Patent ID: 8157768

Claim:
An injection device, comprising; a housing having a first end defining a first opening; a plunger received within the first opening of the housing to move between first and second positions; a cartridge disposed in the housing and having an interior serving as a reservoir for a drug; a delivery needle disposed within the housing and in fluid communication with the reservoir via an interruptible fluid channel; a locking mechanism disposed in the housing, said locking mechanism including a first resilient member having a relaxed position towards a center of the first opening; a latch configured for holding the first resilient member clear of the first opening to enable the delivery needle to be placed into an injection position; and a needle hub carrying the delivery needle, wherein, in the first position of the plunger, the delivery needle is enclosed by the plunger, wherein, in the second position of the plunger, the latch is released by the needle hub with the first resilient member resting against a side of the needle hub while the delivery needle is in the injection position, and, wherein when the plunger returns to the first position from the second position, the locking mechanism prevents the needle from being placed in the injection position.