Electromagnet with plunger-type armature and a method for the production thereof

Claim 1

An electromagnet with a plunger-type armature and guide means therefor, said electromagnet comprising: an elongated, tubular body made of an insulating thermoplastic material and having a stepped bore therethrough that defines an annular, axially oriented wall which is thinner at the opposed ends thereof than in the central portion, said tubular body further including a radially extending flange at both axially opposed ends thereof; a pair of hollow, magnetic bodies positioned, respectively, within said stepped bore at the axially opposed ends of said tubular body, each said hollow body having a radially outwardly directed flange that bears against one of said flanges of said tubular body; a pair of laterally spaced apart, axially extending and generally chordally oriented ribs on each said flange of said body; a U-shaped magnetic back circuit defined by a pair of spaced apart legs that rest on said flanges of said hollow bodies and which are contained between said ribs and a connecting portion extending between a common end of said legs, an opening being further provided in each said leg with said openings in said legs being coaxial with each other as well as with said hollow bodies and said tubular body when said legs are positioned over said flanges of said hollow bodies whereby the armature is slidingly received therein; two terminals partially imbedded in one of said flanges of said tubular body; electrically conductive coil means wound about said tubular body between said flanges thereof and attached to said terminals; and said insulating material encapsulating all of said electromagnet except the interior of said tubular body and said hollow bodies and the non-imbedded portion of said terminals.