The invention relates to ink jet printers and in particular to ink reservoir configurations for multi-color ink cartridges.
Multi-compartmented ink cartridge bodies generally have reduced spacing requirements as compared to multiple single color ink cartridges. There are generally two types of multi-compartmentalized ink cartridges; parallel chamber ink cartridges, and ink cartridges having a T-shaped divider between the chambers. Each of the chambers is filled with a negative pressure inducing device such as a capillary foam, bladders, or lungs.
Regardless of the negative pressure inducing device, ink flow paths must be provided from the reservoir area of each chamber to the printhead. The ink flow paths to the printheads from ink cartridges having parallel chambers are quite different from the flow paths in multi-compartmentalized ink cartridges having a T-shaped divider between the chambers. Thus manufacturing techniques for each type of ink cartridge are also quite different.
As the cost of materials increases, there is a need for improved ink cartridge designs that enable use of less material and improved production techniques. There is also a need for manufacturing techniques, that enable production of ink cartridges having integral ink flow paths, and ink cartridges that can be formed with fewer process steps.
With regard to the foregoing, the invention provides multi-compartmentalized ink cartridges and improved methods for making the ink cartridges. A first embodiment of the invention provides a multi-compartmentalized ink cartridge body for an ink jet printer including a molded unitary body structure having exterior side walls and a bottom wall forming an open-topped, interior cavity, and a printhead surface area on a portion of the bottom wall opposite the interior cavity. A divider wall is integrally molded with the molded body structure and disposed in the interior cavity between the side walls to provide at least three segregated ink chambers within the interior cavity of the body. Each of the ink chambers has a chamber axis, wherein the divider wall includes a first wall section and a second wall section attached substantially perpendicular to the first wall section and each wall section is substantially parallel with at least one chamber axis. At least first, second, and third molded ink flow paths connect each of the at least three segregated ink chambers with the printhead surface area. The ink flow paths each have an ink flow axis with respect thereto. At least the second and third ink flow paths are oriented relative to their corresponding ink chambers for molding with a mold insert tool so that the cartridge body does not require a separately attached member to close mold insert tool insertion areas on one or more of the exterior side walls of the body.
In second embodiment, the invention provides a method for making a multi-compartmentalized ink cartridge body for an ink jet printer. The method includes the steps of providing a mold body for molding a unitary body structure. The unitary structure has exterior side walls and a bottom wall forming an open-topped, interior cavity. A printhead surface area is provided on a portion of the bottom wall opposite the interior cavity. A divider wall is disposed in the interior cavity between the side walls, the divider wall having first and second wall sections providing at least three segregated ink chambers within the interior cavity of the body. Each ink chambers has a chamber axis, and at least one ink flow path connecting each of the segregated chambers with the printhead surface. A mold core is provided having first, second, and third chamber forming segments parallel with the chamber axes and a first ink flow path segment pending from the first chamber forming segment. The mold core is inserted into the mold body. The mold body is then injected with a thermoplastic material at a temperature sufficient to form the unitary body structure between the mold core and the mold body. The thermoplastic material is cooled to a temperature sufficient to form a solidified unitary body structure. Then the mold core is removed from the solidified unitary body structure to provide a multi-compartmentalized ink cartridge body, wherein openings on the exterior side walls of the cartridge body for forming the ink flow paths are avoided.
In another embodiment, the invention provides a molded unitary body structure having exterior side walls and a bottom wall forming an open-topped, interior cavity, and a printhead surface area on a portion of the bottom wall opposite the interior cavity. A divider wall is integrally molded with the molded body structure and disposed in the interior cavity between the side walls to provide at least three segregated ink chambers within the interior cavity of the body. The divider wall includes a first wall section and a second wall section attached substantially perpendicular to the first wall section, wherein each wall section is parallel with at least one chamber axis. At least first, second, third molded ink flow paths connect each of the at least three segregated ink chambers with the printhead surface area. At least the second and third ink flow paths are oriented relative to their corresponding ink chambers for molding with a mold insert tool through access ports in exterior side wall of the body structure. Injection molded plugs close the access ports in the exterior side wall of the body structure.
An important advantage of the invention is that the ink flow paths can be molded integral with a unitary cartridge body without having to attach a separate cover to access openings in an exterior wall of the ink cartridge body for use in forming the ink flow paths. The invention thus eliminates a step of fabricating and gluing a cover plate to the access openings thereby reducing manufacturing costs and increasing product yield. Multi-compartmentalized ink cartridges having separate access covers are often attached with adhesives, which may introduce contaminants into the ink.
