Filament reinforced plastic screen and apparatus for making same
US4381820A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 24, 1981 |
| Grant date | May 3, 1983 |
| Priority date | — |
| Expiry date | Dec 24, 2001 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D29/48
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Filament reinforced cylindrical plastic screens having open slots defined by their surface wires which are of substantially different widths can be produced on a single helically finned mandrel. The slot widths are varied in accordance with the amount of wire-forming material placed in the generally V-shaped grooves defined by the mandrel fins. The grooves have a double relief angle so that the lower support portions of the surface wires will be formed so as to have a slightly tapered, radially elongated cross-section and the upper portions of the wires will have their sides at a substantially greater relief angle. This relationship permits a relatively small change in the total height of the wires to have a substantial effect on the width of the top portion of the wires, and thus, on the width of the slot openings which can be formed between adjacent wires.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.