This invention pertains to a seal for a fluid-discharge port on a fluid reservoir. The seal is configured to prevent loss of fluid from the fluid reservoir through the port, for example, during shipping or storage. In particular, this invention pertains to aspects of a surface of the seal that faces the port opening and opposes a direction in which the port is configured to discharge fluid. Such aspects improve, among other things, the retention of fluid on the surface of the seal during removal of the seal, thereby reducing spillage or splattering of fluid during removal of the seal.
Fluid reservoirs, such as ink cartridges for ink jet printers, commonly have one or more fluid-discharge ports with an opening through which fluid is delivered during use. In order to prevent loss of fluid, for example by spillage or evaporation during shipping or storage, it is common to provide a seal for the port or each of the ports. When the seal is removed so that the fluid reservoir can be used, it is important not to spill or splatter droplets of the fluid.
Fluid-ejection printing devices, such as ink jet printers, commonly have at least one fluid reservoir (or ink cartridge) and a printhead chassis that supports the ink cartridge. The ink cartridge may contain one or more fluid chambers that provide fluid to a printhead. If the ink cartridge has more than one ink chamber, each such chamber often retains fluid of a different color or function for multi-color printing. On the other hand, if the ink cartridge has only a single ink chamber, typically such chamber is used to retain a single fluid, such as black ink for black-and-white printing.
The printhead die containing the nozzles is typically connected directly or indirectly to the chassis. In order to form an image, the printhead die, along with the chassis and the ink cartridge, generally are moved in a lateral direction across a width of a substrate, such as paper, as fluid is ejected from the printhead. After the printhead forms a row-portion of the image along the width of the substrate, the substrate is advanced in a direction perpendicular to the lateral direction along a length of the substrate, so that the printhead can form a subsequent row-portion of the image. This process of advancing the substrate for each row-portion is repeated until a next substrate is needed or the image is completed.
When an ink chamber in the ink cartridge runs out of ink, a user is charged with the responsibility of removing the empty ink cartridge from the chassis and replacing it with a full ink cartridge. The task of replacing an ink cartridge must be simple and clean. Ink should not be allowed to stain the user's hands or clothes, and it also must not be allowed to drip into areas of the printer where it might cause damage.
When a new ink cartridge is shipped, a shipping seal is provided to seal the fluid discharge port(s). The shipping seal helps to prevent ink evaporation during long-term storage, as well as ink spillage due to air pressure changes that occur, for example, during air travel. However, subsequent to shipping, conventional seals have been found to allow fluid to splatter during a user's removal of the seal, thereby possibly causing staining or damage. Accordingly, a need in the art exists for a solution that mitigates the risk of fluid splatter during removal of a shipping seal from an ink cartridge.
The above-described problem is addressed and a technical solution is achieved in the art by a seal for a fluid-discharge port on a fluid reservoir, according to various embodiments of the present invention. The seal has a surface containing channels that oppose a direction in which the port is configured to discharge fluid. Such channels facilitate the retention of fluid by the seal during removal of the seal, thereby reducing the likelihood of fluid spillage.
At least one of the channels may have a smallest dimension, such as a width of approximately 0.05 mm to 0.25 mm. At least one of the channels may have a rounded or substantially rounded bottom. And, at least one of the channels may have a pointed or substantially pointed bottom.
According to various embodiments of the present invention, at least some of the channels may intersect at right angles, at substantially right angles, or obliquely. According to various embodiments of the present invention, the channels may be formed between protrusions. The protrusions may comprise a sloped side wall. In addition, the protrusions may include sloped side walls that form a point, substantially a point, an edge, or substantially an edge. In this case, the smallest dimension of the point or edge may be approximately 0.05 mm or 0.25 mm. According to an embodiment of the present invention, the protrusions may comprise rounded or substantially rounded tops.
According to various embodiments of the present invention, the protrusions may have approximately a first height and the seal may further include a containment wall around or substantially around a periphery of the seal, such that the containment wall has a height approximately greater than or equal to the first height. A width of a top surface of the containment wall may be approximately between 1 mm and 2 mm. The containment wall may have an outside edge that is stepped, and the outside edge may include a plurality of steps.
According to various embodiments of the present invention, the seal may include a storage area configured to retain excess fluid from the reservoir. In this case, the surface of the seal may include openings communicatively connected to the storage area. The storage area may be located beneath the surface.
According to various embodiments of the present invention, the seal may be formed of a compressible material, such as EPDM rubber or a thermoplastic elastomer, known in the art. The seal may be a hydrophilic material.
