MXPA98001297A - Ink jet cartridge with an improved seal in the container of the ink and printer head - Google Patents

Abstract

An inkjet print cartridge is described, wherein the ink flows from an ink container to a print head, via a multiple of the ink, which includes a plurality of ink ducts projecting toward the outlet orifices in the ink jet. ink containers, the interface between the manifold and the outlet orifice is sealed by placing an open silicone element through the ink conduit and compressing the element between the manifold and the outlet surface of the container. The sealing element has a circular opening of a diameter that varies inversely from both sides towards the center, eg, the diameter is greater on the outer surface and smaller in the center, to reduce compression of the assembly and reduce migration of ink (cross-talk) between the adjacent ink channels. Preferably, the sealing element has a raised lip on both surfaces of the opening.

Description

INK JET CARTRIDGE WITH AN ENHANCED SEAL BETWEEN THE INK CONTAINER AND THE PRINT HEAD BACKGROUND OF THE INVENTION v_ EXPLANATION OF THE DESCRIPTION OF THE MATERIAL The present invention relates to recording devices in ink and, more particularly, to an improved seal between an ink supply container and the housing of a printing head. The ink jet recording devices include one or more print heads that drive the ink on a printing medium, such as paper, in controlled patterns of points very close to each other. To form color images, multiple print heads are used, where each print head is fed with an ink of a different color, from an associated ink container. Thermal inkjet printing systems use thermal energy selectively, produced by resistors located in ink-filled capillary channels near the nozzles or channel termination holes, to vaporize the ink momentarily and form bubbles of agreement. to the demand. Each temporary bubble expels a droplet of REF .: 26560 ink and drives it towards the recording medium. The printing system is usually incorporated into a car-type printer. A car-type printer generally has a relatively small print head that contains the channels and nozzles of the ink. The print head is generally attached, in a sealed connection, to an ink feed container, and the combined print head and container form a cartridge assembly that moves in a reciprocating motion to print a row of information at the same time on a recording medium that remains stationary, like paper. After the row is printed, the paper is advanced a distance equal to the height of the row of the print head, so that the next printed row will be contiguous with that. The procedure is repeated until the entire page is printed. The ink, from the ink supply container, is removed by capillary action, through an outlet hole in the container, and towards a manifold that fluidly connects the ink to the print head. The manifold provides the ink to the ink channels supplying ink after each ejection of the ink or triggering of the associated nozzle. It is necessary to ensure that the ink, as it leaves the ink container, flows, or escapes, to another part of the print head cartridge, such as the print head housing. Various methods are known to provide an effective seal. US Patent No. 5,519,425 discloses a thin polyester film, having an opening therethrough, which is attached to the ink container and to the print head. In order to obtain a more effective extraction of the ink from an ink tank, it is known to project a manifold of the ink duct towards the ink container, so that either the liquid ink of the ink is extracted. same or the ink of a foam element impregnated with ink. The North American Patent No. 4,771,295 is representative of this type of extraction system. A problem with the removal of the ink from the foam element system is the need to maintain a leak-tight seal between the manifold and the outlet orifice of the ink container. Any seal material must be capable of forming a seal against the differential pressure associated with the supply of the ink, while maintaining a compression load of the manifold against the surface of the ink container. The prior art devices use a closed-cell neoprene seal element, which works well with most inks and seals against differential pressures of up to 10 inches of H_0. However, seal efficiency decreases with repeated replacements of the ink container; e.g., suffers from compression "hardening" and loses the ability to return to the initial state of compression. This leads to the possibility of leakage by migration of the ink (crossover - s-t to k) between the loca 1 i zac i one s of the foam interface. Some improvement was obtained in the seal with the seal arrangement described in copending application USSN 08 / 664,581, filed on 6/17/96 describing a dual foam membrane that seals the interface between a multiple of the ink duct and the exit hole of the ink container.

