EP3231615B1 - Inkjet printer for printing on goods with a filter and filter of such an inkjet printer - Google Patents

Description

The invention relates to an inkjet printer for the labeling of goods according to the preamble of claim 1. It further relates to a filter of such an inkjet printer. Such an inkjet printer and a filter are off WO 2013/120702 A1 known.
The invention relates both to such ink jet printers in the form of handsets, see, for example, the aforementioned WO2013 / 120702 A1 , as well as in the form of stationary devices, see eg EP 1 064 153 B1 , In handheld devices, the pump is preferably a compressed air pump, in stationary devices usually a liquid pump. Handsets are self-sufficient, they are such as cordless screwdriver with an internal voltage source, in particular accumulator, equipped. In stationary devices, the power supply is usually from the outside, for example via the normal power grid.
Out US 9 278 542 B1 An ink jet printer is known for the labeling of sheet material, in particular paper. He has a housing within which ink droplets are directed from a printing unit on the sheet material. He also has a pump for the liquid of the ink droplets, an electronic control and a filter, which has a filter medium for the liquid. This filter has its own filter housing, in which a filter medium is housed, and is releasably secured to the housing.
The inkjet printer typically includes at least one reservoir for a liquid needed for the printing process and flowing through the filter, such as ink, pigment or solvent. Preferably, the reservoir is arranged in the housing or releasably connected to the housing, this is on the WO 2013/120702 A1 directed. The reservoir must be relatively frequently replaced in practical operation, since the liquid consumed constantly during printing and the stock is exhausted after a certain number of printing operations.
Also, the filter must be replaced relatively frequently, at least the filter medium of the filter must be renewed. In the case of the prior art ink jet printers, the housing must be opened in each case and the filter be replaced. This procedure is complicated and in particular not suitable for a customer. However, having the filter replaced by an authorized specialist in each case entails high costs and also costs. It would therefore be desirable to make the filter change easier. In particular, it should be able to be done without any special tool, preferably entirely without tools. The replacement should be possible without contamination.

It should be noted that a filter has about a capacity of a few hundred liters of liquid, then the filter medium is exhausted. Typically, the capacity is about 200 liters.

This is where the invention begins. It has made it its mission to make the replacement of the filter much easier, with not a special service technician called for the filter replacement or the inkjet printer must be transported to a service point.

This object is achieved by the inkjet printer having the features of patent claim 1.

The filter now has its own filter housing in which it is housed, and is located outside the housing. About the two hydraulic couplings and counter-couplings, the filter housing is mechanically and hydraulically releasably connected to the housing of the ink jet printer or with a housing of a reservoir. The two clutches can be solved without special tools, ie by hand, and also restored.

The hydraulic couplings each have a mechanical connector and a valve. The hydraulic counter-couplings each have a mechanical connection counterpart and a valve The valves are self-closing. They are therefore normally in closed valve position. This is maintained, for example by a closing spring. The valves are thereby brought into the open position, that is pushed over the respective plunger of the valve body in an open position, this is done against the action of the closing spring or a corresponding element. To both valves when mating To be able to open, the double path between closed position and open position of a valve must be covered during mating, so that both valves are opened safely. The two hydraulic couplings and the two counter-couplings are preferably identical in each case. The valves are preferably identical

The mechanical coupling of the hydraulic coupling and the mechanical counterpart of the counter-coupling hydraulic coupling are adapted to each other and can be connected without special tools, only by hand and from each other. The mechanical connecting piece may be, for example, a plug-in part, a bayonet plug or a socket with an external thread. Then, the connector is a male part adapted to the socket part, a bayonet socket, or a nozzle adapted to the external thread threaded ring with internal thread. Other embodiments are possible, e.g. with locking projections. Likewise, a kinematic reversal is possible. The mechanical connectors and connecting counterparts have the task to releasably hold the filter housing to the housing of the ink jet printer and preferably to secure. If they are connected, the plungers of the valves come into contact with each other, thereby the valves are held in the open position, as soon as the mechanical connection is made. Furthermore, a liquid-tight contact is obtained and a mechanical connection of the two housings is achieved.

