Injection molding machine with pressure assist nozzle

Claim 2

An injection apparatus comprising: extruder means for supplying molten plastic; nozzle means for directing said molten plastic, said nozzle means being in fluidic communication with said extruder means via a fluidic passage, said fluidic passage having a bore wherein, said bore defining an aperture within said fluidic passage; an annular sleeve reciprocally residing within said bore, said annular sleeve being reciprocated between an extended position and a retracted position by actuating means, said annular sleeve closing said aperture when said annular sleeve is in an intermediate position between said retracted position and said extended position; and a plunger piston reciprocally residing within said annular sleeve, said plunger piston having engagement means in communication with said annular sleeve, said engagement means acting to couple said plunger piston with said annular sleeve as said annular sleeve traverses from said intermediate position to said extended position, said plunger piston thereby acting to reduce said internal volume of said fluidic passage.

Claim 3

An injection apparatus as claimed in claim 1, wherein said bore defines a passage portion and a plunger portion, said annular sleeve reciprocating within both said passage portion and said plunger portion, said aperture being located in a wall of said passage portion.

Claim 4

An injection apparatus as claimed in claim wherein said annular sleeve has an abutment means in communication with said engagement means, said abutment means engaging said engagement means when said annular sleeve is at said intermediate position.

Claim 5

An injection apparatus as claimed in claim 1, wherein said extruder means is operable to displace a fluidic injection material from said extruder means through said fluidic passage to said nozzle means.

Claim 6

An injection apparatus as claimed in claim 4, wherein said actuating means traverses said annular sleeve from said retract position to said intermediate position after said extruder means displaces a predetermined quantity of said fluidic injection material, said annular sleeve thereby closing said aperture to prevent further displacement of said fluidic injection material from said extruder means.

Claim 7

An injection apparatus as claimed in claim 5, wherein said plunger piston acts to compress and pressurize said fluidic injection material within said nozzle means while said plunger piston is being traversed with said annular sleeve from said intermediate position to said extend position.

Claim 8

An injection molding apparatus providing a two step shut off and compression action upon a molten plastic, said injection mold apparatus comprising: an extruder; an extruder nozzle in fluidic communication with said extruder via a fluidic passage, said fluidic passage defining an internal volume between said extruder and said extruder nozzle; a bore defining a portion of said fluidic passage, said bore having an aperture in a side wall thereof, said aperture providing fluidic communication between said extruder and said extruder nozzle therethrough, said bore extending beyond said fluidic passage to form a plunger bore; a plunger reciprocally residing within said plunger bore, said plunger being reciprocated by actuating means between an extended position and a retracted position, said plunger having a plunger end extending toward said bore when said plunger is in said extended position; an annular sleeve attached to said plunger end, said annular sleeve being reciprocable within said plunger bore and said bore by said plunger, said annular sleeve closing said aperture of said bore when said plunger is in an intermediate position between said retracted position and said extended position, said annular sleeve having abutment means; and a plunger piston reciprocally residing within said annular sleeve, said plunger piston having engagement means in communication with said abutment means of said annular sleeve, said engagement means engaging said abutment means thereby urging said plunger piston into said bore while said plunger traverses from said intermediate position to said extended position, said plunger piston thereby acting to reduce said internal volume of said fluidic passage.

Claim 9

An injection molding apparatus providing a two step shut off and compression action upon a molten plastic, said injection mold apparatus comprising: an extruder; an extruder nozzle in fluidic communication with said extruder via a fluidic passage, said fluidic passage defining an internal volume between said extruder and said extruder nozzle; a bore defining a portion of said fluidic passage, said bore having an aperture in a side wall thereof, said aperture providing fluidic communication between said extruder and said extruder nozzle therethrough, said bore extending beyond said fluidic passage to form a plunger bore; a plunger reciprocally residing within said plunger bore, said plunger being reciprocated by actuating means between an extended position and a retracted position, said plunger having a plunger end extending toward said bore when said plunger is in said extended position; an annular sleeve attached to said plunger end, said annular sleeve being reciprocable within said plunger bore and said bore by said plunger, said annular sleeve closing said aperture of said bore when said plunger is in an intermediate position between said retracted position and said extended position, said annular sleeve having abutment means; and a plunger piston reciprocally residing within said annular sleeve, said plunger piston having engagement means in communication with said abutment means of said annular sleeve, said engagement means engaging said abutment means thereby urging said plunger piston into said bore while said plunger traverses from said intermediate position to said extended position, said plunger piston thereby acting to reduce said internal volume of said fluidic passage.

Claim 10

An injection molding apparatus as claimed in claim 7, wherein said annular sleeve performs a shut off action and said plunger piston performs a compression action to constitute said two step shut off and compression action.

Claim 11

An injection molding apparatus as claimed in claim 7, wherein said actuating means is a hydraulic actuating cylinder.

Claim 12

An injection molding apparatus as claimed in claim 7, further comprising a mounted housing mounted between said extruder and said injection manifold, said fluidic passage and said bore being formed within said housing.

Claim 13

An injection molding apparatus as claimed in claim 10, further comprising heating elements for heating said housing.

Claim 14

An injection molding apparatus as claimed in claim 10, further comprising an actuating housing, said actuating housing being mounted to said mounted housing, said plunger bore being formed in part within said actuator housing.

Claim 15

An injection molding apparatus as claimed in claim 7, wherein said extruder is operable to displace said molten plastic from said extruder through said fluidic passage to said extruder nozzle.

Claim 16

An injection molding apparatus as claimed in claim 13, wherein said actuating means traverses said plunger from said retract position to said intermediate position after said extruder displaces a predetermined volume of molten plastic, said annular sleeve thereby closing said aperture to prevent further displacement of said molten plastic from said extruder.

Claim 17

An injection molding apparatus as claimed in claim 13, wherein said plunger piston acts to compress and pressurize said molten plastic within said extruder nozzle while said plunger piston is being traversed with said annular sleeve from said intermediate position to said extend position.

Claim 18

An injection molding apparatus as claimed in claim 7, wherein said engagement means is a pin extending radially from said plunger piston and said abutment means is formed on a longitudinal slot within said annular sleeve, said pin traversing said slot between said retract and said intermediate positions, said pin abutting said abutment means between said intermediate and said extend positions.