US 12,187,083 B2
Heavy duty tire and production method for heavy duty tire
Tadashi Ito, Kobe (JP); and Tetsuya Kitano, Kobe (JP)
Assigned to SUMITOMO RUBBER INDUSTRIES, LTD., Kobe (JP)
Filed by SUMITOMO RUBBER INDUSTRIES, LTD., Kobe (JP)
Filed on Mar. 22, 2023, as Appl. No. 18/124,635.
Claims priority of application No. 2022-046572 (JP), filed on Mar. 23, 2022; and application No. 2023-023441 (JP), filed on Feb. 17, 2023.
Prior Publication US 2023/0302850 A1, Sep. 28, 2023
Int. Cl. B60C 9/08 (2006.01); B60C 3/04 (2006.01); B60C 9/02 (2006.01); B60C 15/04 (2006.01); B60C 15/06 (2006.01); B29D 30/06 (2006.01)
CPC B60C 3/04 (2013.01) [B60C 9/0292 (2013.01); B60C 15/04 (2013.01); B60C 15/0603 (2013.01); B60C 15/0607 (2013.01); B29D 30/0601 (2013.01); B60C 2015/061 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A heavy duty tire comprising a pair of beads and a carcass extending on and between a first bead and a second bead out of the pair of beads, wherein
each of the beads includes a core and an apex located radially outward of the core,
the carcass includes a carcass ply,
the carcass ply includes a large number of carcass cords aligned with each other,
each of the carcass cords is a steel cord,
in a meridian cross-section of the tire, a contour of the carcass includes an outwardly bulging curved portion and an inwardly recessed inversely curved portion located radially inward of the curved portion,
the inversely curved portion is connected to the curved portion,
a boundary between the curved portion and the inversely curved portion is an inflection point,
a part or an entirety of the curved portion is represented by a first arc including the inflection point,
a part or an entirety of the inversely curved portion is represented by a second arc including the inflection point,
the first arc and the second arc are tangent to each other at the inflection point,
a ratio of a distance in an axial direction from an equator plane of the tire to the inflection point to a distance in the axial direction from the equator plane to an axially outer end of the contour of the carcass is not less than 70% and not greater than 85%,
a ratio of a distance in a radial direction from a bead base line of the tire to the inflection point to a distance in the radial direction from the bead base line to a point of intersection of the contour of the carcass and the equator plane is not less than 15% and not greater than 22%,
the apex includes an inner apex and an outer apex located radially outward of the inner apex,
the inner apex has an outer end tapered outward in the radial direction,
the carcass ply has a ply body which extends between the cores of the beads, and a pair of turned-up portions which are connected to the ply body and turned up around the respective cores from the inner side toward the outer side in the axial direction,
the inflection point is located, in the axial direction, between a radially outer end of the core and the outer end of the inner apex, and the inflection point is located, in the radial direction, between an end of the turned-up portion and the outer end of the inner apex, and
a normal line being normal to an interface between the ply body of the carcass and the apex and passing through the inflection point, intersects the turned-up portion.