Video disc molding process
US4318877A · kind A · utility
2Cited by
2References
3Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Dec 28, 1979 |
| Grant date | Mar 9, 1982 |
| Priority date | — |
| Expiry date | Dec 28, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S425/81
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An improved apparatus and method of molding a high density information disc which includes maintaining the molding composition at an elevated temperature between the extrusion step and the record pressing step, such that the resultant disc is of improved quality. A heated shot cup is provided to maintain the extruded molding composition at the elevated temperature and in which the same is molded into a preform from which the disc is pressed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.