NON-PNEUMATIC TIRE

Abstract

The present invention is directed to a non-pneumatic tire comprising a hub portion, a ring member essentially concentrically arranged about the hub portion, a plurality of tread portions radially extending out of a radially outer surface of the ring member, and a plurality of spokes extending from a radially outer surface of the hub portion to a radially inner surface of the ring member for supporting the ring member on the hub portion. Moreover, the tire comprises a plurality of channels fluidly connecting the hub portion with radially inner sides of the tread portions. In addition, the present invention is directed to a kit comprising such a tire and a capsule receivable in the tire.

Claims

1. A non-pneumatic tire comprising: a hub portion; a ring member essentially concentrically arranged about the hub portion; a plurality of tread portions radially extending out of a radially outer surface of the ring member; a plurality of spokes extending from a radially outer surface of the hub portion to a radially inner surface of the ring member for supporting the ring member on the hub portion; and a plurality of channels fluidly connecting the hub portion with radially inner sides of the tread portions.

2. The non-pneumatic tire of claim 1 wherein the hub portion comprises a reservoir for receiving a liquid, the reservoir being in fluid communication with the plurality of channels.

3. The non-pneumatic tire of claim 1 wherein the spokes have rod-like shapes.

4. The non-pneumatic tire of claim 1 wherein at least some of the channels extend between the spokes from the hub portion to the radially inner sides of the tread portions.

5. The non-pneumatic tire of claim 1 wherein one or more of the spokes are hollow and form portions of the channels.

6. The non-pneumatic tire of claim 1 wherein the channels comprise a plurality of flexible tubes extending from the hub portion to the ring member.

7. The non-pneumatic tire of claim 1 wherein the spokes are made of one or more of carbon fiber composite materials, polymeric materials or metals.

8. The non-pneumatic tire of claim 2 wherein the tire further comprises at least one check valve adapted to avoid flow back of liquid from the channels back into the reservoir.

9. The non-pneumatic tire of claim 2 wherein the reservoir comprises or is an exchangeable capsule.

10. The non-pneumatic tire of claim 9 wherein the capsule comprises at least one opening which is adapted to be closable to fluid communication with the channels when inserted in the hub portion.

11. The non-pneumatic tire of claim 1 wherein the tire comprises pressuring means for pumping liquid out of the reservoir and through the channels.

12. The non-pneumatic tire of claim 1 wherein the ring member comprises a plurality of recesses extending from a radially outer surface of the ring member through the ring member, wherein each recess is covered, at its radially outer portion, by at least one of the tread portions, and wherein each of the recesses is, at a radially inner portion, in fluid communication with at least one of the channels.

13. The non-pneumatic tire of claim 12 wherein the recesses at least partially taper from the radially outer surface of the ring member in a radially inner direction.

14. The non-pneumatic tire of claim 12 wherein sidewalls of the recesses have, at a radially outer portion of the recesses, a rough surface.

15. The non-pneumatic tire of claim 12 wherein one or more of the recesses comprise a grid transversely extending across a radially outer side of the recesses and supporting the tread portions covering the recesses.

16. The non-pneumatic tire of claim 1 wherein the ring member comprises a reinforced polymer material.

17. The non-pneumatic tire of claim 1 wherein the hub portion is adapted to be mounted to a vehicle wheel hub or a rim.

18. The non-pneumatic tire of claim 1 wherein each tread portion is made of rubber material.

19. The non-pneumatic tire of claim 1 wherein the tread portions form rubber material studs extending out of the radially outer surface of the ring member.

20. A tire kit comprising: A) a non-pneumatic tire comprising: a hub portion comprising an opening for receiving a liquid-filled capsule, a ring member essentially concentrically arranged about the hub portion, a plurality of tread portions radially extending out of a radially outer surface of the ring member, a plurality of spokes extending from a radially outer surface of the hub portion to a radially inner surface of the ring member for supporting the ring member on the hub portion, and a plurality of channels fluidly connecting the capsule with radially inner sides of the tread portions when received in the opening of the hub portion; and B) a liquid-filled capsule receivable in the opening of the hub portion for providing the channels with liquid upon insertion of the capsule into the hub portion.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0064] The structure, operation, and advantages of the invention will become more apparent upon contemplation of the following description taken in conjunction with the accompanying drawings.

[0065] FIG. 1 is a schematic perspective view of a tire kit in accordance with an embodiment of the invention.

[0066] FIG. 2 is a partial perspective view of parts of the hub portion, spokes and the ring element of the tire of FIG. 1, in which the spokes are better visible.