Further advantages of the invention will become apparent by reference to the detailed description of preferred embodiments when considered in conjunction with the drawings, wherein like reference characters designate like or similar elements throughout the several drawings as follows:
With reference to
The cartridge body 12 is preferably molded as a unitary piece in a thermoplastic molding process. The body 12 is preferably made of a polymeric material selected from the group consisting of glass-filled polybutylene terephthalate available from G. E. Plastics of Huntersville, N.C. under the trade name VALOX 855, amorphous thermoplastic polyetherimide available from G. E. Plastics under the trade name ULTEM 1010, glass-filled thermoplastic polyethylene terephthalate resin available from E. I. du Pont de Nemours and Company of Wilmington, Del. under the trade name RYNITE, syndiotactic polystyrene containing glass fiber available from Dow Chemical Company of Midland, Mich. under the trade name QUESTRA, polyphenylene ether/polystyrene alloy resin available from G. E. Plastics under the trade names NORYL SE1 and NORYL 300X and polyamide/poly-phenylene ether alloy resin available from G. E. Plastics under the trade name NORYL GTX. A preferred material for making the body 12 is VALOX 855 resin.
First, second, third ink flow paths 44, 46 and 48 connect each of the ink chambers 38, 40 and 42 with a printhead chip attached to the printhead area 28 of the body 12. As shown in
As shown in plan view in
A second embodiment of an ink cartridge 60 of the invention is illustrated in
A third embodiment of the invention is illustrated in
In the alternative, transverse wall section 86 may be parallel to end side wall 18 rather than being angled, provided the angle of the flow paths 96 and 98 along axes represented by arrow 94 correspond to the angle of end wall 84. The angle Θ that end side wall 84 and transverse wall section 86 make with the bottom wall 22 preferably ranges from about 65 to about 75 degrees.
As in the cartridge 80 of the third embodiment described above, a single mold insert shaped to form chambers 114 and 116 substantially simultaneously with ink flow paths, such as path 124, may be provided with removal of the mold insert along the chamber axes 120. Likewise ink chamber 118 and ink flow path 128 may be formed with a single insert tool shaped to provide the chamber 118 and flow path 128 with removal of the tool along axis 122. Such a mold and insert are described below with reference to FIG. 18.
In all of the foregoing embodiments illustrated in
As beforementioned, a thermoplastic material is injected into a mold to form the body 142. After the body 142 has solidified, but before the body 142 is removed from the mold, the mold inserts are removed from ink flow paths 148 and 150 and pins are inserted in filter towers 152 and 154 from the ink chamber side of the cartridge body 142 to block the flow of injection molded plastic material in ink flow paths 148 and 150. Next an injection tool is partially inserted in access ports 144 to inject molten plastic material therein to form integrally molded plugs 162 closing the access ports 144. The process described above is referred to as a “two shot” molding process, because two shots of molten plastic material are inserted in the mold for body 142. The first shot of thermoplastic material provides body 142 and the second shot of thermoplastic material provides plugs 162.
With reference now to
The mold 184 for molding ink cartridges 10 is shown in cross-sectional view in FIG. 15. The mold 184 includes a bottom section 186 and a top section or mold core 188 having an upper section 190 and pending chamber forming segments such as segments 192 and 194 attached to the upper section of the mold core 188. Segment 192 forms ink chamber 42 and segment 194 forms ink chamber 38 and ink flow path 44. As described above, mold inserts such as insert 182 is used to form ink flow paths 46 and 48. Arrows 1 and 2 in
A mold 200 having a bottom section 202 and mold core 204 for forming an ink cartridge 60 according to the second embodiment of the invention is provided in FIG. 16. In this embodiment, the ink flow paths 66 and 68 are formed by a mold insert 206 inserted from the printhead area 28 side of the ink cartridge 60. Mold segments, such as segment 208 attached to the upper section 210 of the mold core 204 form ink chambers 40 and 42 and mold segment 212 forms ink chamber 38 and ink flow path 44. Once the cartridge body 62 has solidified, the insert 206 is removed from the solidified cartridge body 62 along the direction of arrow 1, then the cartridge body 62 is removed from the mold 200 by opening the mold 200 along the direction of arrow 2.
The mold for forming the ink cartridge 270, according to this embodiment is similar to the mold 184 (
After the ink cartridges 10, 60, 80, 110, 140, and 270 are formed in the molds described above, the thermoplastic material forming the cartridges is cooled to solidify the material and the cartridges are removed from their respective molds. A printhead chip and corresponding flexible circuit is attached to the cartridge bodies. Next, the ink chambers may be filled with a capillary material, such as foam, and/or ink in the absence of a capillary material and a cover is attached by adhesives or thermoplastic welding to the open-topped body of the ink cartridge to provide a closed container.
It is contemplated, and will be apparent to those skilled in the art from the preceding description and the accompanying drawings, that modifications and changes may be made in the embodiments of the invention. Accordingly, it is expressly intended that the foregoing description and the accompanying drawings are illustrative of preferred embodiments only, not limiting thereto, and that the true spirit and scope of the present invention be determined by reference to the appended claims.
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Number | Date | Country |
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0 88 893 | Jul 1999 | EP |
Number | Date | Country | |
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20040095447 A1 | May 2004 | US |