HK1091442B - Ink cartridge - Google Patents

Description

Ink box

Reference is made to the introduction

The present application is based on two japanese patent applications 2004-359730 and 2004-359742 filed 12/13/2004, the contents of which are incorporated herein by reference.

Technical Field

The present invention relates to an ink cartridge for supplying ink to a recording apparatus.

Background

JP-2001-113723 (particularly fig. 4) discloses an ink cartridge for supplying ink to a recording apparatus such as an ink jet printer, the ink cartridge of the recording apparatus being configured so that the ink does not leak when the ink cartridge is removed from the recording apparatus. Such an ink cartridge has an ink chamber that stores ink, an ink outlet through which the ink is supplied to the outside, and an ink communication chamber.

A valve member is accommodated in the ink communication chamber, and an annular seal is fitted in the ink outlet. The valve member is biased by a compression spring and is held in contact with the annular seal to close the ink passage, thereby preventing ink from leaking from the ink chamber. When the ink cartridge is attached to the recording apparatus, the ink inlet pipe provided on the recording apparatus enters the annular seal, pushes the valve member to the side of the ink chamber against the biasing force of the compression spring, so that the ink passage is opened, and ink can be supplied.

However, in the above-described ink cartridge, the movement of the valve member is achieved by using the compression spring, so that the internal structure of the ink cartridge using the compression spring is complicated. Moreover, the compression spring is made of metal and the cartridge cannot be discarded in the presence of the spring. That is, when the used ink cartridge is discarded, the compression spring should be removed from the ink cartridge so that the spring is discarded separately from the rest of the ink cartridge, thereby increasing the process cost.

In order to solve the above-mentioned problems, the present application proposes to replace the compression spring with a biasing member made of an elastic material to integrally include an elastic side wall portion surrounding the valve member and capable of deforming in the direction in which the valve member moves, and an engaging portion projecting inwardly from an end of the side wall portion so as to contact a surface of the valve member opposite to the valve hole. The resilient contractive force of the side wall portions biases the valve member to a position adjacent to the ink passage or valve opening.

The use of the biasing member makes it possible to omit the compression spring, thereby preventing the internal structure of the ink cartridge from being complicated. Also, the biasing member may be made of an elastic material such as rubber, so that the biasing member does not need to be removed from the ink cartridge when the ink cartridge is discarded. Thus, the processing cost is not increased.

When an ink cartridge including a biasing member is attached to a recording apparatus, an ink inlet pipe provided on the recording apparatus pushes a valve member as approaching an ink passage, and the valve member is moved by stretching a side wall portion of the biasing member against an elastic biasing force so as to open the ink passage. Thus, a space for allowing the sidewall portion of the biasing member to expand should be provided.

However, the user may couple the ink cartridge to the recording apparatus in an inappropriate manner or in a manner that damages the ink cartridge, so that the valve member is pushed by an amount larger than the valve member is expected to be pushed, or in a direction different from the direction in which the valve member is expected to be pushed. In this case, the side wall portion of the biasing member is excessively stretched, or the engaging portion becomes irregular in shape with a portion locally deformed more than the remaining portion, causing the valve member to disengage from the engaging portion of the biasing member, that is, the valve member is disengaged from the biasing member, enters the above-mentioned space, and becomes unable to return to a position close to the ink passage in the valve chamber defined inside the biasing member. This can cause ink to leak from the cartridge and water or other components to evaporate from the ink.

Disclosure of Invention

The present invention has been developed in view of the above circumstances, and it is therefore a direct object of the present invention to provide an ink cartridge including a valve member that can remain in operation even when the valve member is pushed by an amount larger than normal or in a direction different from the normal direction, thereby preventing leakage of ink from the ink cartridge and evaporation of moisture and other components from the ink.

To achieve this object, the present invention provides an ink cartridge comprising:

an ink chamber storing ink;

a valve seat having a valve aperture;

a communicating chamber communicating the ink chamber with an outside of the ink cartridge via the valve hole;

a valve member provided in the communication chamber such that the valve member is movable between a first position separated from a valve seat to allow communication between the ink chamber and the outside via the valve hole and a second position held in close contact with the valve seat to close the communication; and

a biasing member, comprising: (a) a side wall portion surrounding the valve member and (b) an engaging portion projecting inwardly from an end of the side wall portion and engaging with the valve member;

the biasing member normally holds the valve member in the second position but allows the valve member to be placed in the first position by means of elastic deformation of at least one of the side wall portion and the engaging portion, and generates a biasing force that restores the valve member to the second position; and

a disengagement prevention device that prevents disengagement of the valve member from the engagement portion when the valve member is operated toward the first position.

According to this arrangement, when the ink cartridge is not mounted on the recording apparatus, the valve is biased in the direction to be held at the second position at which the valve member closes between the ink chamber and the outside. When the ink cartridge is mounted on the recording apparatus, the valve member is moved to the first position while stretching the biasing member against the biasing force of the biasing member, thereby establishing communication between the ink chamber and the outside.

When the valve member is pushed by an amount greater than a predetermined, normal, or desired amount after the ink cartridge is mounted or attached to the recording apparatus, the valve member tends to disengage from the engagement portion. However, according to the present invention, such detachment is prevented by means of the detachment prevention device. Thus, there is no case where the valve member is disengaged from the engagement portion and becomes unable to return to the first position that closes the communication between the ink chamber and the outside, which would otherwise cause leakage of ink from the ink cartridge or evaporation of moisture or other components from the ink.

