Cock comprising indexable rotating key

A cock comprising a rotating key, the key of which rotates in a tubular housing of a barrel where the key has been axially introduced through an end of the housing up into an axial position determined by blocking means, the side wall of the housing including passages which open into an area of the housing through apertures while the key is designed with passage(s) for blocking these apertures or establishing a communication between certain apertures according to service positions of the key during a rotation of the key, the cock including in another area of the housing, indexing means in order to tactilely tell the operator that the key has arrived in a service position where it establishes a communication, these indexing means comprising stubs and notches distributed over the faces facing the key and the housing so that during a rotation of the key, the stubs penetrate the notches when the key arrives in a service position and may only emerge therefrom when a substantial force is exerted on the key to rotate it, the key or the barrel being designed in order to allow the stubs to emerge from the notches by an elastic effect resulting from this force, the housing including a closed base which has a raised element determining between it and the side wall of the housing, an annular groove, the key having at its end a ring which rotates in this groove, the stubs and the notches being formed on said raised element and said ring wherein said ring is elastically deformable in a plane transverse to the axis of rotation of the key, and the area where the indexing means are found, has a reduced diameter relative to the area into which said apertures open.