EP1504905A1 - On the fly ink-jet nozzle cleaning device - Google Patents

Abstract

The device has two vane-rotors (38A, 38B) placed in a mail article transport path (28), to the right of ink ejection nozzles (12A, 14A). The vane-rotors are actuated by a mail article (30) during its advancement under the nozzles. The vane-rotors are mounted on a support arm moving between scraping and rest positions. The vane-rotors are placed in the path in the scraping position and are withdrawn from the path in the rest position.

Description

Field of the invention

The present invention relates to the field of the treatment of mail and it relates more particularly to a device for cleaning the ink ejection nozzles of an inkjet printhead of a postage meter for mail items.

Prior art

Conventionally, the cleaning of ink ejection nozzles of a franking machine is carried out periodically when the head printing is removed from the transport path of mail items and disposed in a maintenance position in which the nozzles ink ejection is subjected to scraping means which rid of pollutants (dried ink particles, paper waste for example) they were able to accumulate during impressions preceding. US Pat. No. 5,813,326 perfectly illustrates such a device.

This solution generalized to many models of Mail processing gives overall satisfaction. However, she still has some disadvantages. First, it forces to stop the printing process periodically except to provide two heads alternating printing, as proposed by the applicant in his patent application US2002 / 0040354A1, solution expensive and therefore difficult to envisage on a franking machine to cheap. Then, depending on the quality of paper used for printing, the moment the ink ejection nozzles start to clog strongly. In particular, when this paper is of very poor quality, the clogging of the ejection nozzles can appear very quickly, by example after 10 impressions, which in practice prohibits any recourse at a maintenance station even with low processing rates high.

Object and definition of the invention

The present invention provides a nozzle cleaning device ink ejection which does not require the passage of these nozzles to a maintenance station and which can be implemented during their operation. An object of the present invention is also to propose a simple and inexpensive device, so as to allow its installation on cheap franking machines.

These goals are achieved by a nozzle cleaning device ink ejection of a machine inkjet print head mail processing, characterized in that it comprises a means of scraping disposed in a transport path of mail items at right of the ejection nozzles and actuated by a mail item at its advanced under the print head.

With this configuration, the cleaning of polluted nozzles is carried out directly during the printing of mail items. It is therefore not no longer necessary to stop the machine for the traditional scraping of these nozzles at a maintenance station.

The scraping means, which preferably comprises a wheel optionally motorized fins, is articulated between a position of scraping in which the scraping means is disposed in the path of transport of mail items and a rest position in which the scraping means is set back from this transport path.

Advantageously, there is provided means for cleaning said means scraper comprises a scraper which rubs each fin of the wheel fins.

When said finned wheel is mounted on a support arm swivel which can move between the scraping position and the position of rest, the displacement of said support arm can be controlled according to the number of mail items counted by a position sensor arranged on the way of transport of the articles of mail. This sensor position is advantageously arranged upstream of said means of scraping.

Brief description of the drawings

• la figure 1 est une vue schématique d'un premier mode de réalisation de l'invention,
• la figure 2 est une loupe de la figure 1 dans une variante de réalisation,
• la figure 3 est une loupe d'un deuxième mode de réalisation de l'invention,
• les figures 4, 5 et 6 sont des vues schématiques du deuxième mode de réalisation,
• la figure 7 est une loupe d'un troisième mode de réalisation de l'invention,
• les figures 8 et 9 illustrent en loupe et en détail une variante du mode de réalisation de la figure 7, et
• la figure 10 est une vue partielle d'une machine à affranchir de l'art antérieur au niveau des moyens d'impression.

The features and advantages of the present invention will emerge more clearly from the following description, given by way of non-limiting indication, with reference to the appended drawings in which:

• FIG. 1 is a schematic view of a first embodiment of the invention,
• FIG. 2 is a magnifying glass of FIG. 1 in an alternative embodiment;
• FIG. 3 is a magnifying glass of a second embodiment of the invention,
• Figures 4, 5 and 6 are schematic views of the second embodiment,
• FIG. 7 is a magnifying glass of a third embodiment of the invention,
• FIGS. 8 and 9 illustrate in a magnifying glass and in detail a variant of the embodiment of FIG. 7, and
• Figure 10 is a partial view of a franking machine of the prior art at the printing means.

Detailed description of a preferred embodiment

FIG. 10 is a partial view at the level of the means printing of a mail processing machine. The print head 10 which conventionally comprises two printed modules 12, 14 staggered in a direction perpendicular to the direction D of advancing articles mail is mounted between two sets of drive rollers, a first series of two upstream rollers 16, 18 superimposed one of which preferably the upper roller 16, is motorized and a second series of two downstream rollers 20, 22 superimposed also one of which, preferably the upper roller 20 is motorized. At the level of the printing means, an upper fixed plate 24 and a lower mobile plate 26 (also called ski mobile) define a path 28 for transporting mail items 30. These trays are of course perforated to the right of the ejection nozzles of ink 12A, 14A of each print module. Reference 32 illustrates one of the corresponding openings (the second 34 is behind the plane cutting due to the offset of the two modules).

In mail processing machines of the prior art, the printhead 10 is movable and can take two positions, a print position in which printing a postal imprint is possible and a rest or maintenance position in which this print head is set back from the transport path 28 at the level a maintenance station to allow nozzle cleaning ink ejection, thus prohibiting any printing of an impression PO.

According to the invention, and as illustrated in the first embodiment of FIG. 1, the print head 10 is now fixed in the position printing and cleaning the ink ejection nozzles is carried out directly in that position, ie in the very course of printing process.

