Fabrication of screen devices
US4238877A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 22, 1978 |
| Grant date | Dec 16, 1980 |
| Priority date | — |
| Expiry date | Dec 22, 1998 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49734
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Screen devices for use with an automatic screen changer (10) of an extruder (11) are fabricated from a screen preform (32) including an elongated carrier strip (36) having a plurality of screen elements (33--33) connected thereto. The screen changer (10) includes a pair of recesses (21,22) for receiving screen devices and is movable between a first position in which one recess is in the path of the extrudate (11) while the other recess is outside the path thereof and a second position in which the dispositions of the recesses is reversed. While a recess (21 or 22) is outside of the path of the extrudate, a used, clogged screen device is ejected therefrom and a new screen device is fabricated, in situ, therein. The screen device is fabricated by feeding the preform (32) between a punch (54) and the recess. The punch (54) is then actuated to sever an element (33) from the preform (32) and in the same motion insert it into the recess.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.