One-way valve for medical infusion lines and the like

A one-way valve for medical infusion lines comprising:

• a first tubular element and a second tubular element, which define, respectively, a passage upstream and a passage downstream which are coaxial to one another and transversely set between which is a diaphragm made of elastically deformable material co-operating in a fluid-tight way with an annular valve seat of said first tubular element to keep said valve normally closed,
• wherein a predetermined pressure of fluid in said passage upstream brings about a displacement or an elastic deformation of said diaphragm and consequent opening of said valve;
• said annular valve seat defined by a wall with a conical surface of said first tubular element diverging towards said second tubular element;
• said diaphragm comprising an end wall of a cup-shaped element having an outer peripheral edge, said outer edge normally pressed in sealed contact against said annular valve seat under an axial thrust exerted by a side wall of said cup-shaped element wherein a deflection or an axial displacement of said end wall of the cup-shaped element is brought about in use by said predetermined pressure of fluid determining a radial contraction of said outer peripheral edge and a consequent separation of said outer edge from said annular valve seat wherein said side wall of the cup-shaped element has a free edge resting against a grooved transverse surface of said second tubular element communicating with said passage downstream;
• said grooved transverse surface having a plurality of radial channels, said radial channels alternately angularly separated from each other by raised angular resting portions and sunken angular non-resting portions, said free edge of the side wall of said cup-shaped element being in contact only with said resting portions and avoiding contact with said non-resting portions, said sunken angular non-resting portions extending further toward said diaphragm than said plurality of channels extends toward said diaphragm and less than said resting portions extend toward said diaphragm.