[0067] FIG. 3 is a schematic side view of the hub, spokes, ring member assembly shown in FIG. 2.

[0068] FIG. 4 is a schematic cross section of a portion of the ring member with a recess covered by a tread portion and a liquid line attached to the recess.

DETAILED DESCRIPTION OF THE INVENTION

[0069] The subject invention specifically discloses a non-pneumatic tire comprising: a hub portion; a ring member essentially concentrically arranged about the hub portion; a plurality of tread portions radially extending out of a radially outer surface of the ring member; a plurality of spokes extending from a radially outer surface of the hub portion to a radially inner surface of the ring member for supporting the ring member on the hub portion; and a plurality of channels fluidly connecting the hub portion with radially inner sides of the tread portions. In one embodiment of this invention the hub portion comprises a reservoir for receiving a liquid, the reservoir being in fluid communication with the plurality of channels. In another embodiment of the subject invention the spokes have rod-like shapes.

[0070] The present invention also reveals a tire kit comprising: (A) a non-pneumatic tire comprising a hub portion comprising an opening for receiving a liquid-filled capsule, a ring member essentially concentrically arranged about the hub portion, a plurality of tread portions radially extending out of a radially outer surface of the ring member, a plurality of spokes extending from a radially outer surface of the hub portion to a radially inner surface of the ring member for supporting the ring member on the hub portion, and a plurality of channels fluidly connecting the capsule with radially inner sides of the tread portions when received in the opening of the hub portion; and (B) a liquid-filled capsule receivable in the opening of the hub portion for providing the channels with liquid upon insertion of the capsule into the hub portion.

[0071] FIG. 1 shows a tire kit 10 comprising a non-pneumatic tire 1 and a refilling capsule 8, in accordance with a first embodiment of the invention. The tire 1 comprises a hub portion 2, a ring member 3, a plurality of spokes 4 supporting the ring member 3 on the central hub portion 2. Furthermore, the tire 1 comprises tread portions 5 extending radially out of the ring portion 3. The hub portion 2 is in fluid communication with a radially lower side of the tread portions 5 via liquid lines 6. The hub portion 2 comprises a (closable) opening 7 which is adapted to receive a capsule 8 which is insertable into the opening 7.

[0072] Said capsule 8 comprises a liquid polymer composition which is supplied to the liquid lines 6 or tubes upon insertion of the capsule 8 into the opening 7 of the hub portion 2. In particular, the opening 7 may be capable of being closed, such as by an iris shutter or door. While the liquid lines 6 have been schematically shown in FIG. 1 only in an axially outer plane perpendicular to the axis of rotation of the tire 1, such liquid lines 6 are preferably also provided at an axially central position of the tire 1, i.e. in one or more planes essentially perpendicular to the axis of rotation of the tire 1 between the axially outer edges of the tire 1, such as adjacent or essentially in the equatorial plane of the tire 1. Moreover, the liquid lines 6 extend in the depicted embodiment in a spiral manner. In an alternative embodiment, such liquid lines 6 could also extend essentially in a radial direction or in other shapes. The terms composition and compound are used interchangeably herein. In a preferred embodiment, the capsule 8, i.e. the liquid polymer composition therein is under high pressure forcing the liquid rubber composition out of the capsule 8 as soon as it is received in the opening 7 of the hub portion 2. In particular, the capsule 8 may have one or more closable apertures 9 which are brought into liquid communication with the liquid lines 6 upon insertion of the capsule into the opening 7. Preferably, one or more check valves (not shown) avoid that liquid rubber composition material may flow back into the capsule 8 once the capsule 8 is removed again from the tire 1. Alternatively, or in addition, the tire 1 may comprise pressuring means (not shown), e.g. a pump, such as an electrical, peristaltic or hydraulic pump which forces liquid out of the capsule 8 and into the liquid lines 6. The liquid lines 6 supply liquid rubber composition to the ring member 3. As is illustrated in FIG. 4 the liquid polymer is pushed into recesses 11 in the ring member 3.

[0073] The spokes 4 of the tire may have elongated shapes, in particular rod-like shapes and may be made of carbon fiber-based material.

[0074] FIG. 2 shows a schematic perspective view of an outer shell of the tire hub portion 2, the spokes 4 and the ring member 3. In particular, the tire hub portion 2 has in this present and non-limiting embodiment an essentially cylindrical shape. The inner diameter of the ring member 3, measured in the radial direction, is preferably within a range of two to four times the radially outer diameter of the hub portion 2.

