Abstract:
An injection molding apparatus includes an injection manifold having an inlet and a melt channel. The manifold melt channel branches to a plurality of melt channel outlets. A hot runner injection nozzle includes an axial melt channel extending along a central axis and communicating with one of the manifold melt channel outlets. The nozzle further includes at least two angled melt channels disposed at an angle to the central axis. At least two nozzle tips are provided, and each includes a nozzle tip melt channel in communication with one of the angled melt channels. A valve pin is disposed at least partially within the axial melt channel coaxially with the central axis and movable within the axial melt channel. Lateral valve pins movable within the nozzle tip melt channels are disposed at an angle to the valve pin. Linkage elements continuously connect the lateral valve pins to the valve pin. Axial movement of the valve pin is transmitted through the linkage elements to the lateral valve pins to open and close communication between the nozzle tip melt channels and the lateral mold gates.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. provisional patent application No. 60/871,668 filed Dec. 22, 2006, which is hereby incorporated by reference in its entirety herein. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to an injection molding apparatus and, in particular, to a valve pin mechanism for use in an edge-gated injection molding apparatus. 
     2. Related Art 
     Edge gating from a nozzle of an injection molding apparatus through a number of edge gate tips is well known. A multi-cavity edge, or side, gated injection molding apparatus is described in U.S. Pat. No. 5,494,433 to Gellert, issued Feb. 27, 1996, which is incorporated in its entirety herein by reference thereto. Generally, the multi-cavity edge-gated injection molding apparatus includes several nozzles that are coupled to a manifold to receive a melt stream of moldable material therefrom. Each nozzle is mounted in a cylindrical opening in a mold to convey pressurized melt through a nozzle melt channel to mold gates, which lead to mold cavities in the mold. The mold cavities are spaced radially around the nozzle. Each mold gate extends through a gate insert, which is held in position by a gate insert retainer plate. Each mold gate is aligned with a gate seal that is threadably coupled to the nozzle. As such, the location of the gate seals is generally fixed relative to the mold. 
     A multi-cavity edge gated injection molding apparatus with a first nozzle, a nozzle link, and a second nozzle is described in U.S. Published Application Publication No. 2005-0196486 A1, published Sep. 8, 2005, which is incorporated in its entirety herein by reference thereto. U.S. Published Application Publication No. 2005-0196486 does not disclose a valve pin mechanism for opening and closing communication to the mold gates. 
     An edge gated injection molding nozzle including a valve pin mechanism is disclosed in U.S. Published Patent Application Publication No. 2006-0233911 A1 to Spuller, published Oct. 19, 2006. However, the nozzle of the Spuller publication includes a nozzle melt channel on either side of the valve pin. In such an arrangement, melt distributed to the cavities on either side of the valve pin travel different distances, and may therefore lead to a melt flow imbalance towards the lateral gates. 
     SUMMARY OF THE INVENTION 
     According to an embodiment of the present invention, an injection molding apparatus includes an injection manifold having an inlet and a melt channel. The manifold melt channel branches to a plurality of melt channel outlets. A hot runner injection nozzle includes an axial melt channel extending along a central axis and communicating with one of the manifold melt channel outlets. The nozzle further includes at least two angled melt channels disposed at an angle to the central axis. At least two nozzle tips are provided, and each includes a nozzle tip melt channel in communication with one of the angled melt channels. A valve pin may be disposed at least partially within the axial melt channel coaxially with the central axis and movable within the axial melt channel. Lateral valve pins movable within the nozzle tip melt channels are disposed at an angle to the valve pin. Linkage elements continuously connect the lateral valve pins to the valve pin. Axial movement of the valve pin is transmitted through the linkage elements to the lateral valve pins to open and close communication between the nozzle tip melt channels and the lateral mold gates. 
     The nozzle includes a first nozzle portion and a second nozzle portion. In one embodiment, the first and second nozzle portions are separate pieces and are joined by a nozzle link. In such an embodiment, the axial melt channel is disposed in the first nozzle portion and the angled melt channels are disposed in the second nozzle portion. The nozzle link also includes a melt channel that is aligned with the axial melt channel. In another embodiment, the first nozzle portion and the second nozzle portion are integral. The axial melt channel is disposed in the first nozzle portion and the angled melt channels are disposed in the second nozzle portion. 
     The nozzle is heated. The first and second nozzle portions may be heated by a single heater or may be heated by independently controlled heaters. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       Embodiments of the present invention will now be described more fully with reference to the accompanying drawings where like reference numbers indicate similar structure. 
         FIG. 1  is a partial cross-sectional view of a portion of an injection molding apparatus according to an embodiment of the present invention. 
         FIG. 2  is a partial cross-sectional view of a nozzle of  FIG. 1  with the valve pins in the open position. 
         FIG. 3  is a partial cross-sectional view of the nozzle of  FIG. 2  with the valve pins in the closed position. 
         FIG. 4  is cross-sectional view of another embodiment of a nozzle with the valve pins in the open position. 
