3D Printer Having a Coating Device and a Coating Device Cleaning Device

Abstract

The invention relates to a 3D printer (10) having a coater (30) and a coater-cleaning device (50). The coater (30) has a container (32), which defines an inner hollow space (34) for receiving particulate building material, and a discharge region (36) for discharging the particulate building material, said coater being movable into a cleaning position in which the coater is arranged above the coater-cleaning device (50). The coater-cleaning device (50) has a wiper element (52) for wiping the discharge region (36), said wiper element being formed from an absorbent material which is configured to receive a liquid cleaning agent inside the material.

Claims

1. A 3D printer (10) having a coating device (30) and a coating device cleaning device (50), wherein the coating device (30) comprises a container (32) which defines an inner cavity (34) for receiving particulate construction material, and an output region (36) for outputting the particulate construction material, and is movable into a cleaning position in which it is arranged above the coating device cleaning device (50), wherein the coating device cleaning device (50) comprises a wiping member (52) for wiping the output region (36), characterized in that the wiping member (52) is made from an absorbent material which is configured to absorb a liquid cleaning agent in itself.

2. The 3D printer (10) according to claim 1, wherein the wiping member (52) is made from an absorbent, porous sponge or an absorbent textile material.

3. The 3D printer (10) according to claim 1, wherein the wiping member (52) is movable from a cleaning device cleaning position in which the wiping member (52) is aligned for wiping the output region (36) into a wiping member cleaning position in which the wiping member (52) is aligned for a cleaning of the wiping member (52) itself, and back into the cleaning device cleaning position.

4. The 3D printer (10) according to claim 3, wherein the coating device cleaning device (50) comprises a cleaning station (70) which is configured to clean the wiping member (52) and infiltrate it with liquid cleaning agent; when the wiping member (52) is positioned in its wiping member cleaning position.

5. The 3D printer (10) according to claim 4, wherein the cleaning station (70) comprises a cleaning bath (72) of the liquid cleaning agent.

6. The 3D printer (10) according to claim 5, wherein the cleaning station (70) comprises a wiping member cleaning and cleaning agent transmission device (74) which is configured to transport cleaning agent from the cleaning bath (72) to the wiping member (52) and to clean the wiping member (52) when the wiping member (52) is located in its wiping member cleaning position, wherein the wiping member cleaning and cleaning agent transmission device (74) comprises a rotatable roller (76) having an absorbent material, which is configured to absorb liquid cleaning agent in itself.

7. The 3D printer (10) according to claim 6, wherein the cleaning station (70) comprises a cleaning agent amount adjusting device (78) which is configured to adjust the cleaning agent amount which is transported by the wiping member cleaning and cleaning agent transmission device (74) from the cleaning bath (72) to the wiping member (52).

8. The 3D printer (10) according to claim 3, wherein the wiping member (52) is further movable into a wiping member conditioning position which is located between the coating device cleaning position and the wiping member cleaning position, and in which a cleaning agent amount which is received in the wiping member (52) is adjustable.

9. The 3D printer (10) according to claim 8, wherein the coating device cleaning device (50) comprises a conditioning station (90) which is configured to adjust the cleaning agent amount which is received in the wiping member (52) when the wiping member (52) is in its wiping member conditioning position.

10. The 3D printer (10) according to claim 9, wherein the conditioning station (90) comprises a stripping and/or squeezing device (92) where the wiping member (52) can be stripped off and/or cleaning agent can be squeezed out of the wiping member (52); to discharge a part of the cleaning agent which is received in the wiping member (52) from the wiping member (52), wherein the stripping and/or squeezing device (92) is arranged above the cleaning bath (72) or is otherwise in fluid connection with the same so that the cleaning agent stripped off and/or squeezed out of the wiping member (52) can be returned to the cleaning bath (72), and/or comprises a roller (94) by which the wiping member (52) can be squeezed.

11. The 3D printer (10) according to claim 9, wherein the conditioning station (90) comprises a fluid stream supply device (96) which is configured to direct a fluid stream onto the wiping member (52) to discharge, by means of the fluid stream, a part of the cleaning agent received in the wiping member (52) from the wiping member (52), wherein the fluid stream supply device (96) is further configured to set a temperature of the fluid stream.