According to various embodiments of the present invention, a printer ink cartridge is provided, the printer ink cartridge including a fluid reservoir, a fluid-discharge port, a porous media, and a seal according to one of the various embodiments of the present invention highlighted above. The porous media is positioned in the port. According to these embodiments, the surface of the seal includes (a) protrusions between which are the channels, and (b) a containment wall around or substantially around a periphery of the seal. Also according to these embodiments, a space may exist between the protrusions and the porous media, and a space may exist between the containment wall and the porous media.
In addition to the embodiments described above, further embodiments will become apparent by reference to the drawings and by study of the following detailed description.
The present invention will be more readily understood from the detailed description of exemplary embodiments presented below considered in conjunction with the attached drawings, of which:
It is to be understood that the attached drawings are for purposes of illustrating the concepts of the invention and may not be to scale.
Embodiments of the present invention provide one or more channels in the surface of a sealing member which faces the opening of a port of a fluid reservoir. Although particular examples of a fluid reservoir often are provided in the context of an ink jet ink cartridge, it is to be understood that the invention is applicable more generally to sealing members for ports of fluid reservoirs.
Before the ink cartridge 20 is ready to be shipped to the customer, the ports must be sealed in order to prevent leakage or excessive evaporation of volatile ink components. Many different styles of seals are possible to be used. For example, a film may be affixed to the outer rim of each port. For this type of seal, the customer may pull a tab at an end of the film and thereby pull the seal away from each port. A second alternative is a twist-off seal, although this type of seal is more compatible with a cartridge having only a single port. With a row of ports 24 as in multi-chamber ink cartridge 20, the amount of torque to twist off seals from five adjacent chambers would be excessively difficult for the user to apply. A third alternative is a seal of the type provided by seal assembly 50 shown in
As the sealing member 52 is pulled away from the port, some amount of ink may be located on the surface of the sealing member which had faced the port opening and which opposed a direction in which the port 24 is configured to discharge ink. If the seal is pulled away suddenly, droplets of ink may splatter out and stain the hands of the user or get onto the printer or other objects. This is true whether the seal is a compliant seal such as sealing member 52, or whether the seal is an adhesively affixed film. This problem, which is addressed by the present invention, is exacerbated for configurations of fluid reservoirs and seals such that transient pressure changes occur when the seal is removed, due to air volume changes between the port and the surface of the seal. Somewhat less susceptible to such pressure changes are the types of seals which may be removed in a twisting motion, since the volume change is very small as the seal is broken. However, as mentioned above, twist-off type seals are not very compatible with multi-chamber ink cartridges having a row of adjacent ports 24.
In a preferred embodiment, the sealing member 52 is formed of a compressible material, such as EPDM rubber or a thermoplastic elastomer. The port seals 70 are configured such that each containment wall 74 fits within the outer rim 26 of the corresponding fluid discharge port 24. When the sealing member 52 is pressed against the fluid discharge ports 24 (for example by seal retainer 54), it is the stepped edge 76 that provides the seal against the inner surface 27 of the outer rim 26. Although not required, providing a plurality of steps in stepped edge 76 can improve seal reliability. A function of containment wall 74, protrusions 82 and channels 84 is to retain residues of ink or other fluid which may be on the surface of the port seal 70 when the sealing member 52 is removed from the fluid discharge ports 24. The channels 84 between the protrusions 82 provide capillary forces, which tend to hold the fluid residue, as well as some amount of storage volume, so that the fluid has less tendency to splatter off the surface of the port seal 70 when the sealing member 52 is removed from the fluid discharge ports 24. In some applications, for example, when the inks or fluids are water-based, the surface of the sealing member 52 may be made of a hydrophilic material to provide additional holding forces for the fluid residue.
Further geometrical details of shapes and dimensions will be discussed with reference to
Although the examples above discuss embodiments in a multi-chamber fluid reservoir 20, it is to be understood that the same advantages apply to a single chamber fluid reservoir.
The various embodiments of this invention are particularly advantageous for, among other things, fluid reservoirs and sealing members such that the sealing member is removed in a fashion that momentarily increases the air volume between the sealing member and the interior of the fluid discharge port, such that a transient reduction of air pressure occurs within the fluid discharge port. Such configurations are particularly susceptible to fluid residue being transferred to the surface of the sealing member, resulting in ink splatters if the surface cannot hold the residue. For example, embodiments of the present invention are particularly advantageous for, among other things, seals which are not removed by twisting them off.
It is to be understood that the exemplary embodiments are merely illustrative of the present invention and that many variations of the above-described embodiments can be devised by one skilled in the art without departing from the scope of the invention. It is therefore intended that all such variations be included within the scope of the following claims and their equivalents.