# US 2019/0168544 A1 · Tire

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2019/0168544 A1
- Document ID: US20190168544A1
- Status: Published application
- Kind: A1
- Application number: 16/206,481
- Filed: 2018-11-30
- Published: 2019-06-06
- Earliest claimed: 2017-12-01
- Assignees: Sumitomo Rubber Industries, Ltd.
- Applicants: Sumitomo Rubber Industries, Ltd.
- Inventors: Sawa OGIHARA; Emi UEDA; Ken MIYAZAWA; Tatsuya SASAKI; Ryuhei SANAE; Masatoshi TANAKA
- Web page: https://patentgrep.com/patent/US20190168544A1

## CPC

- B60C 11/0318: {irregular patterns with particular pitch sequence}
- B60C 11/0306: {Patterns comprising block rows or discontinuous ribs}
- B60C 11/0332: {by the footprint-ground contacting area of the tyre tread}
- B60C 11/11: in which the raised area of the pattern consists only of isolated elements, e.g. blocks (B60C11/12, B60C11/13 take precedence)
- B60C 2011/0341: {Circumferential grooves}
- B60C 2011/0358: {Lateral grooves, i.e. having an angle of 45 to 90 degees to the equatorial plane}
- B60C: VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES

## Abstract

A tire is provided with a tread pattern comprising a series of a number N of tread design units arranged repeatedly and circumferentially of the tire in a sequence and having a number m of different circumferential lengths. A first pulse train is defined by viewing the tread design units as pulses arranged in the same sequence as the tread design units at intervals which are defined by the circumferential lengths of the corresponding tread design units expressed in term of a ratio to one of the number m of different circumferential lengths. A maximum value Pmax of amplitudes P(k) (k=order from 1 to 2N) of frequencies obtained by Fourier transforming the first pulse train is limited to specific values. The amplitudes P(k) and P(k+1) of every two of the adjacent orders (k) and (k+1) do not satisfy a condition that both of the amplitudes P(k) and P(k+1) have values of 2/3 or more times the maximum value Pmax.

## Claims

### Claim 1

A tire comprising:
a tread portion provided with a tread pattern,
the tread pattern comprising a series of a number N of tread design units arranged repeatedly and circumferentially of the tire in a sequence,
the tread design units having a number m (m=2, 3 or 5) of different circumferential lengths,
wherein
when
viewing the tread design units as the number N of pulses, and
defining a first pulse train such that the number N of the pulses are arranged in the same sequence as the tread design units at intervals which are defined by the circumferential lengths of the corresponding tread design units expressed in term of a ratio to one of said number m of different circumferential lengths,
then
a maximum value Pmax of amplitudes P(k) (k=order from 1 to 2N) of frequencies obtained by Fourier transforming said first pulse train with the following formula (1) is not more than 18.50-0.05N when m=2, 17.50-0.05N when m=3, and 15.00-0.05N when m=5,
P

(
k
)
=
100
N
2

(
a
k
2
+
b
k
2
)


a
k
=
∑
j
=
1
N

sin
(
2

π


k
l
·
X

(
j
)
)


b
k
=
∑
j
=
1
N

cos
(
2

π


k
l
·
X

(
j
)
)
(
1
)
wherein
X(j) is the position of the j-th pulse from a beginning of the first pulse train, and
l is a circumference length parameter equal to the sum of said ratios expressing the circumferential lengths of all the tread design units in said series,
and
the amplitudes P(k) and P(k+1) of every two of the adjacent orders (k) and (k+1) do not satisfy a condition that both of the amplitudes P(k) and P(k+1) have values of ⅔ or more times said maximum value Pmax.

### Claim 2 (depends on 1)

The tire according to claim 1, wherein
the maximum value Pmax is not more than 15.50-0.05N when m=2, 14.50-0.05N when m=3, and 12.00-0.05N when m=5.

### Claim 3 (depends on 1)

The tire according to claim 1, wherein when a second pulse train is further defined by
viewing the above-said tread design units as the number N of pulses, and
arranging the number N of the pulses in the same sequence as the tread design units at intervals which are defined by the circumferential lengths of the corresponding tread design units expressed in term of a ratio to one of the above-said number m of different circumferential lengths, and further
defining magnitudes of the number N of the pulses by the respective circumferential lengths in term of a ratio to the median value of the above-said number m of different circumferential lengths, wherein the average of the magnitudes of the pulses corresponding to the above-said number m of different circumferential lengths is set to 1.00,
then
amplitude F(1) among amplitudes F(k) (k=order from 1 to 2N) of frequencies obtained by Fourier transforming the second pulse train with the following formula (2), is not more than 0.6,
F

(
k
)
=
10
k
2

c
k
2
+
d
k
2


c
k
=
∑
j
=
1
N

p

(
j
)
·
sin
(
2

π


k
l
·
X

(
j
)
)


d
k
=
∑
j
=
1
N

p

(
j
)
·
cos
(
2

π


k
l
·
X

(
j
)
)
(
2
)
wherein
P(j) is the magnitude of the j-th pulse (j=1 to N) counted from a beginning of the second pulse train, and
l is a circumference length parameter equal to the sum of the above-said ratios expressing the circumferential lengths of all the tread design units in said series.

### Claim 4 (depends on 3)

The tire according to claim 3, wherein
the amplitude F(1) of the 1st order is not more than 0.5.

### Claim 5 (depends on 1)

The tire according to claim 1, wherein
the number N of the tread design units in said series is not less than 30 and not more than 90.

### Claim 6 (depends on 1)

The tire according to claim 1, wherein
the increasing rate of the circumferential lengths of every two of the tread design units arranged adjacently to each other in the tire circumferential direction is in a range from 0.08 to 0.25.

### Claim 7

A tire comprising:
a tread portion provided with a tread pattern,
the tread pattern comprising a series of a number N of tread design units arranged repeatedly and circumferentially of the tire in a sequence,
the tread design units having a number m (m=4) of different circumferential lengths, wherein
when
viewing the tread design units as the number N of pulses, and
defining a first pulse train such that the number N of the pulses are arranged in the same sequence as the tread design units at intervals which are defined by the circumferential lengths of the corresponding tread design units expressed in term of a ratio to one of the above-said number m of different circumferential lengths,
then
a maximum value Pmax of amplitudes P(k) (k=order from 1 to 2N) of frequencies obtained by Fourier transforming the above-said first pulse train with the following formula (1) is not more than 16.50-0.05N,
P

(
k
)
=
100
N
2

(
a
k
2
+
b
k
2
)


a
k
=
∑
j
=
1
N

sin
(
2

π


k
l
·
X

(
j
)
)


b
k
=
∑
j
=
1
N

cos
(
2

π


k
l
·
X

(
j
)
)
(
1
)
wherein
X(j) is the position of the j-th pulse from a beginning of the first pulse train, and
l is a circumference length parameter equal to the sum of the ratios expressing the circumferential lengths of all the tread design units in said series,
and
the amplitudes P(k) and P(k+1) of every two of the adjacent orders (k) and (k+1) do not satisfy a condition that both of the amplitudes P(k) and P(k+1) have values of ⅔ or more times the above-said maximum value Pmax.

### Claim 8 (depends on 7)

The tire according to claim 7, wherein
the maximum value Pmax is not more than 13.50-0.05N.