Plastic pipe
US4690174A · kind A · utility
12Cited by
6References
10Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jul 8, 1986 |
| Grant date | Sep 1, 1987 |
| Priority date | — |
| Expiry date | Jul 8, 2006 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16L9/006
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
This invention relates to a plastic pipe. The wall thickness of this kind of pipes is very small and, consequently, the impact strength is poor. The impact strength of pipes made of polyvinyl chloride can be improved by adding an admixture to the raw material, which, however, increases costs. According to the invention the impact strength can be improved by a ring-shaped elevation formed at the foot of the ribs on both sides thereof, which elevation joins the side wall of the rib over a sharp transitional juncture.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.