Patent ID: 7637475

Claim:
A solenoid comprising: a housing having an axial length, an external surface, an axial opening extending through the axial length and a divider mounted in the axial opening to separate the axial opening into a first segment and a second segment; a first pole piece moveable with the first segment between an extended position and a retracted position, the first pole piece having a plunger positioned at an end of the first pole piece; a second pole piece fixed within the second segment; and a permanent magnet positioned within the second segment between the divider and the second pole piece, the permanent magnet movable within the second segment between a first position adjacent the second pole piece and a second position adjacent the divider, wherein the permanent magnet in the second position draws the first pole piece from the extended position to the retracted position to magnetically couple the first pole piece to the permanent magnet and to move the plunger toward the divider.