BRIEF DESCRIPTION OF THE INVENTION It is an object of the invention to provide a sealant for an ink-jet ink-charging mechanism, wherein a plurality of ink conduits carry ink from the outlet orifices of a plurality of ink tanks. It is another objective to provide a seal that allows a consistent compressive load for the ink tanks installed in the printhead. It is still another object of the invention to avoid crossing the ducts of the ink.

It is another objective to provide a compressive, progressive load during the installation of the ink tank. These and other objects are achieved by providing a radial / surface seal, of silicone, having an opening therethrough that has a variable cross section. The variable cross-section provides a micially less installation force, the force then progressively increases in proportion to the increase in the cross-sectional area of the openings. The micially lower force is user friendly while the fully installed end load is greater to provide the necessary load against the surface of the ink tank outlet orifice. More particularly, the present invention relates to a print cartridge for an ink jet printer comprising at least one ink container, fluidly connected to at least one print head, an improved sealing accessory, to avoid ink leaks, comprising in combination: - an ink manifold positioned adjacent to the outlet orifice of the at least one ink container, the ink manifold includes at least one ink conduit extending towards the outlet orifice of the ink. ink; and - a sealing element positioned between the surface of the ink manifold, around the duct of the ink, and the surface of the container, around the outlet orifice, where the sealing element is characterized in that it has at least one opening with cross section of variable diameter to seat the ink duct.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 illustrates a perspective view of a full color inkjet printer (quadratic) incorporating the ink manifold with the sealing elements of the ink tank, present invention. Figure 2 is a cross-sectional view through one of the print head cartridges, shown in Figure 1, showing a first embodiment of an ink sealing member.

Figure 3 is a developed view of the manifold toward the ink tank arrangement of Figure 1. Figure 4 is an end view of the sealing element showing the openings in the ink duct, with variable cross sections.