12. The 3D printer (10) according to claim 1, further comprising a sensor device (110) by which an amount of cleaning agent received in the wiping member (52) can be determined, wherein the sensor device (110) comprises one or more capacitive sensors (112) and/or one or more electrolytic sensors (112) and/or one or more resistive sensors (112), wherein the sensor device (110) is configured to determine the amount of cleaning agent received in the wiping member (52) when the wiping member (52) is located in one or more or each of the positions selected from the wiping member conditioning position, the coating device cleaning position and the wiping member cleaning position.

13. The 3D printer (10) according to claim 12, further comprising a control (C) which is connected to the sensor device (110) and configured to prompt, on the basis of a value received from the sensor device (110), which is representative of the amount of cleaning agent received in the wiping member (52), an adjustment of a residual amount of cleaning agent in the wiping member (52) by means of driving/controlling the conditioning station (90), wherein the control (C) sets a residual amount of cleaning agent in the wiping member (52) depending on a used construction material and/or binder system and/or cleaning agent and/or a type of the absorbent material and/or a cleaning interval of the coating device and/or a degree of contamination of the coating device.

14. The 3D printer (10) according to claim 1, wherein the coating device cleaning device (50) further comprises a driving device (54) for moving the wiping member (52), which is configured to move the wiping member (52) relative to the output region (36) for a cleaning thereof when the coating device (30) is positioned above the coating device cleaning device (50), and/or to move the wiping member (52) between the coating device cleaning position, the wiping member cleaning position and the wiping member conditioning position.

15. The 3D printer (10) according to claim 14, wherein the driving device (54) comprises a carrier structure (56) to which the wiping member (52) is releasably attached.

16. The 3D printer (10) according to claim 14, wherein the driving device (54) is configured to move the wiping member (52) into a lowered position in which a collision with the coating device (30) is avoided, wherein the wiping member (52) is located in the lowered position in the wiping member cleaning position and/or in the wiping member conditioning position, whereas it is arranged in an elevated position in the coating device cleaning position.

17. The 3D printer (10) according to claim 14, wherein the driving device (54) is configured to move the wiping member (52) for a cleaning of the output region (36) along the same when the coating device (30) is positioned above the coating device cleaning device (50), wherein the driving device (54) is configured to move the wiping member (52) along a circulating path which extends with a first path section along the output region (36) when the coating device (30) is in the coating device cleaning position, wherein the driving device (54) comprises an elongate carrier structure (56) to which the wiping member (52) is attached and which is movable in a longitudinal direction in a way to revolve around an external point to thereby move the wiping member (52) along its circulating path.

18. The 3D printer (10) according to claim 1, wherein the output region (36) comprises an elongate output slot (40) and/or at least one elongate stroking surface which is configured to stroke construction material output from the container (32) to thereby level and/or compress the output construction material, wherein the at least one elongate stroking surface can be wiped off by the wiping member (52) and/or, wherein, the wiping member (52) has an extension in a width direction extending crosswise to the longitudinal direction of the elongate stroking surface; which is greater than or equal to that of the elongate stroking surface.

19. The 3D printer (10) according to claim 1, wherein the coating device cleaning device (50) comprises a plurality of wiping members (52) which are movable together into a respectively lowered position to avoid a collision with the coating device (30).

20. The 3D printer (10) according to claim 1, further comprising a first sensor (170) which is configured to detect a position of the wiping member (52), and/or a second sensor (82) which is configured to detect a filling level of the cleaning bath (72).

21. The 3D printer (10) according to claim 1, further comprising a printing device having a print head for selectively solidifying a partial area of a construction material layer applied by means of the coating device and/or for selectively printing a treatment agent onto a construction material layer applied by means of the coating device.

22. A method for cleaning a coating device (30) of a 3D printer (10), the coating device (30) comprising a container (32) which defines an inner cavity (34) for receiving particulate construction material and has an output region (36) for outputting the particulate construction material, the method comprising: moving the coating device (30) into a cleaning position in which the coating device (30) is arranged above a coating device cleaning device (50) comprising a wiping member (52) which is made from an absorbent material configured to absorb a liquid cleaning agent in itself, and wiping the output region (36) by the wiping member (52) in a state in which the wiping member (52) is moistened with a liquid cleaning agent.

