Injection mold

Claim 2

An injection mold comprising: a mold body containing a mold cavity and a nozzle chamber opening at one end into said cavity through a gate opening in the cavity wall and including separable mold body sections movable relative to one another between closed positions for molding a part in said cavity and open positions for removing the molded part from the cavity and having a parting plane intersecting said cavity, an injection nozzle in said chamber having a tip positioned within and smaller in diameter than said gate opening so as to define an annular injection orifice between said tip and the edge of said gate opening, said nozzle containing passages opening to said chamber through which a molten molding medium is adapted to be injected into said chamber, said molding medium flowing from said chamber into said mold cavity through said annular orifice, and means movably supporting said nozzle on one mold body section for relatively free centering movement of the nozzle laterally of the axis of said gate opening by the pressure of the molding medium passing through said orifice to permit centering of said nozzle tip in said gate opening by said molding medium.

Claim 3

An injection mold according to claim 1 wherein: said nozzle includes a nozzle body extending axially through said chamber and terminating at one end in said nozzle tip, and said chamber and nozzle body are conically tapered to a decreasing diameter in the direction of said gate opening.

Claim 4

An injection mold according to claim 2 wherein: said chamber and nozzle body have different taper angles, such that the cross-sectional area of the annular chamber space between the nozzle body and the chamber wall decreases in the direction of said gate opening.

Claim 5

An injection mold according to claim 1 wherein: said nozzle supporting means comprises a wall member extending across the opposite end of said chamber and slidably seating the opposite end of said nozzle for self-centering movement of the latter laterally of said gate opening axis.

Claim 6

An injection mold according to claim 4 wherein: said nozzle includes a nozzle body extending axially through said chamber and terminating at one end in said nozzle tip and a nozzle ring surrounding the opposite end of said nozzle body and slidably seating on said wall member, and said nozzle passages include a passage extending axially through said nozzle body and communicating with a passage in said wall member through which said molding medium enters said nozzle body, and injection ports opening laterally through the wall of said nozzle body into said chamber.

Claim 7

An injection mold according to claim 5 wherein; said nozzle includes a nozzle body extending axially through said chamber and terminating at one end in said nozzle tip, and said chamber and nozzle body are conically tapered to a decreasing diameter in the direction of said gate opening.

Claim 8

An injection mold according to claim 6 wherein: said chamber and nozzle body have different taper angles, such that the cross-sectional area of the annular chamber space between the nozzle body and the chamber wall decreases in the direction of said gate opening.

Claim 9

An injection mold according to claim 7 including: an infeed hot box within said mold body which furnishes said nozzle supporting wall member and contains an infeed passage communicating with said wall member passage through which said molding medium flows to said nozzle, means for heating said hot box, and said nozzle member is constructed of a material having high thermal conductivity.

Claim 10

An injection mold according to claim 1 wherein: said nozzle supporting means comprises an infeed hot box in said mold body having a wall member extending across the opposite end of said chamber and slidably seating the opposite end of said nozzle for self-centering movement of the nozzle laterally of said gate opening axis, and an infeed passage opening through said wall member to said nozzle passages through which said molding medium is fed to said nozzle, means for heating said hot box, and said nozzle is constructed of a material having high thermal conductivity.

Claim 11

An injection mold according to claim 9 including: a second mold cavity intersected by said parting plane and communicating nozzle chamber in said mold body spaced along said hot box from said first mentioned cavity and chamber, a second injection nozzle in said second chamber having a tip positioned within the gate opening communicating said second cavity and chamber and slidably seating against said wall member for self-centering movement of said second nozzle in said latter gate opening, and passages in said second nozzle communicating with said hot box infeed passage and opening to said second chamber.

Claim 12

An injection mold according to claim 10 wherein: each of said nozzles includes a nozzle body extending axially through the corresponding nozzle chamber and terminating at one end in the respective nozzle tip, and each chamber and nozzle body are conically tapered to a decreasing diameter in the direction of the respective gate opening.

