Tire stud provided with recesses configured to improve its retention in the tire

1. A stud for a tire, the tire comprising a tread made of rubber mix, the stud having an axis and two axial ends and comprising:

a first part configured to come into contact with the ground when the stud is fitted to the tire and the tire is rolling along the ground, said first part being positioned at one of the two axial ends of the stud;

a head configured to anchor the stud into the tread of the tire, said head being positioned at the other axial end of the stud and having no central recess along said axis; and

a body connecting said first part and said head of the stud, the mean diameter of said body being smaller than the mean diameter of said head of the stud, these mean diameters being measured at right angles to the axis of the stud,

wherein said head comprises at least one lateral recess opening onto a surface of said head, said at least one lateral recess being configured to be filled with rubber mix of the tread so as to provide additional anchorage for the stud in the tread,

wherein said at least one lateral recess opening onto a surface of said head is located in regions laterally spaced from the axis of the stud, and

wherein the combined surface area of the cross sections of said at least one lateral recess in said surface of said head is greater than or equal to 15% and less than or equal to 35% of the maximum cross section of said head at right angles to the axis of the stud.

2. The stud of claim 1 , wherein a mean axial depth of said at least one lateral recess is greater than or equal to 0.5 mm.

3. The stud of claim 1 , wherein said head has a flat surface at the opposite end to said first part and said at least one lateral recess opens onto said flat surface of the head.

4. The stud of claim 1 , wherein said head comprises a surface configured to act as an anti-pull-out surface and said at least one lateral recess opens onto said surface configured to act as an anti-pull-out surface.

5. The stud of claim 1 , wherein said head comprises a lateral surface and said at least one lateral recess opens onto said lateral surface.

6. The stud of claim 5 , wherein a mean radial depth of said at least one lateral recess is greater than or equal to 0.5 mm.

7. The stud of claim 1 , wherein the geometry of said at least one lateral recess is one or more of a parallelepiped, a prism, a pyramid, a hemisphere, a cylinder and an ellipsoid.

8. An assembly formed by a tire and at least one stud according to claim 1 .

9. The stud of claim 1 , wherein the cross section of said at least one lateral recess at the surface of said head is greater than or equal to 10% of the maximum cross section of said head at right angles to the axis of the stud.

10. A stud for a tire, the tire comprising a tread made of rubber mix, the stud having an axis and two axial ends and comprising:

a first part configured to come into contact with the ground when the stud is fitted to the tire and the tire is rolling along the ground, said first part being positioned at one of the two axial ends of the stud;

a head configured to anchor the stud into the tread of the tire, said head being positioned at the other axial end of the stud and having no central recess along said axis; and

a body connecting said first part and said head of the stud, the mean diameter of said body being smaller than the mean diameter of said head of the stud, these mean diameters being measured at right angles to the axis of the stud,

wherein said head comprises at least one lateral recess opening onto a surface of said head, said at least one lateral recess being configured to be filled with rubber mix of the tread so as to provide additional anchorage for the stud in the tread,

wherein said at least one lateral recess opening onto a surface of said head is located in regions laterally spaced from the axis of the stud, and

wherein the cross section of said at least one lateral recess at the surface of said head is greater than or equal to 10% of the maximum cross section of said head at right angles to the axis of the stud.

11. An assembly formed by a tire and at least one stud, the tire comprising a tread made of rubber mix, the stud having an axis and two axial ends and comprising:

a first part configured to come into contact with the ground when the stud is fitted to the tire and the tire is rolling along the ground, said first part being positioned at one of the two axial ends of the stud;

a head configured to anchor the stud into the tread of the tire, said head being positioned at the other axial end of the stud and having no central recess along said axis; and

a body connecting said first part and said head of the stud, the mean diameter of said body being smaller than the mean diameter of said head of the stud, these mean diameters being measured at right angles to the axis of the stud,

wherein said head comprises at least one lateral recess opening onto a surface of said head, said at least one lateral recess being configured to be filled with rubber mix of the tread so as to provide additional anchorage for the stud in the tread,

wherein said at least one lateral recess opening onto a surface of said head is located in regions laterally spaced from the axis of the stud, and

wherein the tire comprises a tread made of rubber mix, said tread having at least one stud hole comprising a cylindrical portion open to the outside of the tread, said at least one stud hole being configured to accept said at least one stud, wherein the tread comprises a projecting part situated on the inside of said at least one stud hole and configured to fill said at least one lateral recess of said at least one stud when said at least one stud is fitted into said at least one stud hole.