23. The method for cleaning a coating device (30) of a 3D printer (10) according to claim 22, further comprising: moving the wiping member (52) to a cleaning station (70) and cleaning the wiping member (52) and/or infiltrating the wiping member (52) with cleaning agent in the cleaning station (70), and/or moving the wiping member (52) to a conditioning station (90) and adjusting a cleaning agent amount received in the wiping member (52), in the conditioning station (90), and/or determining an amount of cleaning agent received in the wiping member (52) using a sensor (112), and/or moving the wiping member (52) into a lowered position to avoid a collision with the coating device (30), after wiping the output region (36) using the wiping member (52), and/or replacing the wiping member (52) with another wiping member (52) once the wiping member (52) is worn out or is adapted to use a construction material and/or binder system and/or cleaning agent.

24. The method for cleaning a coating device (30) of a 3D printer (10) according to claim 22, wherein the output region (36) has an elongate shape and wiping the output region (36) using the wiping member (52) is substantially carried out in a longitudinal direction of the output region (36), and/or moving the wiping member (52) takes place on a closed trajectory, and/or the method for cleaning the coating device (30) takes place in a software-controlled way.

Description

[0082] Exemplary but non-limiting embodiments of the present invention are shown in the Figures and are hereinafter described in detail.

[0083] FIG. 1 and FIG. 2 show lateral views of a coating device and a coating device cleaning device of a 3D printer according to an embodiment of the present invention, parts of the coating device cleaning device having been omitted in FIG. 1.

[0084] FIG. 3 shows a cross-sectional view of the coating device and the coating device cleaning device according to the embodiment shown in FIG. 1 and FIG. 2, the wiping member being arranged in its coating device cleaning position.

[0085] In the following detailed description, reference is made to the enclosed Figures which are incorporated therein and in which specific embodiments are shown by way of illustration, according to which the invention can be performed. In this respect, the terms up, down, front, rear, etc. are used with reference to the orientation in the described Figures. As components of embodiments may be positioned in a number of different orientations, the terminology indicating the different directions serves for illustration and shall not be restrictive in any way.

[0086] It shall be understood that other embodiments may be used and structural or logical changes may be made without deviating from the scope of protection of this invention. It goes without saying that the features of the various exemplary embodiments described herein may be combined unless specified otherwise. Thus, the following detailed description should not be understood in a restrictive sense and the scope of protection of the invention shall be defined by the attached claims.

[0087] In this description, terms such as connected, attached and coupled may be used to describe both a direct and indirect connection, a direct or indirect attachment and a direct or indirect coupling.

[0088] In the Figures, identical or similar members are provided with identical reference numbers where appropriate.

[0089] FIG. 1 and FIG. 2 show a simplified lateral view of a coating device 30 which, for cleaning its output region 36, is moved into a cleaning position in which it is arranged vertically above a coating device cleaning device 50; in this respect, parts of the coating device cleaning device 50 have been omitted in FIG. 1 for the sake of clarity (such as the electric motor of the driving device, various sensors, and the control, which are all shown in FIG. 2). The coating device 30 and the coating device cleaning device 50 form part of a 3D printer 10, and the cleaning position may, for example, be located near a construction field of the 3D printer 10, which construction field is not shown.

[0090] As shown herein, the coating device 30 comprises a container 32 which defines an inner cavity 34 for receiving particulate construction material. Cf. also FIG. 3. In addition, the coating device 30 shown herein has an output region 36 for outputting the particulate construction material onto a construction field. The output region 36 may, for example, be elongate.

[0091] The coating device 30 shown herein and the container 32 shown herein each may, for example, have an elongated shape, i.e. an extension in the longitudinal direction L which is greater than an extension in the transverse direction Q (also see FIG. 3). The same applies to the output region 36 which may also have an extension in the longitudinal direction L which is greater than its extension in the transverse direction Q. For example, the output region 36 in FIG. 1 and FIG. 2 may extend substantially over the entire length of the container 32.

