Injection molding apparatus

Claim 2

Injection molding apparatus comprising a rotatable member having a plurality of mold assemblies disposed about the periphery thereof, each mold assembly having an injection chamber and an openable mold cavity, said injection chamber having a volume substantially equal to the volume of the mold cavity, said injection chamber having an outlet into said mold cavity and an inlet opening, means for substantially continuously rotating said rotatable member and said mold assemblies, stationary molten plastic extruder means disposed adjacent the periphery of the rotatable member and having a stationary outlet arranged to directly contact said injection chamber inlet opening to continuously supply molten thermoplastic material directly into the injection chamber of a mold assembly as it is continuously moved past said extruder outlet, each mold assembly having injection means arranged for movement into said injection chamber after said mold assembly has moved past said extruder outlet to inject the molten thermoplastic material in said injection chamber into said mold cavity, means for opening each of said molds after the molten material injected therein has solidified, and means for closing the mold after removal of the solidified material therefrom and before the mold reaches the extruder outlet.

Claim 3

The invention according to claim 1 wherein said rotatable member is rotated substantially continuously.

Claim 4

The invention according to claim 1 wherein said rotatable member moves in a substantially horizontal plane and said molds open and close substantially vertically.

Claim 5

The invention according to claim 1 including means for removing the solidified material in a predetermined orientation and maintaining said orientation while said part is transferred to a conveyor.

Claim 6

Continuous thermoplastic injection molding apparatus comprising a stationary base member, a rotor member mounted on said base member for horizontal rotation thereabout, means arranged to continuously rotate said rotor member, a plurality of mold assemblies mounted about the outer periphery of said rotor member, each of said mold assemblies comprising an assembly base member mounted on the outer periphery of said rotor member, a stationary mold member mounted on the assembly base member and having a first die, a movable mold member mounted on the assembly base member and having a second die, said movable die arranged to mate in molding engagement with said stationary die to form a mold cavity, means to space said dies apart with substantially no alignment members extending therebetween, means forming at least one injection chamber disposed in one of said mold members and having a total volume only slightly greater than the volume of said mold cavity, said injection chamber having an outlet opening through a sprue opening into said mold cavity and an inlet opening through an outer surface of said injection chamber forming means, and stationary extruder means having a stationary outlet arranged to directly contact said injection chamber inlet opening to continuously supply molten thermoplastic directly into said injection chamber as said mold assemblY with said injection chamber, substantially continuously moves past said stationary extruder outlet, each of said mold assemblies including a ram means arranged to force thermoplastic in said injection chamber into said mold chamber.

Claim 7

Continuous thermoplastic injection molding apparatus comprising a stationary base member, a rotor member mounted on said base member for horizontal rotation thereabout, means arranged to continuously rotate said rotor member, a plurality of mold assemblies mounted about the outer periphery of said rotor member, each of said mold assemblies comprising an assembly base member mounted on the outer periphery of said rotor member, a stationary mold member mounted on the assembly base member and having a first die, a movable mold member mounted on the assembly base member and having a second die, said movable die arranged to mate in molding engagement with said stationary die to form a mold cavity, means to space said dies apart with substantially no alignment members extending therebetween, means forming at least one injection chamber disposed in one of said mold members and having a total volume only slightly greater than the volume of said mold cavity, said injection chamber having an outlet opening through a sprue opening into said mold cavity and an inlet opening through an outer surface of said injection chamber forming means, and stationary extruder means having a stationary outlet arranged to directly contact said injection chamber inlet opening to continuously supply molten thermoplastic directly into said injection chamber as said mold assemblY with said injection chamber, substantially continuously moves past said stationary extruder outlet, each of said mold assemblies including a ram means arranged to force thermoplastic in said injection chamber into said mold chamber.

