Patent ID: 7145423

Claim:
An electromagnetic actuator, comprising: (A) a stationary assembly that includes (1) a hollow stator yoke composed of a soft magnetic material and (2) two coils disposed coaxially in a traveling direction of the actuator inside the hollow stator yoke; and (B) a movable assembly disposed in a hollow space of the two coils to oppose thereto with a very small clearance that includes (1) a movable magnet unit and (2) a movable yoke unit, both units mounted on a single supporting shaft adjacently to each other in an axial direction of the supporting shaft; wherein the movable assembly travels in the axial direction by an electromagnetic force generated with the coils by interaction between a magnetic field generated by the movable magnet unit and a current flowing in the coils, and wherein said movable magnet unit is disposed on said single supporting shaft so as to oppose said coils radially, wherein the two coils are wound on one bobbin made of a synthetic resin and having a substantially identical shape with each other, wherein the bobbin has a separator at the middle thereof, and a terminal block is provided on the separator, and the bobbin with the coil wound thereon is disposed axially inside the stator yoke, and wherein the stator yoke has a rectangular shape, and an opening for receiving the terminal block formed on the separator of the bobbin is provided at the center of the stator yoke.