Regulator for a free-ink inkjet pen

• US 5,975,686 A
• Filed: 06/12/1997
• Issued: 11/02/1999
• Est. Priority Date: 10/31/1994
• Status: Expired due to Term

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Company (HP Inc.)
• Inventors: Hauck, Mark, Pawlowski, Norman E. Jr., Harvey, James A.
• Primary Examiner(s): Le, N.
• Assistant Examiner(s): Vo, Anh T. N.
• Application Number:
  US08/873,612
• Time in Patent Office: 873 Days
• Field of Search: 347/85, 347/86, 347/87
• US Class Current: 347/85
• CPC Class Codes: B41J 2/175 Ink supply systems ; Circuit parts therefor
• CPC Class Codes: B41J 2/17513 Inner structure
• CPC Class Codes: B41J 2/17523 Ink connection
• CPC Class Codes: B41J 2/17553 Outer structure
• CPC Class Codes: B41J 2/17556 Means for regulating the pressure in the cartridge
• CPC Class Codes: B41J 2/17566 Ink level or ink residue control
• CPC Class Codes: B41J 2/17596 Ink pumps, ink valves
• CPC Class Codes: G01F 23/003 with a probe suspended by rotatable arms with floats G01F23/32
• CPC Class Codes: G01F 23/72 using magnetically actuated indicating means

Abstract

A free-ink inkjet pen is adapted to be fluidically coupled to a positive pressure, off-axis ink reservoir. The pen includes a pressure regulator mechanism in an ink accumulation chamber fluidically coupled to a print head mechanism maintained at a predetermined back pressure by the pressure regulator. A flexible bag is maintained at atmospheric pressure within the accumulator and acts as an actuator against a pressure regulator bias. In the preferred embodiment, the pressure regulator mechanism includes an actuation lever and a pressure regulation lever biased toward each other. The flexible bag is mounted between the levers where by expanding and contracting both levers are actuated appropriately. A variety of bag fabrication configurations, bag materials, and valve seat materials are disclosed.

Claims

1. A pressure regulator device for an ink-jet pen, comprising:

an inlet valve means for controlling flow of ink into the pen, said inlet valve means is coupled releasably to an ink supply; and

,

coupled to said inlet valve means, first lever means for maintaining a predetermined back pressure within said ink-jet pen, second lever means for opening and closing said valve means, bias means for biasing said first lever means with a predetermined bias force such that said predetermined back pressure is established within said ink-jet pen and such that said first lever means and said second lever means are mounted with said predetermined bias force toward each other, and a flexible inflation-deflation means, vented to ambient atmospheric pressure, for balancing ambient atmospheric pressure against said bias means, said inflation-deflation means is mounted between said first lever means and said second lever means such that predetermined areas of said inflation-deflation means contact each said first lever means and said second lever means respectively and have shapes and dimensions such that said predetermined areas constitute maximized contact areas.

2. The device as set forth in claim 1, said inflation-deflation means further comprising:

a thin-film fabricated from the materials selected from the group consisting of

(1) PE/tie/PVDC/tie/PE;

(2) PE/tie/PVDF/tie/PE;

(3) PE/tie/EVOH/tie/PE;

(4) LDPE/tie/EVOH/tie/LDPE (both laminated or co-extruded);

(5) MDPE/tie/EVOH/tie/MDPE (both laminated or co-extruded);

(6) HDPE/tie/EVOH/tie/HDPE (both laminated or co-extruded);

(7) LDPE/tie/PVDC/tie/LDPE (both laminated or co-extruded);

(8) MDPE/tie/PVDC/tie/MDPE (both laminated or co-extruded);

(9) HDPE/tie/PVDC/tie/HDPE (both laminated or co-extruded);

(10) LDPE/tie/PVDF/tie/LDPE (laminated);

(11) MDPE/tie/PVDF/tie/MDPE (laminated);

(12) HDPE/tie/PVDF/tie/HDPE (laminated);

(13) LDPE/tie/ALUMINUM/tie/LDPE;

(14) MDPE/tie/ALUMINUM/tie/MDPE;

(15) HDPE/tie/ALUMINUM/tie/HDPE;

(16) LDPE/tie/ALUMINUM OXIDE/tie/LDPEL

(17) MDPE/tie/ALUMINUM OXIDE/tie/MDPE;

(18) HDPE/tie/ALUMINUM OXIDE/tie/HDPE;

(19) LDPE/tie/SILICON DIOXIDE/tie/LDPE;

(20) MDPE/tie/SILICON DIOXIDE/tie/MDPE;

(21) HDPE/tie/SILICON DIOXIDE/tie/HDPE;

(22) PE/tie/LCP/tie/PE;

(23) ECTFE;

(24) PCTFE;

(25) LCP thin films; and

(26) CVD diamond-like coated films.