Claim 8

Continuous thermoplastic injection molding apparatus comprising a stationary base member, a rotor member mounted on said base member for horizontal rotation thereabout, drive means arranged to continuously rotate said rotor member, a plurality of mold assemblies mounted about the outer periphery of said rotor member, each of said mold assemblies comprising a substantially vertically disposed assembly base member mounted on the outer periphery of said rotor member, a lower stationary mold member mounted on the lower portion of said assembly base member and having a female die, an upper movable mold member mounted on the upper portion of said assembly base member and having a male die, said upper mold die arranged to mate in molding engagement with said lower mold die to form a mold cavity, part ejector means disposed in said upper mold member, means arranged to vertically lift said upper mold member from said lower mold member whereby said mold members are vertically spaced apart, said upper mold lifting means operable after lifting said upper mold to actuate said part ejector means, means forming an injection chamber disposed beneath said lower mold member, said injection chamber opening upwardly through a sprue opening into said mold cavity and downwardly through the lower surface of said injection chamber forming means, a thermoplastic extruder disposed adjacent the periphery of said rotor member and having a feed plenum for the thermoplastic material disposed contiguous with the lower surface of said injection chamber forming means, said feed plenum having an outlet slot conforming to the path followed by the injection chamber opening in the lower surface of said injection chamber forming means, said outlet slot having a length substantially equal to the distance between injection chamber openings in adjacent mold assemblies and arranged to feed molten thermoplastic into said injection chamber as said mold assembly moves past said feed plenum, said thermoplastic extruder having means arranged to maintain the feed plenum outlet slot in contact with the lower surface of said injection chamber with a predetermined pressure regardless of vertical motion of said lower surface during rotation of said rotor member, each of said mold assemblies including a vertically movable injection ram mounted on the lower portion of said assembly base member below said lower mold member and arranged for movement into and out of said injection chamber, means arranged to drive said ram upwardly to force thermoplastic in said injection chamber into said mold cavity and to withdraw said ram downwardly out of said injection chamber and to space the upper end of said ram from the lower surface of said injection chamber forming means, means operable in response to the position of said mold assembly about the periphery of said base member to cause said mold cavity to be closed and the upper end of said injection ram to be spaced from the lower surface of the injection chamber before that mold assembly reaches said feed plenum and, after passing said feed plenum, to cause said injection ram to be driven upwardly into said injection chamber to force thermoplastic therein into said mold cavity and to withdraw said ram downwardly out of said injection chamber after a time sufficient to permit said thermoplastic to solidify in said mold cavity, said means operable in response to the position of said mold assembly about the periphery of said base member arranged to cause said upper mold member to be lifted opening said mold cavity after said ram is withdrawn, and conveyor means disposed adjacent said holding apparatus arranged to extend between said open mold members, said conveyor means having a path of movement substantially coincident with the path of movement of saiD mold assembly at the location where said conveyor means extends between said open mold members, and means arranged to cause a solidified plastic part to be ejected from said upper mold member directly onto said conveyor means.

