Nozzle end for multiple tipped injection molding nozzle

Abstract

A nozzle end is provided for removable mounting to a nozzle body for use in multiple-tipped molding applications such as edge-gated systems. The nozzle end is made of a highly thermally conductive material and is preferably inserted at least partially inside the forward end of the heated nozzle body. Removable nozzle tips are insertable in the front end of the nozzle end.

1. An injection molding apparatus comprising:
 a plurality of mold cavities formed between at least one pair of mold plates, each cavity having a gate for communicating with an interior of said cavity;  
 at least one injection molding nozzle body having a back end, a front end, at least one melt channel through said body and a heating member for heating said body, said nozzle body capable of receiving heated pressurized melt from a source and capable of feeding said heated pressurized melt from said back end through said melt channel to said front end; and  
 a nozzle end threadably coupled to said front end of said nozzle body, said nozzle end having a bore therethrough extending from said melt channel at said body front end and communicating with at least two tips, each of said at least two tips having a tip melt channel extending from said nozzle end and communicating with at least one of said mold cavities, said at least two tips being threadably coupled to said nozzle end.  
 
     
     
       2. The apparatus of  claim 1  wherein said nozzle end is made substantially of a material having a higher thermal conductivity than said nozzle body. 
     
     
       3. The apparatus of  claim 1  wherein a rear portion of said nozzle end extends inside said nozzle body. 
     
     
       4. The apparatus of  claim 3  wherein said rear portion of said nozzle end extends inside a heated portion of said nozzle body. 
     
     
       5. The apparatus of  claim 3  wherein said rear portion of said nozzle end is made of a material having a higher thermal conductivity than said nozzle body. 
     
     
       6. The apparatus of  claim 1  further comprising sealing means for inhibiting leakage of pressurized melt between said nozzle end and said mold. 
     
     
       7. In an injection molding apparatus having at least one heated nozzle extending forwardly into a well in a mold, said well having a wall with a plurality of gates spaced therein, each gate extending to a cavity in said mold, said nozzle having a rear end, a front end and a melt channel, said melt channel extending from an inlet at said rear end of said nozzle to an outlet at said front end of said nozzle, the improvement comprising:
 a nozzle end having a threaded rear portion that is coupled to said front end of said nozzle and a plurality of tips projecting from said nozzle end opposite said rear portion, said nozzle end having a bore extending therethrough, said bore extending between said melt channel outlet at said front end of said nozzle and said tips to communicate with said plurality of gates, said tips being removably attached to said nozzle via said threaded rear portion  end.  
 
     
     
       8. The apparatus of  claim 7  wherein said nozzle end is made substantially of a material having a higher thermal conductivity than said nozzle. 
     
     
       9. The apparatus of  claim 7  wherein a rear portion of said nozzle end extends inside said nozzle. 
     
     
       10. The apparatus of  claim 9  wherein said rear portion of said nozzle end extends inside a heated portion of said nozzle. 
     
     
       11. The apparatus of  claim 9  wherein said rear portion of said nozzle end has a higher thermally conductivity than said nozzle. 
     
     
       12. An injection molding apparatus comprising:
 at least one heated nozzle extending forwardly into a well in a mold, said well having a wall with a plurality of gates spaced therein, each gate extending to a cavity in said mold, said nozzle having a rear end, a front end and a melt channel, said melt channel extending from an inlet at said rear end of said nozzle to an outlet at said front end of said nozzle;  
 a nozzle end having a threaded rear portion that is coupled to said front end of said nozzle and an opposite end, said nozzle end having a bore extending therethrough, said bore extending between said melt channel at said front end of said nozzle and a plurality of tips located adjacent said opposite end of said nozzle end to communicate with said plurality of gates, said tips being removably attached to said nozzle via said threaded rear portion  end.  
 
     
     
       13. An injection molding apparatus as claimed in  claim 12 , wherein each of said plurality of tips is removable from  removably attached to said nozzle end by a separate sealing means. 
     
     
       14. An injection molding apparatus as claimed in  claim 13  wherein each of said plurality of tips is independently removable from said nozzle end. 
     
