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:
Jan. 02, 1990
Filed:
Apr. 18, 1988
Applicant:
Inventors:
Assignee:
Ferrofluidics Corporation, Nashua, NH (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F16J / ; F16J / ;
U.S. Cl.
CPC ...
277 80 ; 277135 ;
Abstract
A ferrofluid seal wherin the amount of ferrofluid which may be used is increased by tapering the gap in which the ferrofluid is retained from one end of the gap to the other. One side of this gap is the magnet and, where used, pole pieces used to generate the magnetic field retaining the sealing ferrofluid, and the other side is a wall forming the opening to be sealed. The tapering of the gap width may be achieved by tapering either side forming the gap or by tapering both sides. The taper is preferably uniform from one end of the gap to the other.