Drainage unit with external covering and method for manufacture
US8256990B2 · kind B2 · utility
9Cited by
17References
24Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Nov 21, 2006 |
| Grant date | Sep 4, 2012 |
| Priority date | — |
| Expiry date | Sep 14, 2027 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE02B11/005
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
Drainage units comprise lightweight aggregate held within a perforated sleeve having an exterior surface, where at least a portion of the exterior surface comprises a barrier material which is substantially impervious to solids.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.