To do this, a scraper means is provided in the path 28 for transporting mail items to the nozzle of ink ejection 12A, 14A and actuated by a mailpiece 30 when of its progress under these nozzles. More specifically, this scraping means comprises two impeller wheels 38A, 38B each provided with at least one blade or blade and disposed in line with a row of nozzles 12A, 12B of a given print module, in the opening made in the trays fixed 24 and mobile 26, and whose rotation is controlled by the advance of a mail article. The impeller 38A, 38B being fixed, that is to say solidary of the body of mail processing machine, it is provided a light 26A, 26B in the fixed plate 26 so as to allow the moving this tray according to the thickness of the mail to print. Good heard, each fin combines elasticity and rigidity effective cleaning without altering the nozzles.

In order to guarantee the maintenance of the effectiveness of the scraping means, it cooperates with a means of automatic cleaning of the fins polluted by the debris from the ink ejection nozzles, formed of a scraper 40A, fixed 40B, ie integral with the machine body of mail processing, and on which will rub one after another the pale wing wheels 38A, 38B.

FIG. 2 illustrates an embodiment variant of FIG. which the impeller 38A, 38B is motorized by a motor 40A, 40B so that the scraping of the ejection nozzles can be carried out also between mail items, or even in the absence of articles from mail.

A second embodiment of the invention is illustrated in FIGS. 3 to 6. In this embodiment, each wheel provided with at least a fin or blade is mounted on a support arm 44A, 44B pivoting around an articulation axis 46A, 46B secured to the movable plate 26, to against an elastic means, for example a spring 48A, 48B, secured to this support arm at one end and the movable plate to its other end. This spring-mounted arrangement allows the cleaning of nozzles with an optimal application constraint.

The support arm can move between a scraping position (corresponding to the position of the first embodiment) and a rest position set back from the transport path (preferably retracted under this path and can be if necessary also clear of the nozzle spitting area) under the influence of a means of control, for example a motor or an electromagnet 50A, 50B whose the motor shaft or the corresponding control rod 52A, 52b is connected to the associated support arm. If necessary, and according to the configuration of the mail processing machine, kinematics with levers and pulleys (not shown) may be provided between this control means and the finned wheels. The control means is actuated from a means of treatment 54 according to different parameters, the number of mail items counted by a position sensor, such as tilting lever 56, arranged on the transport path of the articles of mail upstream of the scraping means and actuated by the front of each mail item. This number of mail items can be set according to the type of paper used or any other consideration, for example the country of installation of the machine. So, in this embodiment, the scraping of the nozzles is not performed when the printing of each mail item but after the passage of a number of these articles.

In order to ensure optimum efficiency by means of scraping, and as before, it cooperates in its rest position with a automatic cleaning means of the polluted fins formed of the scraper fixed 40A, 40B integral with the body of the machine and on which will rub one after the other the blades of the finned wheels 38A, 38B under the effect of the motorization of the wheel 42A, 42B. Cleaning can be synchronized or not with the return of the support arm in its rest position. So, by for example, nozzle scraping can be performed every 10 impressions but the cleaning of the fins (thus the launch of the motorization 42A, 42B) only every 100 impressions.

FIG. 7 illustrates a third embodiment of the invention wherein the hinge axis 46A, 46B of the support arm 44A, 44B and the control means 50A, 50B are no longer fixed on the moving plate but attached directly to the body of the processing machine mail. With this advantageous embodiment, the engine control is simplified because it is no longer necessary to compensate for the movable platen 26, the distance impeller / nozzles now being fixed.

An alternative embodiment of FIG. 7 is illustrated in FIG. 8. In this variant, the control means 50A, 50B is arranged directly on the hinge axis 46A, 46B which further supports the elastic means 48A, 48B. We thus obtain a more compact realization which can then be easily integrated into existing machines without big change of structure.

Of course, the present invention can not be limited to illustrated figures only and the person skilled in the art will be able to complete them without demonstrate inventive activity. For example, to promote evacuation progressive drying of the dried ink and paper particles while reducing significantly the scraping forces exerted on the nozzles, the wheel with fins may have a form of forest (or worm), each helical cutting edge corresponding to a scraping edge of a blade. Similarly, if the invention has been illustrated with a print head to two modules, the use of a single module is equally conceivable.

Claims (9)

Device for cleaning the ink ejection nozzles of a franking machine ink jet printhead, characterized in that it comprises scraper means (38A, 38B) arranged in a transport path (28) Mailpieces (30) at the ink ejection nozzle (12A, 12B) and actuated by a mailpiece as it advances under the print head (10). Cleaning device according to claim 1, characterized in that said scraping means is articulated between a scraping position in which the scraper means is arranged in the transport path of the mail items and a rest position in which the scraper means scraping is set back from this transport path. Cleaning device according to claim 1 or claim 2, characterized in that it further comprises cleaning means of said scraping means. Cleaning device according to claim 1 or claim 2, characterized in that said scraping means comprises a vane wheel (38A, 38B). Cleaning device according to claim 3 and claim 4, characterized in that said cleaning means comprises a scraper (40A, 40B) which rubs each fin of the finned wheel. Cleaning device according to claim 4 in that it depends on claim 2, characterized in that said fin wheel is mounted on a pivotable support arm (44A, 44B) movable between the scraping position and the position of rest. Cleaning device according to claim 6, characterized in that the displacement of said support arm is controlled according to the number of mail items counted by a position sensor (56) disposed on the transport path of the mail items. Cleaning device according to claim 7, characterized in that said position sensor is disposed upstream of said scraping means. Cleaning device according to claim 4 or claim 6, characterized in that said impeller is motorized (42A, 42B).

Images