EP3733417B1 - Ink supply and test printing system - Google Patents

Description

The present invention relates to an ink feed and a test printing system with such an ink feed.

Testing newly developed inks for industrial printing systems is costly. For example, newly developed inks, insofar as they are tested on active production systems, can lead to damage to the print heads used for production if the newly developed ink is found to be incompatible with the printing system. On the one hand, therefore, tests on existing production plants are associated with a high risk of failure for the production plant. On the other hand, it is not economical for a supplier to purchase industrial printing systems solely for the purpose of developing new inks, particularly if the ink in question is to be compatible with industrial printing devices from different manufacturers.

Furthermore, industrial printing systems designed for mass production are not suitable for experimental purposes. So large amounts of ink are required to allow a test operation at all. In addition, it requires complex cleaning and maintenance processes to such an industrial Convert the printing system from a first ink to a different, second ink for test purposes. The preceding explanations can be transferred equally to the testing of new print heads of industrial printing devices, which likewise cannot be tested without further ado during ongoing operation.

Against this background, the invention is based on the technical problem of specifying a device and a system for cost-effective and efficient testing of new print heads and/or inks. The technical problem described above is solved by a fluid supply according to claim 1 and a test printing system according to claim 18. Further refinements of the invention result from the dependent claims and the following description.

document EP1955853 discloses a conventional fluid supply for a printing system.

According to a first aspect, the invention relates to a fluid supply for a test printing system, with a first fluid channel for supplying a first print head, with a second fluid channel for supplying a second print head, with a distribution device for connecting the first fluid channel to the second fluid channel and for separating the first fluid channel from the second fluid channel, wherein the distribution device is set up so that in a first operating state of the distribution device a fluid transfer takes place between the first fluid channel and the second fluid channel and wherein the distribution device is set up such that in a second operating state of the distribution device no liquid transfer takes place between the first fluid channel and the second fluid channel.

The fluid supply therefore enables the fluid channels to be coupled to one another or separated from one another as required. If the fluid channels are connected to one another via the distribution device, the fluid channels can be fed, for example, via a single shared liquid or ink reservoir. In this case, for example, the first fluid channel is coupled to an ink reservoir, so that cleaning liquid and/or ink is sucked in from the reservoir via the first fluid channel and distributed via the distribution device to the second fluid channel. In this way, the first fluid channel and the second fluid channel and a first and second print head can be fed via a common reservoir in a simple and efficient manner.

Alternatively, the fluid channels can be operated autonomously and independently of one another. In this case, the distribution device is in the second operating state, so that no liquid transfer takes place between the first fluid channel and the second fluid channel. In this operating state, there is therefore no fluid connection between the first fluid channel and the second fluid channel, in contrast to the first operating state. There is therefore no fluid exchange between the first fluid channel and the second fluid channel. In this case, the first fluid channel and the second fluid channel can each be fed independently of one another via a separate liquid or ink reservoir. For example, a first ink reservoir with a be associated with the first color of the first fluid channel, so that the first printhead is supplied with the first color of the first ink reservoir. The second fluid channel can be coupled to a second ink reservoir in which a second color is stored, so that the second printhead is supplied with the second ink, which is different from the first ink and has a different color than the first ink.

The fluid supply therefore enables the assigned print heads to be supplied flexibly.

The possibility of interconnecting the fluid channels with the aid of the distribution device in the first operating state also has the advantage that the fluid channels can be cleaned together. If the fluid channels are connected to one another via the distribution device in the first operating state, a liquid container or a reservoir with cleaning liquid stored therein can be assigned to a fluid channel, with the cleaning liquid being routed via the first fluid channel to the first print head and via the distribution device also to the second fluid channel and is thus conveyed to the second print head.

If, for example, a change from a first ink to a second ink is to take place between two test runs, the first fluid channel, the first print head, the second fluid channel and the second print head and the associated hose lines can be cleaned efficiently by supplying a cleaning liquid a single liquid reservoir. This is particularly advantageous in the event that the fluid supply is not is set up only to supply a first and second print head, but also to supply a third, fourth, fifth or sixth print head, the fluid supply can in turn be set up in such a way that all print heads can be interconnected in order to have a common supply of one ink or one to allow cleaning fluid.

