Manhole grade adjusting ring and method
US5209601A · kind A · utility
47Cited by
18References
15Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 14, 1991 |
| Grant date | May 11, 1993 |
| Priority date | — |
| Expiry date | Aug 14, 2011 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE02D29/14
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A manhole grade adjusting ring has an adjustable diameter with a V-shaped expansion lock bridging the ends of the ring. The expansion lock has radial flanges which are adjustably pinned in slots in the ends of the ring after the ring is expanded or contracted to fit a particular manhole frame using an expansion/contraction tool. The "V" is then hammered to expand the diameter of the ring so as to form a tight friction fit between the ring and the manhole frame.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.