Title:
重荷重用空気入りタイヤ
Document Type and Number:
Japanese Patent JP4934178
Kind Code:
B2
Abstract:
A heavy duty pneumatic tire (1) comprises a carcass ply (6A) of steel cords turned up around a bead core (5) in each bead portion (4) so as to form a pair of turned up portions (6b) and a main portion (6a) therebetween. The steel cords (6c) of the carcass ply are rubberized with a topping rubber (Tg1) having a hardness Ht1 of from 68 to 90 degrees. The bead core is composed of: a bead core main (10) made of windings of a steel wire (5w); a rubber coating (12) penetrating into the bead core main and having a hardness Hb of from 78 to 90 degrees; and a bead core wrapping layer (11) surrounding the bead core main and composed of at least one ply of parallel organic fiber cords (11a) rubberized with a topping rubber (Tg2) having a hardness Ht2 of from 70 to 90 degrees. The fineness of each of the organic fiber cords of the bead core wrapping layer is in a range of from 940 to 4200 dtex. The distances between the organic fiber cords of the bead core wrapping layer is in a range of from 0.3 to 1.4 mm. The organic fiber cords of the bead core wrapping layer are inclined at an angle ±1 in a range of from 20 to 70 degrees with respect to the tire circumferential direction. A minimum distance (L1) between the carcass cords (6c) and the axially innermost winding of the steel wire (5w1) of the bead core main is in a range of from 0.8 to 3.0 mm.
Inventors:
Kazumi Yamazaki
Application Number:
JP2009205032A
Publication Date:
May 16, 2012
Filing Date:
September 04, 2009
Export Citation:
Assignee:
Sumitomo Rubber Industries, Ltd.
International Classes:
B60C15/04; B60C9/04; B60C15/00; B60C15/06
Domestic Patent References:
| JP2004142478A | ||||
| JP2001329477A | ||||
| JP2001206027A | ||||
| JP2004058840A | ||||
| JP2001071716A |
Attorney, Agent or Firm:
Sumitomo Shintaro