According to a further embodiment of the fluid supply, it is therefore provided that one of the fluid channels is connected to a supply line for removing liquid from a reservoir and in the event that the distribution device is in the first operating state, the other fluid channel is connected to the supply line via the distribution device is. Consequently, the supply line establishes a connection between a fluid channel and a liquid reservoir, with the supply line being in particular a suction line for sucking liquid from the reservoir. As already described above, liquid can therefore be distributed from a single reservoir to both fluid channels, or if more than two fluid channels are provided, to three, four or more fluid channels.

According to a further embodiment of the invention, it is provided that each of the fluid channels is connected to a separate supply line for removing liquid from a separate fluid channel-specific reservoir and, in the event that the distribution device is in the second operating state, a separate fluid supply for each fluid channel is provided. Accordingly, each of the fluid channels is self-sufficient and can be connected separately to an associated reservoir independently of the other fluid channels, so that each fluid channel together with the associated print head can be fed separately. In this way, individual fluid channels and/or print heads can be supplied with different colors or cleaned separately or independently of one another, provided a cleaning liquid is stored in the connected reservoir.

According to a further embodiment of the fluid supply, it is provided that the fluid channels are set up for the circulation of fluid via the respective associated print head, with each fluid channel having a supply line for supplying fluid to the respective print head and a return line for returning fluid from the respective print head. Unused, excess ink can therefore be fed back into a separate residual ink reservoir or into the original ink tank via the return line in order to keep ink consumption low.

According to a further embodiment of the fluid supply, it is provided that one of the fluid channels is connected to a return line for returning liquid to a reservoir, and if the distribution device is in the first operating state, the other fluid channel is connected to the return line via the distribution device connected is. Accordingly, for example, the first fluid channel can be connected both to the supply line for removing liquid from a reservoir and to the return line for returning liquid to the same reservoir, with the aid of the distribution device the liquid taken from the reservoir also circulates via the flow and return of the second fluid channel and thus via the second print head, so that both the first print head and the second print head are supplied with ink or liquid circulating via the assigned flows and returns will.

If a cleaning process takes place, the first and the second fluid channel can be fed via a common cleaning liquid reservoir, but the return line can be routed into a container separate from the cleaning liquid container, which serves as a waste reservoir for storing used cleaning liquid. Accordingly, the cleaning liquid flows from the cleaning liquid reservoir via the first fluid channel, the distribution device, the second fluid channel to the print heads and via the print heads back into the reservoir for receiving used cleaning liquid.

According to a further embodiment of the fluid supply, it is provided that each of the fluid channels is connected to a separate return line for returning liquid to a separate fluid channel-specific reservoir and, in the event that the distribution device is in the second operating state, a separate fluid return is provided for each fluid channel is.

Accordingly, each fluid channel can be independently supplied with circulating ink or cleaning liquid from a fluid channel-specific reservoir e.g. towards the first printhead and returned to the same reservoir from the first printhead. Likewise, a second ink or liquid reservoir can be associated with the second fluid channel and the associated second print head in order to return a fluid via the second fluid channel to the second print head and from the second print head via the return into the same second container.

It goes without saying that an autonomous supply of each individual fluid channel with a separate cleaning liquid reservoir can also be provided in order to clean the respective system of fluid channel and associated print head.

When fluids are mentioned here, they are in particular inks or cleaning liquids that are liquid at room temperature and under ambient pressure, ie in particular liquids.

Provision can be made for the fluid supply to have three, four or more fluid channels which can be connected to one another and separated from one another via the distribution device. The above statements can therefore be transferred equally to the coupling of three, four or more fluid channels with associated print heads, so that for example three, four or more fluid channels are fed via a common reservoir, including any circulation of liquid provided via a flow and return, or the fluid channels can be operated separately from one another.

Alternatively, it can be provided that, for example, only two fluid channels are interconnected in pairs, with the fluid supply for example having four channels for supplying four print heads. Accordingly, a first and a second printhead can be fed from a first reservoir and a third and a fourth printhead can be fed from another common reservoir. In this way, two or more print heads can be interconnected or separated from one another as required.

It can be provided that the interconnection or connection and disconnection of the fluid channels takes place via a controllable valve block, so that the fluid channels can be connected to one another or separated from one another with the aid of an electronic controller.