The ink cartridge according to the present invention is not limited to the above-described one including the biasing member integrally made of an elastic material including the side wall portion and the engaging portion, but the present invention is also applicable to an ink cartridge including a biasing member having a more general structure. Further, the present invention is applicable not only to a communication chamber on the ink supply side (i.e., a communication chamber formed through which ink in the ink chamber is supplied to the outside) but also to a communication chamber on the air introduction side (i.e., an air communication chamber formed in the ink cartridge through which outside air is introduced into the inside of the ink cartridge).

Drawings

The above and other objects, features, advantages and technical and industrial significance of this invention will be better understood by reading the following detailed description of preferred embodiments of the invention when considered in conjunction with the accompanying drawings, in which:

fig. 1 is a schematic view of an inkjet recording apparatus to which an ink cartridge according to a first embodiment of the present invention is attached;

fig. 2 is a sectional view showing a state before an ink cartridge is attached to the inkjet recording apparatus;

fig. 3 is a sectional view showing a state when an ink cartridge is attached to the inkjet recording apparatus;

FIGS. 4A, 4B, 4C and 4D are a plan view, a side view, a sectional view taken along line A-A in FIG. 4A, and a bottom view, respectively, of a valve member in the ink cartridge;

FIGS. 5A, 5B and 5C are plan, side and bottom views of another valve component of the ink cartridge;

FIG. 6 is a cross-sectional view of an ink cartridge showing how a valve arrangement including valve components operates;

FIG. 7 is another cross-sectional view of the ink cartridge showing how the valve arrangement works;

FIG. 8 is a partial cross-sectional view of an ink cartridge according to a second embodiment; and

fig. 9 is a partial sectional view of an ink cartridge according to a third embodiment.

Detailed Description

Several presently preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

Referring to fig. 1 to 7, an ink cartridge according to a first embodiment will be described. In the schematic view shown in fig. 1, reference numerals 1 and 2 denote an ink cartridge and an inkjet recording apparatus to which the ink cartridge is attached.

The ink cartridge 1 can be detachably attached to an ink jet recording apparatus 2 including a print head 7 for ejecting ink droplets, and stores ink to be supplied to the print head 7.

The ink cartridge 1 includes a box-like hollow casing 1a whose upper side is open and a cartridge cover 1b which closes the open upper side of the casing 1 a. Ink to be supplied to the print head 7 is stored in an ink chamber 16 in the housing 1 a. A plurality of ink cartridges, each of which is loaded with one of the following four colors, are attached to the inkjet recording apparatus 2: namely cyan, magenta, yellow and black.

The inkjet recording apparatus 2 includes a mounting portion 3, to which each ink cartridge 1 is detachably attached; an ink tank 5 that stores ink supplied from the ink cartridge 1 through a flexible ink supply tube 4; the print head 7 that ejects the ink stored in the ink tank 5 onto the recording sheet 6; a carriage on which the ink tank 5 and the print head 7 are mounted, the carriage reciprocating in a horizontal direction; a carriage shaft 9 as a guide along which the carriage 8 reciprocates; a feeding mechanism 10 for feeding the recording sheet 6; and a cleaning device 11.

The mounting portion 3 has a base portion 3a and two guide portions 3b rising vertically from opposite sides of the base portion 3 a. A hollow ink inlet pipe 12 is provided in the base portion 3a interposed between the two guide portions 3b, and the ink stored in the ink cartridge 1 flows into the ink supply pipe 4 via this pipe 12; and an air supply passage 13 through which air is supplied into the ink cartridge 1.

The ink supply tube 4 is connected to one end of an ink inlet tube 12 such that the ink inlet tube 12 communicates with the ink tank 5 through the ink supply tube 4. One of opposite ends of the air supply pipe 15 is connected to the air supply passage 13, and the other end of the air supply pipe 15 is communicated with the atmosphere.

A plurality of nozzles are arranged on a face of the print head 7 opposite to the recording paper 6. This surface will be referred to as "nozzle face" hereinafter. By driving an actuator constituted by a piezoelectric element, the ink stored in the ink tank 5 is ejected through a nozzle toward the recording paper 6 in the form of ink droplets. Recording or printing is performed on the recording paper 6 while the carriage 8 on which the print head 7 is mounted reciprocates.

The print head 7 is located above the mounting portion 3 so that ink inside the nozzles is applied with a negative back pressure due to a difference in head pressure between the nozzles and the ink cartridge 1 when the ink cartridge 1 is attached to the mounting portion 3.

The cleaning device 11 is provided at a position outside the recording area, opposite to the print head 7, and includes a cleaning cap 11a for covering the nozzle face of the print head 7; a waste ink tube 11b communicating with the cleaning cap 11 a; and a pump 11c that sucks ink from the nozzles through the waste ink tube 11 b.

In the cleaning operation, the carriage 8 is moved to the cleaning position, and the nozzle face of the print head 7 is covered with the cleaning cap 11 a. In this case, the pump 11c is driven to suck out the inferior ink containing bubbles and other substances and accumulated inside the print head 7. The drawn-out inferior ink flows into a waste ink tank (not shown) to be stored via the waste ink tube 11 b. The recording and purging operations are controlled by a central processing unit or CPU (not shown) in the inkjet recording apparatus 2.

