Ink cartridge

Abstract

This invention relates to an ink cartridge which has at least one ink container which has an ink outlet with an ink outlet opening which extends from the inside to the outside, in the ink outlet opening a differential pressure valve is mounted which includes a valve seat and a valve body which can move relative to it, the valve seat has a continuous valve opening which has a peripheral sealing surface outside, a spring means is attached between the movable valve body and the stationary ink outlet, the valve body is pressed by the spring means with a predetermined closing force to form a seal from the outside against the sealing surface of the valve seat, and can be moved against the closing force to the outside from the sealing surface. In order to form an ink cartridge with a differential pressure valve which works more reliably, the invention proposes that the valve seat be made deformable so that the sealing surface can be moved relative to the ink outlet opening.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is detailed below using drawings.

FIG. 1 shows a sectional view of an ink cartridge as claimed in the invention;

FIG. 2 shows a detailed view of the valve of the ink cartridge as shown in FIG. 1; and

FIG. 3 shows the valve seat of the valve according to FIG. 2.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically shows in a section an ink cartridge which is provided as a whole with reference number 1.

The ink cartridge 1 has an essentially box-shaped ink tank 2 which has a cover 2a, side walls 2b and a bottom 2c. Through the bottom 2c and a tubular ink outlet 3 which is attached thereto on the outside an ink outlet opening 4 extends from the inside to the outside.

The ink cartridge 1 is filled with free flowing ink up to the fill level F.

In the cover 2a there is a ventilation opening 5 which connects the ink-filled interior of the ink tank 2 to the vicinity and provides for the ambient air to flow after into the ink tank 2 when ink is removed through the ink outlet 3.

In the output of the ink outlet 3, a sealing element 6 is inserted through which a hollow ink removal needle for ink supply of an inkjet printer which is not individually shown can be connected to the ink outlet 3 for removing ink. The sealing element 6 can be for example an elastic gasket or a pierceable septum.

In the ink outlet opening 4 of the ink outlet 3 there is a differential pressure valve 8. This valve 8 is shown enlarged in FIG. 2 for better explanation.

Inside, therefore on the input side which is at the top in the drawings, the differential pressure valve 8 has a valve seat 9 with a continuous valve opening 10. Outside, i.e. down in the drawings, the valve seat 9 has a conical sealing surface 11 which runs around the valve opening and which widens to the outside. On the inner end of the valve seat 9 a tubular connecting piece 12 is made which is slipped onto an outlet sleeve 13 molded on the ink outlet opening 4. Between the sealing surface 11 and the connecting piece 12 the valve seat 9 is made with a peripheral molding 14, i.e. a bellows-like bead.

The valve seat 9 is shown enlarged in FIG. 3 for illustration of the details. It is likewise clearly recognizable in it how the sealing surface 11 is shaped on the valve seat 9 which runs out in the shape of a conical jacket so that a peripheral, resilient sealing lip is formed. The bent double arrow indicates how the sealing surface 11 can be laterally tilted around an articulation point located within the molding 14; the double arrow pointed up and down indicates axial mobility.

A valve body 15 which is supported to move lengthwise in the ink outlet 3, is pressed from the outside against the conical sealing surface 11 of the valve seat 9 to form a seal; this is indicated by the arrow. The closing force acting on the valve body 15 is produced by a spring means which is supported on a fixed abutment 16 in the ink outlet 3. The spring means can be implemented by a compression spring 17 which is shown schematically here being inserted between the valve body 15 and abutment 16, or alternatively by the valve body 15 and the abutment 16 being provided with mutually repelling magnets.

The valve body 15 has a crowned sealing side (top in the drawings) which is pressed against the sealing surface 11 by the spring means. In this way the valve opening 10 is closed, i.e. in the rest state no ink flows through the ink outlet opening 4 to the printer.