Claim 9

Continuous thermoplastic injection molding apparatus comprising a stationary base member, a rotor member mounted on said base member for horizontal rotation thereabout, drive means arranged to continuously rotate said rotor member, a plurality of mold assemblies mounted about the outer periphery of said rotor member, each of said mold assemblies comprising a substantially vertically disposed assembly base member mounted on the outer periphery of said rotor member, a lower stationary mold member mounted on the lower portion of said assembly base member and having a female die, an upper movable mold member mounted on the upper portion of said assembly base member and having a male die, said upper mold die arranged to mate in molding engagement with said lower mold die to form a mold cavity, part ejector means disposed in said upper mold member, means arranged to vertically lift said upper mold member from said lower mold member whereby said mold members are vertically spaced apart, said upper mold lifting means operable after lifting said upper mold to actuate said part ejector means, means forming an injection chamber disposed beneath said lower mold member, said injection chamber opening upwardly through a sprue opening into said mold cavity and downwardly through the lower surface of said injection chamber forming means, a thermoplastic extruder disposed adjacent the periphery of said rotor member and having a feed plenum for the thermoplastic material disposed contiguous with the lower surface of said injection chamber forming means, said feed plenum having an outlet slot conforming to the path followed by the injection chamber opening in the lower surface of said injection chamber forming means, said outlet slot having a length substantially equal to the distance between injection chamber openings in adjacent mold assemblies and arranged to feed molten thermoplastic into said injection chamber as said mold assembly moves past said feed plenum, said thermoplastic extruder having means arranged to maintain the feed plenum outlet slot in contact with the lower surface of said injection chamber with a predetermined pressure regardless of vertical motion of said lower surface during rotation of said rotor member, each of said mold assemblies including a vertically movable injection ram mounted on the lower portion of said assembly base member below said lower mold member and arranged for movement into and out of said injection chamber, means arranged to drive said ram upwardly to force thermoplastic in said injection chamber into said mold cavity and to withdraw said ram downwardly out of said injection chamber and to space the upper end of said ram from the lower surface of said injection chamber forming means, means operable in response to the position of said mold assembly about the periphery of said base member to cause said mold cavity to be closed and the upper end of said injection ram to be spaced from the lower surface of the injection chamber before that mold assembly reaches said feed plenum and, after passing said feed plenum, to cause said injection ram to be driven upwardly into said injection chamber to force thermoplastic therein into said mold cavity and to withdraw said ram downwardly out of said injection chamber after a time sufficient to permit said thermoplastic to solidify in said mold cavity, said means operable in response to the position of said mold assembly about the periphery of said base member arranged to cause said upper mold member to be lifted opening said mold cavity after said ram is withdrawn, and conveyor means disposed adjacent said holding apparatus arranged to extend between said open mold members, said conveyor means having a path of movement substantially coincident with the path of movement of saiD mold assembly at the location where said conveyor means extends between said open mold members, and means arranged to cause a solidified plastic part to be ejected from said upper mold member directly onto said conveyor means.

Claim 10

The invention according to claim 6 wherein said mold assemblies are mounted substantially contiguously about the periphery of said rotor member and wherein the lower surfaces of all said injection chamber forming means are in a substantially common horizontal plane.

Claim 11

The invention according to claim 6 wherein means is provided for individually horizontally and vertically aligning said mold assemblies on said rotor member.

Claim 12

The invention according to claim 6 wherein said upper mold lifting means and said injection ram drive means are hydraulic cylinders.

Claim 13

The invention according to claim 9 wherein a hydraulic fluid reservoir is disposed in the lower central portion of said stationary base member with means including a hydraulic fluid manifold disposed on the inner periphery of said rotor means communicating said reservoir with said hydraulic cylinders of said mold assemblies.

