Covering for an opening with a cover or grating placed in a frame
US4861186A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 29, 1988 |
| Grant date | Aug 29, 1989 |
| Priority date | — |
| Expiry date | Jan 29, 2008 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE02D29/14
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A covering for an opening in road surfaces, squares or the like comprises a frame and a cover. The cover has a conical, downwardly and inwardly inclined contact surface by which the cover is supported on a bearing surface provided on a support flange of the frame. The bearing surface is also conical and inwardly inclined. At the bearing surface are provided spaced, circumferentially distributed wedge-shaped grooves, which cooperate with lugs on the cover. By means of the inwardly and downwardly inclined surfaces of the lugs and grooves, a self-centering of the cover is obtained. The centering is guided by the lugs. Thus, even in the case of high traffic loads, the cover is not moved from its position.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.