Self-sealing filter module for inkjet printing

Patent metadata

Field	Value
Publication number	US-10071559-B2
Application number	US-201515316330-A
Country	US
Kind code	B2
Filing date	Jun 3, 2015
Priority date	Jun 5, 2014
Publication date	Sep 11, 2018
Grant date	Sep 11, 2018

Abstract

A filter module ( 38 ) for a continuous inkjet printer ( 10 ) comprising a filter housing ( 40 ) and a filter medium ( 42 ) fixed within the housing ( 40 ). The filter housing ( 40 ) further includes an inlet portal ( 44 ) through which ink flows into the housing under pressure and a first self-sealing valve assembly ( 54 ) disposed within the inlet portal. In addition, housing includes an outlet portal ( 46 ) through which ink flows out of the housing ( 40 ) under pressure and a second self-sealing valve assembly ( 56 ) disposed within the outlet portal ( 46 ). The first and second valve assemblies ( 54, 56 ) open when mechanically connected to an ink flow path ( 34 ) from an ink tank ( 18 ) to a print head ( 14 ), and the first and second valve assemblies ( 54, 56 ) seal closed when mechanically disconnected from the ink flow path ( 34 ).

First claim

What is claimed is:

1. A filter module for a continuous inkjet printer, comprising:
a filter housing having a top end and a bottom end;
a filter medium fixed within the housing, wherein the filter medium has a wall defining an internal open volume of the filter medium, and an end of the filter medium facing the bottom end of the filter housing;
an inlet portal at the bottom end of the filter housing and through which ink flows into the filter housing under pressure and through the wall of the filter medium into the internal volume of the filter medium and the end of the filter medium;

a first self-sealing valve assembly disposed within the inlet portal;
an outlet portal at the bottom end of the filter housing and through which ink flows out of the housing under pressure from the end of the filter medium;
a second self-sealing valve assembly disposed within the outlet portal;
wherein the first and second valve assemblies open when mechanically connected to an ink flow path from an ink tank to a print head, and the first and second valve assemblies seal closed when mechanically disconnected from the ink flow path; and,
an ink flow pressure damper disposed within the filter housing to control pressure fluctuations of ink in the ink flow path, the ink flow pressure damper, comprising:
a diaphragm at least a portion of which is disposed within the open internal volume of the filter medium and having an end facing the bottom end of the housing and the outlet portlet; and,
a biasing mechanism operatively connected to the filter housing and the second end of the diaphragm to bias the diaphragm toward the outlet portal.

2. The filter module of claim 1 , wherein each of the first and second self-sealing valve assemblies includes a spring actuated ball valve comprising:
a valve housing with a first opening at a bottom of the valve housing and through which ink may flow and a top end with one or more second openings through which ink may flow;
a ball within the valve housing;
a biasing mechanism that biases the ball toward the first opening and against a seal of the housing; and,
wherein when the filter is connected to the ink flow path from an ink tank, the ball is forced against biasing mechanism and from contact with the seal to open the valve, and when the filter is disconnected from the ink flow path the biasing mechanism forces the ball toward the opening and against the seal to close the valve.

3. The filter module of claim 1 , wherein the outlet portal is a first outlet portal and the filter module further comprising:
a second outlet portal; and,
a third self-sealing valve assembly disposed within the second outlet portal;
wherein the third valve opens when mechanically connected to an ink flow path from the filter to the ink tank, and the third valve seals closed when mechanically disconnected from this ink flow path.

4. The filter module of claim 1 further comprising an electronic storage device for storing data relating to the filter module.

5. A continuous inkjet printer comprising:
an ink tank for holding ink;
a print head in fluid communication with the ink tank and the print head, comprising:
an ink nozzle and droplet generator configured to generate ink droplets that are ejected onto a substrate to print an image;
a charging electrode downstream of the droplet generator to selectively apply a charge to ink droplets;
a deflection electrode for deflection charged ink droplets; and,
a gutter comprising a gutter entrance through which uncharged droplets enter for recirculation; and,

an ink flow path providing fluid communication from the ink tank to the print head;
a pump disposed in the ink flow path and in fluid communication with the ink tank and print head for delivering ink from the ink tank to the print head under pressure; and,
a filter module disposed in the ink flow path between the pump and the print head, wherein the filter module, comprises:
a housing;
a filter medium fixed in the housing;
an inlet portal in the housing through which ink flows into the housing;
a first self-sealing valve disposed within the inlet portal that opens when the filter module is mechanically connected to the ink flow path and seals closed when mechanically disconnected from the ink flow path;
an outlet portal in the housing through which ink flows out of the housing;
a second self-sealing valve assembly disposed within the outlet portal that opens when the filter module is mechanically connected to the ink flow path and is sealed closed when mechanically disconnected from the ink flow path; and,
wherein the ink tank defines a generally enclosed internal volume holding the ink, and the filter medium is within the filter housing and disposed externally relative to the internal volume of the ink tank.

6. The continuous inkjet printer of claim 5 , wherein the outlet portal is a first outlet portal and the housing includes a second outlet portal and the printer further comprising:
a third self-sealing valve assembly disposed within the second outlet portal;
wherein the third valve opens when mechanically connected to an ink flow path from the filter to the ink tank, and the third valve seals closed when mechanically disconnected from this ink flow path.

7. The continuous inkjet printer of claim 6 , further comprising a venturi pump in the ink flow path from the filter module to the ink tank.

8. The continuous inkjet printer of claim 5 , further comprising an ink flow pressure damper disposed within the module housing to control pressure fluctuations of ink in the ink flow path, and the ink flow pressure damper, comprising:
a diaphragm having an opening in a first end thereof facing a top end of the filter housing, and at least a portion of the diaphragm is disposed through the opening of the filter housing and within the filter housing, and the diaphragm having a second end facing the outlet portal at the bottom end of the filter housing; and,
a biasing mechanism operatively connected to the filter housing and the second end of the diaphragm to bias the diaphragm toward the outlet portal.

9. The continuous inkjet printer of claim 8 , wherein the filter medium has a generally cylindrical configuration and at least a portion of the diaphragm is disposed within a circumference of the filter medium.

10. The continuous inkjet printer of claim 5 , wherein the ink tank comprises a first ink flow pin to engage and actuate the first self-sealing valve assembly and a second ink flow pin to engage and actuate the second self-sealing valve assembly.

11. The continuous inkjet printer of claim 5 wherein the filter module comprises an electronic data storage device for storing data relating to the filter module and the inkjet printer is configured to read the data from the electronic data storage device.

12. The continuous inkjet printer of claim 5 wherein the filter module is configured such that after the filter module has been used in the printer and then removed from the printer, the filter module includes less than 30 mL of liquid.

13. A filter module of claim 1 , wherein the filter medium has a first end with an opening facing the top end of the filter housing and the end of the filter medium facing the bottom end of the filter housing is a second end, and the diaphragm has an opening in a first end thereof facing the top end of the filter housing, and the end of the diaphragm facing the bottom end of the filter housing and the outlet portal is a second end, and wherein at least a portion of the diaphragm extends through the opening of the filter medium and in the open internal volume of the filter medium.

Assignees

• Videojet Technologies Inc
• Videojet Technologies Inc

Inventors

• Smith Robert
• Stamp Michael
• King Paul

Classifications

• B41J2/17513 Primary

  Inner structure · CPC title

• B41J2/17596

  Ink pumps, ink valves · CPC title

• B41J2/17553

  Outer structure · CPC title

• B41J2/02

  generating a continuous ink jet · CPC title

• B41J2/17523

  Ink connection · CPC title