Flow control system for ink cartridges
US4931812A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 18, 1989 |
| Grant date | Jun 5, 1990 |
| Priority date | — |
| Expiry date | Jul 18, 2009 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61P25/06
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
An ink cartridge system is provided which includes a reservoir maintained at a negative pressure in communication with a printing system. As the printing system is activated, ink is expelled from the cartridge which draws ink from the reservoir by capillary action. To prevent the reverse flow of air and ink into the reservoir, a control unit is provided. The control unit includes an ink conduit communicating with a standpipe. A medial section is provided between the ink conduit and standpipe. The medial section includes an opening adapted to receive a ball within the ink conduit. The ball is freely movable within the ink conduit, but is larger than the opening. As a result, the outward flow of ink from the reservoir is allowed, while the backflow of ink and air into the reservoir is prevented by movement of the ball into the opening of the medial section.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.