Variable rate spring ink pressure regulator for a thermal ink jet printer

摘要

An ink pressure regulator system disposed inside of a flexible ink bag reservoir for a replaceable or refillable computer driven printer ink cartridge comprises a pair of parallel piston plates and a spring system therebetween having a variable spring function relating force to displacement of the spring such that the regulator collapses to a substantially flat shape under decreasing amounts of added spring collapsing force as the plates approach each other to allow substantially complete evacuation of ink from the bag.