Process for making cassette spring
US4845820A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 22, 1987 |
| Grant date | Jul 11, 1989 |
| Priority date | — |
| Expiry date | May 22, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49609
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method for making a reel-pressure spring for a magnetic tape cassette begins by feeding a strip of spring material from a traverse-wound coil into a first work station of a punch press. The strip material has a width equal to the width of the finished spring. A die pierces the strip material to form mounting holes. The strip material is then fed into a shaping die of a second work station. A cutoff punch severs a blank from the end of the strip material by cutting across the full width of the strip. A shaping die at the second work station shapes the blank into a finished spring, which is then ejected from the second work station to a discharge chute. Finished springs are stacked in the discharge chute in the order in which they are made in the second work station. The stack is packaged so as to maintain the stack intact until such time as the springs are assembled into a cassette.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.