Patent ID: 8517526

Claim:
A print cartridge comprising: an ink housing having a top and a base and at least one interior compartment; a print head mounted at the base of the housing in fluid communication with the compartment via a passageway having an entrance above the bottom of the compartment; a compressed foam block substantially filling the compartment above the passageway entrance so as to leave a free space laterally adjacent to the passageway; and a rib extending upwardly along one wall of the compartment from the free space partially to the top of the foam block, the foam block not conforming fully to the cross-section of the rib to leave an air vent channel along at least one side of the rib between the at least one side of the rib and the foam block, wherein the rib is a non-grooved rib having a top side facing a corresponding first surface of the foam block with just air in-between and a sidewall side facing a corresponding second surface of the foam black with just the air vent channel in-between, wherein the foam block has a shape having a cut-out portion corresponding to a portion of the rib, and wherein no part of the rib is in contact with the foam block.