         FIG. 5  is a cross-sectional view of the nozzle of  FIG. 4  with the valve pins in the closed position. 
         FIG. 6  is perspective view of the linkage elements of a valve pin mechanism. 
         FIG. 7  is a perspective view of the linkage elements of  FIG. 6 . 
         FIG. 8  is a cross-sectional view of the nozzle of  FIG. 4 . 
         FIG. 9  is a partial cross-sectional view of another embodiment of a nozzle with the valve pins in the open position. 
         FIG. 10  is a cross-sectional view of the nozzle of  FIG. 9  with the valve pins in the closed position. 
         FIG. 11  is a cross-sectional view of the linkage elements of  FIG. 9 . 
         FIG. 12  is a partial cross-sectional view of another embodiment of a nozzle with the valve pins in the open position. 
         FIG. 13  is a cross-sectional view of the nozzle of  FIG. 12  with the valve pins in the closed position. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A partial sectional view of an injection molding apparatus in accordance with the present invention is illustrated in  FIG. 1  and is generally indicated by reference numeral  150 .  FIGS. 2 and 3  show an enlarged view of a nozzle  10  of injection molding apparatus  150  of  FIG. 1 . Injection molding apparatus  150  includes a melt distribution manifold  44  that is located between a spacer plate  30  and a back plate  34 . While molds have a wide variety of configurations, in this case spacer plate  30  is mounted between a cavity plate  32  and back plate  34  which are secured together by bolts  36  in a conventional manner. Spacer plate  30  and cavity plate  32  are aligned by dowel pins (not shown). Manifold  44  is supported on the spacer plate  30  by a locating and supporting ring  45 . Manifold  44  includes a branched melt channel  16  and is heated by an integral electrical heating element  50 . An insulative air space  52  is provided between manifold  44  and the surrounding cooled spacer plate  30  and back plate  34 . 
     Melt channel  16  receives melt from a molding machine (not shown) through a central inlet  54  in a locating ring  56  seated in back plate  34 . Locating ring  56  is secured in place by bolts  60  which extend through an insulation ring. Locating ring  56  has a sprue stem  64  projecting into a cylindrical inlet portion  66  of heated manifold  44  to allow for movement of manifold  44  during installation and to provide for thermal expansion and contraction. 
     A plurality of nozzles  10  are coupled to the manifold  44  (only one is shown in  FIG. 1  for simplicity). In the embodiment shown in  FIGS. 1 and 2 , nozzle  10  includes a first nozzle portion  68 , a second nozzle portion  200 , and a nozzle link  80  coupling the first nozzle portion  68  and the second nozzle portion  200 . In this embodiment, the first nozzle portion  68  is coupled to the manifold  44  by bolts  48  (one shown), which provide a mechanical connection and a melt sealing means/force between the first nozzle portion  68  and manifold  44 . First nozzle portion  68  includes a flange portion  74 . In other embodiments, the flange portion  74  can sit on a corresponding shoulder portion of the spacer plate  30 , which can act to limit axial movement of the rear-mounted first nozzle portion  68  in the direction of the second nozzle portion  200  and can further obviate the need for bolts  48 . During operation, the nozzle flange and mold plate shoulder arrangement would support the load from manifold  44  while still allowing the load from manifold  44  to be used as a sealing means/force between first nozzle portion  68  and manifold  44 . 
     First nozzle portion  68  includes a first nozzle melt channel  58  extending therethrough along a central longitudinal axis  71 . Melt channel  58  includes an inlet  59  that is aligned with an outlet  17  of manifold melt channel  16 . A nozzle body  69  of first nozzle portion  68  extends through an opening  12  which extends through spacer plate  30  and a cavity plate  32 . A nozzle heater  85  is coupled about nozzle body  69  of first nozzle portion  68  to provide heat thereto. In the embodiment shown in  FIGS. 1-3  nozzle heater  85  is embedded in a groove in an outer surface of nozzle body  69 , although those skilled in the art would recognize that other ways to heat melt within melt channel  58  may be used. The nozzle heater  85  is in communication with a power source (not shown) through an electrical connector  86 . A thermocouple (not shown) is coupled to first nozzle portion  68  to provide temperature measurements thereof. 