Referring now to the sectional views of fig. 2 and 3, the structure of an engagement portion, indicated by reference character a in fig. 1, on which the ink cartridge 1 is attached to the ink jet recording apparatus 2 will be described. Fig. 2 shows a state before the ink cartridge 1 is attached to the ink jet recording apparatus 2, and fig. 3 shows a state when the ink cartridge 1 is attached to the ink jet recording apparatus 2.

The ink cartridge 1 includes a housing 1a, a cartridge cover 1b, and a cartridge cap 1 e. The casing 1a has a bottom wall 1c and a side wall 1i partially defining the ink chamber 16, and the casing 1a is open at an upper side. The lid 1b covers the upper open edge of the housing 1a, while the cap 1e covers the bottom wall 1c of the housing 1 a. The ink cartridge 1 is formed by melting the cartridge cover 1b and the cartridge cap 1e to be bonded to the case 1 a. Through this cartridge cap 1e, two exposed holes 1f, 1g are formed through which valve devices 23, 24 (described later) are exposed, respectively.

On the lower side of the bottom wall 1c, an ink communication chamber 30 and an air communication chamber 50 are formed. The ink in the ink chamber 16 is supplied to the outside through the ink communication chamber 30, and atmospheric air is introduced into the ink chamber 16 through the air communication chamber 50. The two communication chambers 30, 50 partially define inner tubular wall portions 1h, 1k projecting from the lower surface of the bottom wall 1c, respectively.

An ink inlet 1d is formed in the bottom wall 1c for communication between the ink communication chamber 30 and the ink chamber 16; and an air introduction port 1j for communication between the air communication chamber 50 and the ink chamber 16. The air introduction port 1j has substantially the same inner diameter as the air communicating chamber 50. The tubular member 62 extends in the ink chamber 16 at a position where the upper surface of the bottom wall 1c corresponds to the air introduction port 1 j.

An internal passage having a first portion 62a and a second portion 62b is defined within the tubular portion 62. The first portion 62a of the internal passage extends from the air introduction port 1j in the direction into the ink chamber 16 and becomes gradually narrower in the direction in the sectional view, while the second portion 62b extends from the first portion 62a substantially straight into the ink chamber 16. The air communication chamber 50 is opened above the ink surface in the ink chamber 16 via the first and second portions 62a, 62b of the internal passage.

A plurality of ribs 70 are continuously formed from the inner surface of the first portion 62a of the internal passage to the upper portion of the air communication chamber 50 bordering the internal passage such that each rib extends toward the guide bar 66 of the valve member 65 (described later). The number of the ribs 70 is 3 or more than 3. The distance T1 between the lower end surface 70a of each rib 70 and the engagement portion 73 of the biasing member 63 (described later) is determined such that, when the ink cartridge 1 is attached to the ink jet recording apparatus 2, as shown in fig. 3, the engagement portion 73 is spaced apart from the lower end surface 70a of the rib 70 by a distance smaller than the distance T1 between the engagement portion 73 and the lower end surface 70 a.

On the inner surface of the ink communication chamber 30, a predetermined number of ribs 71 are formed, which extend from the lower surface of the bottom wall 1c toward the engagement portion 37 of the biasing member 46 and are accommodated in the ink communication chamber 30 as described later. The number of ribs is 3 or more than 3. The distance T2 between the lower end surface 71a of each rib 71 and the engaging portion 73 is determined such that, when the ink cartridge 1 is attached to the inkjet recording apparatus 2, as shown in fig. 3, the engaging portion 37 is spaced apart from the lower end surface 71a of the rib 71 by a distance smaller than the distance T2 between the engaging portion 37 and the lower end surface 71 a.

Valve devices 23, 24 are provided in the ink and air communication chambers 30, 50, respectively. Hereinafter, the side associated with the ink communication chamber 30 may be referred to as an "ink supply side", and the side associated with the air communication chamber 50 may be referred to as an "air introduction side". The valve device 23 on the ink supply side includes a biasing member 46 integrally made of an elastic material, and a valve member 54 made of resin. The biasing member 46 is substantially cylindrical in shape. The biasing member 46 includes a valve seat portion 46a, a biasing portion 46b on a side of the valve seat portion 46a close to the ink chamber, and a coupling portion 33 surrounding the valve seat portion 46a, wherein the valve seat portions 46a, 46b, 33 are integrally formed. The valve member 54 is accommodated in a valve chamber defined inside the biasing portion 46b, and is biased by the biasing portion 46b in a direction to be held in contact with the valve seat portion 46 a.

The coupling portion 33 has an outer diameter larger than that of the biasing portion 46 b. The ink communication chamber 30 has an expanded portion 44 in which the diameter of the ink communication chamber 30 is larger than the diameter of the remaining portion. The coupling portion 33 is fitted in the expanded portion 44. The biasing member 46 is fixed in position together with the coupling portion 33 held between the inner surface of the ink communication chamber 30 and the cartridge cap 1 e.

The valve seat portion 46a has a through hole formed at the center thereof. The through hole includes an upper portion 41, an insertion portion 35 below the upper portion 41, and a tapered guide passage 40 below the insertion portion 35. The insertion portion 35 is formed in a size that allows fitting insertion of the ink inlet tube 12 when the ink cartridge 1 is attached to the mounting portion 3.

