Manhole
US5785452A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 10, 1996 |
| Grant date | Jul 28, 1998 |
| Priority date | — |
| Expiry date | Apr 10, 2016 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE02D2300/0032
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A manhole embodiment that includes a skirt made of flexible material, such as rolled sheet steel, having a stiffening flange extending laterally from the bottom rim of the skirt to increase the manhole lateral strength and provide a footing for the manhole and an outwardly extending lip at the skirt upper rim. The manhole top ring connects directly to the top of the lip. This eliminates the need for a separate piece such as the lower L-shaped ring piece included in conventional manholes. An optional extension skirt can telescope into the bottom of the upper skirt that can be held to the upper skirt by fasteners. The telescoping extension skirt can be height adjusted in the field so that the over-all height of the manhole can be adjusted to any desired height, say between 8 and 16 inches.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.