     Second nozzle portion  200  is shown coupled to first nozzle portion  68  by nozzle link  80 . Second nozzle portion  200  includes a second nozzle melt channel  202  with a plurality of melt passages  204  that extend at an angle from a forward end of second nozzle melt channel  202 . Angled melt passages  204  are angled to guide a melt stream toward radially extending melt passages  210  that branch out from angled melt passages  204  to deliver melt through mold gates  18  to a series of mold cavities  20 . Mold cavities  20  are radially spaced around nozzle tips/gate seals  206  coupled to a front surface  208  of second nozzle portion  200 . Second nozzle portion  200  is substantially conical as shown, although other arrangements of internal components can lead to other practical shapes. A nozzle heater  84  is coupled to the second nozzle portion  200  to provide heat thereto. In the embodiment of  FIGS. 1-3 , nozzle heater  84  is embedded in grooves provided in an outer surface of second nozzle portion  200 , although those skilled in the art would recognize that other ways to heat melt within melt channel  202  and angled melt passages  204  may be used. The nozzle heater  84  is in communication with a power source (not shown) through an electrical connector (not shown). A thermocouple  88  is coupled to second nozzle portion  200  to provide temperature measurements thereof. In the embodiment of  FIGS. 1-3 , first nozzle portion  68  and second nozzle portion  200  are heated by the independent heaters  85 ,  84  that can be independently controlled to precisely control the heat profile of the melt. However, as would be understood by one of ordinary skill in the art, a single heater may be used for both first and second nozzle portions  68 ,  200 . Such a single heater can have a wire portion that loosely bridges the gap between the first and second nozzle portions  68 ,  200 , so that the first and second nozzle portions  68 ,  200  can be separated to allow the nozzle link  80  to be easily removed. Alternatively, the single heater may have a connector to allow separation of the first and second nozzle portions  68 ,  200 . 
     Nozzle tips or gate seals  206  threadably engage second nozzle portion  200  and include melt passages  212  to deliver melt from radial melt passages  210  to mold cavities  20  via mold gates  18 . Each nozzle tip/gate seal  206  is longitudinally fixed in position relative to each respective mold gate  18  and mold cavity  20 . Nozzle tips/gate seals  206  shown in  FIGS. 1 and 2  are of a one-piece construction, however, one of ordinary skill in the art would recognize that two-piece nozzle tips/gate seals may be used. 
     Further details regarding first nozzle portion  68 , second nozzle portion  200 , and nozzle link  80  can be made similar to those provided in U.S. Published Patent Application Publication No. 2005-0196486 A1, the entirety of which is incorporated herein by reference. 
     A melt stream of molten material is delivered under pressure from a machine nozzle (not shown) to manifold channel  16  of manifold  44 . The melt is distributed from manifold channel  16  to nozzle melt channels  58  of a plurality of first nozzle portions  68 . The melt flows from the nozzle melt channels  58 , through melt passages  81  of nozzle links  80  and into the second nozzle melt channels  202 . The melt then flows through angled melt passages  204 , through radial melt passages  210 , through melt passages  212  of gate seals  206 , past gates  18  and into a respective mold cavity  20 . Once the injection portion of the cycle is complete, the molded parts are cooled and ejected from the mold cavities. 
     In the embodiment shown in  FIG. 1 , several elongated cavities  20  are spaced around each nozzle  10  and each gate  18  extends through a gate insert  22  seated in the mold  14 . In this arrangement, each elongated cavity  20  extends partially in the gate insert  22  and partially in a cavity insert  38  against which the gate insert  22  is securely mounted. A number of the cavity inserts  38  are spaced around each nozzle  10  in holes  40  in the cavity plate  32 . Cooling water is pumped through cooling conduits  42  extending around each cavity insert  38  to provide cooling between the heated nozzle  10  and the cavities  20 . 
     A gate insert retainer plate  114  has recesses  116  therein in which the gate inserts  22  are received. This holds the gate inserts  22  in place. The recesses  116  in the gate insert retainer plate  114  and the inserts  22  are tapered to provide for easy assembly and ensure a tight fit. Cavity cores  118  with central cooling conduits  120  are secured in place extending through a hole  122  in each gate insert  22  into the adjacent cavity insert  38 . 
     In order to control flow of the melt from manifold  44 , through nozzle  10 , and into mold cavities  20 , a valve pin system is provided. As shown in  FIG. 1 , an actuator  62  is disposed in an opening in back plate  34 . Actuator  62  can be a hydraulic actuator, a pneumatic actuator, or an electrical actuator, as would be apparent to one of ordinary skill in the art. A head  102  of a valve pin  100  is coupled to a piston  63  of actuator  62 . Valve pin  100  extends from actuator  62 , through manifold  44 , including a portion of manifold melt channel  16 , through first melt channel  58  of first nozzle portion  68 , through link melt channel  81  of nozzle link  80 , and through second nozzle melt channel  202  of second nozzle portion  200 , as shown in  FIGS. 1 and 2 . Valve pin  100  is disposed within and coaxial with melt channels  58 ,  81 , and  202 . 
     Further, lateral valve pins  104  are provided at least partially within radial melt passages  210  and through melt passages  212  of gate seals  206 . Lateral valve pins  104  include a tip portion  106  to engage gate  18  to shut off flow to the respective cavity  20 . Lateral valve pins  104  also include a head portion  108  that is seated in a slider  110 . Each slider  110  is coupled to valve pin  100  such that axial movement of valve pin  100  along central axis  71  results in lateral movement of lateral valve pins  104  along an axis  105  disposed at an angle with respect to central axis  71  such that the axes are not parallel. In the particular embodiment shown in  FIGS. 1 and 2 , axis  105  is perpendicular to central axis  71 . However, one of ordinary skill in the art would understand that axis  105  can be disposed at various angles with respect to central axis  71  ranging from 1 degree to 179 degrees. Sliders  110  shown in  FIGS. 1 and 2  include a slot  112  disposed at an angle with respect to central axis  71 . Further, a Y-shaped linkage element  130  is coupled to an end  132  of valve pin  100  and disposed in slots  112 . In particular, Y-shaped linkage element  130  includes a head portion  136  coupled to end  132  of valve pin  100  and arms  134  disposed in slots  112  of sliders  110 . Sliders  110  are movable within an opening  138  between second nozzle portion  200  and a plate  113 . Plate  113  is secured to second nozzle portion  200  using blots (not shown), as further described with respect to  FIGS. 6 and 7 , below. 
