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:
May. 22, 1990
Filed:
Aug. 08, 1988
Kuldip Raj, Merrimack, NH (US);
Joseph Moses, Tyngsboro, MA (US);
Ronald Moskowitz, Hollis, NH (US);
Frank Bloom, Windham, NH (US);
Ferrofluidics Corporation, Nashua, NH (US);
Abstract
In a ferrofluid seal which comprises a magnet and at least one pole piece, the pole piece is fabricated from a ferromagnetic material which directly bonds to the magnet face. Since the pole piece material directly bonds to the magnet, no additional adhesive is necessary. Thus, the conventional steps of applying an adhesive and mounting pole pieces on the magnet are eliminated. In addition, voids and bubbles in the adhesive are eliminated, thus, enhancing seal integrity. In one embodiment, the ferromagnetic material is a ferromagnetic epoxy compound comprising a mixture of conventional epoxy materials plus a fine powder of ferromagnetic material such as iron, cobalt, nickel or various metal alloys.