Method and apparatus for adjusting fiberglass manholes
US6431789B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 15, 2000 |
| Grant date | Aug 13, 2002 |
| Priority date | — |
| Expiry date | Feb 15, 2020 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE02D29/124
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A fiberglass manhole adjustment ring comprising a fiberglass pipe and a self-centering lip attached to the edge of the pipe, and a method for installing the fiberglass manhole adjustment ring in an existing fiberglass manhole. The self-centering lip can either be attached to the interior edge of the pipe to form a sleeve or to the exterior edge of the pipe to form a collar. An interior self-centering lip, or sleeve, slides into an adjoining fiberglass manhole section while an exterior self-centering lip, or collar, slides over an adjoining manhole section. The manhole adjustment ring is inserted between the cone section and barrel section of an existing fiberglass manhole to accommodate changes in elevation of the surrounding grade level. The self-centering lip may also be used on manhole sections to enable field assembly of a manhole.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.