Extrusion apparatus for producing thermoplastic pipe
US4548570A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 12, 1983 |
| Grant date | Oct 22, 1985 |
| Priority date | — |
| Expiry date | May 12, 2003 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C2948/92961
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Apparatus is disclosed for the formation of pipe comprising one or more layers of thermoplastic resin. The apparatus comprises a die housing having a bore therethrough with a mandrel longitudinally supported within the bore by radial members extending from the inside surface of the bore to provide an annular extrusion passageway defined by the inside surface of the housing and the outer surface of the mandrel. The housing includes therein a plurality of electrically resistive heating elements longitudinally positioned parallel to the extrusion passageway to selectively heat the thermoplastic material flowing therethrough in proximity to the heated section thereby increasing the laydown of thermoplastic material. Also included in the housing is plurality of radially adjustable elements having electrically resistive heating elements therein to radially reposition a moveable discharge sleeve held therebetween thereby controlling the wall thickness of the thermoplastic material passing in proximity thereto. The extrusion passageway is constricted downwstream of the radial support but prior to the annular sequentially positioned feed rings to reunite the thermoplastic material after the…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.