Patent ID: 8235701
Filing Date: 2012-08-07
Classification: B29C,B29L

Abstract:
1. Apparatus comprising: a die mounted, in an extrusion die assembly having a central axis, said die being mounted in a coaxial relation with the central axis and displaced outward from the central axis to define a passage for the flow of material, the die further being mounted for movement to allow adjustment of the die with respect to the central axis; a die retainer configured to engage the die and secure the die in the extrusion die assembly; at least one compound screw adjustment assembly mounted in the die retainer configured to apply a force to the die in a first inward direction; and at least one spring loaded plunger mounted in the die retainer to apply a spring biased force on the die in a second inward direction opposite to the first inward direction, said spring biased force being weaker than the force exerted by the compound screw adjustment assembly so that movement of the die is allowed as the compound screw applies a force that exceeds the spring biased force, wherein the compound screw adjustment assembly comprises: a primary screw element constructed with an external thread for engagement with a matching thread constructed in an inward extending bore in the die retainer, the primary screw element is adapted to be engaged in the bore for movement in an inward direction as the primary screw element is rotated in threaded engagement with the die retainer bore, the primary screw element having an outer end accessible by a tool for applying a torque to the primary screw element and an inward extending end, said primary screw element further having an internal thread formed in a bore constructed in the inward extending end; a pusher element mounted in threaded engagement with said internal threads of said primary screw element to provide an inward extension of the primary screw element for engagement with the die, the pusher element comprising a locking mechanism configured to prevent rotation in the die retainer bore, wherein said external thread and said internal thread are constructed with a first and a second pitch respectively and wherein said first and second pitches are different and selected to allow relative motion of the primary screw element and the pusher element, and wherein said first and second pitches are further selected to provide a positive motion of the compound screw adjustment assembly toward the die, and wherein said locking mechanism comprises a key fixedly attached to said pusher element and configured to engage a slot formed in the die retainer bore.