Air extraction manufacturing method

1. A method of making an ink cartridge comprising:

forming an ink cartridge having an ink chamber and an air accumulation chamber therein;

forming a cap including a vent hole;

affixing the cap at a first end of the air accumulation chamber and disposing a one way valve at the vent hole for preventing gas from entering the air accumulation chamber through the vent hole when a pressure in the air accumulation chamber is less than a cracking pressure of the one-way valve;

forming a neck region narrower than the ink chamber and the air accumulation chamber for fluidically connecting the ink chamber and the air accumulation chamber within the ink cartridge; and

placing a mass within the air accumulation chamber, the mass having a dimension smaller than an interior dimension of the air accumulation chamber such that the mass is movable between the first end and a second end of the air accumulation chamber.

2. The method of claim 1 , further comprising forming the mass such that the dimension of the mass is greater than a dimension of the neck region for preventing the mass from entering the ink chamber.

3. The method of claim 1 , further comprising forming the mass such that it comprises an average density of less than two grams per cubic centimeter.

4. The method of claim 1 , further comprising forming a through-hole through the mass such that a first end of the through-hole faces the first end of the air accumulation chamber and a second end of the through-hole faces the second end of the air accumulation chamber.

5. The method of claim 4 , further comprising forming a one way valve at the first end of the through-hole for preventing gas from entering the through-hole through the first end of the through hole.

6. The method of claim 5 , wherein the one-way valve at the first end of the through hole is a flapper valve attached on the outside of the first end of the mass.

7. The method of claim 1 , wherein the one-way valve is a flapper valve outside the air accumulation chamber.

8. The method of claim 7 , wherein forming a cap including a vent hole further includes forming a cap assembly and securing the cap assembly around an outside of the first end of the air accumulation chamber such that the cap assembly forms a cap chamber outside of the flapper valve and prevents any ink that has passed through the vent hole and has accumulated in the cap chamber from passing through the cap assembly.

9. The method of claim 8 , further comprising forming a breather membrane in the cap assembly, the breather membrane allowing gas within the cap chamber to pass therethrough but blocking ink from passing therethrough.

10. The method of claim 1 , wherein the ink chamber and the air accumulation chamber contains an ink having a density d i grams/cm 3 , and further comprising forming the mass such that the mass has an effective density d m grams/cm 3 , wherein 0.8d i <d m <1.2d i .

11. A method of making an ink cartridge comprising:

forming an ink cartridge having a first chamber for holding ink and a second chamber smaller than the first chamber for holding a smaller portion of the ink and for holding air, including forming a neck region for fluidically connecting the first chamber and the second chamber;

forming a cap including a vent hole;

affixing the cap at a first end of the second chamber for evacuating a portion of the air in the second chamber;

disposing a one way valve at the vent hole for preventing gas from entering the second chamber through the vent hole when a pressure in the second chamber is less than a cracking pressure of the one-way valve; and

disposing a mass within the second chamber, the mass having a dimension smaller than an interior dimension of the first second chamber such that the mass is movable between the first end and a second end of the second chamber, the mass also having a dimension large enough such that air is forced out of the vent hole when the mass moves in a direction toward the first end of the second chamber.

12. The method of claim 11 , wherein the step of forming the neck region comprises forming the neck region proximate the second end of the second chamber.

13. The method of claim 12 , wherein the step of forming the neck region further comprises forming the neck region smaller than the mass for preventing the mass from entering the first chamber.

14. The method of claim 13 , further comprising forming the mass such that it comprises an average density of less than two grams per cubic centimeter.

15. The method of claim 14 , further comprising forming a through-hole through the mass such that a first end of the through-hole faces the first end of the second chamber and a second end of the through-hole faces the second end of the second chamber.

16. The method of claim 15 , further comprising disposing a one way valve at the first end of the through-hole for preventing gas from entering the through-hole through the first end of the through hole.

17. The method of claim 16 , wherein the one way valve at the first end of the through hole is a flapper valve attached on an outside of the first end of the mass.

18. The method of claim 11 , wherein the one way valve at the vent hole is a flapper valve attached on an outside of the second chamber.

19. The method of claim 11 , wherein the ink comprises a density d i grams/cm 3 , and further comprising forming the mass such that the mass has an effective density d m grams/cm 3 , wherein 0.8d i <d m <1.2d i .