According to a further embodiment of the invention, it is provided that the distribution device of the fluid supply has a modular system with distribution sockets and distribution plugs, the distribution sockets and distribution plugs being set up to mechanically connect the fluid channels to one another in order to mechanically connect them using the distribution plugs or mechanically from one another to separate. The distribution plugs therefore have line sections in order, depending on the application, to connect fluid channels to one another or to separate fluid channels from one another. Adding and removing the distribution plugs thus corresponds to adding and removing line sections between the fluid lines in order to create or separate fluid connections between the fluid lines.

According to a further embodiment of the fluid supply, it is provided that each fluid channel is assigned a distribution bushing, with each distribution bushing having four separate bushings, namely a first feed bushing, a first return bushing, a second feed bushing and a second return bushing, the first feed bushing having one respective distribution socket is connected to the flow of the associated fluid channel and the first return socket of a respective distribution socket is connected to the return of the allocated fluid channel, the second flow sockets of the distribution sockets being connected to one another and the second return sockets of the distribution sockets being connected to one another.

The second flow bushings and the second return bushings accordingly form switchable connections between the fluid channels, which can also be referred to as a bypass between the fluid channels. If no distribution plug is attached to the distribution sockets, the first flow sockets are separated from the second flow sockets, so that the second flow sockets are separated from the flow, and the second return sockets are separated from the first return sockets, so that the second return sockets are separated from the respectively assigned return are separated.

A further embodiment of the fluid supply is characterized by first distribution plugs, which are plugged onto the distribution sockets to provide the first operating state, with a respective first distribution plug establishing a fluid connection between the first advance bushing and the second advance bushing respective distribution socket in order to connect the flows of the fluid channels with one another, with a respective first distribution plug producing a fluid connection between the first return socket and the second return socket of a respective distribution socket in order to connect the returns of the fluid channels with one another, with one of the first distribution plugs being connected to the supply line and wherein one of the first distribution plugs is connected to the return line.

In particular, one and the same distribution plug can be connected both to the supply line and to the return line. It can be provided that all other first distribution plugs have no connection to a supply or return line, i. H. no direct connection, but only connections to the adjacent fluid channels or the adjacent fluid channel. The relevant first distribution plugs, to which neither a supply line nor a return line is directly connected, are therefore only indirectly connected to the supply line and the return line, namely via the distribution system and that distribution plug that is connected to the supply line or return line.

A further embodiment of the fluid supply is characterized by second distribution plugs, which are plugged onto the distribution sockets to provide the second operating state, with a respective second distribution plug not establishing a fluid connection between the first supply socket and the second supply socket of a respective distribution socket and the supply lines of the fluid channels are separated from one another , wherein a respective second distribution plug establishes no fluid connection between the first return socket and the second return socket of a respective distribution socket and the returns of the fluid channels are separated from one another, wherein each of the second distribution plugs is connected to the respective separate supply line and wherein each of the second distribution plugs is connected to the respective separate return line is connected. The second distribution plugs therefore enable autonomous operation of each individual fluid channel and associated print head, so that separate and independent fluid circulation can take place for a respective print head, without fluid transfer taking place between the fluid channels.

A further embodiment of the fluid supply is characterized in that the supply line and the return line are accommodated within a lance, the lance being set up for insertion into a reservoir, one of the first distribution plugs being connected both to the supply line and to the return line, wherein the lance is connected to this first distribution plug and wherein the lance forms a separately manageable unit together with the supply line, the return line and the first distribution plug. To connect a reservoir, in which ink is stored, for example, the lance is inserted into the reservoir and screwed to the reservoir, for example, so that the reservoir is sealed in particular in a dust-tight and airtight manner.

The first distribution plug can be connected to a distribution socket in order to establish a fluid connection, for example of the first fluid channel and the first print head, to the reservoir.

In this way, an ink supply of a print head can be specified in a simple and efficient manner, the ink being circulated from the reservoir via the forward flow, the print head and the return flow, with the print head being supplied with ink. It goes without saying that an adjacent fluid line or the adjacent fluid lines is assigned a first distributor plug which is not directly connected to a supply or return line, but is only indirectly connected to the reservoir via the distributor device.

According to a further embodiment of the fluid supply, it is provided that the supply line and the return line of a respective fluid channel are each accommodated within a lance, with the respective lance being set up for insertion into the respective separate, fluid channel-specific reservoir, with the lance being connected to the respective second distribution plug and wherein each lance forms a separately manageable unit together with the supply line, the return line and the respective second distribution plug.

