Zero-pressure tire
A pneumatic radial tire includes a carcass structure having a pair of sidewalls and a crown, a pair of beads, a tread, a belt structure, and a plurality of reinforcing hoops. The plurality of spaced apart reinforcing hoops are disposed intermediate the crown of the carcass structure and the tread, and are formed of a rigid material coated in an elastomeric material. The plurality of reinforcing hoops includes a pair of outer reinforcing hoops disposed adjacent the sidewalls of the carcass, and an at least one inner reinforcing hoop disposed between the outer reinforcing hoops.
1. A pneumatic radial tire comprising:
a carcass formed of at least one body ply and sidewalls;
a tread disposed radially outwardly of the at least one body ply, the tread including a top tread portion, a cushion portion, a base tread portion, and a cushion filler portion, the base tread portion disposed between and contacting the cushion portion and the cushion filler portion of the tread;
at least one belt disposed radially intermediate the at least one body ply and the cushion portion of the tread; and
a plurality of reinforcing hoops embedded within the tread and disposed radially intermediate the cushion portion and the top tread portion of the tread, each of the reinforcing hoops including both a metal ring and non-metal reinforcing fibers, wherein the base tread portion has grooves, the reinforcing hoops are disposed within the grooves of the base tread portion, and a portion of the cushion filler extends into the grooves between the reinforcing hoops and the base tread portion.
2. The pneumatic radial tire of claim 1 , wherein the metal ring is formed of one of a solid ring and a continuously wound wire.
3. The pneumatic radial tire of claim 1 , wherein the tread further includes a rubber base portion disposed between the cushion filler portion and the top tread portion.
4. The pneumatic radial tire of claim 1 , wherein each of the plurality of reinforcing hoops has a radial thickness that is between 20% and 25% of a radial thickness of the tread.
5. The pneumatic radial tire of claim 1 , wherein each of the plurality of reinforcing hoops has an axial width that is between 5% and 25% of an axial width of the tread.
6. The pneumatic radial tire of claim 1 , wherein at least one of the plurality of reinforcing hoops is one of substantially circular in cross sectional shape and substantially rectangular in cross sectional shape.
7. The pneumatic radial tire of claim 1 , wherein the metal ring of each of the reinforcing hoops is formed from steel.
8. The pneumatic radial tire of claim 7 , wherein the metal ring is formed from brass coated steel wire.
9. The pneumatic radial tire of claim 1 , wherein the non-metal reinforcing fibers include at least one of a composite fiber, a carbon fiber, an ultra-high-molecular-weight polyethylene, and an epoxy resin composite filled with reinforcement fibers.
10. The pneumatic radial tire of claim 9 , wherein the non-metal reinforcing fibers are carbon fibers.
11. The pneumatic radial tire of claim 1 , wherein the metal ring of each of the reinforcing hoops further has a skim rubber coating, the skim rubber coating providing enhanced adhesion between the metal ring and the non-metal reinforcing fibers.
12. The pneumatic radial tire of claim 11 , wherein the skim rubber coating includes a methylene donor/methylene acceptor resin system.
13. The pneumatic radial tire of claim 11 , wherein the non-metal reinforcing fibers are carbon fibers, and the non-metal reinforcing fibers of each of the reinforcing hoops includes a first carbon fiber layer and a second carbon fiber layer.
14. The pneumatic radial tire of claim 13 , wherein the first carbon layer is disposed over the reinforcing hoop between the skim rubber coating and the cushion filler portion of the tread.
15. The pneumatic radial tire of claim 13 , wherein the second carbon layer is disposed under the reinforcing hoop between the skim rubber coating and the cushion portion of the tread.
16. A pneumatic radial tire comprising:
a carcass formed of at least one body ply and sidewalls;
a tread disposed radially outwardly of the at least one body ply, the tread including a top tread portion and a cushion portion;
at least one belt disposed radially intermediate the at least one body ply and the cushion portion of the tread; and
a plurality of reinforcing hoops embedded within the tread and disposed radially intermediate the cushion portion and the top tread portion of the tread, each of the reinforcing hoops including both a metal ring and non-metal reinforcing fibers;
wherein the plurality of reinforcing hoops includes a pair of outer reinforcing hoops disposed adjacent to the sidewalls, at least one inner reinforcing hoop is disposed axially intermediate the pair of outer reinforcing hoops, and a radial thickness of the outer hoops is less than a radial thickness of the at least one inner hoop.