Evolving tread for a tyre

Abstract

Heavy goods vehicle tyre tread (1) of total thickness PMU, this tread in the new state having a tread surface (10) and comprising at least one cut (2) opening in the initial state onto the tread surface (10), this cut (2) being such that it comprises an external part (E) in the form of a groove (21) in a main direction, this groove (21) being of mean depth Pe less than 80% of the thickness PMU, an internal part (I) forming the end of the cut, this internal part having the form of a canal (22) of mean width Le and of mean height Hc, this canal being intended to form a new continuous groove after the tread has suffered partial wear at most equal to 80% of the thickness PMU; an intermediate part (X) making the connection between the internal part (I) and the external part (E), this intermediate part (X) comprising in alternation - in the main direction of the groove that forms the external part - a succession of wide parts (23) and of narrow parts (24), the wide parts (23) being suited to not closing up as they enter the contact patch and the narrow parts (24) being suited to closing up as they enter the contact patch thus limiting the reduction in stiffness of the tread which reduction is associated with the presence of this cut (2).

Description

technical field [0001] The present invention relates to tire treads, and more particularly to the design of the tread pattern of these treads and to tires provided with such treads, which have a permanent drainage of the standing water present on the road in rainy weather The ability of these treads improves ride performance. Background technique [0002] As is known, rainy driving conditions require water to be removed as quickly as possible from the contact patch in which each tire contacts the road in order to ensure the tread is in contact with the road. Water that is not pushed forward of the tire flows partly along the grooves and sipes formed in the tread of the tire, regardless of whether these grooves and sipe are oriented in the circumferential direction or in the transverse direction or Orient even along an oblique direction. [0003] By incision is meant any cavity created in the tread by molding, which incision extends in the main direction and into the depth ...

AI Technical Summary

Problems solved by technology

[0009] The disadvantage of creating multiple grooves in the tread is that the amount of tread material is reduced for a given width of the tread and thus has a significant effect on the stiffness of the tread

Therefore, in order to cope with the loads experienced during running, those skilled in the art need to compensate for said decrease in stiffness in any way available to them, and in particular by modifying the internal structure of the tyre, It is difficult to change the internal structure of the tire without affecting the cost price of the tire itself.

Said reduction in stiffness may also adversely affect the rate of wear, the uniformity of that wear and some desired aspects of performance during travel

[0010] Furthermore, it was found that there is an increase in rolling resistance which manifests itself in the form of a marked increase in the fuel consumption of vehicles fitted with such tires, said increase being related to the manufactured The result of increased hysteresis losses associated with the deformation cycle of the rubber material of the tread

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