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:
Feb. 01, 1994
Filed:
May. 09, 1991
Bernhard Hoffmann, Starnberg, DE;
Magnet-Bahn GmbH, Starnberg, DE;
Abstract
An overcurrent relay device is provided for monitoring current in a multi-phase current system including separate conductors each carrying a respective one of the current phases between a multi-phase current source and a load. The current system includes a system switch having a displaceable contact for switching the multi-phase current on and off. A plurality of electromagnets are provided, each including a magnetic core having a core pole and being associated with a respective one of the conductors for generating a magnetic attraction force in the vicinity of the core pole. The core poles all face in the same direction. An armature is rotatably mounted adjacent to the core poles and gaps are defined between the armature and the respective core poles so that the magnitude of a magnetic attraction moment on the armature generated by each electromagnet is the same for a given magnitude of the multi-phase current. The armature is disposed for moving the displaceable contact of the system switch for switching off the multi-phase current when the magnitude of the multi-phase current exceeding a predetermined trip value. A mounting mechanism mounts the armature for rotation about a point for presenting a restoring moment on the armature for returning the armature to a predetermined position defining the gaps, wherein the restoring moment presented by the mounting mechanism corresponds to the sum of the magnetic attraction moments on the armature generated by the respective current phases when the magnitude of the multi-phase current equals the predetermined trip value.