     Thus, when valve pin  100  is moved towards plate  113 , as shown in  FIGS. 1 and 2 , Y-shaped linkage element  130  is pushed downward in slots  112 . Such action causes the sliders  110  to move towards each other, thereby moving lateral valve pins  104  towards central axis  71 . Such movement of lateral valve pins  104  towards central axis  71  causes tip portions  106  of lateral valve pins  104  to move away from respective gates  18  such that melt can flow into respective cavities  20 . Moving piston  63  of actuator  62  away from manifold  44  causes valve pin  100  to move away from retainer plate  113 . Such movement of valve pin  100  thereby causes Y-shaped linkage element  130  to move upward with valve pin  100 , thereby causing arms  134  to move upward and act on slots  112 . Such movement causes sliders  110  to move apart from each other, thereby moving lateral valve pins  104  away from central axis  71  and towards gates  18 . Tip portion  106  of each lateral valve pin  104  thereby engages gate  18  to shut off flow to the respective cavity  20 , as shown in  FIG. 3 . 
       FIGS. 4 and 5  show another embodiment of a nozzle  310  made in accordance with the present invention. Nozzle  310  is used in an injection molding apparatus such as the injection molding apparatus  150  shown in  FIG. 1 . Nozzle  310  is similar to nozzle  10  shown in  FIGS. 1-3  except that nozzle  310  does not include separate nozzle pieces coupled together, such as first nozzle portion  68  and second nozzle portion  200  coupled via nozzle link  80 , as shown in  FIGS. 1-3 . Instead, nozzle  310  is a unitary piece. 
     In the embodiment shown in  FIGS. 4 and 5 , nozzle  310  includes a first nozzle portion  368  and a second nozzle portion  500 . First and second nozzle portions  368 ,  500  are unitary. Nozzle  310  further includes a flange portion  374  similar to flange portion  74  described above with respect to  FIG. 1 . 
     Nozzle  310  includes an axial melt channel  358  extending therethrough along a central axis  371 . Melt channel  358  includes an inlet  359  that is aligned with an outlet of a manifold melt channel, as described with respect to  FIG. 1 . Nozzle  310  includes a nozzle heater (not shown) disposed in groove  383 . The nozzle heater is in communication with a power source (not shown) through an electrical connector (not shown), as shown in  FIG. 1 . A thermocouple (not shown) is coupled to nozzle  310  to provide temperature measurements thereof. 
     Melt channel  358  of nozzle  310  branches into angled melt passages  504  in second nozzle portion  500 . Angled melt passages  504  extend at an angle from a forward end of melt channel  358 . Angled melt passages  504  are angled to guide a melt stream toward radially extending melt passages  510  that branch out from angled melt passages  504  to deliver melt through mold gates to a series of mold cavities, as described with respect to  FIG. 1 . Nozzle tips/gate seals  506  are coupled to a front surface  508  of second nozzle portion  500 . 
     Nozzle tips/gate seals  506  threadably engage second nozzle portion  500  and include melt passages  512  to deliver melt from radial melt passages  510  to the mold cavities via the mold gates. Each nozzle tip/gate seal  506  is longitudinally fixed in position relative to each respective mold gate and mold cavity. Nozzle tips/gate seals  506  shown in  FIGS. 4 and 5  are of a one-piece construction, however, one of ordinary skill in the art would recognize that two-piece nozzle tips/gate seals may be used. 
     A melt stream of molten material is delivered from a manifold channel of a manifold to nozzle melt channel  358  through inlet  359 . The melt flows from the nozzle melt channel  358 , through angled melt passages  504 , through radial melt passages  510 , through melt passages  512  of nozzle tips/gate seals  506 , past the mold gates and into a respective mold cavity. Once the injection portion of the cycle is complete, the molded parts are cooled and ejected from the mold cavities. 
     In order to control flow of the melt from the manifold, through nozzle  310 , and into the mold cavities, a valve pin system is provided. Although not shown in  FIGS. 4 and 5 , such a valve pin system includes an actuator as described with respect to  FIG. 1 . A valve pin  400  includes a head (not shown) coupled to the actuator, as described with respect to  FIG. 1 . Valve pin  400  extends from the actuator, through the manifold, including a portion of the manifold melt channel, and through nozzle melt channel  358 , as shown in  FIGS. 4 and 5 . Valve pin  400  is disposed within and coaxial with melt channel  358 . 
