Patent ID: 12227009

DETAILED DESCRIPTION

Referring first toFIG.14, there is shown a printer1according to document DE 20 2006 005 458 U1 for printing plate-like print media such as marker cards2with markers3for marking electrical appliances, connectors, cables or the like. Each marker card2is conveyed in a conveying direction41through the printer1without changing direction. The printer1has several functional apparatuses I, II, III, IV for printing the marker cards2.

The first functional apparatus I is a separating apparatus which includes a magazine for receiving the marker cards2. The marker cards2, which are stacked in the magazine, are separated in the separating apparatus I. They are then fed to the second functional apparatus II which is a printing apparatus and printed. In the third functional apparatus Ill configured as a fixing apparatus, the printed image printed on the marker card2is fixed. With the fourth functional apparatus IV which is a dispensing apparatus, the marker card2is then dispensed. The dispensing apparatus may optionally include a cooling zone.

Such printers1function in accordance with the inkjet principle. Their printing apparatus II has a printing unit100with at least one print head104,105. Ink is applied by the print head104,105onto an area20to be printed of the plate-like printing medium2.

FIG.12shows a printing apparatus II of a printer1according to the invention in a perspective view. The printing unit100has two print heads104,105to provide two differently colored inks for example. Depending on the number of print colors desired, such a printer1can also have more print heads104,105.

A marker card2having an area20to be printed is shown diagrammatically in order to illustrate the position of the marker card2during printing. The area20to be printed faces the two print heads104,105.

The print heads104,105are arranged on a print-head carrier101and can be moved with the carrier along two guide rails102,103in and counter to the conveying direction41. They are affixed to the print-head carrier101beside one another in the conveying direction41. A print-head drive mechanism for moving the print-head carrier101in and counter to the conveying direction41is not shown.

The guide rails102,103are arranged spaced apart from one another in an emission direction4, which extends transverse to the conveying direction41and are oriented parallel to one another. In the depicted embodiment, the emission direction42is a vertical direction and the conveying direction41is a horizontal direction. Therefore, the terms vertical direction and emission direction42, as well as horizontal direction and conveying direction41, respectively, will be used synonymously below.

In order to clean the print heads104,105, the printing apparatus II has a cleaning unit200. This includes a cleansing device210with which ink can be extracted from each of the print heads104,105, and a collecting device230which includes a collecting container231for the ink.

FIG.12depicts the print-head carrier101in a cleaning position of the printer1in which the print-head carrier101is arranged above the cleaning unit200. The cleaning position will be explained in greater detail below in connection with the description ofFIG.1.

The cleaning unit200furthermore has a driving device250for driving a frame211of the cleansing device210. With the driving device250, the frame211is displaceable in and counter to the vertical direction42relative to the printing unit100. For this purpose, tooth sections212a-212dare provided on the frame211as gear elements. The driving device250will be explained in greater detail below in connection with the description ofFIGS.7and8.

The cleansing device210additionally includes a mounting plate213which is arranged on the frame211and on which one suction cup215,216is arranged for each print head104,105, respectively. The suction cups215,216are arranged beside one another in the conveying direction41and are spaced apart from one another by the same distance as the print heads104,105. In the cleaning position R, they are therefore currently positioned in such a way that they are arranged below the print heads104,105.

Furthermore, a wiping blade or lip214for wiping the ink from the print heads104,105is arranged on the mounting plate213. In order to clean the wiping lip, the cleaning unit also includes a cleaning device240for the wiping lip214.

FIG.1depicts the printing unit100in the cleaning position R. A first suction cup215and a second suction cup216are arranged on the mounting plate213. In the cleaning position R, the print heads104,105are positioned in the horizontal direction corresponding to the suction cups215,216and above them. Furthermore, the cleansing device210is moved vertically upwards so that the suction cups215,216fit closely against a nozzle side (not shown) of the print heads104,105.

For this purpose, the suction cups215,216are connected via a first pipe217,219, respectively, to a pump with which the ink can be extracted from the print heads104,105. Each of the pumps221,222is connected via a second pipe218,220, respectively, to the collecting container231of the collecting device230by one free pipe end223,224of the second pipe218,220being introduced into the collecting container213. The excess ink is collected in the collecting container231of the collecting device230. The pipes217,218and219,220are preferably formed from elastic hoses, so that they are deformable (as also shown inFIG.11andFIG.9). During extraction, the nozzle side of the print heads104,105is sealed off from the surrounding atmosphere by the suction cups215,216.

The pumps221,222extract excess ink by the suction cup215,216attached to them from the print head104,105against which each suction cup215,216abuts, respectively. Since one pump221,222and one suction cup215,216is assigned to each print head104,105, extraction can take place in a single step. The excess ink is conveyed by the pumps221,222into the collecting container231of the collecting device230.

The pumps221,222are affixed to the frame211of the cleaning unit210so that they can be moved together with the cleansing device210by the driving device250. As a result, they can be serviced or exchanged together with the cleaning unit210.