The biasing portion 46b includes a cylindrical side wall portion 36 rising from the valve seat portion 46a toward the ink chamber 16, and an engaging portion 37 projecting inward from the side wall portion 36, i.e., extending to the side of the valve member 54 close to the ink chamber 16. At the center of the engaging portion 37, it has an opening 37a having a diameter d1 smaller than a diameter d2 (shown in fig. 4C) of a protrusion 57a (described later) of the valve member 54.

The biasing portion 46b biases the valve member 54 toward the valve seat portion 46a by means of the elastic forces of the side wall portion 36 and the engaging portion 37. Generally, the valve member 54 remains in contact with the valve seat portion 46 a. When the ink inlet tube 12 is inserted into the insertion portion 35, the ink inlet tube 12 pushes the valve member 54 toward the ink chamber 16, and the pushed valve member 54 in turn pushes the engagement portion 37 upward with the side wall portion 36 stretched, so that a gap is formed between the lower surface of the valve member 54 and the valve seat portion 46a so as to allow ink to pass.

According to the embodiment of the present invention in which the biasing members 46, 63 are integrally formed, including the valve seat portions 46a, 63a, the side wall portions 36, 72, and the engaging portions 37, 73, the number of components can be reduced, so that the production process of the ink cartridge 1 can be simplified. Further, since the valve seat portions 46a, 63a are formed of an elastic material, the sealability between the valve seat portions 46a, 63a and the valve members 54, 65(68) is improved, so that the communication between the ink chamber 16 and the outside of the ink cartridge 1 can be reliably closed when the valve members 54, 64(68) are in contact with the valve seat portions 46a, 63 a.

As shown in fig. 4A to 4D, the valve member 54 includes a bottom portion 57, a cylindrical side wall portion 56 extending vertically upward from the periphery of the bottom portion 57, and a communication passage 58 formed continuously from the bottom portion 57 to the side wall portion 56. The bottom portion 57 has an annular projection 57a on the side thereof opposite to the valve seat portion 46 a. The projection 57a is formed radially inside the communication passage 58 except for the outside of the open end of the upper portion 41 or a through hole formed in the valve seat portion 46 a. When the biasing portion 46b on the valve seat portion 46a presses the valve member 54, the projection 57a of the valve member 54 is elastically deformed and closely contacts the upper surface of the valve seat portion 46 a. The diameter d2 (shown in fig. 4C) of the protrusion 57a is larger than the diameter d1 (shown in fig. 2) of the opening 37a formed at the center of the engagement portion 37.

Similar to the valve device 23 on the ink supply side, the valve device 24 on the air introduction side includes a biasing member 63 integrally made of an elastic member, and a valve member 65 made of resin. The biasing member 63 is similar to the biasing member 46 on the ink supply side, that is, the biasing member 63 includes a valve seat portion 63a, a biasing portion 63b, and a coupling portion 63e, which are integrally formed. The biasing portion 63b is similar to the biasing portion 46b on the ink supply side, and includes a cylindrical side wall 72 standing vertically from the periphery of the valve seat portion 63a toward the ink chamber 16, and an engaging portion 73 projecting inward from the side wall portion 72, i.e., extending to the side of the valve member 65 close to the ink chamber 16. At the center of the engaging portion 73, it has an opening 74, and the diameter d3 (shown in fig. 2) of the opening 74 is smaller than the diameter d4 (shown in fig. 5C) of a protrusion 157a (described later) of the valve member 65. The functions of the members of the biasing member 63 are the same as those of the biasing member 46 on the ink supply side, and therefore, the description of the members of the biasing member 63 is omitted.

The valve seat portion 63a has a through hole 63c through which an operating portion 67 (described later) of the valve member 65 is inserted. Below the valve seat portion 63a, a cylindrical seal portion 63d is integrally formed around the open end of the through hole 63 c.

As shown in fig. 5A to 5C, the valve member 65 includes a guide rod 66 at an upper edge thereof, the operating portion 67 at a lower edge thereof, and a valve portion 68 substantially at a middle portion thereof. Similar to the valve member 54 shown in fig. 4A-4D, the valve portion 68 includes a base 157, a sidewall portion 156, a communication passage 158, and a protrusion 157a on a lower surface of the base 157. The valve portion 68 is similar in structure to the valve member 54, and members or elements corresponding to the valve member 54 will be denoted by the same reference numerals, and their descriptions will be omitted. That is, on the air introduction side, the valve portion of the valve member 65 corresponds to the valve member defined in the appended claims.

The guide rod 66 is cylindrical, and stands upright from the bottom 157. The guide rod 66 is inserted through the opening 74 of the offset portion 63b with a gap between the guide rod 66 and the inner peripheral surface of the opening 74 so that the guide rod 66 is located at a position surrounded by the rib 70.

The operating portion 67 is a member that protrudes vertically or downward from the bottom portion 157, passes through a through hole 63c formed in the valve seat portion 63a, and has a gap between the inner peripheral surface of the through hole 63c and the operating portion 67 to allow air to pass therethrough.

At the position where the ink chamber 1 of the mounting portion 3 is coupled, the ink inlet pipe 12 protrudes on the ink supply side, and an elastic porous material 3c such as a sponge material is embedded around the lower bottom portion of the ink inlet pipe 12. Although the arrangement according to the present invention prevents ink leakage, an elastic porous material 3c is provided at the lower bottom portion to absorb ink leaking from the ink cartridge 1. That is, the elastic porous material 3c is provided for some extreme cases.

