Spring element and ink cartridges therewith

Abstract

The invention relates to ink cartridges having spring elements according to the invention and a spring element itself having a relatively constant spring force over a substantial part of the overall spring travel and comprising at least one first individual element of substantially S-bow or S-curve shape with a first spring characteristic and at least one second individual element of substantially single-bow or curve shape with a second spring characteristic, a regulating spring characteristic with a relatively constant spring force being obtained over the substantial part of the spring travel. Practical embodiments with frame parts and/or cover parts can be favorably produced by injection molding. The individual elements are provided with differing cross-sectional dimensions over their length for reducing stress at bending points susceptible to stress. The spring elements can be used for ink cartridges for removal of the liquid or paste while at the same time generating negative pressure, or else generally for keeping pressure constant in pneumatic and hydraulic systems in general.

Dependencies are inferred from the claim text.