     
       15. An injection molding apparatus as claimed in claim  14    13 , wherein each of said plurality of tips includes a melt channel  sealing surface that sealing engages the wall of the well. 
     
     
       16. An injection molding apparatus comprising:
   at least two mold cavities, wherein each mold cavity has a mold gate; and        a nozzle including a nozzle body, a nozzle end and at least two nozzle tips,      said nozzle body having a melt channel extending therethrough,        said nozzle end being removably coupled to said nozzle body and having a melt bore extending between said nozzle body melt channel and respective melt channels of said at least two nozzle tips,        said at least two nozzle tips being removably coupled to said nozzle end, wherein each of said nozzle tips includes a sealing means and is in fluid communication with one of said mold cavities via said mold gate to deliver melt thereto.        
     
     
       17. The injection molding apparatus of  claim 16 , wherein said sealing means is a separate nozzle seal sleeve.  
     
     
       18. The injection molding apparatus of  claim 17 , wherein each of said nozzle seal sleeves is threadably coupled to said nozzle end to secure said tips thereto.  
     
     
       19. The injection molding apparatus of  claim 18 , wherein said nozzle seal sleeves secure said tips within a side surface of said forward end of said nozzle end.  
     
     
       20. The injection molding apparatus of  claim 18 , wherein said nozzle seal sleeves secure said tips within a front surface of said forward end of said nozzle end.  
     
     
       21. The injection molding apparatus of  claim 16 , wherein said sealing means is a flat face of said nozzle tip for sealingly engaging against a wall surrounding said mold gate.  
     
     
       22. The injection molding apparatus of  claim 16 , wherein each of said nozzle tips is threadably coupled within a side surface of said forward end of said nozzle end.  
     
     
       23. The injection molding apparatus of  claim 16 , wherein each of said nozzle tips is threadably coupled within a front surface of said forward end of said nozzle end.  
     
     
       24. The injection molding apparatus of  claim 16 , wherein said heated nozzle further comprises:
   a first heating element attached to said nozzle body; and        a second heating element attached to said nozzle end.      
     
     
       25. The injection molding apparatus of  claim 24 , wherein said first and second heating elements are separately controllable.  
     
     
       26. The injection molding apparatus of  claim 24 , further comprising:
   a first thermocouple positioned within said nozzle body for monitoring said first heating element; and        a second thermocouple positioned within said nozzle end for monitoring said second heating element.      
     
     
       27. The injection molding apparatus of  claim 24 , further comprising:
   at least one thermocouple for monitoring said first and second heating element.      
     
     
       28. An injection molding apparatus comprising:
   at least two injection molding cavities each having a mold gate;        an injection nozzle having a nozzle body, a nozzle end and at least two nozzle tips, said nozzle body having a nozzle melt channel, said nozzle end having a melt bore in fluid communication with said nozzle melt channel, and said at least two nozzle tips having enclosed melt channels in fluid communication with said nozzle end melt bore, wherein said nozzle end is removably coupled to said nozzle body and said at least two nozzle tips are removably coupled to said nozzle end and wherein each of said nozzle tip melt channel communicates with a respective mold gate of a respective mold cavity;        a first heater for heating said nozzle body;        a second heater for heating said nozzle end; and        nozzle tip seal means associated with each nozzle tip for sealingly engaging against a wall surrounding said mold gate.      
     
     
       29. The injection molding apparatus of  claim 28 , wherein said first heater is embedded within an outer surface of said nozzle body and said second heater is embedded within an outer surface of said nozzle end.  
     
     
       30. The injection molding apparatus of  claim 28 , wherein said first and second heaters are separately controllable.  
     
     
       31. The injection molding apparatus of  claim 28 , further comprising:
   a first thermocouple positioned within said nozzle body for monitoring said first heater; and        a second thermocouple positioned within said nozzle end for monitoring said second heater.      
     
     
       32. The injection molding apparatus of  claim 28 , further comprising:
   at least one thermocouple for monitoring said first and second heaters.