Manhole ladder
US5277272A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 2, 1993 |
| Grant date | Jan 11, 1994 |
| Priority date | — |
| Expiry date | Mar 2, 2013 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE06C7/08
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A non-metallic ladder for use in a manhole in which permanent manhole steps have been installed and spaced relation from the top of the manhole to a position above the bottom and there being a pair of spaced side members on said ladder connected transversely by spaced steps to form corners at the top in which there are spaces to fit over a respective side members on the step. The spaces may be in the shape of a rectangular cross-section or other configuration. The ladder is "hung" from the step to resist dislodgment therefrom. There may be provided a wall bumper member at the bottom of the ladder to engage the inside wall of the manhole.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.