The printing unit100and the cleansing device210are always in the cleaning position when the printer is in a “stand-by” operating mode, i.e. is ready to operate, but currently has no printing task to perform or is switched off. In this way, the print heads can become sealed and potential ink residues do not dry and the print heads do not clog.

FIG.2depicts the printing unit100as freely movable. The printer1is therefore in a printing position D. “Freely” here means that the cleansing unit210is located below the print heads104,105, in the vertical direction42, to such an extent that the printing unit100above the cleansing unit210is movable in and counter to the horizontal direction41without touching it.

InFIG.3, the printer is located in a wiping position A, in which, when the printing unit100is moving, ink can be wiped away from the print heads104,105by the wiping lip214. For this purpose, the wiping lip214is affixed to the mounting plate213such that its free end extends out upwardly from the mounting plate213counter to the vertical direction42. Furthermore, the cleansing device210is moved counter to the vertical direction42to such an extent that a free end (not shown) of the wiping lip214touches a nozzle side (not shown) of one of the print heads104,105. The printing unit100is then moved in the horizontal direction over the wiping lip214with the excess ink being wiped by the wiping lip214off the nozzle side of that print head104,105along which it is currently being moved. This preferably takes place at pre-set time intervals. After wiping of the excess ink has taken place, the wiping lip214is regularly cleaned.

Cleaning of the wiping lip214is shown inFIG.4and inFIGS.13a-13d.

In addition to the collecting container231for the excess ink, the collecting device230has a cleaning device240for the wiping lip214. The cleaning device240is arranged on the collecting container231. It has a sponge242in which a receptacle244for the wiping lip214is arranged. On both sides of the sponge242, there are provided adjustable walls246a,246bwhich each have a ramp-like contour and which are formed by ribs248a,248b,249a, and249b. The walls246a,246bare adjustable in or counter to the horizontal direction41by applying pressure on the ribs248a,248b,249a, and249bwith the sponge242being compressed by the walls246a,246b.

In order to clean the wiping lip214with the aid of the cleaning device240, the cleansing device210moves downwardly in the vertical direction42. The mounting plate213is moved downwardly together with the cleansing device210.

The cleaning device240is arranged on that side of the collecting container231which faces the mounting plate213and is raised compared to the collecting container231. In the horizontal direction41, the mounting plate213additionally has openings225,226on both sides of the wiping lip214. Furthermore, the wiping lip214is arranged in a lip-cleaning position L from which it can be retracted for cleaning above the receptacle244of the sponge242.

Therefore, when moving in the vertical direction42, the wiping lip dips into the receptacle244, wherein the sponge242and the walls246a,246bwhich surround it dip into the openings225,226of the mounting plate213. Since the ribs248a,248b,249a, and249bare configured in a ramp shape, the walls246a,246bare pressed closer and closer together. As a result, the sponge242is compressed further and further. This process is shown inFIGS.13a-13d.

InFIG.13d, the cleansing device210is moved to such an extent that the wiping lip214dips fully into the receptacle244of the sponge242and is cleaned as a result. Through the temporally/spatially coordinated dipping, the sponge is not damaged by the frame and only comes into contact with the lip for cleaning.

FIGS.5aand5beach show an exchanging position T in which the collecting container can be removed from the printer1. For this purpose, the printing unit100is moved horizontally until it is arranged offset from the cleansing device210counter to the horizontal direction41. The cleansing device210is then moved counter to the vertical direction until the wiping lip214is fully extended out of the cleaning device240. The free ends223,224of the second pipes218,220are then arranged in the vertical direction42above the collecting container231of the collecting device230. In this exchanging position T, the collecting device230can be manually taken out of the printer1together with the cleaning device240which is affixed to it. A handle234is provided on the collecting container231for this purpose as shown inFIG.5b.

Exchange of the collecting device230can be performed after approximately 2000 to 3000 marker cards2have been printed. The specific exchanging interval of the collecting device230depends on the volume of ink extracted or wiped off by the cleaning unit210.

Complete removal of the cleansing device210from the printer1is depicted inFIG.6aandFIG.6b. For this purpose, the cleansing device210is moved counter to the vertical direction42until the tooth sections212a-212dof the cleansing device210are out of engagement with the output pinions257a,257b,258a, and258bof the driving device250. The cleansing device210is then in the servicing position W.

Analogous to the exchanging position T, the printing unit100must also be moved horizontally for the servicing position W until it is arranged offset relative to the cleansing device210counter to the horizontal direction41.

Servicing or exchange of the cleansing device210may be required after a certain length of operation of the printer such as two to three years. The specific exchanging interval of the cleansing device210depends on wear and use.

