Patent ID: 7398768

Claim:
An electromagnetic drive mechanism comprising: a movable plunger operated by an electromagnetic force, a restricting member for restricting the displacement of the plunger in a specific position, and a biasing member for biasing the movable plunger to the opposite side of the restricting member, wherein the biasing member is the sole biasing member for biasing the movable plunger along the direction of closing the fluid intake port, a force other than the electromagnetic force may be applied to aid the movable plunger for resisting the force of the biasing member along the same direction in which the movable plunger moves due to the electromagnetic force, and the electromagnetic force is applied to the plunger after the movable plunger has been displaced a specific distance in the direction toward the direction of opening the fluid intake port against the biasing member by the force other than the electromagnetic force, wherein the specific distance is a portion of the specific position at which the restricting member restricts the displacement of the movable plunger, and the application of the electromagnetic force displaces the movable plunger from the specific distance to the specific position at which the restricting member restricts the displacement of the movable plunger.