US Patent 7959368 Ink cartridge structure for pens

An ink cartridge structure includes a resilient device coupled to an ink cartridge for absorbing impact energy acting on the ink cartridge for protection of the ink cartridge. The resilient device includes a connection bar mounted to the ink cartridge and is coupled to a retention bar that is accessible by a user with a resilient element therebetween so that the resilient element provides cushioning to the ink cartridge. The connection bar is partially fit into a hollow portion of the retention bar and forms a vent hole that is in communication with the ink cartridge so that when the retention bar, under the resilient support by the resilient element, is manually moved reciprocally with respect to the connection bar, air is pumped, through the vent hole, into the ink cartridge to force the ink contained in the ink cartridge to ward a writing tip.