A communication opening 12a in the form of a slit is formed at the upper end of the ink inlet tube 12 so as to communicate an internal passage formed in the ink inlet tube 12 with a space around the ink inlet tube 12 in the radial direction of the ink inlet tube 12. The communication opening 12a ensures that the internal passage defined in the ink inlet tube 12 communicates with the ink chamber 16 when the ink inlet tube 12 is in contact with the valve member 54.

On the air introducing side of the mounting portion 3, a recess 3d is formed at a position corresponding to the sealing portion 63d of the biasing member 63 of the ink cartridge 1. In this recess 3d, the air supply passage 13 is opened at a position such that it is not completely covered by the lower end of the operating portion 67. When the ink cartridge 1 is attached to the mounting portion 3, as shown in fig. 3, the sealing portion 63d is fitted in the recess 3d, and the end of the sealing portion 63d is elastically deformed so that it is held in close contact with the bottom of the recess 3d, thereby establishing airtight communication between the air supply passage 13 and the air introduction port 1 j.

Referring to fig. 2 and 3, a case when the ink cartridge 1 is attached to the mounting portion 3 will be described. Before the ink cartridge 1 is attached to the mounting portion 3, as shown in fig. 2, on the air introducing side, the operating portion 67 projects downward from the cartridge cap 1e, the lower end of the operating portion 67 is located slightly above the lower end extremity of the sealing portion 63d, and the valve member 65 is biased by the biasing portion 63b to be held in close contact with the valve seat portion 63 a. Meanwhile, on the ink supply side, the valve member 54 is biased by the biasing portion 46b to be held in close contact with the valve seat portion 46 a.

When the ink cartridge 1 is attached to the mounting portion 3, as shown in fig. 3, on the ink supply side, the upper end of the ink inlet pipe 12 pushes the valve member 54 upward, thereby stretching the side wall portion 36 of the biasing portion 46b, so that the valve member 54 is disengaged from the valve seat portion 46a, thereby placing the valve device in an open state in which the valve member 54 is in the first position, allowing communication between the ink chamber 16 and the outside of the ink cartridge. Thus, the ink stored in the ink chamber 16 is supplied to the ink inlet tube 12 via the ink inlet 1D, the ink communication chamber 30, the opening 37a formed in the joint portion 37, the communication passage 58 in the valve member 54 (shown in fig. 4A to 4D), and the opening 12a on the end of the ink inlet tube 12.

Meanwhile, on the air introducing side, when the end of the operating portion 67 is held in contact with the bottom of the groove 3d to fix the valve member 65 in position, the valve seat portion 63a of the biasing member 63 is moved downward relative to the valve member 65, in other words, the valve member 65 is pushed upward relative to the valve seat portion 63a, and the side wall portion 72 of the biasing portion 63b is stretched so that the valve member 65 is disengaged from the valve seat portion 63a, thereby placing the valve device in an open state in which the valve member 65 is placed in the first position to communicate the inside of the ink cartridge with the outside. The guide rod 66 of the valve member 65 moves along the vertically extending end face of the rib 70 opposite to the inner surface of the air introduction port 1j, so that even when the direction in which the valve member 65 is urged deviates from the exact vertical direction in which the normal direction in which the valve member 65 is expected to move by means of urging (hereinafter the direction in which the valve member 65 is expected to be urged may be referred to as "the normal direction in which the valve member 65 is expected to move"), the deviation is restricted by the rib 70 that moves the valve member 65 in the substantially vertical direction. That is, the end surface of the rib 70 extending vertically corresponds to the guide portion. Thus, the side wall portion 72 is stretched substantially uniformly over its entire periphery, thereby preventing the localized stretching on the side wall portion that would tend to pull the valve member away from the engagement portion, as is often seen, and enabling the valve member to function properly.

When the valve device 24 is placed in the open state, the ink chamber 16 communicates with the space outside the recording apparatus 2 via the air supply passage 13, the gap between the operating portion 67 and the through hole 63C, the communication passage 158 in the valve member 65 (as shown in fig. 5A to 5C), the gap between the guide rod 66 and the inner peripheral surface of the opening 74 in the engaging portion 73, the air communication chamber 50, the space between the two ribs 70 in the first portion 62a of the internal passage defined adjacent to the tubular member 62, and the second portion 62b of the internal passage.

Referring next to fig. 6, it will be described how the valve arrangements 23, 24 operate when the valve members 54, 65 are pushed upward by more than a normal, desired amount, for example, in the event that the ink cartridge 1 is improperly coupled, or in the event that a user has damaged the ink cartridge 1.

The biasing members 46, 63 that support the valve members 54, 65, respectively, are made of an elastic material. Thus, when the valve member 54, 65 is pushed upward, the side wall portion 36, 72 is stretched relatively long, so that the engaging portion 37, 73 is inclined to widen the opening 37a, 74 of the engaging portion 37, 73. When the side wall portion 36, 72 is further stretched upward, the valve member 54, 65 causes the engaging portion 37, 73 to be greatly inclined to enlarge the opening 37a, 74, so that the valve member 54, 65 is disengaged from the biasing member 46, 63 through the opening 37a, 74, or is separated from the biasing member 46, 63. Once the valve members 54, 65 are moved away from the biasing members 54, 65 in this manner, they will not be able to return to a position where they remain in close contact with the valve seat portions 46a, 63 a.