In this case, each fluid channel is therefore assigned a separate unit consisting of a lance supply line, return line and second distribution plug, so that each fluid channel can be self-sufficient with its associated print head Circulation of liquid is set up via the inlet, the printhead and the return.

According to a further embodiment of the fluid supply, it is provided that the supply line is accommodated within a lance, with the lance being set up for insertion into a first reservoir, with one of the first distribution plugs being connected both to the supply line and to the return line, the lance is connected to this first distribution plug, the return line being set up for insertion into a second reservoir, and the lance forming a separately manageable unit together with the supply line, the return line and the first distribution plug.

Dividing the supply line and the return line into two separate reservoirs can be useful, for example, when rinsing or cleaning the fluid supply and the associated print head, in which used cleaning fluid can be fed into a separate reservoir as a waste product.

According to a further embodiment of the fluid supply, it is provided that the lance has at least one fill level sensor for detecting a fill level in a reservoir, such as a float switch, an ultrasonic sensor or the like, with the distribution plug having an electrical sensor line and associated plug connector, which are connected to the fill level sensor. In this way, the level in a reservoir can be measured and be transferred to a controller. This can be useful for both an ink reservoir and a cleaning fluid reservoir to avoid air being sucked in.

Furthermore, a fill level sensor can be assigned to a reservoir for receiving used cleaning liquid in order to prevent the collection container from overflowing.

Alternatively or additionally, it can be provided that the distribution plug that is connected to the lance has a device for identifying the distribution plug and/or the lance. In this way, information can be given to a controller as to whether a first distribution plug, a second distribution plug, a lance with an integrated supply and return line or with a separate return line is plugged in, in order to enable appropriate control of the test printing or cleaning process.

The identification can take place, for example, via hard-wired bit lines, RFID codes, barcodes or non-volatile memories that are accommodated in the connector.

In addition, for example, data on the type, color and origin of an ink can be stored in a non-volatile memory of the distribution plug.

The features described above with reference to the distribution plug assigned to the lance can also be applied to the other first and second distribution plugs. So a respective first or second distribution plug can be a device for Have identification of the distribution plug and alternatively or additionally have a non-volatile data memory to provide the aforementioned information.

The first and second distribution plugs can be, for example, heavy industrial plugs that can be modularly equipped with electrical connections with fluid connections or electrical plug connections. The heavy industrial plugs can have a lock so that they cannot be accidentally removed when plugged in, with a mechanical lock, for example, holding the plug positively and non-positively on the intended socket. Provision can be made for the respective distribution plugs and sockets to have protective covers in order to protect the internal components from damage or contamination.

It can be provided that all components of the fluid supply that are in contact with the ink are designed to be inert to the ink and consist of, for example, polypropylene, nylon or stainless steel. Provision can be made for the sockets of the distribution sockets and/or the distribution plugs to have self-closing valves which prevent ink from escaping when they are not plugged in.

A further embodiment of the fluid supply is characterized by evaluation electronics and a controller with control software.

In particular, the distribution sockets are connected to the evaluation electronics. The electronic evaluation unit collects information on the assignment or non-assignment of the distribution sockets, on the type of distribution plugs, i.e. whether a first or second plug is connected with or without a supply and/or return line, on the fill level of a reservoir or several reservoirs and on the inks or cleaning liquids stored in the reservoir or reservoirs. For example, the evaluation electronics can be set up to read out the non-volatile data memory of the distribution plugs.

The evaluation unit can be connected to the controller via an interface, such as USB, Ethernet, fieldbus or the like.

The controller can be a PLC or IPC controller or the like.

The control software of the controller receives the data from the evaluation electronics. The control software is set up to output various maintenance or error messages or to display actual states via a graphical user interface, such as the presence of distribution plugs on distribution sockets or the absence of distribution plugs on distribution sockets, as well as recognizing certain types of plugs and lances for a test print.

The control software is used to control a test printing process based on the connected reservoirs and connectors.

For example, the controller can specify that if a first plug is used without a connected supply or return line, at least one plug with a connected supply and return line must be provided or with a connected lance.

It can also be specified that if a flushing process takes place, only one lance with an associated first distribution plug should be connected to the system.

Provision can be made for the controller to monitor the filling level of individual fluid channels, so that a printing process for a print head is only enabled if sufficient ink is available in an associated reservoir for the fluid channel in question. This applies equally to filling the fluid channels before printing, in which case the condition of a sufficient fill level must also be met.

