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. 24, 1981
Filed:
Apr. 26, 1979
Applicant:
Inventors:
Kuldip Raj, Medford, MA (US);
Ronald Moskowitz, Merrimack, NH (US);
Raoul Casciari, Bedford, NH (US);
Alvan F Chorney, Stoughton, MA (US);
Assignee:
Ferrofluidics Corporation, Nashua, NH (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F16J / ; F16J / ;
U.S. Cl.
CPC ...
277 80 ; 277135 ;
Abstract
A self-activating seal is formed by inserting a magnetically permeable shaft into a module which comprises: a magnet, two pole pieces and a magnetic fluid. The module is so constructed that the magnet and pole pieces form a cavity for storing the magnetic fluid until the shaft or similar element is inserted. Upon insertion of the shaft, the magnetic field is altered and the flux path diverted to the small gaps separating the pole pieces and the shaft. The magnetic fluid is drawn to the gas to form hermetic seals.