In the ink cartridge according to the embodiment of the present invention, the lower end faces 71a, 70a of the ribs 71, 70 function as stoppers for preventing an excessive movement amount of each valve member 54, 65. That is, the distances T1, T2 between the upper surfaces of the engaging portions 37, 73 and between the lower end surfaces 71a, 70a of the ribs 71, 70 are determined so that the upper surfaces of the engaging portions 37, 73 come into contact with the lower end surfaces 71a, 70a of the ribs 71, 70 before the openings 37a, 74 are enlarged to be larger than the size of the valve member 54, 65 to allow the valve member 54, 65 to leave the engaging portions 37, 73, as shown in fig. 6.

Therefore, even when the valve members 54, 65 are pushed upward by an amount exceeding the normal desired amount, the valve members 54, 65 do not disengage from the biasing members 46, 63, that is, do not leave the biasing members 46, 63 through the openings 37a, 74, thereby preventing the valve devices 23, 24 from leaving in their open state, which would otherwise occur and cause problems such as leakage of ink out of the ink cartridge and an increase in viscosity of the ink due to evaporation of moisture or other components in the ink.

According to the ink cartridge of the present invention, the restrictor is constituted by a surface (i.e., the lower end surface of each rib) with which the engaging portion is in contact before the valve member is disengaged from the engaging portion. That is, the surface can be used as a restrictor by appropriately determining the distance between the surface and the engagement portion, so that the internal structure of the ink cartridge can be simplified.

Note that the place where the ink leakage occurs is not limited to the valve device 23 on the ink supply side. That is, ink leakage may occur where ink is introduced into the first and second portions 62a, 62b of the internal passage, for example, when the user drops the ink cartridge while holding the ink cartridge, and thereafter ink leaks out from the valve device 24 when the valve device 24 is placed on the air introduction side in an open state. Similarly, an ink component such as water may evaporate at the valve device 23 on the ink supply side.

When the valve member 54, 65 is urged in an obliquely upward direction that is offset from the normal vertical direction in which the valve member 54, 65 is expected to move by virtue of the urging, a portion of the side wall portion 36, 72 is greatly stretched, deforming the opening 37a, 74 such that the valve member 54, 65 tends to exit the biasing member 46, 63 through the opening 37a, 74. On the air introduction-side valve member 24, the guide rod 66 slides on the rib 70 and is thereby guided in the substantially vertical direction, as described above. Thus, there is no chance that only a portion of the side wall portion 70 will be greatly stretched, thereby reducing the likelihood that the valve member 65 will disengage from the biasing member 63 through the opening 74. In the present embodiment, since the air communication chamber has an internal passage communicating with the ink chamber, when the valve member is pushed upward at a position where the valve member is allowed to enter the internal passage while the guide portion constituted by the rib extending from the internal passage toward the guide rod cooperates with the guide rod to constitute the guide means, the fluid passage between the inner surface of the internal passage and the guide rod is formed and the guide rod can be appropriately guided along the rib.

In the present embodiment, such guiding of the valve member 54 is performed on the air guiding side valve device 24 to prevent a local large stretching of the engaging portion 73, but it is also possible to employ a guiding rod in the ink supplying side valve device 23 so as to guide the valve member 54 by the ink inlet 1d or the rib 71.

According to the present embodiment, even when the valve member 54, 65 is pushed abruptly due to the biasing member 46, 63 having a size smaller than the nominal size due to a manufacturing error or the like or due to the side wall portion 36, 72 being insufficiently expanded to push the valve member 54, 65, the valve device 23, 24 of the ink cartridge is prevented from remaining in the open state when the valve member is disengaged from the biasing member 46, 63 through the opening 37a, 74 for the following reason.

That is, as described above, the diameter d2, d4 of the projection 57a, 157a of the valve member 54, 65 is larger than the diameter d1, d3 of the opening 37a, 74 (shown in fig. 2), while the distance T1, T2 (shown in fig. 2) is substantially equal to or slightly smaller than the height or thickness of the valve member 54, 65 in a direction parallel to the moving direction of the valve member 54, 65, i.e., the dimension from the lower end of the projection 57a, 157a to the lower surface of the engaging portion 37, 73 when not stretched. Thus, when the valve member 54, 65 is disengaged or moved away from the biasing member 46, 63 through the opening 37a, 74, as shown in fig. 7, the side wall portion 36, 72 contracts so that the engaging portion 37, 73 changes its shape along the lower surface of the valve member 54, 65 back to its original shape. Thereby, the valve member 54, 65 is sandwiched between the upper surface of the engaging portion 37, 73 and the lower end surface 71a, 70a of each rib 71, 70, so that the lower surface of the valve member 54, 65 closes the opening 37a, 74. Thus, in the case where the valve members 54, 65 are disengaged from the biasing members 46, 63 through the openings 37a, 74, the valve devices 23, 24 are prevented from being in the open state. On the other hand, in the conventional arrangement, the valve devices 23, 24 cannot be restored from such an open state to a closed state, when the valve members 54, 65 are placed in the second position to close the communication between the ink chambers and the outside of the ink cartridge. Thus, according to the present embodiment, problems such as ink leakage caused by the valve devices 23, 24 being in the open state are prevented.

