Adjustable height extension stem and valve box assembly
US5738140A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 26, 1996 |
| Grant date | Apr 14, 1998 |
| Priority date | — |
| Expiry date | Dec 26, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/8275
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
An adjustable-height extension stem and valve box assembly is provided for use with buried valves that is lightweight, readily adjustable to a large range of heights, and is capable of absorbing loads and impacts such that the loads and impacts are substantially not transmitted to the buried valve or surrounding pipeline. The valve box is made up of a valve box base, a valve box lower section, a valve box upper section that telescopes within the lower section, and a valve box top. An upper section of the extension stem extends from the interior of the valve box top through a bottom opening, and an extension stem lower section extends downwardly from the upper section, with the two sections being made from square hollow metal tubing such that the upper section telescopes within the lower section. A grit washer having grooves cut in a bearing surface is attached to the extension stem upper section and supports the upper section in place within the valve box top. The valve box upper and lower sections are quickly secured at a desired height or extension by a reducer coupling and a reducer cap which operate to compress an O-ring against an outer surface of the valve box upper section t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.