Patent ID: 7033343

Claim:
A medical device, comprising: a hollow barrel having an open rearward end; a cartridge containing a quantity of fluid; an inner housing slidably displaceable within the barrel, and having an opening for receiving the cartridge; a needle having a sharpened tip in fluid communication with the cartridge; an axially displaceable plunger operable to expel fluid from the cartridge; a connector for connecting the plunger to the inner housing; a first lock releasably retaining the needle in a projecting position in which the sharpened tip of the needle is exposed for use; a second lock releasably retaining the needle in a retracted position in which the sharpened tip of the needle is shielded against inadvertent contact; a biasing element biasing the needle rearwardly; and an actuator manually operable to release the first lock for rearward retraction of the needle into displacement with the second lock, and manually operable to release the second lock for forward displacement of the needle back into the first lock.