Single nozzle valve gate
AssigneePolyshot Corporation
InventorDOUGLAS C HEPLER
Life of this patent
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Abstract
An in-line single nozzle valve gate apparatus for injection molding comprises upper and lower rnatable annular cylinder bodies that house an annular dual sided piston having opposed pressure bearing upper and lower surfaces. The piston has a cross beam to which a valve gate pin is attached for movement therewith. The valve gate pin passes through a sprue bushing flow path to selectively open and close a part cavity gate. An interface is provided to receive molten plastic from the injection machine nozzle and pass it into the sprue bushing flow path. The cylinder bodies reside largely outside of the mold plate architecture to lessen thermal damage too piston seals.
Claims8
A single nozzle valve gate apparatus for use in a mold to convey molten plastic directly from an injection machine nozzle to a cavity formed within the mold, said apparatus comprising:
- a cylinder housing comprising upper and lower cylinder bodies structured to mate with one another to provide a pair of spaced apart interior annular cylinder spaces that face one another and an interior vertically extending through hole, said upper cylinder body having an outside diameter and height such that said upper cylinder body, including the upper one of said pair of spaced apart interior annular cylinder spaces, resides outside of a mold plate and serves as a ring for directly locating said valve gate apparatus with respect to the injection machine nozzle, said spaced apart interior annular cylinder spaces having ports for pressurization and depressurization of said spaced apart interior annular cylinder spaces;
- an annular dual sided piston having opposed pressure bearing upper and lower surfaces that fit respectively into said spaced apart upper and lower interior annular cylinder spaces, said annular dual sided piston having a cross beam that extends between the inner surfaces of said annular dual sided piston at approximately midway between its opposed upper and lower pressure bearing surfaces;
- a sprue bushing having a head and an elongated body having a tip, said sprue bushing having a central through bore extending from said head to said tip, said central through bore being at least in part for transporting molten plastic to said tip, said head having at least one angled flow path running between said head and said central through bore;
- an injection machine interface body for receiving molten plastic from the nozzle of the injection machine and transporting said molten plastic to said sprue bushing angled flow path after which said molten plastic enters said central through bore for travel to said tip;
- and
- a valve gate pin connected to said piston cross beam extending therefrom to said sprue bushing tip, said valve gate pin moving up and down with the motion of said piston in response to said annular spaced apart cylinder spaces being selectively pressurized and depressurized.
A single nozzle valve gate apparatus for use in a mold to convey molten plastic directly from an injection machine nozzle to a cavity formed within the, mold, said apparatus comprising:
- a cylinder housing consisting essentially of upper and lower cylinder bodies structured to mate with one another to provide a pair of spaced apart interior annular cylinder spaces that face one another and an interior vertically extending through hole, said upper cylinder body having an outside diameter and height such that said upper cylinder body, including the upper one of said pair of spaced apart interior annular cylinder spaces, resides outside of a mold plate and serves as the-a ring for directly locating said valve gate apparatus with respect to the injection machine nozzle, said spaced apart interior annular cylinder spaces having ports for pressurization and depressurization of said spaced apart interior annular cylinder spaces;
- an annular dual sided piston having opposed pressure bearing upper rand lower surfaces that fit respectively into said spaced apart upper and lower interior annular cylinder spaces, said annular dual sided piston having a cross beam that extends between said inner surfaces of said annular dual sided piston at approximately midway between said opposed upper and lower pressure bearing surfaces;
- an injection machine interface body for receiving molten plastic directly from the nozzle of the injection machine and transporting said plastic further downstream;
- and
- a valve gate pin connected to said piston cross beam, said valve gate pin moving up and down with the motion of said piston in response to said annular spaced apart cylinder spaces being selectively pressurized and depressurized.
Dependencies are inferred from the claim text.