According to a first embodiment, the guide portion of the guide means and the limiter are constituted by the same element, i.e. the rib. Thus, the number of ink cartridge components can be reduced.

Next, referring to fig. 8, an ink cartridge according to a second embodiment of the present invention will be described. Parts and elements corresponding to those of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

In the first embodiment, the ribs 70, 71 limit the displacement of the valve members 65, 54. However, according to the second embodiment, the engaging portions 73, 37 replace the rib 70 on the air introducing side and the rib 71 on the ink supply side, which are in abutting contact with the top surface 50a of the air communication chamber 50 and the top surface 30a of the ink communication chamber 30, respectively, to restrict the displacement of the valve members 65, 54, as shown in fig. 8.

As shown in fig. 8, the inner surface of the first portion 62a of the internal passage is cylindrical and is spaced a small distance from the outer peripheral surface of the guide rod 66 so that the guide rod 66 can be guided along the inner surface of the first portion 62a of the internal passage in sliding contact therewith.

According to the second embodiment, since the air communication chamber has the internal passage communicating with the ink chamber, at the position where the valve member is allowed to enter the internal passage, when the valve member is pushed upward, the valve member and the guide portion constituted by the inner surface of the internal passage cooperate with the guide rod to constitute the guide means, thereby simplifying the internal structure of the ink cartridge.

According to the ink cartridge of the second embodiment, the restrictor is constituted by a surface (i.e., the top surface of the air communication chamber and the ink communication chamber) with which the engaging portion is in contact before the valve member is disengaged therefrom. That is, the surface is used as a restrictor by appropriately determining the distance between the surface and the engagement portion, so that the internal structure of the ink cartridge can be simplified.

Referring to fig. 9, an ink cartridge according to a third embodiment of the present invention will be described. Parts and elements corresponding to those of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

As shown in fig. 9, a plurality of ribs 76 each having a downwardly projecting portion 76a project from the top surface of the ink communication chamber 30 to meet at a position substantially at the center portion of the ink communication chamber 30 in plan view. These projecting portions 76a cooperatively constitute a projection, the lower end face of which is directly opposed to the valve member 54 through the opening 37a formed in the engaging portion 37, so that when the valve member 54 is lifted, the projection composed of the projecting portions of the ribs 76 enters the opening 37a of the engaging portion 37 to directly contact the valve member 54, thereby preventing excessive displacement of the valve member 54. It is to be noted that the horizontally extending portion corresponds to a bridge, and the projection composed of the plurality of projecting portions 76a of the rib 76 corresponds to a direct contact portion.

The upper end of the guide rod 66 of the valve member 65 is in direct contact with the top surface of the air communication chamber 50 so as to prevent excessive movement of the valve member 65. One of the top surface 75 and the guide bar 66 has a communication passage 66a that allows air communication while the guide bar 66 is in contact with the top surface 75.

According to the ink cartridge of the third embodiment, the restrictor is constituted by a surface (i.e., the top surface, and the lower end surface of the projection composed of the projecting portion 76a of the rib 76), and the valve member is brought into contact before it is disengaged from the engaging portion. That is, by appropriately determining the distance between the surface and the engagement portion, the surface can be used as a restrictor, so that the internal structure of the ink cartridge can be simplified.

In each of the above embodiments, the openings 37a, 74 are formed in the biasing members 46, 63 to open in the moving direction of the valve members 54, 65 so as to allow the ink and the air to communicate. However, the position where the openings 37a, 74 are formed in the biasing members 46, 63 is not limited to this position. For example, the openings 37a, 74 may be formed in the side wall portions 36, 72 of the biasing members 46, 63 as long as communication between the valve chambers housing the valve members 54, 65 and the ink or air communication chambers 30, 50 can be established. When the openings 37a, 74 are formed in the side wall portions 36, 72, the communication passages 58, 158 of the valve members 54, 65 may be omitted.

Each embodiment may be modified such that the air supply channel 13 in the mounting portion 3 takes the same shape as the ink inlet tube 12, i.e., a tubular shape projecting upward from the mounting portion, and the valve device 24 on the air introduction side has the same structure as the valve device 23 on the ink supply side. Alternatively, the embodiments may be modified such that the ink supply tube 12 does not protrude from the mounting portion, and the valve device 23 on the ink supply side has the same structure as the valve device 24 on the air introduction side.

Although several embodiments of the present invention have been described above, it is to be understood that the present invention is not limited to details of the embodiments, but may be otherwise embodied in various changes and modifications that may occur to those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (20)

1. An ink cartridge, comprising:

an ink chamber storing ink;

a valve seat having a valve aperture;

a communicating chamber communicating the ink chamber with an outside of the ink cartridge via the valve hole;

a valve member provided in the communication chamber such that the valve member is movable between a first position separated from a valve seat to allow communication between the ink chamber and the outside via the valve hole and a second position held in close contact with the valve seat to close the communication; and

a biasing member, comprising: (a) a side wall portion surrounding the valve member and (b) an engaging portion projecting inwardly from an end of the side wall portion and engaging with the valve member;

the biasing member normally holds the valve member in the second position but allows the valve member to be placed in the first position by means of elastic deformation of at least one of the side wall portion and the engaging portion, and generates a biasing force that restores the valve member to the second position; and

a disengagement prevention device that prevents disengagement of the valve member from the engagement portion when the valve member is operated toward the first position.

