Fig. 5 shows a tire according to another embodiment of the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

In the following description, this disclosure will be further illustrated with reference to the annexed drawings including schematic representations of some embodiments of this disclosure. As can be understood, the illustrated embodiments are exemplary embodiments of the broad scope of this disclosure, as defined above.

Fig. 1 shows a schematic illustration of a bicycle 10 having a wheel 100 fitted with a tire 102 of this disclosure. The tire fits tightly around the rim 103 of the wheel 100. The tire can better be seen in Figs. 2 and 3A. The tire 102 is made of an elastomeric material, such as vulcanized rubber, and has a circumferential tire body 104 with a circumferential sealed compartment 106 defined between a circumferential ground-bearing portion 108 and a tire base 110. The base is in contact with and bears against the rim 103 of the tire 102. Namely, tire base 110 has an outer face 111, such that is in contact throughout its surface with an outer face 113 of the rim 103. The tire of this example also has two integral flanking portions 112 that, when fitted on the wheel 100, embrace the peripheral circumferential portion of the wheel.

Formed within the sealed compartment is a first circumferential radial wall 114 that extends between apex 116 of the circumferential ground- bearing portion and the tire base 110, and is thus normal to the tire's base. Formed within the compartment is also a second circumferential wall 118, integral with the first circumferential wall 114, and orientated generally normal to said first wall 114 and parallel to base 110. The second wall 118 comprises sections 118A,118B at each side of said first wall 114, extending in the same plane between the first wall and two opposite lateral segments of said circumferential ground-bearing portion 108A,108B.

When a load is applied, as represented by arrow 200 in Fig. 3B, radial wall 114 is slightly compressed and thickens, and due to its elasticity applies a counter force in the direction of arrow 202 in Fig. 3B. Second wall sections 118A,118B support the first wall in position and avoid its deformation as represented by arrows 204.

Three alternative embodiments of this disclosure are represented in Figs. 4A- 4C. In Fig. 4A there is a single radial wall 214 with no second wall; in Fig. 4B there are two first generally radially orientated first walls; and in Fig.4C there are also two such radial walls 214A, 214B and one second wall 218.

As noted above, in order to properly support the load and provide its impact dampening function, the first wall has preferably a thickness between 10-75% of the thickness of the circumferential ground-bearing portion; typically, a thickness between 20-50% of the thickness of the circumferential ground-bearing portion. Where there is more than one first wall, the thickness of each may be relatively similar as the load is then divided between such radial walls.

Another exemplary tire is shown in Fig. 5. In this configuration, tire 300 is formed with two circumferential internal walls 302 and 304, that are angled one with respect to the other, and hence cross each other. Internal wall 302 extends between section 306A of the circumferential ground-bearing portion 306 and section 308A of the tire base 308; similarly, internal wall 304 extends between section 306B of the circumferential ground-bearing portion 306 and section 308B of the tire base 308. Such crossing internal walls may be useful in order to dampen angular impacts that may be exerted onto the tire during use.

In such a configuration, the thickness of each of the crossing internal walls may be relatively similar as the load is then divided between such walls, e.g. a thickness between 10-75% of the thickness of the circumferential ground-bearing portion; typically, a thickness between 20-50% of the thickness of the circumferential ground- bearing portion.