     Further, lateral valve pins  404  are provided at least partially within radial melt passages  510  and through melt passages  512  of nozzle tips/gate seals  506 . Lateral valve pins  404  include a tip portion  406  to engage a respective gate to shut off flow to the respective cavity. Lateral valve pins  404  also include a head portion  408  that is seated in a slider  410 . Each slider  410  is coupled to valve pin  400  such that axial movement of valve pin  400  along central axis  371  results in lateral movement of lateral valve pins  404  along an axis  405  disposed at an angle with respect to central axis  371  such that the axes are not parallel. In the particular embodiment shown in  FIGS. 4 and 5 , axis  405  is perpendicular to central axis  371 . However, one of ordinary skill in the art would understand that axis  405  can be disposed at various angles with respect to central axis  371  ranging from 1 degree to 179 degrees. Sliders  410  shown in  FIGS. 4 and 5  include a slot  412  disposed at an angle to central axis  371 . Further, a Y-shaped linkage element  430  is coupled to an end  432  of valve pin  400  and disposed in slots  412 . In particular, Y-shaped linkage element  430  includes a head portion  436  coupled to end  432  of valve pin  400  and arms  434  disposed in slots  412  of sliders  410 . Sliders  412  are movable within an opening  438  between second nozzle portion  500  and a plate  413 . 
     Thus, when valve pin  400  is moved towards plate  413 , as shown in  FIG. 4 , Y-shaped linkage element  430  is pushed downward in slots  412 . Such action causes the sliders  410  to move towards each other, thereby moving lateral valve pins  404  towards central axis  371 . Such movement of lateral valve pins  404  towards central axis  371  causes tip portions  406  of lateral valve pins  404  to move away from respective gates such that melt can flow into respective cavities. Moving the piston of the actuator (as shown in  FIG. 1 ) away from the manifold causes valve pin  400  to move away from plate  413 . Such movement of valve pin  400  thereby causes Y-shaped linkage element  430  to move upward with valve pin  400 , thereby causing arms  434  to move upward and act on slots  412 . Such movement causes sliders  410  to move apart from each other, thereby moving lateral valve pins  404  away from central axis  371  and towards the gates. Tip portion  406  of each lateral valve pin  404  thereby engages the gate to shut off flow to the respective cavity, as shown in  FIG. 5 . 
       FIGS. 6 and 7  show detailed views of the plate  113 ,  413 , sliders  110 ,  410 , and Y-shaped linkage element  130 ,  430  shown in  FIGS. 1-5 . For convenience of description, the reference numerals used in  FIGS. 4 and 5  will be used in  FIGS. 6 and 7 , although one of ordinary skill in the art would recognize that the description is also applicable to  FIGS. 1-3 . As shown in  FIGS. 6 and 7 , plate  413  includes rails  409  disposed substantially parallel to axis  405 . Sliders  410  are disposed between rails  409 , which serve to limit movement of the sliders  410  to be along the axis  405 . Y-shaped linkage element  430  is disposed above sliders  410  such that arms  434  of Y-shaped linkage element  430  are disposed in slots  412  of sliders  410 , as shown in  FIG. 6 . Each slider  410  further includes a notch  411  for securing head  408  of lateral valve pin  404 . Y-shaped linkage element  430  also includes an opening  437  for coupling to end  432  of valve pin  400 . The opening  437  and the end  432  of valve pin  400  are preferably both threaded for engagement; however thermal bonding, such as brazing or welding, can be used if removability of the valve pin is unimportant. Each slider  410  and Y-shaped linkage element  430  combine to form a linkage between a respective lateral valve pin  404  and valve pin  400 . Plate  413  further includes openings  403  for bolts  407  to go through to retain plate  413  against second nozzle portion  500 , as shown in  FIG. 8 . 
     It would be understood by those of ordinary skill in the art that although two nozzle tips, gates, and cavities are shown associated with each nozzle  10 ,  310 , any number of tips, gates, and cavities may be utilized. For example, and not by limitation, for nozzle tips, gates, and cavities may be associated with a nozzle of the injection molding apparatus. In such an arrangement, four (4) lateral valve pins would be utilized. Further, the Y-shaped linkage element would not be Y-shaped, but would instead include four (4) arms extending from the head portion thereof to engage within slots of four sliders. Similar modification can be made to accommodate other quantities of gates and cavities, as would be understood by those of ordinary skill in the art. 
       FIGS. 9-11  show a nozzle  610  made in accordance with another embodiment of the present invention. Nozzle  610  is used in an injection molding apparatus such as the injection molding apparatus  150  shown in  FIG. 1 . Nozzle  610  is similar to nozzle  10  shown in  FIGS. 1-3  in that it includes a first nozzle portion  668  and a second nozzle portion  800  coupled via a nozzle link  680 . However, it would be understood by one of ordinary skill in the art that a unitary nozzle such as nozzle  310  shown in  FIGS. 4 and 5  can also be used. 
