Winter tyre tread band with three-dimensional sipes

Patent metadata

Field	Value
Publication number	US-9994079-B2
Application number	US-201314432778-A
Country	US
Kind code	B2
Filing date	Oct 7, 2013
Priority date	Oct 5, 2012
Publication date	Jun 12, 2018
Grant date	Jun 12, 2018

Abstract

A winter tire tread band having: a number of longitudinal and transverse grooves defining a number of blocks, each projecting radially upwards from a base surface of the tread band; and a number of sipes formed in at least some of the blocks, and each of which extends radially inwards of a corresponding block, from a top surface forming the rolling surface of the tread band; each sipe has a wave pattern when the corresponding block is viewed in any one of three planes perpendicular to one another and defined by a longitudinal axis, a transverse axis, and a radial axis.

First claim

The invention claimed is:

1. A winter tyre tread band comprising:
a number of longitudinal and transverse grooves defining a number of blocks, each projecting radially upwards from a base surface of the tread band; and
a number of sipes formed in at least some of the blocks, and each of which extends radially inwards of a corresponding block, from a top surface forming the rolling surface of the tread band;
wherein, in section, each sipe has a first wave pattern which is constant when the block is sectioned along a first plane defined by the longitudinal axis and transverse axis;
wherein, along the radial axis, the first wave pattern of each sipe shifts along the longitudinal axis in a second wave pattern which is piecewise linear; and
wherein, along the radial axis, in addition to shifting along the longitudinal axis in the second wave pattern, the first wave pattern of each sipe also shifts along the transverse axis in a third wave pattern;
wherein the second wave pattern of the sipes comprises a half-wave originating from a top surface of the corresponding block and having a given length and a given amplitude; and two successive whole waves following the half-wave and each having a length that is double the length of the half-wave and an amplitude that is equal to the amplitude of the half-wave.

2. The tread band as claimed in claim 1 , wherein the three wave patterns of the sipes differ in shape and/or size.

3. The tread band as claimed in claim 1 , wherein the first wave pattern of the sipes is piecewise linear.

4. The tread band as claimed in claim 1 , wherein the half-wave is smaller in amplitude than the whole waves.

5. The tread band as claimed in claim 1 , wherein the half-wave is smaller in pitch than the two whole waves.

6. The tread band as claimed in claim 1 , wherein the half-wave is oriented the same way as the two whole waves.

7. The tread band as claimed in claim 1 , wherein the half-wave is oriented the opposite way to the two whole waves.

8. The tread band as claimed in claim 1 , wherein the third wave pattern of the sipes comprise linear segments.

9. The tread band as claimed in claim 1 , wherein the tread band comprises at least two rows of lateral blocks and at least one row of central blocks arranged between the two rows of lateral blocks; and wherein the sipes of the central blocks differ from the sipes of the lateral blocks.

10. The tread band as claimed in claim 9 , wherein the sipes of the central blocks differ from the sipes of the lateral blocks by shape of the second wave pattern.

11. The tread band as claimed in claim 10 , wherein in the central blocks, the half-wave of the second wave pattern of the sipes is oriented differently from the half-wave of the second wave pattern of the sipes in the lateral blocks.

12. The tread band as claimed in claim 1 , wherein each sipe is formed starting with the first wave pattern in a first plane defined by the longitudinal axis and the transverse axis, and by moving the first wave pattern, parallel to itself, along the radial axis and, at the same time, by moving the first wave pattern along the longitudinal axis in the second wave pattern, and along the transverse axis in the third wave pattern.

Assignees

• Sabetti Emiliano
• Mangia Massimo
• Bridgestone Corp

Inventors

• Sabetti Emiliano
• Mangia Massimo

Classifications

• B60C2011/1227

  having different shape within the pattern · CPC title

• B60C11/11

  in which the raised area of the pattern consists only of isolated elements, e.g. blocks (B60C11/12, B60C11/13 take precedence) · CPC title

• B60C11/1218 Primary

  Three-dimensional shape with regard to depth and extending direction · CPC title

• B29D30/0606

  Vulcanising moulds not integral with vulcanising presses (for solid tyres B29D30/02) · CPC title

• B60C2011/1213

  sinusoidal or zigzag at the tread surface · CPC title