Coupling for two conduits

A coupling device for joining a main conduit (1), said main conduit being a fluid collector conduit, and a secondary conduit (2), said secondary conduit being a fluid injector conduit which forms a branch on the said main conduit so as to open through a lateral opening (12) into the said main conduit (1), the axis of said main conduit (1) and the axis of said second conduit intersecting, said second conduit (2) being attached to the main conduit by a collar (4, 32), including a tubular sleeve (3) disposed according to the axis (21) of the said secondary conduit (2), said sleeve having an entry mouth (33) in which said entry mouth (33) is connected in a sealed manner to the said secondary conduit (2) and having its end (34) engaged in the said lateral opening (12), providing an orifice, wherein:

• said sleeve (3) is shaped to converge in the direction of the axis (21) of the secondary conduit, in a sense directed from the outside towards the axis (11) of the main conduit (1), an edge (31) of said end of the sleeve being shaped to match the surface of an imaginary cylinder which is coaxial with the axis of the main conduit whereby said sleeve is arranged completely within the said secondary conduit.