Connecting piece for profiled pipes, profiled nipples, corrugated tubes or the like elongate articles

A connecting piece into which is axially insertable in an insertion direction a profiled pipe member having parallel external grooves transverse of said insertion direction, said connecting piece comprising:

• (a) connecting sleeve having an entry end for receiving said profiled pipe member and defining a cylindrical wall with a plurality of apertures extending radially through said wall, and (b) a clamping ring which is axially displaceable in said connecting sleeve and which is provided with a plurality of pressure fingers which extend generally parallel to a longitudinal axis of said sleeve and which are resilient and pivotable radially outward, and wherein in a fixing position each of said pressure fingers is positioned generally adjacent a respective one of said apertures, each of said pressure fingers having a nose part projecting radially inward which is engagable into one of said external grooves of said profiled pipe member, and wherein at least one of said apertures defines a transverse edge forming a barrier portion which projects in a direction opposite to said insertion direction, said barrier portion having a sloping surface which is inclined outwardly from said insertion direction and each of said pressure fingers having an inner surface which bears slidably against said sloping surface of said barrier portion, and wherein upon insertion of said profiled pipe member into said connecting piece said nose parts of said pressure fingers move radially inward into said groove of said profiled pipe member, thus axially fixing it relative to said connecting member, and said pressure fingers are subsequently movable radially outward to free said profiled pipe member when said clamping ring is urged axially in said insertion direction such that said inner surfaces of said pressure fingers slidably bear against said sloping surfaces of said barrier portion and said pressure fingers are driven radially outward into the area of said apertures.