Radial tire for airplane

• US 20070221307A1
• Filed: 01/03/2007
• Published: 09/27/2007
• Est. Priority Date: 01/04/2006
• Status: Active Grant

• Current Assignee: Bridgestone Corporation
• Original Assignee: Bridgestone Corporation
• Inventors: Yano, Takeshi, Ishizaki, Susumu
• Granted Patent: US 7,882,878 B2
• Time in Patent Office: Days
• US Class Current: 152/527
• CPC Class Codes: B60C 2200/02 for aircrafts
• CPC Class Codes: B60C 9/2204 obtained by circumferentially narrow strip winding
• CPC Class Codes: B60C 9/28 characterised by the belt or breaker dimensions or curvature relative to carcass B60C9/30 takes precedence
• CPC Class Codes: Y10T 152/10783 Reinforcing plies made up from wound narrow ribbons

Abstract

A radial tire for airplane comprises a pair of bead cores, a radial carcass, and a belt disposed on an outer periphery of a crown portion of the radial carcass and comprised of plural belt layers each containing organic fiber cords, in which a total strength in a circumferential direction over a full width of the belt T_belt(N) satisfies T_belt/WD≧1.5×10⁶ when an outer diameter of the tire is D (m) and a width of the tire is W (m), and at least one layer of the belt layers is constituted with an organic fiber cord spirally winding at an angle of approximately 0° with respect an equatorial plane of the tire and satisfying the following equations (I) and (II):
σ≧−0.01E+1.2   (I)
σ≧0.02   (II) (wherein σ is a heat shrinkage stress at 177° C. (cN/dtex) and E is an elastic modulus at 25° C. under a load of 49 N (cN/dtex)).

Claims

1. A radial tire for airplane comprising a pair of bead cores, a radial carcass comprised of at least one carcass ply toroidally extending between the pair of bead cores, and a belt disposed on an outer periphery of a crown portion of the radial carcass and comprised of plural belt layers each containing organic fiber cords, in which a total strength in a circumferential direction over a full width of the belt T_belt(N) satisfies Tbelt/WD≧

1.5×

106 when an outer diameter of the tire is D (m) and a width of the tire is W (m), and at least one layer of the belt layers is constituted with an organic fiber cord spirally winding at an angle of approximately 0°

with respect to an equatorial plane of the tire and satisfying the following equations (I) and (II);

σ

≧

−

0.01E+1.2  

 

(I)
σ

≧

0.02  

 

(II)

(wherein σ

is a heat shrinkage stress at 177°

C. (cN/dtex) and E is an elastic modulus at 25°

C. under a load of 49 N (cN/dtex)).

2. A radial tire for airplane according to claim 1, wherein a total strength KO of the belt layer in the circumferential direction per unit width at the equatorial plane PO of the tire and a total strength K2 of the belt in the circumferential direction per unit width at a position P2 corresponding to ⅔

of a maximum width W of the belt layer centering on the equatorial plane satisfy a relation of 0.2≦

K2/KO≦

0.8.

3. A radial tire for airplane according to claim 1, wherein the organic fiber cord satisfying the equations (I) and (II) is a polyketone fiber cord.

4. A radial tire for airplane according to claim 3, wherein the polyketone fiber cord satisfying the equations (I) and (II) is a polyketone fiber cord substantially having a repeated unit represented by the following formula (III):

5. A radial tire for airplane according to claim 4, wherein A in the formula (III) is ethylene.