US-12623489-B2 - Tire band with filaments having a non-circular cross section

Abstract

A non-pneumatic tire includes a lower ring having a first diameter and an upper ring having a second diameter greater than the first diameter. The upper ring is substantially coaxial with the lower ring. Support structure connects the lower ring to the upper ring. A circumferential tread is attached to the upper ring. The circumferential tread includes a tread layer and a tread band. The tread band includes a filament assembly that includes a plurality of individual filaments having a non-circular cross section. The filaments are configured and arranged such that the filaments have a packing density of at least 92% within the filament assembly.

Inventors

• Benjamin E. Rimai

Assignees

• BRIDGESTONE AMERICAS TIRE OPERATIONS, LLC

Dates

Publication Date

20260512

Application Date

20211209

Claims (19)

1. 1 . A non-pneumatic tire comprising: a lower ring having a first diameter; an upper ring having a second diameter greater than the first diameter, the upper ring being substantially coaxial with the lower ring; support structure connecting the lower ring to the upper ring; and a circumferential tread attached to the upper ring, the circumferential tread including a tread layer and a tread band, the tread band including a single filament assembly that includes a plurality of individual filaments having a non-circular cross section, the filaments being configured and arranged such that the filaments have a packing density of at least 92% within the single filament assembly, the packing density being a ratio of the volume occupied by the filaments to the total volume of the single filament assembly, the single filament assembly making up the entire tread band.
2. 2 . The non-pneumatic tire of claim 1 , wherein each of the plurality of filaments has a square cross section.
3. 3 . The non-pneumatic tire of claim 1 , wherein each of the plurality of filaments has a hexagonal cross section.
4. 4 . The non-pneumatic tire of claim 1 , wherein each of the plurality of filaments has a central longitudinal axis, the central longitudinal axes of the filaments being aligned relative to adjacent filaments in one of a circumferential direction and a radial direction of the non-pneumatic tire and offset relative to adjacent filaments in one other of the circumferential direction and the radial direction of the non-pneumatic tire.
5. 5 . The non-pneumatic tire of claim 1 , wherein each of the plurality of filaments has a central longitudinal axis, the central longitudinal axes of the filaments being aligned relative to adjacent filaments in both a circumferential direction and a radial direction of the non-pneumatic tire.
6. 6 . The non-pneumatic tire of claim 1 , wherein corners of the individual filaments are rounded.
7. 7 . The non-pneumatic tire of claim 1 , wherein the individual filaments are secured together using at least one of rubber, adhesive, epoxy, and mechanical fasteners.
8. 8 . The non-pneumatic tire of claim 1 , wherein each of the individual filaments is formed from a cord that initially has a substantially circular cross section and is processed to give the filament the non-circular cross section.
9. 9 . A method of manufacturing a non-pneumatic tire comprising the steps of: providing a lower ring having a first diameter and an upper ring having a second diameter that is greater than the first diameter; connecting the lower ring to the upper ring with support structure; forming a plurality of individual filaments having a non-circular cross section; assembling the plurality of individual filaments into a single filament assembly that makes up the entire tread band, the single filament assembly having a packing density of at least 92%, the packing density being a ratio of the volume occupied by the filaments to the total volume of the single filament assembly; applying a tread layer to the tread band to form a circumferential tread; and attaching the circumferential tread to the upper ring.
10. 10 . The method of manufacturing a non-pneumatic tire of claim 9 , further comprising the step of forming the individual filaments by processing a cord that initially has a substantially circular cross section to impart a non-circular cross section on the filament.
11. 11 . The method of manufacturing a non-pneumatic tire of claim 10 , wherein the imparting of a non-circular cross section on the filament includes imparting a square cross section on the filament.
12. 12 . The method of manufacturing a non-pneumatic tire of claim 10 , wherein the imparting of a non-circular cross section on the filament includes imparting a hexagonal cross section on the filament.
13. 13 . The method of manufacturing a non-pneumatic tire of claim 9 , wherein each of the plurality of filaments has a central longitudinal axis, and wherein the method further comprises the step of aligning the central longitudinal axes of adjacent filaments in one of a circumferential direction and a radial direction of the non-pneumatic tire and offsetting the central longitudinal axes of adjacent filaments in one other of the circumferential direction and the radial direction of the non-pneumatic tire.
14. 14 . The method of manufacturing a non-pneumatic tire of claim 9 , wherein each of the plurality of filaments has a central longitudinal axis, and wherein the method further comprises the step of aligning the central longitudinal axes of adjacent filaments in both a circumferential direction and a radial direction of the non-pneumatic tire.
15. 15 . The method of manufacturing a non-pneumatic tire of claim 9 , further comprising the step of rounding corners of the individual filaments.
16. 16 . A non-pneumatic tire comprising: a lower ring having a first diameter; an upper ring having a second diameter greater than the first diameter, the upper ring being substantially coaxial with the lower ring; support structure connecting the lower ring to the upper ring; and a circumferential tread attached to the upper ring, the circumferential tread including a tread layer, at least one inextensible layer, and at least one extensible layer, the at least one inextensible layer and the at least one extensible layer being disposed between the tread layer and the upper ring along a radial direction of the non-pneumatic tire, the at least one inextensible layer including a single filament assembly that includes a plurality of individual filaments having a non-circular cross section, a circle circumscribing each of the filaments having a diameter of 0.1-25 mm, each of the filaments having a coating with a thickness of 0-10 mm; wherein the filaments are configured and arranged such that the filaments have a packing density of at least 92% within the single filament assembly, the packing density being a ratio of the volume occupied by the filaments to the total volume of the single filament assembly, the single filament assembly making up the entire tread band.
17. 17 . The non-pneumatic tire of claim 16 , wherein each of the plurality of filaments has one of a square cross section and a hexagonal cross section.
18. 18 . The non-pneumatic tire of claim 16 , wherein each of the plurality of filaments has a central longitudinal axis, the central longitudinal axes of the filaments being aligned relative to adjacent filaments in one of a circumferential direction and a radial direction of the non-pneumatic tire and offset relative to adjacent filaments in one other of the circumferential direction and the radial direction of the non-pneumatic tire.
19. 19 . The non-pneumatic tire of claim 16 , wherein each of the plurality of filaments has a central longitudinal axis, the central longitudinal axes of the filaments being aligned relative to adjacent filaments in both a circumferential direction and a radial direction of the non-pneumatic tire.

