Injection devices

Abstract

An injection device includes a forward housing, a drive housing that has a forward end configured to be attached to and detached from a rear end of the forward housing, a syringe holder mounted within the forward housing for longitudinal movement with respect to the forward housing, and a syringe with a needle that is mounted in the syringe holder. The drive housing includes a drive mechanism, and the syringe holder includes detent means for engaging the syringe to prevent or limit relative axial movement of the syringe relative to the syringe holder.

1 . An injection device comprising,
 a forward housing;   a drive housing having a forward end configured to be attached to and detached from a rear end of the forward housing, the drive housing including a drive mechanism;   a syringe holder mounted within said forward housing for longitudinal movement with respect to said forward housing; and   a syringe having a needle, wherein said syringe is mounted in said syringe holder,   said syringe holder including detent means for engaging said syringe to prevent or limit relative axial movement of the syringe relative to the syringe holder.   
     
     
         2 . An injection device according to  claim 1 , wherein said detent means are provided at a rear end of the syringe holder. 
     
     
         3 . An injection device according to  claim 1 , wherein said syringe includes a rear end having a radially extending skirt. 
     
     
         4 . An injection device according to  claim 3 , wherein said detent means include snap detent features which engage a rear surface of the syringe skirt when the syringe is mounted within said syringe holder. 
     
     
         5 . An injection device according to  claim 1 , wherein said syringe holder is slideably mounted in said forward housing. 
     
     
         6 . An injection device according to  claim 5 , wherein said syringe holder is provided with at least one engagement feature on its outer surface which engages said forward housing to limit rearward movement of the syringe holder. 
     
     
         7 . An injection device according to  claim 5 , wherein said the syringe holder is provided with a snap fit annulus having a rearward facing shoulder, wherein the rearward facing shoulder engages with said a forward facing surface provided on an inner surface of said forward housing to limit rearward movement of the syringe holder. 
     
     
         8 . An injection device according to  claim 1 , wherein said syringe being mounted in said forward housing portion for movement between a rearward position in which said needle is shrouded by a forward part of said housing portion, and a forward position in which said needle projects forwardly of said housing for delivery of a dose; and wherein the device is further provided with
 a locking arrangement for locking said syringe in a rearward position, and being releasable to allow forward movement of the syringe; and   a latch arrangement operable to latch the released syringe as it returns to a rearward position after delivery of a dose.   
     
     
         9 . An injection device according to  claim 8 , wherein said syringe is held in a syringe holder and said locking arrangement and said latching arrangement cooperate with said syringe holder to lock and latch said syringe respectively. 
     
     
         10 . An injection device according to  claim 9 , wherein said locking arrangement and said latching arrangement are defined by a common moveable locking/latching element moveable between:
 a locking/latching position in which it
 i) prevents movement of said syringe forwardly from a rearward position, and 
 ii) latches said syringe when returning from a forward position towards a rearward position; and 
   an unlocked position in which the syringe is allowed to move forward.   
     
     
         11 . An injection device according to  claim 10 , wherein said latching/locking element comprises at least one latch portion moveable generally transversely relative to the syringe between said locking/latching position and said unlocked position