[0075] As shown in FIGS. 2 and 3, the spokes 4, which are preferably made of carbon fiber-based material, are arranged in 12 pairs of groups about the circumference of the tire 1. The spokes 4 extend from the radially outer surface of the hub portion 2 to the radially inner surface of the ring member 3. Each pair of groups consists of a first group of spokes 4 extending from a line adjacent and along a first axially outer edge of the ring member 3 towards the hub portion 2, wherein the spokes 4 cross beside each other adjacent a crossing point 12 between the hub portion 2 and the ring member 3 and further extend towards and onto the hub or hub portion 2. As shown in FIG. 2, the spokes 4 connect to the hub portion 2 at axial positions which are closer to the axial center of the hub portion 2 than the axial positions at which the spokes 4 of the first group are attached to the ring member 3. The second group of spokes 4 of the same pair (each group of the pair being essentially arranged at the same circumferential position or angle) extends from a line adjacent and along a second axially outer edge of the ring member 3 (axially opposite to said first edge) towards the hub portion 2. The spokes 4 of the second group cross beside each other adjacent a common crossing point between the hub portion 2 and the ring member 3 and further extend towards and onto the hub portion 2. Again, the spokes 4 connect to the hub at axial positions which are closer to the axial center of the hub portion 2 than the axial position at which the spokes 4 of the second group are attached to the ring member 3. Such an arrangement may improve the stiffness of the tire 1 with regard to lateral forces.

[0076] Moreover, as shown in FIG. 3, the spokes 4 of a group (sharing a common crossing point 12) are preferably attached to the hub portion 2 along a non-straight line extending in the axial and circumferential directions. Such an arrangement further improves stability with regard to lateral forces. Preferably, the crossing points 12 of all pairs have a radial distance to the radially outer surface of the hub portion 2 which is less than 50%, more preferably within the range of 25% to 45%, of the radial distance between the radially outer side of the hub portion 2 and the radially inner side of the ring member 3.

[0077] The suggested construction leaves a space axially between both groups of a pair of groups of spokes 4. By such a construction it is possible to provide liquid lines 6 for liquid rubber material from the hub portion 2 to the ring member 3 axially between the groups of spokes 4. Thus, the spokes 4 protect the liquid lines 6 against mechanical damages. The ring member 3 comprises also openings or in other words recesses for allowing the liquid lines 6 to be fluidly connected to the recesses in the ring member 3, thereby providing the tread portions 5 with liquid polymer composition from below.

[0078] FIG. 4 shows a schematic cross section of a recess 11 provided in the ring member 3 for allowing the liquid rubber composition to be provided to the radially lower surface of a tread portion 5. The recess 11 has a first portion with a cross-section tapering in the inner radial direction. The surface of the tapering portion may be roughened so as to provide a better connection between the cured rubber composition and the walls of the recess 11. The liquid rubber composition is pressed through the liquid line 6 and from a radially inner position of the recess 11 towards a radially outer portion of the recess 11. By reaction with oxygen (typically oxygen present in ambient air), the rubber composition cross-links and forms a cured tread portion layer. It is remarked that oxygen will also diffuse through the crosslinked rubber layer so that constantly new rubber is cured keeping an essentially constant thickness of the tread portion 5.

[0079] In order to further support the cured tread portions 5 against lateral and radial forces, a supporting grid (e.g. made of thermoplastic or metal material) may be provided in the tapering portion of the recess. Such a grid may essentially extend in a circumferential direction c and an axial direction a. The terms axial, radial or circumferential directions (a, r, c), are used herein as commonly understood in the tire art. In particular, a reference to an axial direction means a direction in parallel to the axis of rotation of the tire. A reference to the circumferential direction is a direction concentric about the axis of rotation of the tire and/or in parallel to an equatorial plane of the tire. The radial direction is perpendicular to the axis of rotation of the tire.

[0080] During manufacturing of a tire 1, it is possible to cover the recesses 11 by a semipermeable foil or membrane (not shown) allowing the liquid rubber composition material to move through the channels until touching said membrane covering the recesses 11 on the radially outer surface of the ring member 3. Then oxygen can diffuse through the membrane and create a cured tread portion layer below the membrane. After forming of a stable tread portion layer, the semipermeable membrane may be removed and optionally replaced by a non-oxygen-permeable foil for storage. Alternatively, the semipermeable membrane may be covered by a nonpermeable foil for storage. Depending on the compound, also storage without and addition foil may be possible.

[0081] While certain representative embodiments and details have been shown for the purpose of illustrating the subject invention, it will be apparent to those skilled in this art that various changes and modifications can be made therein without departing from the scope of the subject invention.