Hub assembly for a retractable needle syringe and method of making

Abstract

A fluid handling device comprises a barrel for containing fluid to be delivered through a needle, a needle-mounting hub at one end of the barrel, a biasing element arranged to urge the hub inwardly of the barrel, a stop element blocking inward movement of the hub into the barrel, and a hollow plunger which is movable within the barrel to deliver fluid from the barrel via the needle and has at its forward end a portion which is severable in response to movement of the plunger over the final part of, or at the conclusion of, its delivery stroke to allow retraction of the needle-mounting hub into the hollow plunger, the hub and the stop element being formed as plastics mouldings in such a way that the stop element is axially captive with the hub and the plunger being arranged to disengage the stop element and the hub during said final part of, or at the conclusion of, the delivery stroke to allow the biasing element to drive the needle into the hollow plunger.

1 - 26 . (canceled)  
   
   
       27 . A hub assembly for a retractable needle syringe, said hub assembly comprising: 
 a hub, said hub including a bore for accommodating a mounting portion of a syringe needle, said hub made of a first moldable plastic material;    a crown made of a second moldable plastic material, said crown surrounding said hub and defining a substantial axial interface with said hub, said hub and crown separably, sealingly, intimately, and form fittingly engaging one another along said axial interface, whereby said hub and crown can disengage from one another along said interface to define an aperture in said crown when said crown and hub are subjected to a separating force.    
   
   
       28 . The hub assembly of  claim 27  wherein said hub is held captive in said crown.  
   
   
       29 . The hub assembly of  claim 27  wherein said hub assembly comprises a two-shot molding.  
   
   
       30 . The hub assembly of  claim 27  wherein said crown includes a lip seal.  
   
   
       31 . The hub assembly of  claim 27  wherein said lip seal is an annular lip seal.  
   
   
       32 . The hub assembly of  claim 27  wherein said hub is elongated.  
   
   
       33 . The hub assembly of  claim 27  wherein said crown and hub each include a formation, said formations inter-engaging one another along said interface.  
   
   
       34 . The hub assembly of  claim 27  wherein said hub and crown adhere to one another along said interface.  
   
   
       35 . The hub assembly of  claim 27  wherein said hub and crown are fusingly bonded to one another along said interface.  
   
   
       36 . The hub assembly of  claim 27  wherein said first and second plastic material are substantially similar.  
   
   
       37 . The hub assembly of  claim 27  wherein said hub and crown each include an annular surface, said annular surfaces are complementary with one another and defining said interface.  
   
   
       38 . The hub assembly of  claim 37  wherein said annular surfaces are substantially cylindrical.  
   
   
       39 . The hub assembly of  claim 33  wherein said formations define detents.