Single pass ink ribbon cassette for typewriters or similar machines
US4688954A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 7, 1986 |
| Grant date | Aug 25, 1987 |
| Priority date | — |
| Expiry date | Oct 7, 2006 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41J35/38
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A single pass ink ribbon cassette for typewriters or like machines is designed to track ribbon extending between a supply and take-up spool in such a manner that text contained on used ribbon beyond a point of impression is rendered illegible. Used ribbon is rendered illegible in that upon its entry into the cassette, it is guided around a turn around roller for passage past the point of impression a second time before re-entry again into the cassette, and conducted via guide means for take-up by a driven take-up spool. Due to the fact that the ink ribbon is guided past the point of impression a second time, subsequent impressions on the used ribbon render the text from the used ribbon unreadable. In addition, in the zone of the turn around roller a scraper is provided for scraping the residual ink particles off the used ribbon before it is guided past the point of impression the second time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.