Description

FIELD OF INVENTION The present disclosure relates to tire bands that include filaments. More particularly, the present disclosure relates to a tire band with filaments having a non-circular cross section. BACKGROUND Various tire constructions have been developed that enable a tire to run in an uninflated or underinflated condition. Non-pneumatic tires do not require inflation, while “run flat tires” may continue to operate after being punctured and becoming partially or completely depressurized, for extended periods of time and at relatively high speeds. Non-pneumatic tires may include support structure, such as spokes or webbing, that connects a lower ring to an upper ring. In some non-pneumatic tires, a circumferential tread may be attached to the upper ring of the tire. The circumferential tread may contain a tread band. The tread band may be a single layer of material or a multi-layer band. Such tread bands may also be referred to as a shear band, a shear element, or a thin annular high strength band element. When used in a non-pneumatic tire, or in a pneumatic tire in a partially pressurized or unpressurized state, the shear element acts as a structural compression member. When used in a fully pressurized pneumatic tire, the shear element acts as a tension member. SUMMARY OF THE INVENTION In one embodiment, a non-pneumatic tire includes a lower ring having a first diameter and an upper ring having a second diameter greater than the first diameter. The upper ring is substantially coaxial with the lower ring. Support structure connects the lower ring to the upper ring. A circumferential tread is attached to the upper ring. The circumferential tread includes a tread layer and a tread band. The tread band includes a filament assembly that includes a plurality of individual filaments having a non-circular cross section. The filaments are configured and arranged such that the filaments have a packing density of at least 92% within the filament assembly. In another embodiment a method of manufacturing a non-pneumatic tire includes providing a lower ring having a first diameter and an upper ring having a second diameter that is greater than the first diameter. The method further includes connecting the lower ring to the upper ring with support structure. The method further includes forming a plurality of individual filaments having a non-circular cross section, and assembling the plurality of individual filaments into a tread band. Furthermore, the method includes applying a tread layer to the tread band to form a circumferential tread, and attaching the circumferential tread to the upper ring. In yet another embodiment, a non-pneumatic tire includes a lower ring having a first diameter and an upper ring having a second diameter greater than the first diameter. The upper ring is substantially coaxial with the lower ring. Support structure connects the lower ring to the upper ring. A circumferential tread is attached to the upper ring. The circumferential tread includes a tread layer, at least one inextensible layer, and at least one extensible layer. The at least one inextensible layer and the at least one extensible layer are disposed between the tread layer and the upper ring along a radial direction of the non-pneumatic tire. The inextensible layer includes a filament assembly that includes a plurality of individual filaments having a non-circular cross section. A circle circumscribing each of the filaments has a diameter of 0.1-25 mm. Each of the filaments have a coating with a thickness of 0-10 mm. BRIEF DESCRIPTION OF DRAWINGS In the accompanying drawings, structures are illustrated that, together with the detailed description provided below, describe exemplary embodiments of the claimed invention. Like elements are identified with the same reference numerals. It should be understood that elements shown as a single component may be replaced with multiple components, and elements shown as multiple components may be replaced with a single component. The drawings are not to scale and the proportion of certain elements may be exaggerated for the purpose of illustration. FIG. 1 is a side view of one embodiment of an undeformed non-pneumatic tire; FIG. 2 is a side view of the non-pneumatic tire of FIG. 1 being deformed when subjected to a load; FIG. 3 is a schematic drawing illustrating a partial cross-section along line 3-3 of the non-pneumatic tire shown in FIG. 1; FIG. 4 is a close up of part of the non-pneumatic tire as shown in FIG. 3 according to one embodiment of a filament assembly; FIG. 5 is a close up of part of the non-pneumatic tire as shown in FIG. 3 according to another embodiment of a filament assembly; and FIG. 6 is a schematic drawing illustrating a partial cross-section of another embodiment of a non-pneumatic tire; DETAILED DESCRIPTION The following includes definitions of selected terms employed herein. The definitions include various examples or forms of components that fall within the sco