Patent ID: 6955336

Claim:
A solenoid for providing linear actuation, comprising: a) first and second polepieces having axial bores coaxially disposed along a common axis; b) an electrical conductor wound about said polepieces in a plurality of turns; c) an armature movably disposed in said axial bores, wherein said armature includes an outer surface, wherein at least a portion of said outer surface is frusto-conical, said frusto-conical portion of said outer surface being adjacent to a substantial portion of said first and second polepieces; d) a bearing axially retained in one of said first and second polepieces, said axial bore of said polepiece not retaining said bearing being non-frusto-conical; and e) a shaft attached coaxially to said armature and extending through a supportive bore in said bearing wherein said bearing radially supports said shaft, said shaft being axially displaceable by electromagnetic displacement of said armature to provide said actuation, wherein said armature is entirely separated from said axial bores of said polepieces by an air gap, and wherein the armature is prevented from contacting the polepieces.