Electromagnet with expandible cores for exciting coils

US4530028A · kind A · utility

Assignee

• EMAG Maschinenfabrik GmbH · DE

Inventors

• Rudi Metz · Donzdorf, DE
• Herbert Scholl · Göppingen, DE

Key dates

• Filing date: Mar 31, 1983
• Grant date: Jul 16, 1985
• Expiry date: Mar 31, 2003

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01F2007/208
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

A lifting electromagnet for ferromagnetic workpieces has two composite cores which extend downwardly from a yoke. Each core has a first section which is rigid with the yoke and is surrounded by an exciting coil, a second section which is connected with the respective first section, and at least one third section which is movable with reference to the second section, either up or down or horizontally. The poles at the lower ends of the third sections make an angle of 120 degrees, the same as the poles at the lower ends of the second sections. The second sections are surrounded by induction coils, and a further induction coil is disposed between each pair of neighboring third sections. The distance between the second sections is less than the distance between the first sections, and the distance between the second sections exceeds the distance between each pair of third sections. Each pair of third sections forms part of an auxiliary magnet which is movable up and down or horizontally, depending on the nature of the workpieces which are to be lifted and transported by the electromagnet. An electromagnet with one or more horizontally movable auxiliary magnets is used for the transport…