FIG.7ashows the driving device250and the printing unit100in an exemplary position one above the other in the vertical direction and without the cleansing device210and the collecting device230. As a result, it can be seen that the driving device250includes two drive shafts252,253which are parallel to one another and which extend in a third spatial direction43transverse to the vertical and horizontal directions42,41. The output pinions257a,257b,258a, and258bare respectively arranged at opposite ends of the drive shafts252,253to drive the tooth sections212a-212dof the cleansing device210As also shown inFIG.8.

The drive shafts252,253are actuated by sprockets260a,260bwhich are non-rotatably affixed to the drive shafts in an overhung position and which are in engagement with one another. In the process, a first of the two sprockets260a,260badditionally meshes with a driving pinion255of a driving motor256. Therefore, the driving pinion255and the two sprockets260aand260bform a reversing gear, since the two sprockets260a,260brotate in opposite directions when the driving motor256is in operation. The driving motor256is configured as an electric motor.

The driving device250has a base plate251in which one end of each of the drive shafts252,253is rotatably borne. Opposite the base plate251, the driving device250furthermore has a bearing shield254in which the other end of the drive shafts252,253is rotatably borne. The bearing shield254and the base plate251are connected to one another by spacer strips259a,259b,259c. They are provided in a stationary manner.

In each case, one output pinion257a,257b,258a, and258b, with the tooth section212a-212dwhich meshes with it, forms a rack-and-pinion gear with all four rack-and-pinion gears running at a synchronous speed and therefore enabling a uniform movement of the cleansing device210in and counter to the vertical direction42.

The cleansing device210is depicted separately in a perspective view inFIG.7b.

FIG.9shows the cleaning unit200in a three-dimensional view. The cleansing device210, the collecting device230, the cleaning device240for the wiping lip214and the driving device250are visible.

The collecting device230is depicted in three dimensions inFIG.10, without adjacent components. Two through holes232,233can be clearly seen into which, when the collecting device230is in the installed state, one needle or free end223,224, respectively, at the ends of the second pipes218,220of the cleansing device210engage. For simple handling of the collecting device230, a handle234can be formed integrally on the collecting container231. The cleaning unit240for the wiping lip214is arranged in a rectangular-cuboid-shaped dome-like projection241which is formed integrally on the collecting container231.

The cleaning unit240of the wiping lip214has a sponge242which, by way of example here, has a rectangular-cuboid shape and which is manufactured from a porous or foam-like material. The sponge is inserted into the projection241. For this purpose, the projection241has a shape corresponding to the sponge242.

In order to be able to receive the wiping lip214, the receptacle244is provided in the center of the sponge242.

In the region of the sponge242, the projection242includes four walls245a,245b,246a,246bwhich form an insert243. At the level of the sponge242, the walls246a,246bwhich run parallel to the receptacle244are not connected to the walls245a,245bwhich run transverse to these. On the contrary, one gap247a,247b,247c,247d, respectively, runs between the walls246a,246b, which are parallel to the receptacle, and the transversely running walls245a,245b. This is depicted enlarged in a cutout A inFIG.10. The gaps247a,247band247c,247dcause the walls246a,246b, which run parallel to the receptacle244, to each be movable in and counter to the horizontal direction41at least in a limited manner.

The walls246a,246brunning parallel to the receptacle244each have, at their side which faces away from the receptacle244, ramp-shaped ribs248a,248band249a,249b.

The projection241, or insert243with its walls245a,245b,246a,246b, is dimensioned such that it can engage in the openings225,226of the mounting plate213when the cleansing device210is moved downwards in the vertical direction relative to the collecting device230. Via the ramp-like ribs248a,248band249a,249b, the vertical movement of the mounting plate213is deflected into a quasi-horizontal movement of the respective walls246a,246bwhich run parallel to the receptacle242. In this case, the sponge242is pushed onto the wiping lip214which dips continuously further into the receptacle244, and the wiping lip214is cleaned with the sponge242. In the process, ink which adheres to the wiping lip214is taken up by the sponge242and drains off into the collecting container231. The sponge does not come into contact with the frame through movement.

The cleaning unit200is depicted without the collecting device230inFIG.11. Furthermore, direction arrows which depict the direction of flow of the excess ink during a cleaning process of the first print head104are arranged on the pipes217,218. In the cleaning process, excess ink is extracted from the first print head104by the first suction cup215via the first pipes217and is conveyed via the second pipe218by the free pipe end223, which is mandrel-like, into the collecting container231of the collecting device230to which the second pipe218is affixed by a connecting piece. In this case, the first pump221is actuated in order to extract the ink.

In an analogous manner, the second print head105is connected to the second suction cup216, a first pipe219assigned to it, the second pump222and a second pipe220assigned to it. This second pipe220also has a second free pipe end224which is mandrel-like and which dips into the collecting container231of the collecting device230and to which the second pipe220is affixed by a connecting piece. The ink in the second print head105can therefore be extracted in an analogous manner through the driving of the second pump222. However, for greater clarity, the first pipe219and the second pipe220, which connect the second suction cup216to the second pump222, are not shown inFIG.11but are shown inFIG.9.