Manhole assembly with T-shaped hinge
US4840514A · kind A · utility
22Cited by
5References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 7, 1988 |
| Grant date | Jun 20, 1989 |
| Priority date | — |
| Expiry date | Apr 7, 2008 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE02D29/14
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A manhole assembly includes a circular cover 4 seated in a frame 1 and removably hinged thereto by a T-shaped lug 16 extending radially from the cover and lying within a matingly configured receptacle 5 defined in an upper edge of the frame. Lips 9 overhang opposite interior ends of the deepened receptacle trough 7 to restrain the pivot shaft 18 of the lug against vertical removal with the cover closed, in which position the lug has no contact with the receptacle surfaces to avoid clanking noise upon the passage of a vehicle.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.