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. 25, 1992
Filed:
Jul. 17, 1990
Applicant:
Inventors:
Glenn G Pecht, Wheeling, IL (US);
Jon Hamaker, Schaumburg, IL (US);
Assignee:
John Crane Inc., Morton Grove, IL (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
F16J / ; F16C / ;
U.S. Cl.
CPC ...
277 961 ; 384123 ;
Abstract
A seal face of a ring used in a non-contacting, gap-type seal having an annular groove area with microdams, each having a preferable width of about 0.025 inches, between a plurality of groove surface areas. The microdams provide a boundary to the groove surface areas whereby the recess of each groove surface area bounded by the microdams acts as a unitary pressure zone and the pressure in the separate zones decreases in a series of steps as measured from one circumference of the ring to the other circumference.