Transverse grooves providing venting in treads for retreaded tires

Patent metadata

Field	Value
Publication number	US-10150269-B2
Application number	US-201114367011-A
Country	US
Kind code	B2
Filing date	Dec 20, 2011
Priority date	Dec 20, 2011
Publication date	Dec 11, 2018
Grant date	Dec 11, 2018

Abstract

The present invention includes an improved tire tread having recessed lateral grooves, and a tire having the same. Particular embodiments of the tread include a tread thickness bounded depthwise by a top side configured to engage a ground surface during tire operation and a bottom side configured to attach to a tire carcass, the thickness extending laterally between a first side edge and a second side edge and longitudinally in a lengthwise direction of the tread. The tread further includes a longitudinal groove in fluid communication with the top side or the bottom side of the tread thickness and a lateral groove in fluid communication with the bottom side of the tread thickness extending from the first side edge intersecting the longitudinal groove forming a vent passageway extending from the longitudinal groove and to the first side edge. The invention includes methods of forming such treads and molds there for.

First claim

What is claimed is:

1. A tire tread for a retread tire comprising:
a plurality of tread wear layers forming a retread having a retread thickness bounded depthwise by a top side configured to engage a ground surface during tire operation and a bottom side configured to attach to a tire carcass, the retread thickness extending laterally between opposing side edges to define a width of the retread and longitudinally in a lengthwise direction of the retread to define a length of the retread, where the opposing side edges form a first side edge and a second side edge and where the width of the retread along the top side is less than the width of the retread along the bottom side,
a bottom longitudinal groove arranged within one tread wear layer of the plurality of tread wear layers and in fluid communication with the bottom side of the retread thickness, and
a lateral groove in fluid communication with the bottom side of the retread thickness extending from at least one of the side edges and intersecting the bottom longitudinal groove and forming a vent passageway extending from the bottom longitudinal groove to the at least one of the side edges without the lateral groove intersecting a top longitudinal groove and without the lateral groove being in fluid communication with the top side of the retread thickness, such that the top longitudinal groove is offset from the lateral groove within the retread thickness without any opening connecting the top longitudinal groove to the lateral groove and where a connecting portion extends into the retread thickness from the bottom side and between the bottom side and the lateral groove, the connecting portion having a width less than a width of the lateral groove.

2. The tire tread of claim 1 , where the bottom longitudinal groove is a first bottom longitudinal groove, the tread further comprising one or more additional bottom longitudinal grooves in fluid communication with the bottom side of the retread thickness, the lateral groove intersecting the first bottom longitudinal groove and the one or more additional bottom longitudinal grooves to form a vent passageway extending from the each of the first bottom longitudinal groove, the one or more additional bottom longitudinal grooves, and at least one of the side edges.

3. The tire tread of claim 1 , where the lateral groove undulates within the retread thickness along a length of the lateral groove.

4. The tire tread of claim 1 , further comprising a plurality of lateral grooves in fluid communication with the bottom side of the retread thickness extending from the first side edge and intersecting the bottom longitudinal groove forming a plurality of vent passageways extending from the bottom longitudinal groove and to the first side edge.

5. The tire tread of claim 1 , where the plurality of tread wear layers forms a new precured tread with the bottom side bonded to a used tire carcass, the lateral groove forming with the tire carcass a vent passageway from the bottom longitudinal groove to the atmosphere through the first side edge.

6. A method of forming a tire tread for a retread tire comprising:
providing a mold comprising:
a first mold portion and a second mold portion cooperatively positionable together to form a cavity there between for molding a retread having a retread thickness formed of a plurality of tread wear layers,
the first mold portion including a top interior surface for forming a top side of the retread thickness configured to engage a ground surface during tire operation,
the second mold portion including a bottom interior surface for forming a bottom side of the retread thickness configured to attach to a tire carcass,
the mold including a first interior side surface for forming a first side edge of the retread thickness and a second interior side surface for forming a second side edge of the retread thickness respectively, each extending longitudinally in a lengthwise direction of the retread, and where a width along the top interior surface between the first side edge and the second side edge is less than a width along the bottom interior surface between the first side edge and the second side edge;

arranging a bottom longitudinal groove core within the mold to project into the cavity, the bottom longitudinal groove core being positioned to form a corresponding bottom longitudinal groove arranged within one tread wear layer of a plurality of tread wear layers and in fluid communication with the bottom side of the retread thickness;
arranging a recessed lateral groove core in operable connection with the bottom interior surface of the second mold portion, the lateral groove core being arranged to extend from the first interior side surface and engage the bottom longitudinal groove core at least when the first mold portion and the second mold portion are positioned together, the recessed lateral groove core being arranged a distance below the top interior surface of the first mold portion; and,
molding tread material in the retread having the retread thickness, the retread thickness including a lateral groove in the retread formed by the lateral groove core, the lateral groove in fluid communication with the bottom side of the retread thickness to form a vent passageway in the retread thickness from the bottom longitudinal groove to the first side edge of the retread thickness without the lateral groove intersecting a top longitudinal groove and without the lateral groove being in fluid communication with the top side of the retread thickness, such that the top longitudinal groove is offset from the lateral groove within the retread thickness without any opening connecting the top longitudinal groove to the lateral groove and wherein a connecting portion core extends between the lateral groove core and the bottom interior surface of the second mold portion, the connecting portion core having a width less than a width of the lateral groove core.

7. The method of forming a tire tread of claim 6 , where the first mold portion having first engaging surfaces and the second mold portion having second engaging surfaces oppositely positioned when the first mold portion and the second mold portion are positioned together such that a compressible material is positioned between the first and second engaging surfaces to form a gap between the lateral groove core and the bottom longitudinal groove core, the method further comprising the step of: pressing the first and second mold portions together compressing the compressible material forming contacting engagement between the lateral groove core and the bottom longitudinal groove core.

8. A mold for forming a tire tread for a retread tire comprising:
a first mold portion and a second mold portion cooperatively positionable together to form a cavity there between for molding a plurality of tread wear layers forming a retread thickness of a retread,
the first mold portion including a top interior surface for forming a top side of the retread thickness configured to engage a ground surface during tire operation,
the second mold portion including a bottom interior surface for forming a bottom side of the retread thickness configured to attach to a tire carcass,
the mold including a first interior side surface and a second interior side surface for forming a first side edge of the retread thickness and a second side edge of the retread thickness respectively, each extending longitudinally in a lengthwise direction of the retread, and where a width of the retread along the top side between the first side edge and the second side edge is less than a width of the retread along the bottom side between the first side edge and the second side edge, the mold including a top longitudinal groove core for forming a top longitud

Assignees

• Colby E Bruce
• Tsihlas Dimitri G
• Zarak Cesar E
• Ikonomov Metodi L
• Michelin & Cie

Inventors

• Colby E Bruce
• Tsihlas Dimitri G
• Zarak Cesar E
• Ikonomov Metodi L

Classifications

• B29D30/56

  Retreading with prevulcanised tread {(B29D30/542 takes precedence)} · CPC title

• B60C11/02

  Replaceable treads · CPC title

• B29D2030/582

  Venting air inclusions, e.g. air trapped between tread and carcass · CPC title

• B60C23/19

  for dissipating heat · CPC title

• B29C33/424

  Moulding surfaces provided with means for marking or patterning (for injection moulding B29C45/372) · CPC title