Claim 14

Continuous thermoplastic injection molding apparatus comprising a stationary base member, a rotor member mounted on said base member for horizontal rotation thereabout, variable speed drive means arranged to continuously rotate said rotor member, a plurality of mold assemblies mounted contiguously about the outer periphery of said rotor member, each of said mold assemblies comprising a substantially vertically disposed C-shaped assembly base member removably mounted on the outer periphery of said rotor member, a lower vertically stationary mold member mounted on the lower portion of said C-shaped assembly base member and having a female mold die disposed substantially horizontally on the top surface of the lower mold member, an upper movable mold member mounted on the upper portion of said C-shaped assembly base member and having a male mold die disposed substantially horizontally on the bottom surface of the upper mold member, said upper mold die arranged to mate in molding engagement with said lower mold die to form a mold cavity, part ejector means disposed in said upper mold member, hydraulic cylinder means arranged to vertically lift said upper mold member from said lower mold member whereby said mold members are vertically spaced apart with substantially no alignment members extending therebetween, said upper mold lifting hydraulic cylinder means operable after lifting said upper mold to actuate said part ejector means, means forming an injection chamber disposed beneath said lower mold member, said injection chamber opening upwardly through a sprue opening into said mold cavity and downwardly through the lower surface of said injection chamber forming means, a thermoplastic extruder disposed substantially perpendicular to the periphery of said rotor member and having a feed plenum for the thermoplastic material disposed contiguous with the lower surface of said injection chamber forming means, said feed plenum having an arcuate outlet slot conforming to the path followed by the injection chamber opening in the lower surface of said injection chamber forming means, said arcuate outlet slot having a length substantially equal to the distance between injection chamber openings in adjacent mold assemblies and arranged to feed molten thermoplastic into said injection chamber as said mold assembly moves past said feed plenum, said feed plenum having a single inlet opening connected to the outlet of said thermoplastic extruder and a plurality of flow paths therefrom to said outlet slot whereby a substantially equal flow of thermoplastic is delivered to the full length of said slot, said thermoplastic extruder being pivotally supported about a vertical axis at the outer end thereof whereby it can be moved horizontally to disengage said feed plenum from the lower surface of said injection chamber forming means, said thermoplastic extruder being piVotally supported about a horizontal axis at the outer end thereof with a vertically acting hydraulic cylinder connected at the inner end thereof to maintain the feed plenum outlet slot in contact with the lower surface of said injection chamber with a predetermined pressure regardless of vertical motion of said lower surface during rotation of said rotor member, each of said mold assemblies including a vertically movable injection ram mounted on the lower portion of said C-shaped assembly base member below said lower mold member and arranged for movement into and out of said injection chamber, a hydraulic cylinder disposed beneath said injection ram and operably connected thereto, said hydraulic cylinder arranged to drive said ram upwardly to force thermoplastic in said injection chamber into said mold cavity and to withdraw said ram downwardly out of said injection chamber and to space the upper end of said ram from the lower surface of said injection chamber forming means, said injection ram arranged upon withdrawal from said injection chamber to remove the thermoplastic remaining therein, means for removing thermoplastic from said injection ram after withdrawal thereof from said injection chamber, a hydraulic fluid reservoir disposed in the lower central portion of said stationary base member, a hydraulic fluid manifold disposed on the inner periphery of said rotor means, means communicating said manifold with each of said mold assemblies and said hydraulic cylinders thereon, valve means cooperating with each of said hydraulic cylinders to control the flow of fluid from said manifold to said cylinders, pump means arranged to receive hydraulic fluid from said reservoir and to supply it to said manifold, a stationary upper mold cylinder cam member disposed about the periphery of said stationary base member, a stationary injection ram cylinder cam member disposed about the periphery of said stationary base member, cam follower means arranged with each of said valve means and cooperating with the respective cam members to selectively operate said hydraulic cylinders in response to the position of said mold assembly about the periphery of said base member, said cam members arranged to cause said mold cavity to be closed and the upper end of said injection ram to be spaced from the lower surface of the injection chamber before that mold assembly reaches said feed plenum and, after passing said feed plenum, to drive said injection ram upwardly into said injection chamber to force thermoplastic therein into said mold cavity, said injection ram cam member arranged to cause said ram to be withdrawn downwardly out of said injection chamber and to space the upper end of said ram from the lower surface of said injection chamber forming means after a sufficient time to permit said thermoplastic to solidify in said mold chamber, said upper mold cylinder cam member arranged to cause said upper mold member to be lifted opening said mold cavity, and a horizontally arranged conveyor means disposed adjacent said molding apparatus arranged to extend between said open mold members, said conveyor means having a part receiving upper surface which has a path of movement substantially coincident with the path of movement of said mold assembly at the location where said conveyor means extends between said open mold members, said conveyor means being pivotally mounted at one end thereof whereby said conveyor means is moved outward from between said mold members by the approach of a closed mold chamber, said upper mold cylinder ram member arranged to cause a part to be ejected from said upper mold member directly downward onto said conveyor upper surface with a predetermined orientation thereon.

