Linear DC permanent magnet motor

Claim 1

A linear DC permanent magnet motor comprising: a stationary wound member, said wound member comprising at least two slip bars adapted for connection to a DC source, a plurality of electrically energizeable windings wound on a slotted magnetic structure and a plurality of commutator bars connected to said windings; a movable field member comprising permanent magnet means for developing a magnetic field, at least two slip bar brushes adapted to engage said slip bars and at least three commutator brushes for energizing with direct current some but not all of said windings at any one time, said second commutator brush being physically located intermediaate said first and third commutator brushes along the longitudinal axis of said wound member, said second commutator brush being electrically connected to one of said slip bar brushes and said first and third commutator brushes being electrically connected to the other of said slip bar brushes, the magnetic field of said permanent magnet means interacting with said energized windings causing said field member to move relative to said wound member to selectively and progressively energize said windings; and support means for maintaining air gaps between said wound member and said field member.