     In this embodiment, the first nozzle portion  668  is coupled to a manifold such as manifold  44  shown in  FIG. 1 . First nozzle portion  668  can be coupled to the manifold by bolts or other means, as described above with respect to  FIGS. 1-3 . First nozzle portion  668  includes a flange portion  674 , as described above with respect to the embodiment of  FIGS. 1-3 . 
     First nozzle portion  668  includes a first nozzle melt channel  658  extending therethrough along a central longitudinal axis  671 . Melt channel  658  includes an inlet  659  that is aligned with an outlet of a manifold melt channel. A nozzle body  669  of first nozzle portion  668  extends through an opening which extends through a spacer plate and a cavity plate, as described above with respect to  FIG. 1 . A nozzle heater  685  is coupled about nozzle body  669  of first nozzle portion  668  to provide heat thereto. In the embodiment of  FIGS. 9-11 , nozzle heater  685  is embedded in grooves provided in an outer surface of nozzle body  669 , although those skilled in the art would recognize that other ways to heat melt within melt channel  658  may be used. The nozzle heater  685  is in communication with a power source (not shown) through an electrical connector  686 . A thermocouple (not shown) may be coupled to first nozzle portion  668  to provide temperature measurements thereof. 
     Second nozzle portion  800  is shown coupled to first nozzle portion  668  by nozzle link  680 . Second nozzle portion  800  includes a second nozzle melt channel  802  with a plurality of melt passages  804  that extend at an angle from a forward end of second nozzle melt channel  802 . Angled melt passages  804  are angled to guide a melt stream toward radially extending melt passages  810  that branch out from angled melt passages  804  to deliver melt through mold gates to a series of mold cavities. The mold cavities are radially spaced around nozzle tips/gate seals  806  coupled to a front surface  808  of second nozzle portion  800 , as shown in  FIG. 1 . Second nozzle portion  800  is substantially conical as shown, although other arrangements of internal components can lead to other practical shapes. A nozzle heater  684  is coupled to the second nozzle portion  800  to provide heat thereto. In the embodiment of  FIGS. 9-11 , nozzle heater  684  is embedded in grooves provided in an outer surface of second nozzle portion  800 , although those skilled in the art would recognize that other ways to heat melt within melt channel  802  and angled melt passages  804  may be used. The nozzle heater  684  is in communication with a power source (not shown) through an electrical connector (not shown). A thermocouple  688  is coupled to second nozzle portion  800  to provide temperature measurements thereof. In the embodiment of  FIGS. 9-11 , first nozzle portion  668  and second nozzle portion  800  are heated by the independent heaters  685 ,  684  that can be independently controlled to precisely control the heat profile of the melt. However, as would be understood by one of ordinary skill in the art, a single heater may be used for both first and second nozzle portions  668 ,  800 . Such a single heater can have a wire portion that loosely bridges the gap between the first and second nozzle portions  668 ,  800 , so that the first and second nozzle portions  668 ,  800  can be separated to allow the nozzle link  680  to be easily removed. Alternatively, the single heater may have a connector to allow separation of the first and second nozzle portions  668 ,  800 . 
     Nozzle tips or gate seals  806  threadably engage second nozzle portion  800  and include melt passages  812  to deliver melt from radial melt passages  810  to the mold cavities via the mold gates. Each nozzle tip/gate seal  806  is longitudinally fixed in position relative to each respective mold gate and mold cavity. Nozzle tips/gate seals  806  shown in  FIGS. 9-11  are of a two-piece construction, however, one of ordinary skill in the art would recognize that one-piece nozzle tips/gate seals as shown in  FIGS. 1-5  may be used. 
     A melt stream of molten material is delivered under pressure from a machine nozzle (not shown) to the manifold channel of the manifold. The melt is distributed from the manifold channel to nozzle melt channels  658  of a plurality of first nozzle portions  668 . The melt flows from the nozzle melt channels  658 , through melt passages  681  of nozzle links  680  and into the second nozzle melt channels  802 . The melt then flows through angled melt passages  804 , through radial melt passages  810 , through melt passages  812  of gate seals  806 , past the gates and into a respective mold cavity. Once the injection portion of the cycle is complete, the molded parts are cooled and ejected from the mold cavities. 
     In order to control flow of the melt from the manifold, through nozzle  610 , and into the mold cavities, a valve pin system is provided. Although not shown in  FIGS. 9-11 , an actuator as shown in  FIG. 1  is provided to move a valve pin  700  axially within nozzle melt channel  658 . A head (not shown) of valve pin  700  is coupled to the piston of the actuator. Valve pin  700  extends from the actuator, through the manifold, including a portion of the manifold melt channel, through first melt channel  658  of first nozzle portion  668 , through a link melt channel  681  of nozzle link  680 , and through second nozzle melt channel  802  of second nozzle portion  800 , as shown in  FIGS. 9 and 10 . Valve pin  700  is disposed within and coaxial with melt channels  658 ,  681 , and  802 . 