For example, it can be provided that a fluid channel can only be emptied in the event that the supply line is not immersed in an ink level in a canister.

Alternatively or additionally, it can be provided that the fluid supply can only be flushed if a flushing liquid is stored in a reservoir. Furthermore, it can be specified that the fluid supply can only be flushed if a reservoir for collecting used game fluid is not full, in order to avoid overflowing.

According to a second aspect, the invention relates to a test printing system with a fluid supply according to the invention, with a first print head and with a second print head, the first print head being coupled to the first fluid channel and the second print head to the second fluid channel. The test printing system can have a modular structure and can be equipped with different print head modules from different industrial printing devices.

A test printing system can thus be specified, with a base station and with a first print head module, namely a print head module with a support structure which is set up for mechanically fastening the print head module (6) to the base station of the test printing system, with a print head of an industrial printing device which is connected to is attached to the support structure, with the print head being usable independently and separately from the support structure in the industrial printing device, with a network interface for connecting a power supply for the print head, with a control interface for connecting a controller for controlling the print head and with a fluid interface for connecting the print head to an ink reservoir, the first print head module being mechanically attached to the base station, the network interface of the print head module being connected to a power supply unit of the base station, the control interface of the print head module being connected to a controller the base station is connected and wherein the fluid interface of the print head module with a Ink reservoir of the base station is connected and wherein the fluid supply as part of the base station provides the ink supply to the print head.

The printhead module is individualized in particular printhead-specifically, while the base station has a universal design and can be used with different printhead modules that have different printheads.

A further embodiment of the test printing system is characterized by a second print head module according to the invention, the print head of the first print head module being set up for use in a first industrial printing device and the print head of the second print head module being set up for use in a second industrial printing device. Each of the print head modules can be supplied with the fluid supply of the base station, so that the base station can be used universally and the print head modules are individualized specific to the print head.

In particular, the first print head is structurally different from the second print head and the first printing device is structurally different from the second print head device.

Fig. 1

eine Fluidzuführung für ein Testdrucksystem mit zweiten Verteilsteckern;

Fig. 2

die Fluidzuführung aus Fig. 1 mit einem ersten Verteilstecker mit Lanze;

Fig. 3

die Fluidzuführung aus Fig. 1 mit einem ersten Verteilstecker mit Lanze und einem ersten Verteilstecker ohne Lanze.

A printhead module can have two or more printheads, which can be supplied with ink or cleaning liquid via the fluid supply. The invention is described in more detail below with reference to a drawing showing exemplary embodiments. They each show schematically:

1

a fluid supply for a test printing system with second distribution plugs;

2

the fluid supply off 1 with a first distribution plug with a lance;

3

the fluid supply off 1 with a first distribution plug with a lance and a first distribution plug without a lance.

figure 1 shows a schematic representation of a fluid supply 2 for a test printing system. The fluid supply 2 has a first fluid channel 4 for supplying a first print head 6. The fluid supply 2 has a second fluid channel 8 for supplying a second print head 10.

The fluid supply 2 has a distribution device 12 for connecting the first fluid channel 4 to the second fluid channel 8 and for separating the first fluid channel 4 from the second fluid channel 8.

The distribution device 12 is set up so that in a first operating state of the distribution device 12 a fluid transfer takes place between the first fluid channel 4 and the second fluid channel 8 .

The distribution device 12 is further set up so that in a second operating state Distribution device 12 no fluid transfer between the first fluid channel 4 and the second fluid channel 8 takes place.

In figure 1 describes the second operating state of the distribution device 12, with the fluid channels 4, 8 each being operated autonomously and independently of one another, with the first fluid channel 4 being coupled to a first ink reservoir 14 and the second fluid channel 8 being coupled to a second ink reservoir 16. Each of the fluid channels 4, 8 is therefore connected to a separate supply line 18, 20 for removing liquid from the associated reservoir 14, 16, so that each fluid channel 4, 8 has a fluid channel-specific reservoir 14, 16.