Claim 15

Continuous thermoplastic injection molding apparatus comprising a stationary base member, a rotor member mounted on said base member for horizontal rotation thereabout, variable speed drive means arranged to continuously rotate said rotor member, a plurality of mold assemblies mounted contiguously about the outer periphery of said rotor member, each of said mold assemblies comprising a substantially vertically disposed C-shaped assembly base member removably mounted on the outer periphery of said rotor member, a lower vertically stationary mold member mounted on the lower portion of said C-shaped assembly base member and having a female mold die disposed substantially horizontally on the top surface of the lower mold member, an upper movable mold member mounted on the upper portion of said C-shaped assembly base member and having a male mold die disposed substantially horizontally on the bottom surface of the upper mold member, said upper mold die arranged to mate in molding engagement with said lower mold die to form a mold cavity, part ejector means disposed in said upper mold member, hydraulic cylinder means arranged to vertically lift said upper mold member from said lower mold member whereby said mold members are vertically spaced apart with substantially no alignment members extending therebetween, said upper mold lifting hydraulic cylinder means operable after lifting said upper mold to actuate said part ejector means, means forming an injection chamber disposed beneath said lower mold member, said injection chamber opening upwardly through a sprue opening into said mold cavity and downwardly through the lower surface of said injection chamber forming means, a thermoplastic extruder disposed substantially perpendicular to the periphery of said rotor member and having a feed plenum for the thermoplastic material disposed contiguous with the lower surface of said injection chamber forming means, said feed plenum having an arcuate outlet slot conforming to the path followed by the injection chamber opening in the lower surface of said injection chamber forming means, said arcuate outlet slot having a length substantially equal to the distance between injection chamber openings in adjacent mold assemblies and arranged to feed molten thermoplastic into said injection chamber as said mold assembly moves past said feed plenum, said feed plenum having a single inlet opening connected to the outlet of said thermoplastic extruder and a plurality of flow paths therefrom to said outlet slot whereby a substantially equal flow of thermoplastic is delivered to the full length of said slot, said thermoplastic extruder being pivotally supported about a vertical axis at the outer end thereof whereby it can be moved horizontally to disengage said feed plenum from the lower surface of said injection chamber forming means, said thermoplastic extruder being piVotally supported about a horizontal axis at the outer end thereof with a vertically acting hydraulic cylinder connected at the inner end thereof to maintain the feed plenum outlet slot in contact with the lower surface of said injection chamber with a predetermined pressure regardless of vertical motion of said lower surface during rotation of said rotor member, each of said mold assemblies including a vertically movable injection ram mounted on the lower portion of said C-shaped assembly base member below said lower mold member and arranged for movement into and out of said injection chamber, a hydraulic cylinder disposed beneath said injection ram and operably connected thereto, said hydraulic cylinder arranged to drive said ram upwardly to force thermoplastic in said injection chamber into said mold cavity and to withdraw said ram downwardly out of said injection chamber and to space the upper end of said ram from the lower surface of said injection chamber forming means, said injection ram arranged upon withdrawal from said injection chamber to remove the thermoplastic remaining therein, means for removing thermoplastic from said injection ram after withdrawal thereof from said injection chamber, a hydraulic fluid reservoir disposed in the lower central portion of said stationary base member, a hydraulic fluid manifold disposed on the inner periphery of said rotor means, means communicating said manifold with each of said mold assemblies and said hydraulic cylinders thereon, valve means cooperating with each of said hydraulic cylinders to control the flow of fluid from said manifold to said cylinders, pump means arranged to receive hydraulic fluid from said reservoir and to supply it to said manifold, a stationary upper mold cylinder cam member disposed about the periphery of said stationary base member, a stationary injection ram cylinder cam member disposed about the periphery of said stationary base member, cam follower means arranged with each of said valve means and cooperating with the respective cam members to selectively operate said hydraulic cylinders in response to the position of said mold assembly about the periphery of said base member, said cam members arranged to cause said mold cavity to be closed and the upper end of said injection ram to be spaced from the lower surface of the injection chamber before that mold assembly reaches said feed plenum and, after passing said feed plenum, to drive said injection ram upwardly into said injection chamber to force thermoplastic therein into said mold cavity, said injection ram cam member arranged to cause said ram to be withdrawn downwardly out of said injection chamber and to space the upper end of said ram from the lower surface of said injection chamber forming means after a sufficient time to permit said thermoplastic to solidify in said mold chamber, said upper mold cylinder cam member arranged to cause said upper mold member to be lifted opening said mold cavity, and a horizontally arranged conveyor means disposed adjacent said molding apparatus arranged to extend between said open mold members, said conveyor means having a part receiving upper surface which has a path of movement substantially coincident with the path of movement of said mold assembly at the location where said conveyor means extends between said open mold members, said conveyor means being pivotally mounted at one end thereof whereby said conveyor means is moved outward from between said mold members by the approach of a closed mold chamber, said upper mold cylinder ram member arranged to cause a part to be ejected from said upper mold member directly downward onto said conveyor upper surface with a predetermined orientation thereon.