     Further, lateral valve pins  704  are provided at least partially within radial melt passages  810  and melt passages  812  of gate seals  806 . Lateral valve pins  704  include a tip portion  706  to engage the gate to shut off flow to the respective cavity. Each lateral valve pin  704  also includes a head portion  708  that is seated in a linkage element  710 . The linkage element  710  is connected to all of the lateral valve pins  704 . In the embodiment of  FIGS. 9-11 , there are four lateral valve pins  704 , as can best be seen in  FIG. 11 . Linkage element  710  is coupled to valve pin  700  such that axial movement of valve pin  700  along central axis  671  results in lateral movement of lateral valve pins  704  along an axis  705  disposed at an angle with respect to central axis  671  such that the axes are not parallel. In the particular embodiment shown in  FIGS. 9-11 , axis  705  is perpendicular to central axis  671 . However, one of ordinary skill in the art would understand that axis  705  can be disposed at various angles with respect to central axis  671  ranging from 1 degree to 179 degrees. Linkage element  710  is movable within an opening  738  between second nozzle portion  800  and a plate  713 . 
     Linkage element  710  shown in  FIGS. 9-11  is a truncated pyramid shape. Each face  712  of linkage element  710  includes a notched slot  711  for receiving a head  708  of a lateral valve pin  704 . In this particular embodiment linkage element  710  includes four notched slots  711 . As would be understood by one of ordinary skill in the art, faces  712  are not vertical, due to the shape of linkage element  710 . Instead, faces  712  are disposed at an angle with respect to central axis  671  such that faces  712  and central axis  671  are not parallel. Due to the angled faces  712 , notched slots  711  are also disposed at an angle with respect to central axis  671 . This arrangement acts on lateral valve pins  704  such that when valve pin  700  is moved toward plate  713  (away from the actuator), linkage element  710  also moves toward plate  713  thereby causing lateral valve pins to move away from central axis  671 , thereby closing the respective gate, as shown in  FIG. 10 . Similarly, when valve pin  700  is moved away from plate  713 , linkage element  710  also moves away from plate  713 , causing heads  708  of lateral valve pins  704  to move towards central axis  671 , thereby opening the respective gate, as shown in  FIG. 9 . 
     Linkage element  710  is coupled to an end  732  of valve pin  700 . In particular, linkage element  710  includes an opening  737  for coupling to end  732  of valve pin  700 . The opening  737  and the end  732  of valve pin  700  are preferably both threaded for engagement; however thermal bonding, such as brazing or welding, can be used if removability of the valve pin is unimportant. Alternatively, valve pin  700  and linkage element  710  may be made of a unitary piece. 
       FIGS. 12-13  show a nozzle  910  made in accordance with another embodiment of the present invention. Nozzle  910  is used in an injection molding apparatus such as the injection molding apparatus  150  shown in  FIG. 1 . Nozzle  910  is similar to nozzle  10  shown in  FIGS. 1-3  in that it includes a first nozzle portion  968  and a second nozzle portion  1100  coupled via a nozzle link  980 . However, it would be understood by one of ordinary skill in the art that a unitary nozzle such as nozzle  310  shown in  FIGS. 4 and 5  can also be used. 
     In this embodiment, the first nozzle portion  968  is coupled to a manifold such as manifold  44  shown in  FIG. 1 . First nozzle portion  968  can be coupled to the manifold by bolts or other means, as described above with respect to  FIGS. 1-3 . First nozzle portion  968  includes a flange portion  974 , as described above with respect to the embodiment of  FIGS. 1-3 . 
     First nozzle portion  968  includes a first nozzle melt channel  958  extending therethrough along a central longitudinal axis  971 . Melt channel  958  includes an inlet  959  that is aligned with an outlet of a manifold melt channel. A nozzle body  969  of first nozzle portion  968  extends through an opening which extends through a spacer plate and a cavity plate, as described above with respect to  FIG. 1 . A nozzle heater  985  is coupled about nozzle body  969  of first nozzle portion  968  to provide heat thereto. In the embodiment of  FIGS. 12-13 , nozzle heater  985  is embedded in grooves provided in an outer surface of nozzle body  969 , although those skilled in the art would recognize that other ways to heat melt within melt channel  958  may be used. The nozzle heater  985  is in communication with a power source (not shown) through an electrical connector  986 . A thermocouple (not shown) may be coupled to first nozzle portion  968  to provide temperature measurements thereof. 