The fluid channels 4, 8 are set up for the circulation of fluid via the associated print head 6,10, each fluid channel 4, 8 having a feed 20, 22 for supplying fluid to the respective print head 6, 10 and a return 24, 26 for returning of fluid from the respective print head 6,10.

how figure 1 As can be seen, in the present case each of the fluid channels 4, 8 is connected to a separate return line 28, 30, which leads into the respective assigned, fluid channel-specific reservoir 14, 16, so that the fluid, starting from the respective reservoir 14, 16 via the assigned flow 20, 22, associated printhead 6,10 and associated return 24,26 back to associated reservoir 14,16.

The fluid supply 2 can have three, four or more print heads, as indicated by way of example by the print head 32 additionally shown. The printhead 32 is assigned a further fluid channel 34, which in the manner described above also has a flow and a return and can be connected to the fluid channels 4.8 or can be operated separately from them.

The distribution device 12 is presently designed as a modular system with distribution sockets 36, 38 and distribution plugs 40, 42, with the distribution sockets 36, 38 and the distribution plugs 40, 42 being set up to mechanically connect the fluid channels 4, 8 to one another and these with the aid of the distribution plugs 40, 42 to be mechanically connected or to be mechanically separated from one another.

In the present example, the distribution bushing 36 is assigned to the fluid channel 4 and the distribution bushing 38 is assigned to the fluid channel 8 .

Each of the distribution bushings 36, 38 has four separate bushings - namely a first forward bushing 44, a first return bushing 46, a second forward bushing 48 and a second return bushing 50.

The first advance bushing 44 of a respective distribution bushing 36, 38 is connected to the respective advance 20, 22 of the associated fluid channel 4, 8. The first return socket 46 of the respective distribution socket 36, 38 is connected to the respective return 24, 26 of the associated fluid channel 4.8. Next, the second flow bushings 48 and the second return bushings 50 of the fluid channels 4, 8 are connected to one another.

In the present example figure 1 it is in the distribution plugs 40, 42 to second distribution plug 40, 42 for providing the second Operating state on the distribution sockets 36, 38 are plugged.

The respective second distributor plugs 40, 42 do not establish a fluid connection between the respective first advance bushing 44 and the respective second advance bushing 48 of the respective distribution bushing 36, 38, so that the advances 20, 22 of the fluid channels 4, 8 are separated from one another and in the present case there is no fluid connection between the heats 20, 22 consists. The respective second distribution plugs 40, 42 do not establish a fluid connection between the respective first return bushing 46 and the respective second return bushing 50 of the respective distribution bushing 36, 38, so that the returns 24, 26 of the fluid channels 4, 8 are separated from one another and in the present case there is no fluid connection between the returns 24, 26 consists. Each of the second distribution plugs 40, 42 is therefore connected to the respectively associated separate supply line 18, 20 and the respectively associated separate return line 28, 30 in order to close the fluid circuit to the fluid channel-specific reservoir 14, 16.

The supply line 18 and the return line 28 are presently housed within a lance, the lance being inserted into the reservoir 14 . The lance (not shown) is connected to the distribution plug 40 and, together with the supply line 18 , the distribution plug 40 and the return line 28 , forms a manageable unit that can be detached from the reservoir 14 and the distribution socket 36 .

Likewise, the supply line 20 and the return line 30 of the fluid channel 8 are within one

lance (not shown), the lance being inserted into the fluid channel-specific reservoir 16 and the lance being connected to the distribution plug 42 and together with the supply line 20, the return line 30 and the distribution plug 42 forming a separately manageable unit which is Distribution sleeve 40 can be removed and removed from the reservoir 16.

figure 2 shows the fluid supply 2 figure 1 , A first distribution plug 52 now being attached to the distribution socket 36 . The first distributor plug 52 bridges the first advance bushing 44 and the second advance bushing 48 so that a fluid connection between the first advance bushing 44 and the second advance bushing 48 of the distributor bushing 36 is established.

Furthermore, the first distribution plug 52 bridges the first return bushing 46 of the distribution bushing 36 and the second return bushing 50 of the distribution bushings 36, so that a fluid connection is formed between the first return bushing 46 and the second return bushing 50 of the first of the distribution bushings 36.

Since there is no distribution plug on the distribution socket 38 in the present case, there is no fluid connection between the first flow 20 of the fluid channel 4 and the first flow 22 of the fluid channel 8 despite the first distribution plug 52 being plugged onto the distribution socket 36. There is also no fluid connection between the first return 24 of the fluid channel 4 and the return 26 of the fluid channel 8, since as mentioned, no distribution plug is attached to the distribution socket 38 .

