US4572264A — Pneumatic radial tires

Claim 1

Independent Claim 350 words

A pneumatic radial tire comprising; a tire reinforcement having steel cords each having a two or three layer construction represented by a designation of l+m or l+m+n, wherein l, m and n are an integer, respectively and satisfy a relation of l<m<n and l is an integer of 2 to 5, in which two layers at a center side of a transverse section in said steel cord represented by the designation of l+m have the same twisting direction but different twisting pitches, wherein m filaments constituting an outer layer among said two layers are arranged to enter into an inside of a circumscribed circle enveloping l filaments constituting an inner layer among said two layers at such a portion that the filaments of said outer layer do not come into contact with the filaments of said inner layer, and an average value x o of a maximum value of an amount of entering a filament into the inside of the circumscribed circle per m filaments in the steel cord of a tire product satisfies the following equations: (-0.24k.sup.2 +0.46k)d<x.sub.O <(-0.73k.sup.2 +1.37k)d, when l is 2 (1) (-0.10k.sup.2 +0.24k)d<x.sub.O <(-0.31k.sup.2 +0.73k)d, when l is 3 (2) (-0.05k.sup.2 +0.16k)d<x.sub.O <(-0.15k.sup.2 +0.49k)d, when l is 4 (3) (-0.02k.sup.2 +0.12k)d<x.sub.O <(-0.06k.sup.2 +0.35k)d, when l is 5 (4), wherein k is a ratio of twisting pitch P 1 of the filament of the inner layer to twisting pitch P 2 of the filament of the outer layer and d is a filament diameter, each of the m filaments in the outer layer has a form ratio of 90% to 110%, a limit entering amount x L forms a ratio x O /x L within a range of 0.33-1.0 wherein said limit entering amount x L is represented by the following four equations: x.sub.L =(-0.73k.sup.2 +1.37k)d, when l is 2 (5) x.sub.L =(-0.31k.sup.2 +0.73k)d, when l is 3 (6) x.sub.L =(-0.15k.sup.2 +0.49k)d, when l is 4 (7) x.sub.L =(-0.06k.sup.2 +0.35k)d, when l is 5 (8) wherein k and d are as defined above and wherein all l and m filaments have the same filament diameter d.

Claim 2

Dependent Claim 350 words

A pneumatic radial tire comprising; a tire reinforcement having steel cords each having a two or three layer construction represented by a designation of l+m or l+m+n, wherein l, m and n are an integer, respectively and satisfy a relation of l<m<n and l is an integer of 2 to 5, in which two layers at a center side of a transverse section in said steel cord represented by the designation of l+m have the same twisting direction but different twisting pitches, wherein m filaments constituting an outer layer among said two layers are arranged to enter into an inside of a circumscribed circle enveloping l filaments constituting an inner layer among said two layers at such a portion that the filaments of said outer layer do not come into contact with the filaments of said inner layer, and an average value x o of a maximum value of an amount of entering a filament into the inside of the circumscribed circle per m filaments in the steel cord of a tire product satisfies the following equations: (-0.24k.sup.2 +0.46k)d<x.sub.O <(-0.73k.sup.2 +1.37k)d, when l is 2 (1) (-0.10k.sup.2 +0.24k)d<x.sub.O <(-0.31k.sup.2 +0.73k)d, when l is 3 (2) (-0.05k.sup.2 +0.16k)d<x.sub.O <(-0.15k.sup.2 +0.49k)d, when l is 4 (3) (-0.02k.sup.2 +0.12k)d<x.sub.O <(-0.06k.sup.2 +0.35k)d, when l is 5 (4), wherein k is a ratio of twisting pitch P 1 of the filament of the inner layer to twisting pitch P 2 of the filament of the outer layer and d is a filament diameter, each of the m filaments in the outer layer has a form ratio of 90% to 110%, a limit entering amount x L forms a ratio x O /x L within a range of 0.33-1.0 wherein said limit entering amount x L is represented by the following four equations: x.sub.L =(-0.73k.sup.2 +1.37k)d, when l is 2 (5) x.sub.L =(-0.31k.sup.2 +0.73k)d, when l is 3 (6) x.sub.L =(-0.15k.sup.2 +0.49k)d, when l is 4 (7) x.sub.L =(-0.06k.sup.2 +0.35k)d, when l is 5 (8) wherein k and d are as defined above and wherein all l and m filaments have the same filament diameter d.

Claim 3

Dependent Claim 14 words

A pneumatic radial tire according to claim 1, wherein l is 2 or 3.

Claim 4

Dependent Claim 268 words

In a pneumatic radial tire comprising as a tire reinforcement steel cords each having a two layer construction represented by a designation of 3+9, in which the two layers at a center side of a transverse section in said steel cord represented by the designation of 3+9 have the same twisting direction but different twisting pitches, the improvement wherein all filaments constituting the cord have the same filament diameter, and 9 filaments constituting an outer layer among said two layers are arranged so as to enter into an inside of a circumscribed circle enveloping 3 filaments constituting an inner layer among said two layers at such a portion that the filaments of said outer layer do not come into contact with the filaments of said inner layer, and an average value x o of a maximum value of an amount of entering a filament into the inside of the circumscribed circle per 9 filaments in the steel cord of a tire product satisfies the following equation: (-0.10k.sup.2 +0.24k)d<x.sub.o <(-0.31k.sup.2 +0.73k)d, wherein k is a ratio of twisting pitch P 1 of the filament of the inner layer to twisting pitch P 2 of the filament of the outer layer and d is a filament diameter, and a ratio of the product entering amount x o to a limit entering amount x L is within a range of 0.33-1.0, wherein said limiting entering amount x L satisfies the following equation: x.sub.L =(-0.31k.sup.2 +0.73k)d wherein k and d are as defined above and each of the 9 filaments in the outer layer has a form ratio of 90% to 110%.

Claim 5

Dependent Claim 268 words

In a pneumatic radial tire comprising as a tire reinforcement steel cords each having a two layer construction represented by a designation of 3+9, in which the two layers at a center side of a transverse section in said steel cord represented by the designation of 3+9 have the same twisting direction but different twisting pitches, the improvement wherein all filaments constituting the cord have the same filament diameter, and 9 filaments constituting an outer layer among said two layers are arranged so as to enter into an inside of a circumscribed circle enveloping 3 filaments constituting an inner layer among said two layers at such a portion that the filaments of said outer layer do not come into contact with the filaments of said inner layer, and an average value x o of a maximum value of an amount of entering a filament into the inside of the circumscribed circle per 9 filaments in the steel cord of a tire product satisfies the following equation: (-0.10k.sup.2 +0.24k)d<x.sub.o <(-0.31k.sup.2 +0.73k)d, wherein k is a ratio of twisting pitch P 1 of the filament of the inner layer to twisting pitch P 2 of the filament of the outer layer and d is a filament diameter, and a ratio of the product entering amount x o to a limit entering amount x L is within a range of 0.33-1.0, wherein said limiting entering amount x L satisfies the following equation: x.sub.L =(-0.31k.sup.2 +0.73k)d wherein k and d are as defined above and each of the 9 filaments in the outer layer has a form ratio of 90% to 110%.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1989-02-24	1989-08-26	1990-02-25	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1993-02-24	1993-08-26	1994-02-25	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1997-02-24	1997-08-26	1998-02-25	$7700.00	Window Closed / Lapsed

Pneumatic radial tires

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