     Second nozzle portion  1100  is shown coupled to first nozzle portion  968  by nozzle link  980 . Second nozzle portion  1100  includes a second nozzle melt channel  1102  with a plurality of melt passages  1104  that extend at an angle from a forward end of second nozzle melt channel  1102 . Angled melt passages  1104  are angled to guide a melt stream toward melt passages  1112  of nozzle tips/gate seal  1106  to deliver melt through mold gates to a series of mold cavities. The mold cavities are radially spaced around nozzle tips/gate seals  1106  coupled to a front surface  1108  of second nozzle portion  1100 , as shown in  FIG. 1 . Second nozzle portion  1100  is substantially conical as shown, although other arrangements of internal components can lead to other practical shapes. A nozzle heater  984  is coupled to the second nozzle portion  1100  to provide heat thereto. In the embodiment of  FIGS. 12-13 , nozzle heater  984  is embedded in grooves provided in an outer surface of second nozzle portion  1100 , although those skilled in the art would recognize that other ways to heat melt within melt channel  1102  and angled melt passages  1104  may be used. The nozzle heater  984  is in communication with a power source (not shown) through an electrical connector (not shown). A thermocouple  988  is coupled to second nozzle portion  1100  to provide temperature measurements thereof. In the embodiment of  FIGS. 12-13 , first nozzle portion  968  and second nozzle portion  1100  are heated by the independent heaters  985 ,  984  that can be independently controlled to precisely control the heat profile of the melt. However, as would be understood by one of ordinary skill in the art, a single heater may be used for both first and second nozzle portions  968 ,  1100 . Such a single heater can have a wire portion that loosely bridges the gap between the first and second nozzle portions  968 ,  1100 , so that the first and second nozzle portions  968 ,  1100  can be separated to allow the nozzle link  980  to be easily removed. Alternatively, the single heater may have a connector to allow separation of the first and second nozzle portions  968 ,  1100 . 
     Nozzle tips or gate seals  1106  threadably engage second nozzle portion  1100  and include melt passages  1112  to deliver melt angled melt passages  1004  to the mold cavities via the mold gates. Each nozzle tip/gate seal  1106  is longitudinally fixed in position relative to each respective mold gate and mold cavity. Nozzle tips/gate seals  1106  shown in  FIGS. 12-13  are of a one-piece construction, however, one of ordinary skill in the art would recognize that two-piece nozzle tips/gate seals as shown in  FIGS. 9-11  may be used. 
     A melt stream of molten material is delivered under pressure from a machine nozzle (not shown) to the manifold channel of the manifold. The melt is distributed from the manifold channel to nozzle melt channels  958  of a plurality of first nozzle portions  968 . The melt flows from the nozzle melt channels  958 , through melt passages  981  of nozzle links  980  and into the second nozzle melt channels  1102 . The melt then flows through angled melt passages  1104 , through melt passages  1112  of gate seals  1106 , past the gates and into a respective mold cavity. Once the injection portion of the cycle is complete, the molded parts are cooled and ejected from the mold cavities. 
     In order to control flow of the melt from the manifold, through nozzle  910 , and into the mold cavities, a valve pin system is provided. Although not shown in  FIGS. 12-13 , an actuator as shown in  FIG. 1  is provided to move a valve pin  1000  axially within nozzle melt channel  958 . A rear head (not shown) of valve pin  1000  is coupled to the piston of the actuator. Valve pin  1000  extends from the actuator, through the manifold, including a portion of the manifold melt channel, through first melt channel  958  of first nozzle portion  968 , through a link melt channel  981  of nozzle link  980 , and through second nozzle melt channel  1102  of second nozzle portion  1100 , as shown in  FIGS. 12-13 . Valve pin  1000  is disposed within and coaxial with melt channels  958 ,  981 , and  1102 . 
     Further, lateral valve pins  1004  are provided at least partially within melt passages  1112  of gate seals  1106 . Lateral valve pins  1004  include a tip portion  1006  to engage the gate to shut off flow to the respective cavity. Each lateral valve pin  1004  also includes a rear surface  1008  that abuts a front head portion  1010  of valve pin  1000 . Front head portion  1010  of axial valve pin  1000  is the shape of a truncated pyramid, and includes outer surfaces  1011  that abut rear surfaces  1008  of lateral valve pins  1004 . In the embodiment shown in  FIGS. 12-13 , front head portion  1010  of valve pin  1000  is unitary with valve pin  1000 , although those skilled in the art would recognize that they could be separate pieces coupled together by a threaded connection such as shown in  FIGS. 9-10 , welding, or other bonding. Front head portion  1010  is movable within an opening  1038  between second nozzle portion  1100  and a plate  1013 . Movement of axial valve pin  1000  toward plate  1013  cause rear surfaces  1008  of lateral valve pins  1010  to slide along outer surfaces  1011  of head portion  1010 , thereby causing lateral valve pins  1010  to move away from central axis  971 , thereby closing the respective gate, as shown in  FIG. 13 . In this embodiment, the gates are opened by melt pressure acting on shoulders  1007  of lateral valve pins  1004  to cause lateral valve pins  1004  to move towards central axis  971 . The actuator acting on axial valve pin  1000  to move it towards plate  1013  is either disconnected or overcome by melt pressure acting on shoulders  1007  of lateral valve pins  1004 . For example, the actuator may be a spring that biases valve pin  1000  in the closed position (towards plate  1013 ). Melt pressure acting on shoulders  1007  of lateral valve pins  1004  overcomes the spring force, moving lateral valve pins  1004  towards central axis  971  and opening the gates to the cavities. 
     The many features and advantages of the invention are apparent from the detailed specification and, thus, it is intended by the appended claims to cover all such features and advantages of the invention that fall within the true spirit and scope of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.