3. The device as set forth in claim 1, wherein said inflation-deflation means further comprises:

a thin film construct of a composition of LDPE/EVA/PVDC/EVA/LDPE, where PVDC is polyvinylidene chloride.

4. The device as set forth in claim 3, wherein said thin film construct further comprises:

a laminated film.

5. The device as set forth in claim 3, wherein said thin film construct further comprises:

a co-extruded film.

6. The device as set forth in claim 3, wherein said thin film construct further comprises:

said thin film having a thickness in a range of approximately one to three mils.

7. The device as set forth in claim 1, said valve means further comprising:

a valve seat fabricated of a complaint material selected from the group consisting of

(1) fluorosilicone elastomers,

(2) silicon rubbers,

(3) blends of fluorosilicone and silicon,

(4) fluoroelastomers, consisting of either a combination of copolymers based on vinylidene fluoride and hexafluoropropylene or a combination of tripolymers based on vinylidene fluoride, hexafluoropropylene, and tetraflurorethylene, and

(5) EDPM (ethylene propylene dimer- or diene-monamers).

8. An ink-jet pen device for an ink-jet pen adapted to be coupled to an off-axis supply of ink, said device comprising:

an ink accumulation chamber;

means for fluidically coupling said supply of ink to said chamber such that ink is transferred from said supply of ink to said chamber at a first predetermined pressure greater than or equal to ambient atmospheric pressure;

a print head fluidically coupled to said chamber;

mounted within said chamber, first means for regulating ink flow into said chamber and for maintaining a predetermined gauge pressure at said print head such that said gauge pressure is less than said first predetermined pressure, said first means having a positive force bias mechanism; and

coupled to said first means via said positive force bias mechanism, second means for compensating for trapped gases within said chamber and for maintaining a predetermined gauge pressure at said print head such that said gauge pressure is less than said first predetermined pressure, said second means including an inflation-deflation means having a vent to ambient atmospheric pressure and being mounted within said chamber such that said inflation-deflation means provides a counter-bias force against said positive force bias mechanism, wherein predetermined areas of said inflation-deflation means abuts said second means and said inflation-deflation means has a shapes and dimensions such that said predetermined areas constitute maximized contact areas.

9. The device as set forth in claim 8, wherein said means for fluidically coupling said supply of ink to said chamber further comprises:

a valve actuated by said first means, having a resilient material valve seat mechanism coupled to said first means.

10. The device as set forth in claim 8, wherein said second means further comprises:

said inflation-deflation means having regions of contact with said first means such that said regions are maximized throughout a relative range of motion between said first means and said inflation-deflation means.

11. The device as set forth in claim 8, wherein said inflation-deflation means further comprises:

a thin film construct of the composition LDPE/EVA/PVDC/EVA/LDPE.

12. An ink-jet printing apparatus, comprising:

a remote ink reservoir containing ink under a pressure of P1;

an ink-jet print head;

an ink accumulation chamber in fluid communication with the print head;

a conduit for ink connecting the remote reservoir and the accumulation chamber;

a valving mechanism in fluid communication with the ink accumulation chamber for selectively connecting said conduit;

a predetermined area within the printing apparatus to collect air;

an expandable/contractible bag mechanism within the ink accumulation chamber having a predetermined internal reference pressure, said bag mechanism having an exterior region in fluid communication with the predetermined air collection area and compensating for air within the print cartridge;

an actuating mechanism for supplying ink to the print head at a substantially constant back pressure of P2, where P1 is substantially greater than P2, said actuating mechanism having a pivot axis and a predetermined pivot range; and

said bag mechanism directly bearing against said actuating mechanism wherein contact areas of said actuating mechanism and said bag mechanism have shapes and dimensions to maximize contact area throughout the pivot range of said actuating mechanism.

13. The apparatus as set forth in claim 12, said valving mechanism further comprising:

a resilient material valve seat wherein compliance in accordance with P2 compensates for air within the print cartridge.

14. A system for delivering ink to a inkjet pen, having a print head operating at a gauged predetermined print head back pressure, the system comprising:

a supply of ink in a positive pressure container wherein said positive pressure is greater than or equal to ambient atmospheric pressure;

a pen cartridge including an ink accumulation chamber;

mounted within said chamber, first means for simultaneously controlling flow of ink from said container into said pen, regulating said back pressure, and compensating for gas bubbles, said first means including a positive bias member acting to retain said first means in a first predetermined position when said chamber is empty; and

coupled to said first means, second means for compensating for trapped gases within said pen and regulating said back pressure, including a compliant means for balancing ambient atmospheric pressure against said positive bias and said back pressure, said compliant means being coupled to said first means such that contact between said first means and said second means is substantially constant.