Multiple mold for producing elongate tubular articles

Claim 1

A mold for simultaneously producing a plurality of elongate tubular plastic workpieces, comprising: a mold body provided with a central axis and with a chamber centered on said axis and flanked by a plurality of elongate parallel recesses each longitudinally divided by an intermediate step into a large-diameter section and a small-diameter section of generally cylindrical shape coaxial with each other; a stepped core extending into each recess and defining therewith an elongate cavity with a first portion formed by said large-diameter section and a second portion formed by said small-diameter section, said portions having a common axis substantially parallel to said central axis and being interconnected by a generally transverse annular gap of greater width than said first and second portions, centered on said common axis and defined by confronting shoulders of said recess and said core, said chamber being provided with a plurality of peripherally spaced, generally radial injection orifices opening from the outside into the annular gaps of respective cavities at points proximal to said central axis; and a source of molten plastic mass under pressure communicating with said chamber for forcing said mass through said injection orifices into said annular gap and thence into both said portions of each cavity.