Device for screwing a writing instrument tip into a writing fluid reservoir
US4981383A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 7, 1989 |
| Grant date | Jan 1, 1991 |
| Priority date | — |
| Expiry date | Dec 7, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S411/911
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
Apparatus for screwing a writing instrument tip into a writing fluid reservoir in a writing instrument in which the connection from the reservoir to the tip, in order to supply the writing fluid to the tip, is made by the screwing action just prior to using the writing instrument, in which the writing instrument tip has at least a first working surface upon which at least a second working surface of a wrench acts, the working surfaces being formed as a ratchet and pawl which only engage in a screwing direction and permitting a relative rotation of the working surfaces in an unscrewing direction. As a result the tip cannot be unscrewed from the writing fluid reservoir, avoiding contamination, air entry or blockages.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.