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. 02, 2000
Filed:
Dec. 02, 1997
Alberto Visconti, Varese, IT;
RFT S.p.A., Torino, IT;
Abstract
A sealing assembly for a pump shaft, having a metal supporting structure, and a sealing ring in turn having a main sealing lip and a secondary lip, which extend axially in opposite directions and define an annular cavity together with a lateral surface of the shaft. When undeformed, the diameters of the two lips are such as to respectively determine a predetermined amount of interference and a radial clearance with the shaft. The sealing ring is so formed as to be deformed elastically by the interference fit between the main lip and the shaft, so as to cause the secondary lip to cooperate with the shaft with substantially no interference. The secondary lip is defined between two annular sides converging with each other to form a sealing edge towards a lateral surface of the shaft; and the side located on the opposite side to the annular cavity is defined by an oblique annular surface defining in radial section an acute angle with the shaft so as to receive, in use, a sufficient radial thrust to raise the secondary lip slightly and allow fluid to leak into the annular cavity.