Syringe tip cap

Abstract

A tip cap is provided for positive sealing engagement with the tip of a syringe barrel. The tip cap includes an inner cap formed from an elastomeric material dimensioned for sealing engagement with the tip of the syringe barrel. The tip cap further includes an outer cap engaged with the inner cap to limit or prevent both axial movement and rotational movement therebetween. The outer cap includes an array of threads for threaded engagement with a luer collar. The luer collar may be a separate component mountable to a syringe barrel or an integral part of the syringe barrel.

What is claimed is:  
     
         1 . A tip cap assembly for a hypodermic syringe barrel having a distally projecting tip with a fluid passageway extending therethrough, said tip cap assembly comprising: 
 a collar securely engageable around said tip;    an inner cap sealingly engageable with said tip;    an outer cap securely disposed around said inner cap and releasably engaged with said collar; and    said assembly being configured so that said inner cap sealingly engages said tip when said collar is securely engaged around said tip, and said inner cap is disengageable from said tip in response to disengagement of said outer cap from said collar.    
     
     
         2 . The tip cap assembly of    claim 1   , wherein said collar includes needle mounting means for releasably engaging a needle assembly, said outer cap being releasably engageable with said needle mounting means of said collar.  
     
     
         3 . The tip cap assembly of    claim 2   , wherein the needle mounting means of said collar comprises an array of threads, said outer cap comprising thread means for releasable threaded engagement with said threads of said collar.  
     
     
         4 . The tip cap assembly of    claim 1   , wherein said inner and outer caps includes means for preventing relative axial movement therebetween.  
     
     
         5 . The tip cap assembly of    claim 1   , wherein said inner cap is formed from an elastomeric material, and wherein said outer cap is formed from a rigid plastic materia.  
     
     
         6 . The tip cap assembly of    claim 1   , further comprising tamper indicator means extending between said collar and said outer cap for indicating separation of said outer cap from said collar.  
     
     
         7 . The tip cap of    claim 1   , wherein said inner cap, a cylindrically shaped side wall defining a cavity to accept said tip and a vent aperture in said side wall for preventing generation of a vacuum during removal of said tip cap assembly from said tip.  
     
     
         8 . A tip cap for a hypodermic syringe barrel having a distally projecting tip with a fluid passage extending therethrough and a luer collar concentrically surrounding said tip, and luer collar including an array of internal threads for threadingly engaging a needle hub, said tip cap comprising: 
 a resilient inner cap and having opposed proximal and distal ends, said proximal end defining a tip engaging portion for sealingly engaging said tip of said syringe barrel; and    a rigid outer cap securely engaged around at least portions of said inner cap, said outer cap having an array of external threads threadably engageable with the threads of said luer collar such that said outer cap securely and releasably retains said inner cap in sealing engagement with said tip.    
     
     
         9 . The tip cap of    claim 8   , wherein said inner and outer cap includes means for limiting relative rotational movement between said inner and outer caps.  
     
     
         10 . The tip cap of    claim 9   , wherein the means for limiting relative rotational movement comprises interdigitated axially aligned anti-rotation ribs on said inner and outer caps respectively.  
     
     
         11 . The tip cap assembly of    claim 8   , wherein said inner and outer caps further include means for limiting relative axial movement therebetween.  
     
     
         12 . The tip cap assembly of    claim 8   , wherein one of said inner and outer caps includes an annular rib, and wherein the other of said inner and outer caps comprises an annular groove engaged with said annular rib for preventing relative axial movement between said inner and outer caps.  
     
     
         13 . The tip cap assembly of    claim 8   , wherein said proximal end of said inner cap includes a cylindrically shaped side wall defining a cavity for accepting said tip and a vent conduit in said side wall for minimizing suction during removal of said inner cap from said tip.  
     
     
         14 . A tip cap assembly for a glass syringe barrel having a distally projecting tip with a fluid passage extending therethrough, said tip cap assembly comprising: 
 a luer collar formed from a thermoplastic material and having means for securely locking said luer collar to said tip, said luer collar having an array of internal threads in spaced concentric relationship around said tip;    an resilient inner cap having opposed proximal and distal ends, said proximal end being configured for sealingly engaging said tip, said proximal end having at least one axially extending projection, porions of said inner cap intermediate said proximal and distal ends defining a locking surface; and    a rigid outer cap disposed in generally surrounding relationship to said inner cap, said outer cap including at least one axially extending projection engaged with said rib of said inner cap for controlling relative rotation between said inner and outer caps, said outer cap further comprising at least one surface engaged with said locking surface of said inner cap for preventing relative axial movement therebetween, and said outer cap comprising an array of external threads threadedly engaging said threads of said luer collar, said threads being disposed for urging said inner cap into tight sealing engagement with said tip in response to tightening of said outer cap to said luer collar whereby threaded disengagement of said outer cap from said luer collar disengages said inner cap from said tip.    
     
     
         15 . The tip cap assembly of    claim 14   , further comprising vent means in said inner cap for minimizing vacuum during separation of said inner cap from said tip.  
     
     
         16 . The tip cap assembly of    claim 14   , further comprising a frangible tamper evident seal extending between and connecting said outer cap and said luer collar.