Wear compensating stem sealing apparatus
US4898393A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 22, 1988 |
| Grant date | Feb 6, 1990 |
| Priority date | — |
| Expiry date | Jun 22, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S277/91
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
The present invention is directed to an improved wear compensating stem sealing apparatus. The elements thereof include a unitarily formed or separably formed O-ring separator disposed upon a valve stem. A first, or "wiper" O-ring is disposed on the stem in a space provided on the O-ring separator. A second (and in some embodiments, a third) O-ring is disposed about the stem in a similar space on the O-ring separator above the level of the first O-ring. The second and/or third O-ring provide a subsequent sealing of the stem from pressurized fluid migrating upwardly upon wear of the first O-ring. The first O-ring may be made of a material which will wear more rapidly and/or wipe more efficiently than the second and/or third O-ring, or provide less radial squeeze, such that the second and/or third O-ring is subjected to increased compressive pressure from the pressurized fluid upon the wearing of the first O-ring.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.