Patent ID: 7227440

Claim:
An electromagnetic actuator comprising: a first member; and a second member moveable relative to the first member, the second member including first end, central and second end magnetostrictive elements, the elements mounted one to another in series with the central element disposed between the first and second end elements, the second member further including means for selectively forcing engagement in a radial direction of the first member by the first and second end elements, said means including means for axially compressing the first and second end elements and means for restraining respective radial expansion of the first and second end elements in a direction opposite to said radial direction, and means for magnetostrictively activating the first end, central and second end elements in a controlled manner to alternatingly maintain and release forced engagement of the respective first and second end elements with the first member while controllably expanding and contracting the central element in a longitudinal direction, thereby causing movement of the first member relative to the second member.