Ribbon tensioning mechanism
US4886385A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 27, 1988 |
| Grant date | Dec 12, 1989 |
| Priority date | — |
| Expiry date | Jun 27, 2008 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41J33/52
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A ribbon or tape tensioning system for typewriter correction ribbons includes a brake for exerting a braking force on a supply or feed ribbon spool. The mounting capstan for the feed spool is provided with a toothed hub which can be engaged by a pawl rotatably mounted on an arm which in turn is rotatably mounted on the typewriter frame. The pawl and the arm are provided with abutments or projections which when brought into contact with the frame cause the pawl to disengage or engage the toothed hub, thus permitting the hub to rotate freely or be braked. A force applied by an element such as a spring biases the assembly in a direction to cause the capstan to exert a tension on the ribbon, except when the pawl is disengaged. When the tension on the ribbon exceeds a predetermined amount, the pawl is disengaged from the toothed hub, permitting its momentary rotation and relief of the tension.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.