Patent ID: 7476217

Claim:
An injection device including: a housing for containing a syringe having a bore extending from an end surface, a needle communicating with the bore through the end surface and a dispensing piston movable in said bore towards said end surface so as to expel the contents of the syringe through the needle, the housing having an opening at one end through which the needle may extend; a resilient member for biassing the syringe and needle inwardly of the housing; a drive element movable towards said one end so as to move the needle of the syringe out of the opening and to move the dispensing piston of the syringe towards the end surface; a mechanism operable to release the syringe such that the needle moves inwardly of the housing; a drive coupling for extending from said drive element to the dispensing piston of the syringe so as to transfer movement of said drive element to the dispensing piston; wherein the drive coupling is compressible in length such that, after the drive element has moved the dispensing piston to the end surface, the drive coupling gradually reduces in length and transfers sufficient force to maintain the needle in its extended position whilst the dispensing piston is maintained at the end surface until said mechanism releases the syringe.