BALL JOINT DEVICE

1 . A ball joint device having an outer cage and a spherical ball, anti-friction means being interposed between the outer cage and the spherical ball, wherein the ball joint device includes wear detection means co-operating with the anti-friction means between the outer cage and the spherical ball, the wear detection means having a first color that is distinct from a second color of said anti-friction means in order to indicate wear visually by means of a change in color.

2 . A device according to claim 1 , wherein the wear detection means are fastened on an outer wall of said spherical ball facing the outer cage, said anti-friction means being fastened to the wear detection means and covering the wear detection means, the anti-friction means being in contact with the outer cage and movable relative to said outer cage.

3 . A device according to claim 2 , wherein said anti-friction means present a friction thickness (e 1 ) that is less than or equal to a maximum amount of play due to wear in order to no longer cover said wear detection means, at least locally, when the maximum amount of play due to wear is reached.

4 . A device according to claim 1 , wherein said anti-friction means are secured to an inner wall of the outer cage facing the spherical ball, the wear detection means being fastened on said spherical ball and being in contact with said anti-friction means and movable relative to the anti-friction means.

5 . A device according to claim 4 , wherein said wear detection means present a wear thickness (e 2 ) less than or equal to a maximum amount of play due to wear so as to no longer cover said spherical ball, at least locally, when the maximum amount of play due to wear is reached.

6 . A device according to claim 1 , wherein said anti-friction means are secured to an inner wall of the outer cage facing the spherical ball, said wear detection means comprising a liquid dye that is arranged in a plurality of receptacles, each receptacle being formed at least in part in said anti-friction means.

7 . A device according to claim 6 , wherein said anti-friction means comprises a plurality of grooves open to said inner wall, each receptacle being defined by said outer cage and said anti-friction means.

8 . A device according to claim 7 , wherein the outer cage includes notches in register with each of the grooves, each receptacle being defined by a groove and a corresponding notch.

9 . A device according to claim 6 , wherein said anti-friction means presents a buffer thickness (e 3 ) between each receptacle and said spherical ball, said buffer thickness (e 3 ) being less than or equal to a maximum amount of play due to wear.