2. The ink cartridge as claimed in claim 1, wherein said disengagement preventing means includes at least one of a restriction member that restricts movement of said valve member before it is disengaged from said engagement portion and an inclination restriction member; the tilt restricting member restricts the valve member from tilting with respect to a normal direction in which the valve member is expected to be moved by pushing.

3. The ink cartridge as claimed in claim 2, wherein the disengagement preventing means includes the restricting member, and the restricting member includes an indirect contact portion that contacts the valve member via the biasing member to prevent the valve member from moving to a degree of disengagement from the engagement portion.

4. The ink cartridge as claimed in claim 2, wherein the disengagement preventing means includes the restricting member, and the restricting member includes a direct contact portion that directly contacts the valve member to prevent the valve member from moving to a degree of disengagement from the engagement portion.

5. The ink cartridge according to claim 3, further comprising: a cylindrical wall in which the communication chamber is formed inside, and which includes a shoulder surface extending in a direction perpendicular to a normal direction in which the valve member is expected to move thereon, the shoulder surface constituting the indirect contact portion.

6. The ink cartridge according to claim 3, further comprising: a cylindrical wall, inside of which a communication chamber is formed; and a plurality of ribs extending from the inner surface of the cylindrical wall into the communication chamber, each rib having a lower end surface extending in a direction perpendicular to the normal moving direction of the valve member, and the lower end surface of the rib constituting the indirect contact portion.

7. The ink cartridge according to claim 3,

the biasing member further includes: a valve chamber defined by: (a) a valve seat portion as the valve seat; (b) said engagement portion having an opening with a diameter smaller than a diameter of said valve member; and (c) the side wall portion, the valve chamber accommodates the valve member and communicates with the outside of the valve chamber only at the valve hole and the opening; and

when a force is not applied to the biasing member, the distance between the engaging portion and the indirect contact portion in the normal direction is smaller than the dimension of the valve member in the normal direction.

8. The ink cartridge according to claim 4, further comprising: a cylindrical wall, inside of which a communication chamber is formed; and a bridge extending across opposite portions of the inner surface of the cylindrical wall, the direct contact portion projecting from a middle portion of the bridge in a direction parallel to the normal direction.

9. The ink cartridge as claimed in claim 2, wherein the detachment preventing means includes the inclination restricting member, and the inclination restricting member includes a guide means including: (a) a guide rod projecting from the valve member in a direction parallel to a normal direction in which the valve member is expected to move; and (b) a guide portion that engages with the guide rod in a sliding contact manner so as to guide the guide rod in a direction parallel to the normal direction.

10. The ink cartridge according to claim 9, further comprising a cylindrical wall inside which the communication chamber is formed; and at least three ribs each extending from an inner surface of the cylindrical wall into the communication chamber, an end surface of each rib opposite to the cylindrical wall engaging the guide rod in sliding contact and functioning as the guide portion.

11. The ink cartridge as claimed in claim 10, wherein an end surface of said rib opposite to said valve member is in contact with said valve member via said biasing member to prevent the valve member from moving to such an extent that the valve member is disengaged from the engaging portion, whereby the end surface functions as a restricting member.

12. The ink cartridge as claimed in claim 9, further comprising a cylindrical wall, an inside of which is formed with a communication chamber and an internal passage communicating with the communication chamber, an inner surface of the internal passage being engaged with the guide rod in a sliding contact manner and thereby functioning as the guide portion.

13. The ink cartridge as claimed in claim 12, further comprising a shoulder surface extending in a direction perpendicular to the normal direction at a boundary between the communication chamber and the internal passage, the valve member being in contact with the shoulder surface via a biasing member so as to prevent the valve member from moving to an extent that the valve member is disengaged from the engagement portion, so that the shoulder surface functions as the restricting member.

14. The ink cartridge as claimed in claim 9, further comprising a cylindrical wall, the communication chamber being formed inside of the wall, the cylindrical wall having a contact surface extending in a direction perpendicular to the normal direction and contacting the guide rod so as to prevent the valve member from moving to an extent that the valve member is disengaged from the engagement portion, the contact surface thereby functioning as the restriction member.

15. The ink cartridge as claimed in claim 1, wherein the side wall portion includes a hollow cylindrical portion surrounding an outer periphery of the valve member, and the engagement portion includes a flange inwardly projecting from an end of the hollow cylindrical portion.

16. The ink cartridge as claimed in any one of claims 1 to 15, wherein said biasing member has a valve hole at its center and is integrally made of rubber so as to include said side wall portion, said engaging portion, and a valve seat portion having a valve surface surrounding the valve hole, with which said valve member is held in contact.

17. The ink cartridge of any of claims 1-6, 8-15, wherein the biasing member further comprises: a valve chamber defined by: (a) a valve seat portion as a valve seat; (b) said engagement portion having an opening with a diameter smaller than the diameter of the valve member; and (c) the side wall portion, the valve chamber communicating with the outside of the valve chamber only at the valve hole and the opening.

18. The ink cartridge as claimed in claim 17, wherein at least one of the biasing member and the valve member has a communication passage for communicating the space inside the biasing member and the opening when the engaging portion is engaged with the valve member.

19. The ink cartridge as in claim 1, wherein said biasing member allows said valve member to be placed in the first position by elastic deformation of at least said side wall portion.

20. The cartridge of claim 19, wherein the elastic deformation comprises stretching of the sidewall.