Patent ID: 8303574

Claim:
A needle injector device for connection in fluid-flow communication with the inlet or outlet port of a reservoir, the needle injector comprising: a base structure for arranging adjacent a user's skin; at least one pivotal arm supported for pivotal motion relative to the base, between a first pivot position and a second pivot position; a moveable needle supported by the base structure for movement between a retracted position and an extended position, the moveable needle having a head and a shaft, the needle shaft having a piercing end for piercing the user's skin when the base structure is arranged adjacent the user's skin and the moveable needle is moved to the extended position, wherein the needle shaft has a sufficient length to extend through a hollow cannula to extend the piercing end of the needle out one end of the cannula and support the cannula on the needle for movement with the needle between the retracted position and the extended position; a first spring supported by the base portion and arranged to provide a first bias force on the needle head at least when the needle is in the extended position, the first bias force directed to bias the needle toward the retracted position; a second spring supported by the base portion and arranged to be held in a compressed state by the at least one pivotal arm, when the at least one pivotal arm is in the first pivot position and, from that state, to be released to expand toward its natural state of uncompression upon the at least one pivotal arm moving to the second pivot position; wherein, when (i) the base structure is arranged adjacent the user's skin, (ii) the moveable needle and cannula are in the extended position and (iii) the second spring is released from its compressed state and expands toward its natural state of uncompression, a second bias force is provided on the needle head by the second spring to move the needle from an extended position to a retracted position, while leaving the cannula in the user's skin.