Patent ID: 6783512
Filing Date: 2004-08-31
Classification: A61M

Abstract:
A powered injector to deliver a liquid, said injector including:a body; a cylinder in the body; a piston slidably mounted within the cylinder so as to cooperate therewith to enclose a variable volume chamber; an outlet extending from said chamber and being adapted to receive a needle through which the liquid is delivered; a needle shroud movably mounted on the body so as to be movable between an extended position at which the needle would be covered by the shroud, and a retracted position at which the needle is exposed; an inlet extending to said chamber to deliver liquid thereto; a solenoid mounted in the body and having a movable actuator connected to the piston, said actuator being caused to move generally linearly from a first position to a second position upon the solenoid being electrically energised, with said piston being caused to reduce the volume of said chamber when said actuator moves from said first position to said second position; an electric switch connected to said solenoid to deliver electric power thereto to energise said solenoid, the switch being mounted on said body so as to be engaged by said shroud when moved to the retracted position thereof; and wherein when said shroud moves to said extended position said electric switch disconnects said solenoid from electric power so that said actuator moves from said second position to said first position causing said piston to increase the volume of said chamber and draw liquid into said chamber via said inlet.