Double parison die head control mechanism

Claim 1

In combination: a double parison extrusion die head having a pair of spaced, vertically movable, die core members extending from the upper surface thereof and operable to vary the wall thickness of parison tubes extruded from said head, and torque equalizing mechanism for actuating said die cores, said actuating mechanism comprising a composite shaft member having a driven section mounted on the top of said head for rotational movement on a horizontal axis normal to the core axes and in laterally adjacent parallel relation to a vertical plane joining and including the axial center lines of said spaced core members, and a driver section rigidly fixed at one end to a central attachment zone of the driven section in equally spaced relation to each of said die core center lines, said driver section at its other end extending outwardly of the driven section and being supported for rotational movement on the axis of the driven section, said other end having means engageable for imparting a rotational rocking movement to said driver section, said driven section having rocker elements extending therefrom at equally spaced positions relative to said central attachment zone, the outer ends of said rocker elements being interconnected with the upper ends of said die core members and engaged therewith for uniformly raising and lowering the latter in response to rocking movement imparted to said driven section, vertical wheel-type apparatus for successively blowmolding hollow articles and having circumferentially disposed means for supporting a plurality of radially disposed mold units in a revolving path of travel, each mold unit including an inner mold half and a radially movable outer mold half, said die head being stationarily supported at its outer end and projecting at its inNer end into adjacent relation with said revolving support means, and adjustable means engaged with said mold units for radially separating said halves and guiding an outer mold half in a predetermined orbital path outwardly of the top and outside wall of said die head and thereafter into a closely spaced mold-loading and then a closed mold condition below said head.