Self-sealing retractable writing instrument
US7059796B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 17, 2003 |
| Grant date | Jun 13, 2006 |
| Priority date | — |
| Expiry date | Apr 17, 2023 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB43K8/028
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
A retractable writing instrument that substantially prevents writing fluid from evaporating through the tip when the tip is in a retracted position to eliminate the need for a cap. Within the writing instrument is an enclosure member that has a vapor chamber. In the retracted position, the tip of the writing instrument is within the vapor chamber to substantially seal the tip from ambient air so that writing fluid does not evaporate through the tip. The enclosure member has a lip that opens to allow the tip to move forward and extend from the writing instrument so that writing fluid can be delivered to the writing surface for writing. When the tip is moved back into the retracted position the lip closes to substantially seal the tip from the ambient air. An external compression force may be applied to the lip to assist in sealing the lip. The enclosure member may be made of a material that is durable so that the lip does not wear out after many cycles of moving the tip between the retracted and protracted positions, such as silicone, butyl rubber, and thermoplastic vulcanizate (TPV) material including butyl rubber cross-linked with polypropylene.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.