Patent ID: 7598830

Claim:
An electromagnetic coil apparatus comprising: a ferrous coil frame including a first end and a second end opposite said first end; a coil assembly comprising a conduit, a number of coils within said ferrous coil frame and being disposed on said conduit, and a ferrous plunger movable in said conduit; a first ferrous member disposed proximate the first end of said ferrous coil frame; a second ferrous member having an opening and being disposed proximate the second end of said ferrous coil frame; a magnetic flux enhancer external to said conduit and being at least partially external to said ferrous coil flame, said magnetic flux enhancer comprising a ferrous conduit coupled to said second ferrous member, said magnetic flux enhancer cooperating with the opening of said second ferrous member to form a passageway; wherein a portion of the ferrous plunger of said coil assembly passes through said passageway; wherein said second ferrous member further has a counter-bore forming a rim within the opening thereof; and wherein said magnetic flux enhancer further comprises a ferrous collar, which engages the rim of said second ferrous member within the opening thereof; and wherein said coil assembly further comprises a non-magnetic conduit coupled to said second ferrous member; wherein said non-magnetic conduit includes a non-magnetic collar, which engages said second ferrous member within the counter-bore thereof; wherein said non-magnetic conduit is internal to said ferrous coil frame; wherein said non-magnetic conduit cooperates with the opening of said second ferrous member and the ferrous conduit of said magnetic flux enhancer to form said passageway; and wherein a portion of the ferrous plunger of said coil assembly passes through said non-magnetic conduit.