US 5,205,880 AGranted

Pneumatic tires with recesses in the bead region

AssigneeBridgestone Corporation

InventorsHiroyuki Iida, Makoto Tsuruta, Yasuhiko Kobayashi, Hiroyuki Koseki

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Abstract

A pneumatic tire involves a toroidal carcass ply extending between a pair of beads. The carcass ply consists of a main body located axially inside the beads and a pair of outer ply portions each extending along the main body of the carcass ply and on an axially outer side of the bead. A recess is provided on an outer surface of the tire between a radially outer end of each of the outer ply portions of the tire and the tire maximum width location such that a part of the recess is located in a zone surrounded by a curve C--C, a curve D--D, and an E-axis. The curve C--C satisfies d/s=1-0.825.times..sqroot.2.64-(h/s), and the curves C--C, and D--D, the E-axis, d, s, h are defined as follows: a widthwise center line of the main body of the carcass ply being taken as A--A; a curve passing through the radially outer end of the outer ply portion and being parallel with the curve A--A being taken as B--B; an axis lying on the curve B--B and extending from the radially outer end of the outer ply portion toward the location having maximum width being taken as an H-axis; an axis extending from the radially outer end of the outer ply portion toward an interior of the tire in a direction orthogonal to the H-axis being taken as the E-axis; a distance from an origin as measured along the E-axis extending the radially outer end of the outer ply portion toward the interior of the tire in a direction orthogonal to the H-axis being taken as d, the origin being an intersection between the E-axis and the H-axis; a distance from the radially outer end of the outer ply portion to the center line A--A as measured on the F-axis being taken as s; a distance from the origin as measured along the H-axis being taken as h; and the curve D--D being a curve extending between the curves A--A and B--B and being parallel with the center line A--A, while being spaced from the center line A--A by 1/3s.

A pneumatic tire comprising a pair of beads and a toroidal carcass ply extending between a pair of said beads, said carcass ply consisting of a main body located axially inside said beads and a pair of outer ply portions each extending along the main body of the carcass ply and on an axially outer side of the bead, and a recess provided on an outer surface of the tire between a radially outer end of each of said outer ply portions of the tire and that location of the tire having a maximum width which is located radially outwardly from the radially outer end of the outer ply portion, wherein a part of said recess is located in a zone surrounded by a curve C--C, a curve D--D, and an E-axis, said curve C--C satisfying the following equation:

d/s=1-0.825.times..sqroot.2.65-(h/s), said curves C--C, and D--D, said E-axis, d, s, h are defined as follows:
a widthwise center line of said main body of the carcass ply being taken as A--A;
a curve passing through said radially outer end of the outer ply portion and parallel with said curve A--A being taken as B--B;
an axis lying on said curve B--B and extending from said radially outer end of the outer ply portion toward said location having maximum width being taken as an H-axis;
an axis extending from said radially outer end of the outer ply portion toward an interior of the tire in a direction orthogonal to said H-axis being taken as the E-axis;
a distance from an origin as measured along the E-axis extending from the radially outer end of the outer ply portion toward the interior of the tire in a direction orthogonal to said H-axis being taken as d, said origin being an intersection between said E-axis and said H-axis;
a distance from the radially outer end of the outer ply portion to the center line A--A as measured on said E-axis being taken as s;
a distance from the origin as measured along the H-axis being taken as h;
and
said curve D--D being a curve extending between said curves A--A and B--B and being parallel with the center line A--A, while being spaced from the center line A--A by 1/3s.

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Abstract

Claims4