It is advantageous that a hydraulic clutch and / or the hydraulic counter-coupling has a sealing means, which comes in contact with the respective other coupling part in the manufacture of the mechanical connection and causes a liquid-tight connection. Other ways to achieve a liquid-tight connection are possible, e.g. a snug fit, conical seat or the like. When making the mechanical connection at the same time a tight contact between the two valves involved is made, which are then tightly interconnected.

The simpler the mechanical connecting means, so the connectors and connecting counterparts are actuated, the easier it is a user can solve and assemble them. A simple embodiment is for example a Screw connection, bayonet connection or simple plug connection, which has already been pointed out.

Self-closing valves are eg from the DE 196 50 379 A1 known. Self-closing valves are normally in the closed state.

The valves are preferably designed such that a space between the valve body in the closed state and a parting plane of the coupling region has the smallest possible volume. This so-called residual volume is filled with liquid prior to separating the main body and printhead. The liquid of the residual volume is lost. It can lead to pollution. Preferably, therefore, the valve bodies are in the closed state of the valve in the immediate vicinity of the parting plane of the coupling portion, preferably at a distance of less than 3, preferably less than 2 mm. Also, the inner diameter of the valve housing between the valve body and parting plane is preferably formed with the smallest possible cross-sectional area, he has for example a diameter less than 5, in particular less than 4 mm. Preferably, the cross-sectional dimension of the plunger is as large as possible. The larger the ram, the smaller the residual volume. These measures help to make the volume as low as possible.

Fig. 1:

eine prinzipielle Darstellung eines Tintenstrahldruckers mit einem Gehäuse und einem Filtergehäuse,

Fig. 2:

eine Seitenansicht, teilweise in schnittbildlicher Darstellung, einer hydraulischen Kupplung und einer damit verbundenen hydraulischen Gegenkupplung im gekuppelten Zustand,

Fig. 3:

die Kupplung und Gegenkupplung gemäß Fig. 2 im teilweise entkuppelten Zustand,

Fig. 4:

eine perspektivische Darstellung eines Filters, teilweise geöffnet

Fig. 5:

eine Stirnansicht des Filters gemäß Fig. 4,

Fig. 6:

eine Draufsicht auf den Filter gemäß Fig. 4, und

Fig. 7:

eine Seitenansicht des Filters gemäß Fig. 4.

Further advantages and features of the invention will become apparent from the other claims and the following description of non-limiting embodiments of the invention, which will be explained in more detail below with reference to the drawings. In this drawing show:

Fig. 1:

a schematic representation of an ink jet printer with a housing and a filter housing,

Fig. 2:

a side view, partially in cross-sectional representation, a hydraulic clutch and an associated hydraulic counter-coupling in the coupled state,

3:

the clutch and counter coupling according to Fig. 2 in the partially decoupled state,

4:

a perspective view of a filter, partially open

Fig. 5:

an end view of the filter according to Fig. 4 .

Fig. 6:

a plan view of the filter according to Fig. 4 , and

Fig. 7:

a side view of the filter according to Fig. 4 ,

In FIG. 1 An ink jet printer is shown schematically in order to recognize and discuss his necessary for the following description components. More concrete embodiments of an inkjet printer can be found, inter alia, in the abovementioned prior publications.

The ink jet printer has a write head 20. In a known manner, the write head 20 has at least one exit opening 28 which is located on a front surface 30. Through the outlet opening 28 ink droplets pass, which supplies a printing unit 32. The printing unit 32 is connected via an ink line 34 to a pump 36 and then further to an external filter 38. This will be discussed in more detail below. Furthermore, a controller 40 is provided, it is connected via electrical leads to the printing unit 32 and the pump 36 and controls them.

The filter 38 is connected via a feed line 42 to a reservoir 44 for a liquid required for the pressure, in particular ink. As FIG. 1 shows, the reservoir 44 is shown separately. However, it is part of the write head 20 and forms with this a common housing 46th

If, as in FIG. 1 2, the write head 20 is divided into a main body 24 and a reservoir 44, provision is made such that the reservoir 44 can be detachably connected to the main body housing. This makes it possible to replace reservoir 44 in a simple manner. The filter 38 is then preferably connected to the main body housing, alternatively to the housing of the separate reservoir 44. In both cases it is connected to the housing 46.

