Apparatus for forming plastic articles

Claim 1

In an apparatus for molding hollow plastic articles by first Producing a parison by injection molding and then expanding the parison by blow molding to produce the desired article, the improvement comprising, a. An injection head having an orifice adapted to supply molten thermoplastic material under pressure, b. A pair of blow molds respectively laterally positioned on opposite sides of said injection head, c. A pair of identical mold parts, each of which is alternatively cooperable with said injection head to define an injection molded parison cavity and with one of the blow molds to define a blow mold cavity conforming to the desired article, d. A frame carrying said mold parts, said parts being positioned on said frame to permit one said mold part to be aligned with the blow mold on one side of the injection head when the other mold part is aligned with the injection head and alternatively to permit said other mold part to be aligned with the blow mold on the other side of said injection head when said one mold part is aligned with the injection head, e. Means for laterally reciprocating said frame between a position where one of said mold parts is aligned with said injection head and a position where said one mold part is aligned with one of said blow molds, f. Power means for reciprocating said frame in an axial direction relative to said orifice to position said mold parts concurrently into and out of engagement respectively with the injection head and a blow mold, and g. Means yieldingly permitting limited axial movement of said blow molds relative to said injection head, whereby a greater clamping force is provided between the one said mold part and said injection head than between said other mold part and one said blow molds.