Backflow preventer
US7128088B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 7, 2004 |
| Grant date | Oct 31, 2006 |
| Priority date | — |
| Expiry date | Jun 30, 2025 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/7932
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A backflow assembly including a housing with a passage having at least one check valve positioned therein to permit fluid flow in one direction while preventing fluid flow in the reverse direction. The check valve includes a valve head connected to a stem having an outer surface. A hump extends radially outward from the outer surface of the stem. The stem is guided by a bushing during opening and closing of the valve. The bushing includes at least one retention member that moves along the outer surface of the stem during opening and closing of the valve. The interaction between the retention member and the hump on the outer surface of the stem causes a higher friction loss during opening and closing of the valve than other portions of the outer surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.