In the present case, the supply line 18 is routed into the fluid canister 14 , in which rinsing liquid is received in the present case in order to clean the print head 6 . The rinsing liquid is fed via a return line 44 into a container 56 in order to receive the used rinsing liquid.

figure 3 is analogous to figure 2 constructed, wherein a first distributor plug 58 is additionally plugged onto the distributor bushing 38 in order to bridge the first flow bushing 44 and the second flow bushing 48 and to establish a fluid connection between them and also to bridge the first return bushing 46 and the second return bushing 50 of the second distribution bushing 38 and establish a fluid connection.

A fluid connection between the first flow 20 and the first flow 22 is established by the first distribution plug 58 now being attached to the socket 38 . The fluid channels 4, 8 are therefore connected to one another on the inflow side. Furthermore, a fluid connection between the return 24 of the first fluid channel 4 and the return 26 of the second fluid channel 8 is now established by the first distributor plugs 52 , 58 plugged onto the sockets 36 , 38 . The print heads 6, 10 can accordingly be fed via a common reservoir 14.

So far in the area of the additional channel 34 of the additional print head 32 shown as an example if a first distribution plug were to be applied, the print head 32 could also be fed together with the print heads 6 and 10 via a common reservoir 14 .

Claims (18)

1. Fluid supply for a test printing system,

   - comprising a first fluid channel (4) for supplying a first print head (6),

   - comprising a second fluid channel (8) for supplying a second print head (10),

   - comprising a distribution device (12) for connecting the first fluid channel (4) to the second fluid channel (8) and for separating the first fluid channel (4) from the second fluid channel (8),

   - wherein the distribution device (12) is designed such that in a first operating state of the distribution device, a fluid transfer takes place between the first fluid channel (4) and the second fluid channel (8), and

   - wherein the distribution device (12) is designed such that in a second operating state of the distribution device, no fluid transfer takes place between the first fluid channel (4) and the second fluid channel (8).
2. Fluid supply according to claim 1,
   characterized in that

   - one of the fluid channels (4) is connected to a supply line (18) for removing liquid from a reservoir (14) and

   - if the distribution device is in the first operating state, the other fluid channel (8) is connected to the supply line (18) via the distribution device (12).
3. Fluid supply according to claim 1,
   characterized in that

   - each of the fluid channels (4, 8) is connected to a separate supply line (18, 20) for removing liquid from a separate, fluid-channel-specific reservoir (14, 16) and

   - if the distribution device (12) is in the second operating state, a separate fluid supply is provided for each fluid channel (4, 8).
4. Fluid supply according to any of claims 1 to 3,
   characterized in that

   - the fluid channels (4, 8) are designed for circulating fluid via the respectively assigned print head (6, 10),

   - each fluid channel (4, 8) having a feed (20, 22) for supplying fluid to the relevant print head (6, 10) and a return (24, 26) for returning fluid from the relevant print head (6, 10).
5. Fluid supply according to claim 2 and claim 4,
   characterized in that

   - one of the fluid channels (4) is connected to a return line (54) for returning liquid to a reservoir (56) and

   - if the distribution device is in the first operating state, the other fluid channel (8) is connected to the return line (54) via the distribution device (12).
6. Fluid supply according to claim 3 and claim 4,
   characterized in that

   - each of the fluid channels (4, 8) is connected to a separate return line (28, 30) for returning liquid to a separate, fluid-channel-specific reservoir (14, 16), and

   - if the distribution device is in the second operating state, a separate fluid return is provided for each fluid channel (4, 8).
7. Fluid supply according to any of the preceding claims,
   characterized in that

   - three, four or more fluid channels (4, 8, 34) can be connected to one another and separated from one another via the distribution device.
8. Fluid supply according to any of the preceding claims,
   characterized in that

   - the distribution device has a modular system with distribution sockets (36, 38) and distribution plugs (40, 42, 52, 58),

   - the distribution sockets (36, 38) and distribution plugs (40, 42, 52, 58) being designed to mechanically interconnect the fluid channels (4, 8) in order to mechanically connect or mechanically separate them using the distribution plugs (40, 42, 52, 58).
9. Fluid supply according to claim 4 and claim 8,
   characterized in that