[0092] The coating device cleaning device 50 shown herein comprises a wiping member 52. The coating device cleaning device 50 may, for example, comprise an optional driving device 54 for moving the wiping member 52 (for example using an electric motor). The wiping member may, for example, be fixed to a carrier structure 56 of the driving device 54, for example releasably. The carrier structure 56 may, for example, be configured in the form of an endless strap. The wiping member 52 is made from an absorbent material which is configured to absorb a liquid cleaning agent in itself. Here, a wiping member 52 is shown by way of example, which is configured as a square-shaped, absorbent, porous sponge (also see FIG. 3). The shape and the material of the wiping member are, however, not limited thereto. The wiping member may, for example, have the shape of a roller or of a prism. Moreover, the wiping member may, for example, be an absorbent non-woven material. The coating device cleaning device 50 may, for example, also comprise more wiping members 52 of this type, which are for example fixed to/arranged on the carrier structure 56 along a portion of the carrier structure at regular intervals. The wiping member 52 may, for example, be fixed to the carrier structure 56 by means of a quick fastener (not shown).

[0093] The output region 36 of the coating device 30 can be cleaned effectively and efficiently due to the fact that the wiping member 52 is made from an absorbent material which is suited to absorb a liquid cleaning agent in itself, especially when the previously absorbed cleaning agent absorbed is being used.

[0094] The driving device 54 may, for example, be configured to move the wiping member 52 for cleaning the output region 36 along a circulating path which extends with a first path section along the output region 36 when the coating device 30 is in the coating device cleaning position, so that wiping the output region 36 may substantially take place in the longitudinal direction of the output region 36. The first path section may, for example, be formed to be linear. A second path section which may, for example, also be formed to be linear, may, for example, extend below the first path section.

[0095] In addition, the driving device 54 may, for example, be configured to reciprocate the wiping member 52 between a coating device cleaning position, a wiping member cleaning position and a wiping member conditioning position (see below).

[0096] The driving device 54 may, for example, further comprise a first and a second disk or deflection pulley 58, 60, one of which being capable of being driven, for example by means of an electric motor, to move the carrier structure 56 and thereby the wiping member 52.

[0097] The wiping member 52 shown in FIG. 1 is located in a position A which corresponds to a wiping member cleaning position. In the wiping member cleaning position, the wiping member 52 may, for example, be cleaned and infiltrated with liquid cleaning agent. The wiping member cleaning position does not necessarily have to correspond to a single position A, but may correspond to a plurality of positions in which the cleaning member is cleaned and infiltrated with liquid cleaning agent.

[0098] The wiping member cleaning position may, for example, be characterized in that the wiping member is located on/in a cleaning station 70 by means of which the wiping member is cleaned and infiltrated with liquid cleaning agent. For this purpose, the cleaning station may, for example, comprise a cleaning bath 72 and a wiping member cleaning and cleaning agent transmission device 74 which may, for example, be configured as a rotatable roller 76. The curved surface area of the rotatable roller 76 may, for example, be made from the same absorbent material as the wiping member 52. The cleaning bath 72 may, for example, contain an organic solvent or an aqueous solution of a surfactant.

[0099] The rotatable roller 76 may, for example, be arranged in a way that part of the curved surface area of the rotatable roller 76 is located in the cleaning bath 72 or immerges therein, so that the shell of the roller 76 can absorb cleaning agent from the cleaning bath 72. The rotation axis of the roller 76 and the plane formed by the liquid surface of the cleaning bath 72 may, for example, be parallel. The part of the curved surface area of the roller 76 located opposite said one part of the curved surface area of the roller 76 may, for example, contact the wiping member 52 or may, for example, touch it, so that the shell can pass the previously absorbed cleaning agent to the wiping member 52 when the roller has rotated by 180?.

[0100] The roller 76 may, for example, be driven by means of a drive 84 (for example by means of an electric motor). The roller 76 may, for example, be capable of being driven by rotational movement in both rotation directions. For example, the roller 76 may be driven by rotational movement in a direction opposed to the direction of movement of the wiping member 52. I.e., when the wiping member 52 in FIG. 1 and in FIG. 2, respectively, is moved in a direction from position A to position B, the roller may preferably be rotated clockwise.

[0101] In order to clean the wiping member 52 and infiltrate it with cleaning agent, the side of the wiping member 52 which is used for cleaning the output region 36 may, for example, be moved across the roller 76; in this context, the roller 76 may, for example, be moved in a direction opposite to the direction of movement of the wiping member 52. Thereby, the surface of the wiping member 52 can be cleaned mechanically by friction, and fresh cleaning agent can be transferred from the cleaning bath 72 to/in the wiping member. In addition, the roller 76 can be cleaned by the cleaning agent of the cleaning bath 72. Depending on the contamination degree of the wiping member 52, the wiping member 52 may, for example, be reciprocated across the roller 76 several times. For this purpose, the driving device 54 may, for example, be configured to move the carrier structure 56 in both directions.

