Hewlett-Packard Company

Patrick W Shelley

John B Dunn

Lowell R McDaniel

Peter R McRostie

Karen M Lewey

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.

Flow control system for ink cartridges

A package for flat lead transistors is provided in which a raised flange provides structural rigidity to prevent damage to the flat leads of the transistor.

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Albany, OR, United States of America

Patrick W Shelley