Injector Nozzle Tip for Plastic Injection Molding Machines

Structure applicable/applied to the end of an injector for injection molding of molten material, the structure comprising from the inside out:

• a nozzle tip formed of a first, second and third portions defining a channel inside the nozzle tip for molten material to be injected, wherein
• the first portion has a first cross-section,
• the second portion has a second cross-section smaller than the first cross-section and is provided at a free end thereof with an outlet for the molten material, and
• the third portion joins the first cross-section and the second cross-section;
• a sleeve or overlay mounted on the external surface of the nozzle tip to enclose it in correspondence with the first portion, the third portion and partially the second portion,
• wherein the second portion has an annular zone uncovered by the sleeve or overlay only in proximity of said end;
• a cup-shaped terminal member having
• an axial central hole delimited by first edges and
• an opening having a diameter greater than the central hole and delimited by second edges;
• a ring nut axially comprising, in order, the sequence of
• a hollow cylindrical body threaded for attachment, e.g. by screwing, to the rest
• of the injector,
• a flange, and
• a circular lip,
• the cylindrical body, the flange and the circular lip being mounted to completely enclose the sleeve or overlay at least at the first portion and partially at the third portion,
• wherein said terminal member extends between the circular lip and the annular zone so that
• the first edges are in contact with and surround the annular zone and
• the second edges surround a terminal portion of the sleeve or overlay.