Claims
- 1. A pneumatic tire comprising a cross belt reinforced with steel cords, the steel cords each comprising:
- a single wavy core steel filament having a sinusoidal shape, and five to eight twisting sheath steel filaments disposed around the wavy core steel filament,
- the pitch Pc of the wavy core steel filament being in the following range,
- 3.0 dc/0.34.ltoreq.Pc.ltoreq.10.0 dc/0.34
- where dc is the diameter of the core steel filament, and the core forming ratio Rc=Lc/dc where dc is as defined above and Lc is an amplitude of the wave of the core steel filament
- being selected from the group consisting of
- 0.12.ltoreq.Rc.ltoreq.1.0
- in the case of five sheath steel filaments,
- 0.12.ltoreq.Rc.ltoreq.1.5
- in the case of six sheath steel filaments,
- 0.48.ltoreq.Rc.ltoreq.1.86
- in the case of seven sheath steel filaments,
- 0.98.ltoreq.Rc.ltoreq.2.36
- in the case of eight sheath steel filaments, and wherein
- (i) an angle .theta. formed by the steel cords and the equatorial plane of the tire is:
- 12.degree..theta..ltoreq.30.degree.;
- (ii) a gap I between any two adjacent steel cords in one layer of the cross belt is:
- 0. 5 mm.ltoreq.I.ltoreq.2.0 mm; and
- (iii) a gauge G of the gum between any two facing steel cords in different layers of the cross belt is:
- 0.35 mm.ltoreq.G.ltoreq.2.0 mm.
- 2. The pneumatic tire according to claim 1 in which the diameter of the core steel filament dc is substantially the same as the diameter of the sheath steel filaments ds.
- 3. The pneumatic tire according to claim 1 in which a spiral filament is added to the steel cord.
- 4. The pneumatic tire according to claim 1 in which the carbon content of the steel in the steel cords is 0.80-0.85% by weight.
Priority Claims (6)
Number |
Date |
Country |
Kind |
4-19374 |
Jan 1992 |
JPX |
|
4-19375 |
Jan 1992 |
JPX |
|
4-19376 |
Jan 1992 |
JPX |
|
4-347279 |
Dec 1992 |
JPX |
|
4-347280 |
Dec 1992 |
JPX |
|
4-347281 |
Dec 1992 |
JPX |
|
Parent Case Info
This is a division of application Ser. No. 08/348,200, filed Nov. 28, 1994, now U.S. Pat. No. 5,584,169, which is a continuation of application Ser. No. 08/002,035, filed Jan. 8, 1993, now abandoned.
US Referenced Citations (11)
Foreign Referenced Citations (12)
Number |
Date |
Country |
0 462 716 |
Dec 1991 |
EPX |
2 476 548 |
Aug 1981 |
FRX |
2 676 466 |
Nov 1992 |
FRX |
56-14396 |
Apr 1981 |
JPX |
56-131404 |
Oct 1981 |
JPX |
59-1790 |
Jan 1984 |
JPX |
60-38208 |
Feb 1985 |
JPX |
60-49421 |
Nov 1985 |
JPX |
60-178204 |
Nov 1985 |
JPX |
62-21641 |
May 1987 |
JPX |
1-175503 |
Jul 1989 |
JPX |
2-154086 |
Jun 1990 |
JPX |
Non-Patent Literature Citations (2)
Entry |
Research Disclosure, No. 175, Nov. 1978, Emsworth GB, pp. 26-28. |
Research Disclosure, No. 327, Jul. 1991, Emsworth GB, pp. 552-558. |
Divisions (1)
|
Number |
Date |
Country |
Parent |
348200 |
Nov 1994 |
|
Continuations (1)
|
Number |
Date |
Country |
Parent |
02035 |
Jan 1993 |
|