Tread including at least one wavy groove, and method for producing same

Patent metadata

Field	Value
Publication number	US-9561630-B2
Application number	US-201214006248-A
Country	US
Kind code	B2
Filing date	Mar 22, 2012
Priority date	Apr 1, 2011
Publication date	Feb 7, 2017
Grant date	Feb 7, 2017

Abstract

Tire for a heavy goods vehicle comprising a tread of total thickness E and total volume V, having a tread surface intended to come into contact with a roadway, at least one cavity or groove that is continuous in a main direction, and delimited by side walls connected by a bottom, a cross section, the points furthest towards the inside of the bottom of each cavity defining a bottom line, wherein each cavity or groove comprises a plurality of open sections open onto the tread surface in the new state and a plurality of closed sections, connected to the open sections being arranged in alternation, each closed section being spaced away from the tread surface by a bridge of rubber, wherein the points on the bottom line of said cavity or groove lie at distances between a minimum distance Dm and a maximum distance DM with respect to the tread surface, the bottom line of each cavity or groove following a wavy geometry of positive amplitude equal to the difference (DM−Dm).

First claim

The invention claimed is:

1. A tire for a heavy goods vehicle comprising:
a tread of total thickness E and total volume V, comprising:
a tread surface intended to come into contact with a roadway;
at least one cavity or groove that is continuous in a main direction, with the at least one cavity or groove being delimited by side walls connected by a bottom, this cavity or groove having a cross section, the points furthest towards the inside of the bottom of each cavity or groove defining a bottom line;
each cavity or groove comprising:
a plurality of open sections that open onto the tread surface in the new state, and
a plurality of closed sections connected to the open sections and arranged in alternation, such that each closed section is spaced away from the tread surface by a bridge of rubber,
a bottom line of the at least one cavity or groove containing points that lie at distances between a minimum distance Dm and a maximum distance DM, these distances, which are measured on the tread in the new state with respect to the tread surface, being at most equal to the thickness E of the tread;

at least one insert to form a cavity that is continuous in a main direction, the formed cavity being delimited by side walls connected by a bottom, the points furthest towards the inside of the bottom of the formed cavity defining a bottom line of wavy shape, the at least one insert being arranged in the tread in such a way as to appear on the tread surface only when the tread is partially worn;
wherein the bottom line of each cavity or groove follows a wavy geometry having a positive amplitude equal to the difference (DM−Dm) and having a wavelength less than a mean length of the contact patch measured under the conditions of use as set forth in the E.T.R.T.O. standard for the new tire,
and wherein the bridge of rubber formed between each closed section and the tread surface is continuous.

2. The tire according to claim 1 , wherein the minimum distance Dm between the bottom line of the formed cavity with a wavy shape and the tread surface is at least equal to 25% of the thickness E of the tread.

3. The tire according to claim 1 , wherein the bottom line of the formed cavity with a wavy shape further comprises an insert that follows a wavy geometry having a wavelength less than the mean length of the contact patch measured under the conditions of use as set forth in the E.T.R.T.O. standard for the new tire.

4. The tire according to claim 1 , wherein the formed cavity with a wavy shape is delimited by walls formed in a material which is different from the material of which the tread is made.

5. The tire according to claim 1 , wherein each insert is surrounded by a material that is different from the material of which the tread is made, this material being adapted to remain connected to the tread after the insert has been eliminated.

6. The tire according to claim 1 , wherein each insert takes the form of a hollow tube.

7. The tire according to claim 6 , wherein each hollow tube is formed from an elastomeric material, each of the tubes being provided to maintain pressure inside the said tube during molding.

Assignees

• Audigier Richard
• Oraison Stéphane
• Bessac Christophe
• Michelin & Cie
• Michelin Rech Tech

Inventors

• Audigier Richard
• Oraison Stéphane
• Bessac Christophe

Classifications

• B29D30/52 Primary

  Unvulcanised treads, e.g. on used tyres; Retreading (apparatus for forming {treads by extrusion B29C48/00; apparatus for} vulcanising treads B29C35/02; apparatus characterised by the means for holding wheels or parts thereof B60B30/00) · CPC title

• B60C11/0306

  Patterns comprising block rows or discontinuous ribs · CPC title

• B29D30/0681

  Parts of pneumatic tyres; accessories, auxiliary operations · CPC title

• B60C11/0323

  tread comprising channels under the tread surface, e.g. for draining water · CPC title