Claim 13

An injection mold according to claim 11 wherein: each chamber and nozzle body have different taper angles, such that the cross-sectional View of the annular chamber space between the nozzle body and the chamber wall decreases in the direction of said gate opening.

Claim 14

An injection mold according to claim 1 wherein: said nozzle supporting means comprises an infeed hot box in said mold body having a wall member extending across the opposite end of said chamber and slidably seating the opposite end of said nozzle for self-centering movement of the nozzle laterally of said gate opening axis, and an infeed passage opening through said wall member to said nozzle passages through which said molding medium is fed to said nozzle, a second mold cavity at the side of said hot box opposite said first mentioned cavity, a second nozzle chamber between said second cavity and hot box opening at one end to said second cavity through a second gate opening in the cavity wall and opening at its other end toward the adjacent wall member of said hot box, a second injection nozzle in said second chamber having a tip at one end positioned within and smaller in diameter than said second gate opening so as to define a second annular injection orifice between the latter tip and the edge of said second gate opening, and passage opening to said second chamber through which said molding medium is adapted to be injected into said second chamber, said molding medium flowing from said second chamber into said second mold cavity through said second annular orifice to effect self-centering of said second nozzle tip in said second gate opening, the opposite end of said second nozzle seating slidably on said adjacent hot box wall member for self centering movement of said second nozzle laterally of the axis of said second gate opening, means for heating said hot box, said nozzles are constructed of a material having high thermal conductivity, and said mold body includes separable mold body sections having a parting plane parallel to said first parting plane and intersecting said second cavity.

Claim 15

An injection mold according to claim 13 wherein: each of said nozzles includes a nozzle body extending axially through the corresponding nozzle chamber and terminating at one end in the respective nozzle tip, and each chamber and nozzle body are conically tapered to a decreasing diameter in the direction of the respective gate opening.

Claim 16

An injection mold according to claim 14 wherein: each chamber and nozzle body have different taper angles, such that the cross-sectional view of the annular chamber space between the nozzle body and the chamber wall decreases in the direction of said gate opening.

Claim 17

An injection mold comprising: a mold body containing a mold cavity and a nozzle chamber opening at one end into said cavity through a gate opening in the cavity wall and including separable mold body sections having a parting plane intersecting said cavity, an injection nozzle in said chamber having a tip positioned within and smaller in diameter than said gate opening so as to define an annular injection orifice between said tip and the edge of said gate opening, said nozzle containing passages opening to said chamber through which a molten molding medium is adapted to be injected into said chamber, whereby said molding medium flows from said chamber into said cavity through said orifice, a hot box extending across the opposite end of said chamber and slidably seating the opposite end of said nozzle for relatively free centering movement of said nozzle laterally of the axis of said gate opening by the pressure of the molding medium flowing through said orifice to permit centering of said nozzle tip in said gate opening by said molding medium, said hot box containing an infeed passage communicating with said nozzle passage through which said molding medium is fed to said nozzle passages, means for heating said hot box, and said nozzle being constructed of a material having a relatively high thermal conductivity.

Claim 18

An injection mold comprising: a mold body containing a mold cavity and a nozzle chamber opening at one end into said cavity through a gate opening in the cavity wall and including separable mold body sections having a parting plane intersecting said cavity, an injection nozzle in said chamber having a tip positioned within and smaller in diameter than said gate opening so as to define an annular injection orifice between said tip and the edge of said gate opening, said nozzle containing passages opening to said chamber through which a molten molding medium is adapted to be injected into said chamber, whereby said molding medium flows from said chamber into said cavity through said orifice, a hot box extending across the opposite end of said chamber and slidably seating the opposite end of said nozzle for relatively free centering movement of said nozzle laterally of the axis of said gate opening by the pressure of the molding medium flowing through said orifice to permit centering of said nozzle tip in said gate opening by said molding medium, said hot box containing an infeed passage communicating with said nozzle passage through which said molding medium is fed to said nozzle passages, means for heating said hot box, and said nozzle being constructed of a material having a relatively high thermal conductivity.