Tension-based non-pneumatic tire
A non-pneumatic tire for supporting a load by working in tension comprising a generally annular inner surface, a generally annular outer ring, and an interconnected web having a plurality of web elements and comprising a plurality of generally polygonal openings. Web elements are sized, oriented and comprised of a material that facilitates buckling when subjected to a compressive load. By buckling, those elements in a deformed portion of the tire between a hub and a footprint region where the tire contacts a surface may assume a significantly reduced portion of the load, if any. This causes web elements in other portions of the interconnected web to operate in tension to support the load. Since the tire is non-pneumatic, it may be easier to maintain and may have a longer life than standard pneumatic tires since it eliminates the possibility of blowouts, flat tires, or tires operating with low air pressure. By virtue of the portion of the tire in the footprint region not bearing a significant portion of the load, non-pneumatic tire may also exhibit a more comfortable ride subject to less noise and vibration and improved handling capabilities.
1. A non-pneumatic tire for supporting an applied load comprising:
a generally annular inner surface that engages a hub having an axis of rotation,
a generally annular outer ring,
an interconnected web between said generally annular inner surface and said generally annular outer ring comprising at least two radially adjacent layers of elements at every radial cross-section of said tire defining a plurality of generally polygonal openings, the interconnected web including a plurality of tangential web elements that are generally aligned with a tangent to a circle centered about the axis of rotation;
said generally annular outer ring and said interconnected web being deformable when said tire is subjected to said applied load;
wherein a plurality of said web elements are angled relative to a plane containing said axis of rotation to facilitate buckling of said web elements, wherein, when the applied load is applied, web elements in a region above the axis of rotation are subjected to a tensile force while web elements in a region between the applied load and a footprint region are subjected to a smaller portion of the applied load as compared to the remaining portions of the web elements.
2. A non-pneumatic tire according to claim 1 , wherein said plurality of generally polygonal openings comprises a first plurality of generally polygonal openings having a first shape and a second plurality of generally polygonal openings having a second shape different from said first shape.
3. A non-pneumatic tire according to claim 2 , wherein at least one of said first plurality of generally polygonal openings and at least one of said second plurality of generally polygonal openings are traversed when moving in any radially outward direction from said axis of rotation.
4. A non-pneumatic tire according to claim 2 , wherein each of said first plurality of generally polygonal openings has a first inner boundary spaced at a first radial distance and each of said second plurality of generally polygonal openings has a second inner boundary spaced at a second, greater radial distance.
5. A non-pneumatic tire according to claim 4 wherein at least one generally polygonal opening of said first plurality of generally polygonal openings is larger than at least one generally polygonal opening of said second plurality of generally polygonal openings.
6. A non-pneumatic tire according to claim 1 , wherein one web element engages said inner surface at a given location.
7. A non-pneumatic tire according to claim 1 , wherein one web element engages said outer ring at a given location.
8. A non-pneumatic tire according to claim 1 , wherein said interconnected web comprises intersections between said web elements, said intersections joining at least three web elements.
9. A non-pneumatic tire according to claim 1 , wherein said generally annular inner surface has a first thickness, said generally annular outer ring has a second thickness, and said web elements have a third thickness, said third thickness being smaller than said first thickness or said second thickness.
10. A non-pneumatic tire according to claim 1 , wherein each one of said plurality of generally polygonal openings is radially oriented.
11. A non-pneumatic tire according to claim 1 , wherein each one of said plurality of generally polygonal openings has at least three sides.
12. A non-pneumatic tire according to claim 1 , wherein said plurality of generally-polygonal openings are generally hexagonally shaped.
13. A non-pneumatic tire according to claim 1 , further comprising a plurality of joined segments each having a width narrower than a width of said tire.
14. A non-pneumatic tire according to claim 13 , wherein a first joined segment is circumferentially offset from an adjoining segment.
15. A non-pneumatic tire according to claim 13 , wherein a first joined segment has an interconnected web that is substantially similar to an interconnected web of a second joined segment.
16. A non-pneumatic tire according to claim 1 , wherein a relatively radially inner layer of said plurality of generally polygonal openings comprises alternating generally wedge-shaped openings.
17. A non-pneumatic tire according to claim 1 , wherein each one of said plurality of generally polygonal openings is generally symmetrical about a radial symmetry plane.
18. A non-pneumatic tire according to claim 1 , wherein said interconnected web comprises a generally continuous, radial web element that is spaced at a generally constant radial distance from the axis of rotation, the web element being intermediate to said generally annular inner surface and said generally annular outer ring.
19. A non-pneumatic tire according to claim 1 , wherein said generally annular inner surface is adhesively engaged with said hub.
20. A non-pneumatic tire according to claim 1 , wherein said generally annular inner surface is chemically bonded to said hub.
21. A non-pneumatic tire according to claim 1 , wherein said interconnected web is made of a polymer.
22. A non-pneumatic tire according to claim 1 , further comprising a tread-carrying layer affixed to a radially external surface of said generally annular outer ring.
23. A non-pneumatic tire according to claim 22 , wherein said tread-carrying layer comprises reinforcing belts.
24. A non-pneumatic tire comprising:
a generally annular inner surface that attaches to a hub,
a generally annular outer ring,
an interconnected web between said generally annular inner surface and said generally annular outer ring, and
an axis of rotation;
said interconnected web defining a plurality of openings circumferentially spaced around said tire and radially spaced at varying distances from said axis or rotation, so as to support an applied load by working in tension, said interconnected web including a plurality of web elements and a plurality tangential web elements that are generally aligned with a tangent to a circle centered about the axis of rotation, said plurality of tangential web elements defining, at least in part, at least some of the plurality of openings circumferentially spaced around said tire, wherein, when the applied load is applied, web elements in a region above the axis of rotation are subjected to a tensile force while web elements in a region between the applied load and a footprint region are subjected to a smaller portion of the applied load as compared to the remaining portions of the web elements.
25. A non-pneumatic tire comprising:
a generally annular inner surface that attaches to a hub,
a generally annular outer ring,
a radially external surface engaging a tread-carrying layer,
an interconnected web between said generally annular inner surface and said generally annular outer ring, and
an axis of rotation said interconnected web comprising web elements and tangential web elements that are generally aligned with a tangent to a circle centered about the axis of rotation, the interconnected web defining a plurality of generally hexagonally shaped openings circumferentially spaced around said tire and radially spaced at varying distances from said axis of rotation, a first plurality of generally quadrilaterally-shaped openings adjacent said generally annular inner surface and a second plurality of generally quadrilaterally-shaped openings adjacent said generally annular outer ring, each of said first plurality of generally quadrilaterally-shaped openings and each of said second plurality of generally quadrilaterally-shaped openings circumferentially separated from each other of said first plurality of generally quadrilaterally-shaped openings and each other of said second plurality of generally quadrilaterally-shaped openings, respectively, by at least one of said plurality of hexagonally shaped openings, so as to support a load by working in tension, wherein web elements positioned above the axis of rotation and directly aligned with the direction of the applied load bear the greatest portion of the load.
26. A non-pneumatic tire according to claim 25 , said tread-carrying layer comprising a reinforcing-belted tread.