In one embodiment, not shown, the reservoir 44 is not formed separately, but both are housed in a single, common housing 46.

The housing 46 has two hydraulic couplings 50 which are accessible and arranged on the outside of the housing 46. A hydraulic clutch 50 is connected to the ink conduit 34. The other is connected to the supply line 42. Each hydraulic coupling 50 has a mechanical connector 52 and a first self-closing valve 54. This first valve 54 has a first valve body 56 and a first plunger 58 connected thereto. Normally, it is in the closed position. The mechanical connecting piece 52 has at least one plug-in part and preferably also a sleeve with a bayonet or a thread in order to mechanically secure the plug-in connection.

The filter 38 is connected to the housing 46 along a parting plane 60 and can be detached therefrom. The filter 38 is formed separately from the housing 46. It has a filter housing 62, in which a filter medium according to the prior art, such as a paper disc, a filter cartridge 78 or the like, housed. Preferably, a filter cartridge is disposed in the filter housing 62. The filter 38 has an input and an output. Both are preferably identical. Inlet and outlet each have a hydraulic counter-coupling 64 which is accessible on the outside of the filter housing 62. Each counter-coupling 64 is in each case adapted to at least one cooperating coupling 50. Each counter-coupling 64 has a mechanical connection counterpart 66 which has at least one bushing part adapted to the plug-in part, and preferably also a bayonet or a thread

Preferably, both clutches 50 are identical, as are preferably both counter-couplings 64 identical. The clutches 50 and also the counter-couplings 64 are arranged coaxially. They have a distance, measured at right angles to their axes, which is the same for the two clutches 50 and the two counter-couplings 64.

In the coupled state, as in FIG. 2 shows, the two clutches 50 and the mating couplings 64 come in the parting plane 60 in contact, which is common to both clutch assemblies.

The hydraulic counter-couplings 64 are formed according to the hydraulic couplings 50. They have a second valve 68 with a second valve body 70 and a second plunger 72 connected thereto. Preferably, the two plungers 58, 72 are integrally connected to the associated valve body 56 and 70, respectively. The mechanical connector 52 and the mechanical connection counterpart 66 are matched to each other, for example, designed as plug-in connections, which are preferably secured by additional means, such as a union nut.

In the coupled state of the two coupling devices, the plungers 58, 72 are in contact with each other. In this state, both valves involved 54, 68 are open. The plungers 58, 72 project to the respective other valve 54 and 68, respectively. You are always within the associated mechanical connector 52 and the mechanical connection counterpart 66. Furthermore, they are always within a valve housing of the respective valve 54 and 68th

In the illustrated embodiment, the plunger 58, 72 are formed differently. The first plunger 58 has a tip, in particular a conical free end region. The second plunger 72 has a correspondingly formed trough, for example a V-shaped trough. This results in a combination of the two plungers 58, 72, as it FIG. 2 shows, certainly.

The valve body 56, 70 are in the closed state, such as FIG. 3 indicates, on the valve body and seal off. There to improve the seal, a ring seal 74 is interposed. In the coupled state, see Fig. 2 , the two ring seals 74 of the two valves 54, 68 are arranged at a relatively small distance from each other. The clear distance between the two ring seals 74 is in the coupled state below two, preferably less than one millimeter. The plungers 58, 72 are located within these ring seals 74. In the embodiment shown, the first plunger 58 jumps by at least 50%. more in the axial direction of the valve body than the second plunger 72. In another embodiment, not shown, the two plungers 58, 72 are identical.

In the coupled state of filter 38 and housing 46, see Fig. 2 , at least one valve body 56, 70 is in contact with an end stop in the valve body for the valve body 56, 70 (not shown). For the other, the end stop does not have to be fully reached, there must only be a sufficiently open position. The end stop limits the travel of the valve body 56, 70 in the valve housing. Between valve body and valve housing is a closing spring (not shown, see DE Registration 10 2016 106 396.7 of 7 April 2016 ) arranged.

