US Patent 8100598 Two-piece magnetically actuated pen

A magnetically actuated writing instrument includes a holder portion including a first magnetically attractive member. The instrument also includes a writing instrument portion having an interior and a second magnetically attractive member. The writing instrument portion includes a barrel having a distal end portion. The barrel member is movable between a retracted position wherein the distal end is disposed within the interior of the writing instrument portion, and an extended position wherein the distal portion is disposed exteriorly of the writing instrument portion. A retractor for moving the barrel between the retracted and extended positions includes the first and second magnetically attractive members. The presence of magnetic attraction between the first magnetically attractive member and the second magnetically attractive member causes the barrel to move toward the retracted position, and the absence of magnetic attraction between the first and second magnetically attractive members causes the barrel to move toward the extended position.