Rotary blow molding machine with moveable mold clamp assemblies and method
OwnerPaul M. Olesinventor
Life of this patent
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Abstract
A continuous blow molding machine includes a mechanism for shifting molds upstream after closing to reduce between-mold flash.
Claims24
The method of blow molding plastic containers using a rotary blow molding machine having a rotating frame, a plurality of blow molds mounted on the frame and spaced around the frame, a mold cavity in each mold, a mold shift mechanism for each mold and a fixed flow head, comprising the steps of:
- A) extruding a parison from the fixed flow head;
- B) rotating the frame to move the molds on the frame downstream past the parison;
- C) maintaining each mold open while moving the mold over the parison and then closing the mold on the parison;
- D) extruding the parison at a speed less than the circumferential speed the mold cavities located away from the parison move downstream with the rotating frame;
- and
- E) slowing downstream movement of each mold on the rotating frame by actuating the mold shift mechanism for the mold and thereafter closing the mold on the parison so that the slowed mold moves downstream at a speed essentially equal to the extrusion rate of the parison for essentially same speed capture in the mold and the mold is moved upstream on the rotating frame to a position adjacent to the next upstream mold to reduce flash between molds.
The method of blow molding plastic containers using a rotary blow molding machine having a rotating frame, a plurality of blow molds spaced around the rotating frame, a mold cavity in each mold and a flow head, comprising the steps of:
- A) extruding a parison from the flow head at a speed less than the circumferential speed of the mold cavities;
- B) rotating the frame downstream to move the molds past the parison;
- C) maintaining each mold open while moving the mold over the parison and then closing the mold on the parison;
- and
- D) moving each mold upstream on the rotating frame after closing of the mold on the parison so that the mold moves downstream at a rate essentially equal to the extrusion rate of the parison and the mold is located adjacent to the next upstream mold to reduce flash between the molds.
The method of blow molding plastic containers using a rotary blow molding machine having a rotating frame, a plurality of blow molds space around the rotating frame, a mold cavity in each mold, a mold shift mechanism for each mold and a fixed flow head, comprising the steps of:
- A) extruding a parison from the flow head;
- B) rotating the molds on the frame downstream past the parison;
- C) maintaining each mold open while moving the mold over the parison and then closing the mold on the parison;
- D) extruding the parison at a speed less than the circumferential speed of the molds when away from the parison;
- and
- E) moving each mold upstream on the rotating frame by actuating the mold shift mechanism for the mold and thereafter closing the mold on the parison so that the mold moves downstream at a rate essentially equal to the extrusion rate of the parison and the mold is located adjacent to the next upstream mold to reduce flash between the molds.
Dependencies are inferred from the claim text.