In order to be able to release the two counter-couplings 64 from the two couplings 50, the mechanical connecting parts 52, 66 must first be released. For this purpose, it is sufficient to solve a mechanical connection part, for example, unscrew. Subsequently, the mating couplings 64 can be removed, FIG. 3 shows an intermediate state of separation. In this intermediate state, the valves 54, 68 are already closed. This shows that, within a relatively short path of a maximum of three, preferably a maximum of two and in particular less than 1.5 mm separation path, closing of the two valves 54, 68 of each coupling device and thus closing of all valves is already achieved. Even with a clearance of the ring seals 74 of less than 6, in particular less than 4 mm, both valves 54, 68 involved are closed. It is sufficient a way starting from Fig. 2 less than 3 mm to bring both valves 54, 68 in the closed state.

In the Figures 2 and 3 are each arranged on the right and left next to the cut middle part shown union nuts. It is possible to use only one union nut. So can be dispensed with the left union nut associated with the housing 46.

The invention also relates to a filter which is offered for example as a replacement part for inkjet printers on the market. This filter is more detailed in the FIGS. 4 to 7 described. As can be seen from these figures, it has a substantially round central part, of which two parallel arms stand out tangentially. At the ends of these arms, the counter-couplings 64 are arranged. The associated valves are connected via lines 76 to a filter cartridge 78. This is the filter medium. In particular FIGS. 6 and 7 show, the free ends of the two counter-couplings 64 are in the parting plane 60. The filter housing 62 is composed of two half-shells, which are substantially identical. They consist of a middle, cup-shaped part and two attached to this half-tubes, which form a tube with a second half-shell. The mechanical connection counterparts 66 consist of a male part and a union nut, which is shown here with a grooved grip area. The male part is formed by a portion of the valve housing. The male part provides the actual mechanical allocation, as a comparison of Figures 2 and 3 shows. In particular FIG. 4 shows, the second plunger 72 is completely within the valve body or the mechanical connection counterpart 66th He is protected by it.

When mating filter 38 and housing 46, the mechanical connectors 52 first come in contact with the mechanical mating counterparts 66. Upon further collapse, the plungers, 58, 72 come into contact, whereby the valves 54, 68 are opened. The state reached in this way is already sufficient for a function. It can still be replaced by the union nuts or other mechanical means such as e.g. a bayonet connection can be secured. This ensures the mechanical hold. The union nuts do not have to be present.

The Applicant reserves the right to introduce features from the description and the patent claims, including parts of sentences from the description and the claims, into a claim and in particular from the subject matter of a new patent claim.

The ink jet printer for labeling goods has a housing 46 which has ink droplet discharge openings 28 on a font surface 30, a printing unit 32, and two hydraulic couplings 50 accessible on the outside of the housing 46. Each hydraulic coupling 50 has a mechanical connector 52 and an automatically closing first valve 54.

Each self-closing first valve has a first valve body 56 and connected to the first valve body 56 first plunger 58. The filter 38 has and a filter housing 62, in which the filter medium is housed and on which two hydraulic counter-couplings 64 are arranged, which the outside of the filter housing 62 are accessible. In an assembled state of the two hydraulic clutches 50 and the hydraulic counter-clutches 64, the plungers are respectively in contact with each other and hold the valve bodies 56, 70 connected thereto in an opening state, respectively.

Terms such as substantially, preferably, and the like, and possibly inaccurate, are to be understood as meaning that a deviation of plus or minus 5%, preferably plus or minus 2%, and more preferably plus or minus one percent, of normal value is possible.

reference numeral

20

Stylus

24

main body

28

outlet opening

30

front surface

32

printing unit

34

ink line

36

pump

38

filter

40

control

42

feed

44

reservoir

46

casing

50

clutch

52

mechanical connector

54

first valve

56

first valve body

58

1st pestle

60

parting plane

62

filter housing

64

counter-coupling

66

mechanical connection counterpart

68

second valve

70

second valve body

72

2nd pestle

74

ring seal

76

management

78

filter cartridge

Claims (11)

