The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 05, 2004
Filed:
Oct. 28, 2002
Jens Schäfer, Herzogenaurach, DE;
Ina-Schaeffler KG, , DE;
Abstract
An electromagnet having a hollow cylindrical coil former fitted with a coil winding and surrounded by a magnet housing. The coil former is bounded by upper and lower pole shoes. A nonmagnetic metal tube in the hollow cylinder of the magnet defines an armature space for a magnet armature that divides the armature space into first and second chambers, which are connected via a pressure equalizing channel in the magnet armature. A push rod passes through an axial hole in the lower pole shoe, to a control piston of a hydraulic valve, whose interior is connected via a further pressure equalizing channel in the lower pole shoe to the first chamber of the armature space. The push rod is a profiled rod contacting the magnet armature, the rod is of a cross-sectional shape different than that of the axial hole in the lower pole shoe and of a cross-sectional area less than that of the axial hole. The magnet armature has a central longitudinal hole of a diameter smaller than the largest profile width and larger than the smallest profile width of the push rod.