Self-supporting pneumatic tire with optimized ply line
The present invention is directed to a self-supporting tire. More specifically, the tire has a carcass, a tread, and a belt reinforcing structure located radially outward of the carcass and radially inward of the tread. The carcass is comprised of a reinforcing ply structure extending between a pair of bead portions, a pair of sidewalls, each sidewall located radially outward of one of the pair of bead portions, and a pair of inserts located in each sidewall. A first insert and second insert are located between the innerliner and the ply.
1. A pneumatic tire comprising: a carcass, a tread, and a belt reinforcing structure located radially outward of the carcass and radially inward of the tread, a pair of sidewalls, each sidewall located radially outward of one of the pair of bead portions, a first and second apex, and a first and second insert, wherein the carcass further includes a first reinforcing ply extending under the tread, wherein the first insert and second inserts are positioned between an innerliner and the first reinforcing ply, wherein a radially inner end of the first insert overlaps with a radially outer end of the second insert, wherein the second insert has a axially inner surface having a radially inner portion and a radially outer portion, wherein the curvature of the radially outer portion is concave and the curvature of the radially inner portion is convex.
2. The tire of claim 1 wherein a second reinforcing ply is located radially outward of the first reinforcing ply.
3. The tire of claim 1 wherein the first ply is anchored about each bead and terminates in a turnup end.
4. The tire of claim 2 wherein the second ply extends from one bead region to the other bead region, but does not wrap around each bead.
5. The tire of claim 2 wherein the second ply is axially outward of the first and second insert.
6. The tire of claim 2 wherein the second ply is axially inward of a first and second apex.
7. The tire of claim 1 wherein the first insert has a shore A hardness measured at 23 degrees C. in the range of about 50 to about 70.
8. The tire of claim 1 wherein the first insert has a shore A hardness value less than the shore A hardness of the second insert.
9. The tire of claim 1 wherein the first insert has a shore A hardness value different than the shore A hardness of the second insert.
10. The tire of claim 1 wherein the first insert has a shore A hardness measured at 23 degrees C. in the range of about 55 to about 65.
11. The tire of claim 1 wherein the second insert has a shore A hardness measured at 23 degrees C. in the range of about 60 to about 80.
12. The tire of claim 1 wherein the second insert has a shore A hardness measured at 23 degrees C. in the range of about 65 to about 75.
13. The tire of claim 1 wherein the first insert has a first end located near the crown portion of the tire, and a second, radially innermost end located in the range of about ¼ to about ½ the section height.
14. The tire of claim 1 wherein the second insert has a radially outermost end located in the range of about ½ to ¾ of the section height, and a second, radially innermost end terminating in abutting contact with the bead.