1. An inkjet printer for the labeling of goods,

   - comprising a housing (46) which a) has at least one outlet opening (28) for ink droplets on a front face (30), in which b) a printing mechanism (32) associated with this outlet opening (28), c) a pump (36) for a liquid of the ink droplets and d) an electronic control system (40) are disposed, and e) with a filter (38) having a filter medium for the liquid,

   characterized in that the housing (46) further has two hydraulic couplings (50) accessible and disposed on the outside of the housing (46), that each hydraulic coupling (50) has a mechanical connection part (52) and an automatically closing first valve (54), that each automatically closing first valve (54) has a first valve body (56) and a first plunger (58) connected to the first valve body (56), that the filter (38) is separate from the housing (46) and has a filter housing (62) in which the filter medium is accommodated and on which two hydraulic mating couplings (64) are disposed that are accessible from the outside of the filter housing (62), are adapted to the hydraulic couplings (50) and are disposed at a distance from each other that corresponds to the distance of the two hydraulic couplings (50), that each hydraulic coupling (64) has a mechanical connection counterpart (66) that is adapted to the mechanical connection part (52) and detachably connectable thereto, and an automatically closing second valve (68), that each automatically closing second valve (68) has a second valve body (70) and a second plunger (72) connected to the second valve body (70), and that, in a joined state of the two hydraulic couplings (50) and the hydraulic mating couplings (64), the plungers (58, 72) are respectively in contact with each other and respectively keep the valve bodies (56, 70) connected to them of the automatically closing valves (54, 68) in an opened state.
2. The inkjet printer according to claim 1, characterized in that a) the two hydraulic couplings (50) are constructionally identical, that the two hydraulic mating couplings (64) are constructionally identical, and that the filter housing can be coupled to the main body (24) at two positions differing by 180°, or b) that the filter housing (62) can only be coupled to the main body (24) in a single orientation.
3. The inkjet printer according to any one of the preceding claims, characterized in that the mechanical connection part (52) has at least one plug-in part and preferably additionally a sleeve with a bayonet or a female thread, and that the mechanical connection counterpart (66) has a bushing part adapted to the plug-in part, and preferably additionally a sleeve with a bayonet or a male thread.
4. The inkjet printer according to any one of the preceding claims, characterized in that the coupling (50) and the mating coupling (64) each have a valve housing, that the valve body (56, 70) can be moved in the valve housing between a closed position and an opened position, and that, in the joined state of the main body (24) and the printing head, at least one valve body is in contact with an end stop of the valve body (66).
5. The inkjet printer according to any one of the preceding claims, characterized in that the two hydraulic couplings (50) each have an axis and the axes extend parallel to each other, and that the two hydraulic mating couplings (64) each have an axis and the axes extend parallel to each other, and that the distance of the axes of the couplings (50) corresponds to the distance of the axes of the mating couplings (64).
6. The inkjet printer according to any one of the preceding claims, characterized in that the hydraulic couplings (50) with their free ends, and also the hydraulic mating couplings (64) with their free ends, respectively lie in a plane that coincide with the separating plane (60) in the coupled state.
7. The inkjet printer according to any one of the preceding claims, characterized in that the filter housing (62) has a disk-shaped part and two tubular arms extending therefrom tangentially that extend parallel to each other, and that the mating couplings (64) are disposed on these arms.
8. The inkjet printer according to any one of the preceding claims, characterized in that it further has at least one storage container (44) for the liquid of the ink droplets, in particular ink, which is detachably connected to the housing (46) or disposed in the housing (46).
9. A filter of an inkjet printer for the labeling of goods, in particular according to any one of claims 1 to 9, characterized in that the filter (38) has a filter housing (62) in which a filter medium is accommodated and on which two hydraulic mating couplings (64) are disposed that are accessible from the outside of the filter housing (62) and that are coaxially disposed at a distance from each other, that each hydraulic mating coupling (64) has a mechanical connection part (66) and an automatically closing second valve (68), and that each automatically closing second valve has a second valve body (70) and a second plunger (72) connected to the second valve body (70).
10. The filter according to claim 9, characterized in that the filter housing (62) has a disk-shaped part and two tubular arms extending therefrom tangentially that extend parallel to each other, and that the mating couplings (64) are disposed on these arms.
11. The filter according to claim 9 or 10, characterized in that the filter housing (62) is composed of two half-shells that are substantially constructionally identical.

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