Claim 16

The invention according to claim 11 wherein said injection ram cam member is arranged to cause said ram to be slightly retracted to reduce the residual pressure within the injection chamber after the sprue has solidified and before the solidification of the plastic remaining in the injection chamber.

Claim 17

Injection molding apparatus comprising a plurality of mold assemblies arranged to follow a closed path, each mold assembly including means defining at least one injection chamber having an inlet opening through which molten plastic material may be introduced into said chamber and an outlet, and an openable mold cavity which communicates with said chamber through said chamber outlet; the total volume of said injection chamber being substantially equal to the volume of the associated mold cavity; means for moving said mold assemblies along said closed path; substantially stationary means disposed adjacent the closed path having a stationary outlet arranged to directly contact said injection chamber inlet for substantially continuously extruding molten plastic material directly into said injection chambers while each of said injection chambers are, in turn, being moved relative to and past said extruding means outlet; each mold assembly further including respective injection means adapted to be moved into a respective injection chamber after a respective mold assembly has moved past said extruding means to inject the molten plastic material in said injection chamber into a respective mold cavity; and means for opening each mold cavity after the molten material injected therein has solidified and for closing each mold cavity after removal of the solidified material therefrom.

Claim 18

Injection molding apparatus comprising a plurality of mold assemblies arranged to follow a closed path, each mold assembly including means defining at least one injection chamber having an inlet opening through which molten plastic material may be introduced into said chamber and an outlet, and an openable mold cavity which communicates with said chamber through said chamber outlet; the total volume of said injection chamber being substantially equal to the volume of the associated mold cavity; means for moving said mold assemblies along said closed path; substantially stationary means disposed adjacent the closed path having a stationary outlet arranged to directly contact said injection chamber inlet for substantially continuously extruding molten plastic material directly into said injection chambers while each of said injection chambers are, in turn, being moved relative to and past said extruding means outlet; each mold assembly further including respective injection means adapted to be moved into a respective injection chamber after a respective mold assembly has moved past said extruding means to inject the molten plastic material in said injection chamber into a respective mold cavity; and means for opening each mold cavity after the molten material injected therein has solidified and for closing each mold cavity after removal of the solidified material therefrom.

Claim 19

The invention according to claim 13 wherein said moving means is adapted to move said mold assemblies in a closed path that is circular.

Claim 20

The invention according to claim 13 wherein said extruding means is adapted to extrude said molten material continuously and under constant pressure and said extruding means further includes means defining a feed plenum having an outlet slot conforming to a portion of the path followed by said injection chambers and along which path said injection chamber openings are adapted to be moved in close proximity to said slot, said outlet slot having a length at least equal to the distance between adjacent injection chamber openings of adjacent mold assemblies.

Claim 21

The invention according to claim 15 wherein each of said mold cavities has at least two injection chambers associated therewith both of which communicate with a respective one of said mold cavities.