DESCRIPTION OF THE INVENTION Figure 1 illustrates a perspective view of a thermal, full-color inkjet printer (quadrature), 8 incorporating a preferred embodiment of the sealing element used to seal the passage of the ink from the ink container to multiple ink ducts. The printer 8 is only exemplary. The invention can be practiced in other types of thermal inkjet printers, as well as other reproduction devices such as pi ez oe 1 e ctri c printers, dot matrix printers and ink jet printers driven by signals from a document Explorer of Sweep Input. The printer 8 includes four cartridges of the inkjet print head, 10, 12, 14, 16, mounted on a carriage 18 supported by the carriage rails, 20. The carriage rails are supported by a printer structure 21. ink jet 8. Each print head cartridge comprises an ink container containing ink to supply a thermal, ink jet print head, which selectively ejects droplets of ink ba or control of electrical signals received from an ink jet. controller (not shown) of the printer 8, through an electrical cable (not shown). Accordingly, the cartridge 10 comprises the ink container, 22, and the print head 24; the cartridge 12 comprises the ink container, 26, and an associated printhead, 27; the cartridge 14 comprises the ink container, 28, and an associated print head, 29; and the cartridge 16 comprises the ink container, 30, and an associated print head, 31. Each container contains a different color ink, which is fluidly connected to an associated print head, by a manifold 42 shown in FIG. the side view of Figure 2, and in a view developed in Figure 3. Each print head comprises a plurality of ink channels that carry the ink from the associated container to the respective ink ejection holes or nozzles. When it is printing, the cartridge 18 has a reciprocal movement, backwards and forwards, along the carriage rails, 20, in the direction of the arrow 19, the entire transverse width constitutes a scanning path. The current printing area is contained within the scan path. As the cartridges 10, 12, 14, 16, move reciprocally, back and forth, along a printing path and past a recording medium, 34, such as a sheet of paper or a transparency, the droplets of the ink are ejected from the selected nozzles, from the print head, towards the sheet of paper. Typically, during each step of the carriage 18, the recording means, 34, is held stationary. At the end of each step, the recording medium is advanced in the direction of the arrow 36. For a more detailed explanation of the operation of the printer 8, reference is here made to US Pat. Nos. 4, 571, 599; 4,833,491; and US Patent No. Reissue No. 32,572, which are incorporated herein by reference. According to the invention, a sealing element 60 is used to seal the ink tank / ink duct. Figure 2 shows the element 60 in a developed view of the manifold towards the arrangement of the ink tank; and Figure 3 is a cross-sectional view of the element 60 sealing (sealing) the surface interface of the inta / multiple ink t. The element 60, in a preferred embodiment, and as shown in Figure 4, is made of a silicone material of 30 hardness units. The openings 62A, 62B, 62C, 62D have an outer diameter, Di, which decreases from both sides toward a central point C, which has a minimum diameter, D. The openings can be characterized as having a variable cross section, where the larger cross section is located on the outer surfaces and the smaller in the central location. The openings are further characterized by having raised lips, 64A, 64B, 64C, 64D, on both surfaces of the opening. I nally, the sealing element 60 is placed on the ducts of the ink, with a micially low installation force, user-friendly (due to the reduced area of the cross-section). The installation can be carried out with any of the sides of the element 60 seated on the ducts, due to the identical nature of the openings. The manifold 42A, which has the sealing element 62 seated, is then brought to a compression coupling with the surface of the container 20, hermetically sealing the outlet orifices of the ink tank, where only one orifice 40 is shown. Shown in Figure 2, the manifold member, 42, comprises a plate, 44, with ink conduits, 46A-46D. The end of the ink duct 46A extends through the opening 62A, of the sealing element, 60, and engages, with a compression contact, with a foam element impregnated with the ink, 48, in the container 22. The lip 64A, of the sealing element 60, is compressed against the surface of the container 22. In tests carried out measuring the compression of the assembly of the element 60 with respect to a neoprene foam element, of the prior art, the silicone seal of the present invention, provided 7% compression of the assembly for more than 30 days at a temperature of 50 ° C on a 30-inch pallet. [Inventor, is this a commercial ink? How can it be characterized?], Against 50% compression of the EPDM foam assembly. The lower value of compression of the assembly implies a more effective hermetic closure. The migration of the ink (cross-talk) is virtually eliminated because the silicone material conforms to the outer diameter of the ink passages to form a seal at the manifold interface, 42A. While the modality discussed here is preferred, it will be appreciated from this teaching that various modifications, variations or alternative improvements may be made therein by those trained in the art, which are projected to be encompassed by the following claims.

It is noted that, in relation to this date, the best method known by the applicant to carry out the aforementioned invention is the conventional one for the manufacture of the objects to which it relates. Having described the invention as above, the content of the following is claimed as property.

Claims (5)

1. CLAIMS 1. In a print cartridge, for an ink jet printer comprising at least one ink container fluidly connected to at least one print head, an improved sealing accessory, to prevent ink leakage, characterized in that it comprises, in combination: • an ink manifold positioned adjacent to an ink outlet orifice, of the at least one ink container, wherein the ink manifold includes at least one ink conduit extending towards the outlet hole of the ink; Y • a sealing element placed between the surface of the ink manifold, around the ink duct, and the surface of the container, around the outlet orifice, where the sealing element is characterized in that it has at least one opening of cross section with variable diameter, this opening seats the duct of the ink.
2. 2. The cartridge, according to claim 1, characterized in that the diameter of the cross section of the opening varies from the outer surface towards the center, where the opening of the diameter at the center is smaller with respect to the diameter at the outer surface.
3. 3. The cartridge, according to claim 2, characterized in that the openings of the element have circular lips raised at the outer edges of the opening.
4. 4. The cartridge, according to claim 1, characterized in that the element is made of a silicone material that is formed with the settled ink duct.
5. 5. The print cartridge, according to claim 1, characterized in that the ink manifold comprises a plurality of ink ducts projecting towards a plurality of ink containers, where the print cartridge is used in a full color printer , and where each ink duct is seated in a respective sealing element.