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:
Oct. 27, 1981
Filed:
Oct. 10, 1979
Hiroshi Inouye, Minorimachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In a mechanical seal for the rotary shaft of a rotary machine wherein the pressure difference between the internal and external liquids acting on the mechanical seal changes from positive to negative, and vice versa, a ring and a seat ring are formed with mating seal faces which coact to seal between the internal and exterior liquid present externally and internally, respectively, of the retainer; the seat ring is securely and liquid-tightly mounted on the rotary shaft for rotation therewith in a casing; the ring is fitted over a retainer axially movably, but nonrotationally and is normally pressed against the seat ring under the force of a bias spring which provides the sealing force for maintaining the seal between the seal faces when the external liquid pressure exceeds the internal liquid pressure, but the pressure difference is relatively small; the retainer in turn is mounted in the casing nonrotationally but axially movably due to the difference in pressure between the internal and external liquids, whereby regardless of the difference in pressure between the internal and external liquids, the seal may be maintained securely.