In operation, the printer intakes ink with a certain negative pressure through the ink removal needle 7 which is inserted sealed into the sealing element 6 in the output of the ink outlet 3. In this way, on the differential pressure valve 8 there is a differential pressure to the interior of the ink tank 2 which thus produces an opening force (pointed down in the drawing) on the valve body 11 which lifts it off the sealing surface 11 of the valve seat 9 against the closing force applied by the spring means, so that at this point ink can flow through the differential pressure valve 8. When there is no longer any negative pressure at the outlet, the pressure difference also disappears and the differential pressure valve 8 closes.

The active closing force is set by the spring means such that on the one hand the differential pressure valve 8 is closed tight when there is a liquid column which corresponds to the height of the ink tank 2 from the top when the ink cartridge 1 is full, and on the other hand the differential pressure valve 8 opens reliably when a printer is intaking ink at the output of the ink outlet 3.

One advantage of the invention arises from the sealing surface 11 being movable relative to the connecting piece 12 of the valve seat 9 which is attached securely in the ink outlet opening 4. This is achieved by the valve seat 9 being made deformable, for example as an elastic rubber molded part. In this connection the molding 14 forms a type of tilt joint around which the sealing surface 11 can tilt laterally, and moreover a bellows-like leveling piece so that the sealing surface can move in the lengthwise direction of the ink outlet opening 4. One advantage of this arrangement is that possible tilting of the valve body 15 in the ink outlet opening 4 is equalized and the valve body 15 in the closed state always optimally seals against the sealing surface 11. Moreover it is advantageous that the valve seat 9 first extends to the outside when the printer is intaking ink, before the valve body 9 is lifted off the sealing surface 11. In this way, first of all a negative pressure gradually builds up, suppressing unwanted valve wobbling. The differential pressure valve 8 as claimed in the invention consequently has especially favorable response behavior. Moreover by pulling back the valve seat 9, afterrunning or dripping of ink is prevented when the printer is no longer intaking ink or the ink cartridge 1 is being removed from the printer.

Claims

1. An ink cartridge having at least one ink container, which has an ink outlet with an ink outlet opening which extends from the inside to the outside, in the ink outlet opening a differential pressure valve is mounted which comprises a valve seat and a valve body which can move relative to it,the valve seat has a through valve opening which has a peripheral sealing surface,a spring means is attached between the movable valve body and the stationary ink outlet,the valve body is pressed by the spring means with a predetermined closing force against the sealing surface of the valve seat from the outside to form a seal and can be moved against the closing force to the outside from the sealing surface,the valve seat being made deformable so that the sealing surface can be moved relative to the ink outlet opening.

2. The ink cartridge as claimed in claim 1, wherein the sealing surface can be moved in the lengthwise direction of the ink outlet opening.

3. The ink cartridge as claimed in claim 1, wherein the sealing surface can be tilted relative to the ink outlet opening.

4. The ink cartridge as claimed in claim 1, wherein the valve seat has an articulated section.

5. The ink cartridge as claimed in claim 1, wherein the valve seat has a tubular section with at least one peripheral molding.

6. The ink cartridge as claimed in claim 1, wherein the sealing surface is made conical.

7. The ink cartridge as claimed in claim 1, wherein the valve body is made crowned.

8. The ink cartridge as claimed in claim 1, wherein the valve seat is made as an elastomer molded part.

9. The ink cartridge as claimed in claim 1, wherein the valve seat has a connecting piece on the inside end.

10. The ink cartridge as claimed in claim 9, wherein the connecting piece of the valve seat is connected to the coupling part of the ink container.

11. The ink cartridge as claimed in claim 1, wherein the spring means has a compression spring which is supported with one end against a fixed axial abutment in the ink outlet opening and with the other end against the valve body.

12. The ink cartridge as claimed in claim 1, wherein the spring means has a first permanent magnet which is mounted on the valve body, and a second permanent magnet which is attached securely in the ink outlet opening relative to the sealing surface and which is opposite the first permanent magnet with the same pole so that the repulsion force between the first and second permanent magnets acts as a closing force on the valve body.