GB1406035A - Electromagnetic devices - Google Patents

Abstract

1406035 Electromagnets EXPERT INDUSTRIAL CONTROLS Ltd 13 Oct 1972 [23 Oct 1971] 49346/71 Heading H1P A solenoid is wound on annular former 13 within magnetizable tube 11 in whose ends are located stacks of washers 12 and the tube may be formed of plural arcuate elements tack welded to the stacks; the winding tube, and stacks being potted in epoxy resin to a moulding enclosing a cylindrical bore having a step at one end defined by the upper stack which has a smaller inner diameter. A cylindrical polepiece 14 located in the bore is stepped to fit the step of the bore over a deformable ring 15, and defines a cylindrical recess accommodating armature 17 with an actuating rod 18 and axial bearing rings 19 engaging a wall of the polepiece, which extends outwardly to a closure member 20 carrying a push piece 20a. A second cylindrical polepiece 21 comprises a central core and a surrounding case, and fits the bore with its case separated from the first polepiece 14 by non-magnetic spacer 22; being retained by base-plate 23 screwed to the lower stack 12 of washers; with an aperture admitting a distance piece connecting rod 18 to, e.g. a valve element (not shown) which exerts resilient loading on the armature. A brass spacer 24 separates the armature 17 and the polepiece 21 in the energized position (shown) and a deformable pad 26 separates polepiece 21 and baseplate 23, while a further resilient pad 27 is mounted on the desire member 20 to cushion the armature motion and seal against moisture.