Injection molding method and apparatus with reduced piston leakage
AssigneeTakata Corporation
InventorKaname Kono
Life of this patent
Estimating the term…
Abstract
A metal injection molding apparatus is provided with features which reduce the amount of metal which enters the drive mechanism of the apparatus. The apparatus contains a piston having the head and the shaft, the shaft having a diameter smaller than the diameter of the head. At least one piston ring circumscribes the piston shaft. The apparatus contains an injection chamber having an accumulation portion and a shaft housing portion. The shaft housing portion has openings in the sidewalls and a polygonal internal cross section. The accumulation portion of the injection chamber is maintained at a higher temperature than the shaft housing portion.
Claims19
An injection molding apparatus, comprising:
- an injection chamber comprising an accumulation portion and a shaft housing portion;
- an injection member comprising a head and a shaft located in the injection chamber;
- at least one protrusion adjacent to the shaft;
- the accumulation portion having a circular internal cross section;
- and
- the shaft housing portion having a polygonal internal cross section.
An injection molding apparatus, comprising:
- a piston comprising a head and a shaft, the shaft having a diameter smaller than a diameter of the head;
- a first injection chamber portion having a front end, a back end and a cavity having a circular internal cross section and containing the piston head;
- a second injection chamber portion joined to the back end of the first chamber portion, the second chamber portion having a front end, a back end and a cavity having a polygonal internal cross section and containing the piston shaft;
- at least one opening in at least one side wall of the second injection chamber portion;
- and
- at least one piston ring circumscribing the piston shaft.
An injection molding apparatus, comprising:
- an injection chamber comprising an accumulation portion and a shaft housing portion;
- an injection piston comprising a head and a shaft located in the injection chamber;
- at least one ring circumscribing the shaft;
- the accumulation portion having a circular internal cross section;
- the shaft housing portion having a polygonal internal cross section;
- and
- at least one opening in a side wall of the shaft housing portion.
Dependencies are inferred from the claim text.