Claim 22

Continuous plastic injection molding apparatus comprising a stationary base member; a rotor member mounted on said base member for horizontal rotation thereabout, means arranged to continuously rotate said rotor member; a plurality of mold assemblies mounted about the outer periphery of said rotor member, each of said mold assemblies comprising an assembly base member mounted on the outer periphery of said rotor member, a mold member relatively fixedly mounted on the assembly base member and having a first die, a mold member movably mounted on the assembly base member and having a second die, said second die arranged to mate in molding engagement with said first die to form a mold cavity, means to space said dies apart with substantially no alignment members extending therebetween, means forming at least one injection chamber disposed in one of said mold members, said injection chamber having a total volume substantially equal to the volume of the mold cavity and having an outlet opening through a sprue opening into said mold cavity and an inlet opening through an outer surface of said injection chamber forming means; and stationary means having a stationary outlet arranged to directly contact said injection chamber inlet opening for substantially continuously extruding molten plastic directly into said injection chamber as said mold assembly moves past said plastic extruding means outlet; each of said mold assemblies further including a ram means arranged to force plastic in said injection chamber into said mold chamber.

Claim 23

Continuous plastic injection molding apparatus comprising a stationary base member; a rotor member mounted on said base member for horizontal rotation thereabout, means arranged to continuously rotate said rotor member; a plurality of mold assemblies mounted about the outer periphery of said rotor member, each of said mold assemblies comprising an assembly base member mounted on the outer periphery of said rotor member, a mold member relatively fixedly mounted on the assembly base member and having a first die, a mold member movably mounted on the assembly base member and having a second die, said second die arranged to mate in molding engagement with said first die to form a mold cavity, means to space said dies apart with substantially no alignment members extending therebetween, means forming at least one injection chamber disposed in one of said mold members, said injection chamber having a total volume substantially equal to the volume of the mold cavity and having an outlet opening through a sprue opening into said mold cavity and an inlet opening through an outer surface of said injection chamber forming means; and stationary means having a stationary outlet arranged to directly contact said injection chamber inlet opening for substantially continuously extruding molten plastic directly into said injection chamber as said mold assembly moves past said plastic extruding means outlet; each of said mold assemblies further including a ram means arranged to force plastic in said injection chamber into said mold chamber.

Claim 24

Injection molding apparatus comprising a rotatable member having a plurality of mold assemblies disposed about the periphery thereof, each mold assembly having an inJection chamber and an openable mold cavity, said injection chamber having an outlet into said mold cavity and an inlet opening and having a volume slightly greater than the volume of the mold cavity, means for rotating said rotatable member and said mold assemblies, stationary molten plastic extruder means disposed adjacent the periphery of the rotatable member having a stationary outlet arranged to directly contact said injection chamber inlet opening to continuously supply molten thermoplastic material substantially directly into the injection chamber of a mold assembly as it is continuously moved past said extruder means, each mold assembly having an injection means arranged for movement into said injection chamber after said mold assembly has moved past said extruder means outlet to inject the molten thermoplastic material in said injection chamber into said mold cavity, means for opening each of said molds after the molten material injected therein has solidified, means for closing the mold after removal of the solidified material therefrom and before the mold reaches the extruder means outlet, and means for removing the excess material from said injection chamber.

Claim 25

Injection molding apparatus comprising a rotatable member having a plurality of mold assemblies disposed about the periphery thereof, each mold assembly having an inJection chamber and an openable mold cavity, said injection chamber having an outlet into said mold cavity and an inlet opening and having a volume slightly greater than the volume of the mold cavity, means for rotating said rotatable member and said mold assemblies, stationary molten plastic extruder means disposed adjacent the periphery of the rotatable member having a stationary outlet arranged to directly contact said injection chamber inlet opening to continuously supply molten thermoplastic material substantially directly into the injection chamber of a mold assembly as it is continuously moved past said extruder means, each mold assembly having an injection means arranged for movement into said injection chamber after said mold assembly has moved past said extruder means outlet to inject the molten thermoplastic material in said injection chamber into said mold cavity, means for opening each of said molds after the molten material injected therein has solidified, means for closing the mold after removal of the solidified material therefrom and before the mold reaches the extruder means outlet, and means for removing the excess material from said injection chamber.