Extruder screw valve
OwnerPaul L. Stubbeinventor
Life of this patent
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Abstract
The invention disclosed herein is an injection molding machine unit having a barrel, with an injection nozzle on one end of the barrel and a screw ram movable in the barrel, a valve member with axially extending grooves in the periphery thereof, supported on the ram shaft, a ring on the ram shaft adjacent the valve. The ring has axially extending grooves in its outer periphery and the ring moves out of alignment with the grooves in the valve. The grooves of the ring form a fluid flow passage for plastic material to the injection nozzle when the screw is rotated and the ram is retracted. The valve closes when the ram moves forward.
Claims15
An injection molding unit comprising,
- a barrel having a generally cylindrical bore therein,
- said bore having its first end closed,
- a nozzle in said closed end,
- a screw having a first end and a second end,
- a ram head on said first end of said screw,
- said ram head having a shoulder means adjacent to said screw,
- a first valve part on the end of said screw adjacent said ram head engaging said shoulder,
- an intermediate part of said ram head extending from said shoulder means to said ram head, slidably receiving a second valve part thereon,
- said first valve part and said second valve part being generally cylindrical in shape and slidably and rotatably received in said barrel,
- flow means in the outer periphery of said first valve part and extending axially along said outer periphery the entire length of said first valve part and cooperating with means in the outer periphery of and extending axially along the entire length of said second valve part providing a flow passage between said nozzle and said barrel,
- said second valve part being adapted to move into seating engagement with said first valve part when said screw is moved in a direction toward the nozzle and means on said second valve part engagable with means on said first valve part holding said flow means in said valve parts out of alignment with each other when said valve parts engage each other interrupting flow from said screw to said nozzle,
- said second valve part being adapted to move away from said first valve part when said screw is moved in a direction away from said nozzle whereby material can flow from said screw into the space in said barrel adjacent said nozzle.
In combination, an injection molding machine having a barrel and a nozzle and a ram in said barrel and a valve supported on said ram adjacent said nozzle,
- said valve comprising a first valve part and a second valve part,
- support means supporting said first valve part on said ram,
- means slidably supporting said second valve part on said ram,
- said first valve part having an outer surface slidably received in said barrel,
- a seating surface on said first valve part,
- a seating surface on said second valve part,
- said second valve part being adapted to slide from a position when said seating surfaces engage each other to a position wherein said seating surfaces are spaced from each other,
- axially extending flow passages in the outer periphery of said first valve part extending the entire length of said outer periphery of said first valve part,
- flow passages in said second valve part extending along the entire length of the outer periphery of the second valve part,
- and restraining means holding said second valve part in a position to misalign said flow passages with said flow passages in said first valve part when said seating surfaces engage each other.
Dependencies are inferred from the claim text.