   - each fluid channel (4, 8) is assigned a distribution socket (36, 38),

   - each distribution socket (36, 38) having four separate sockets (44, 46, 48, 40), namely a first feed socket (44), a first return socket (46), a second feed socket (48) and a second return socket (50),

   - the first feed socket (44) of each distribution socket (36, 38) being connected to the feed (20, 22) of the associated fluid channel (4, 8) and the first return socket (46) of each distribution socket (4, 8) being connected to the return (24, 26) of the associated fluid channel,

   - the second flow sockets (48) of the distribution sockets (36, 38) being connected to one another and the second return sockets (50) of the distribution sockets (36, 38) being connected to one another.
10. Fluid supply according to claim 5 and claim 9,
    characterized by

    - first distribution plugs (52, 58), which are plugged onto the distribution sockets (36, 38) in order to provide the first operating state,

    - each first distribution plug (52, 58) establishing a fluid connection between the first feed socket (44) and the second feed socket (48) of a particular distribution socket (36, 38) in order to interconnect the feeds (20, 22) of the fluid channels (4, 8),

    - each first distribution plug (52, 58) establishing a fluid connection between the first return socket (46, 50) and the second return socket (46, 50) of a particular distribution socket (36, 38) in order to interconnect the returns (24, 26) of the fluid channels (4, 8),

    - one of the first distribution plugs (52) being connected to the supply line (18) and

    - one of the first distribution plugs (52) being connected to the return line (54).
11. Fluid supply according to claim 6 and claim 9,
    characterized by

    - second distribution plugs (40, 42), which are plugged onto the distribution sockets (36, 38) in order to provide the second operating state,

    - each second distribution plug (40, 42) not establishing a fluid connection between the first feed socket (44) and the second feed socket (48) of a particular distribution socket (36, 38) and the feeds (20, 22) of the fluid channels (4, 8) being separated,

    - each second distribution plug (40, 42) not establishing a fluid connection between the first return socket (46) and the second return socket (50) of a particular distribution socket (36, 38) and the returns (24, 26) of the fluid channels (4, 8) being separated,

    - each of the second distribution plugs (40, 42) being connected to the relevant separate supply line (18, 20) and

    - each of the second distribution plugs (40, 42) being connected to the relevant separate return line (28, 30).
12. Fluid supply according to claim 10,
    characterized in that

    - the supply line and the return line are accommodated within a lance,

    - the lance being designed to be inserted into a reservoir,

    - one of the first distribution plugs being connected to both the supply line and the return line,

    - the lance being connected to said first distribution plug and

    - the lance forming a separately manageable unit together with the supply line, the return line and the first distribution plug.
13. Fluid supply according to claim 11,
    characterized in that

    - the supply line (12, 20) and the return line (28, 30) of each fluid channel (4, 8) are each accommodated within a lance,

    - each lance being designed to be inserted into the relevant separate, fluid-channel-specific reservoir (14, 16),

    - the lance being connected to the relevant second distribution plug (40, 42) and

    - each lance forming a separately manageable unit together with the supply line (12, 20), the return line (12, 20) and the relevant second distribution plug (40, 42).
14. Fluid supply according to claim 10,
    characterized in that

    - the supply line is accommodated within a lance,

    - the lance being designed to be inserted into a first reservoir,

    - one of the first distribution plugs being connected to both the supply line and the return line,

    - the lance being connected to said first distribution plug,

    - the return line being designed to be inserted into a second reservoir and

    - the lance forming a separately manageable unit together with the supply line, the return line and the first distribution plug.
15. Fluid supply according to any of claims 12 to 14,
    characterized in that

    - the lance has at least one fill level sensor for detecting a fill level in a reservoir, such as a floating switch, an ultrasonic sensor or the like,

    - the distribution plug having electrical sensor lines and associated plug connectors which are connected to the fill level sensor,
    and/or

    - the distribution plug has a device for identifying the distribution plug and/or the lance
    and/or

    - the distribution plug has a non-volatile data memory.
16. Fluid supply according to any of the preceding claims 9 to 15,
    characterized in that

    - the sockets have self-closing valves.
17. Fluid supply according to any of the preceding claims,
    characterized by

    - an evaluation electronic system and a controller with control software.
18. Test printing system,

    - comprising a fluid supply according to any of the preceding claims,

    - comprising a first print head and with a second print head,

    - the first print head being coupled to the first fluid channel and the second print head being coupled to the second fluid channel.

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