[0102] In addition, the 3D printer may, for example, comprise a sensor 82 which is configured to detect a filling level of the cleaning bath 72. The filling level of the cleaning bath helps, for example, to determine whether the curved surface area of the roller 76 immerges into the cleaning bath 72. Hence, a cleaning of the wiping member 52 and a transfer of cleaning agent to/in the wiping member 52 or rather an infiltration of the wiping member with cleaning agent by means of the roller 76 can be ensured.

[0103] In order to avoid an excessive infiltration of the wiping member 52 with cleaning agent, the cleaning station 70 may, for example, comprise a cleaning agent amount adjusting device 78. This device may, for example, be provided in the form of a roller 80, the rotation axis of which may, for example, be arranged parallel to the rotation axis of the roller 76, and which may, for example, contact or touch the rotatable roller 76, so that a part of the liquid may be squeezed out of the absorbent material of the rotatable roller 76 again. The roller 80 may, for example, be rotatable (for example in a direction opposite to the roller 76), and may, for example, be arranged such that the contact or touch point of the two rollers 76 and 80 is between the site where the curved surface area of the rotatable roller 76 immerges in the cleaning bath and the site where the curved surface area of the roller 76 touches the wiping member 52. The roller 80 may, for example, be configured in such a way the rotation axis of the roller 80 can be displaced back and forth or be adjusted in the direction of the rotation axis of the roller 76. Thereby, the contact pressure of the roller 80 with respect to the roller 76 can be set, whereby the amount of cleaning agent squeezed out of the roller 76 can be controlled.

[0104] The coating device cleaning device 50 may, for example, further comprise a conditioning station 90 which may be configured to adjust the residual cleaning agent amount absorbed in the wiping member 52. For this purpose, the wiping member 52 may, for example, be moved to its wiping member conditioning position after having been cleaned and infiltrated with cleaning agent in the wiping member cleaning position. The positions B and C show two selected positions of the wiping member conditioning position. I.e., the wiping member conditioning position may be formed by a plurality of positions which are explained below in more detail.

[0105] The (residual) amount of cleaning agent to be received in the wiping member 52 may, for example, vary as a function of a used construction material and/or binder system and/or cleaning agent and/or degree of contamination and/or degree of cleaning, etc., and may, for example, be set by a control.

[0106] In general, a cleaning of the coating device 30 or of the output region 36 thereof may be achieved by the cleaning agent absorbed in the wiping member 52. Consequently, the cleaning effect of a wiping member 52 in which a too little amount of cleaning agent is absorbed may be insufficient. However, a too large amount of cleaning agent may result in that a part of the cleaning agent adheres to the coating device or to its output region 36 when the coating device 30 or its output region 36 is wiped, which may result in that the construction material output by the coating device agglutinates. It may therefore be preferred to set a desired amount of cleaning agent received in the wiping member 52.

[0107] In return, the conditioning station 90 may, for example, comprise a stripping and/or squeezing device 92 where the wiping member 52 can be stripped and/or cleaning agent can be squeezed out of the wiping member 52, to discharge a part of the cleaning agent which is received in the wiping member from the wiping member. The stripping and/or squeezing device 92 may, for example, be a roller 94 which is, for example, rotatable. The roller 94 may, for example, be arranged in a way to touch the wiping member 52 when the wiping member is moved across it (position B in FIGS. 1 and 2), so that a part of the cleaning agent absorbed in the wiping member is squeezed out of it. The roller 94 may, for example, be arranged above the cleaning bath 72, so that cleaning agent stripped off/squeezed out of the roller can be returned into the cleaning bath 72.

[0108] The conditioning station 90 may, for example, further comprise a fluid stream supply device 96 which may be configured to direct a fluid stream onto the wiping member 52, to discharge a part of the cleaning agent absorbed in the wiping member 52 from the wiping member 52 by means of the fluid stream. For example, the wiping member 52 may first be stripped/squeezed out on the roller 94 and may then be further treated by means of the fluid stream supply device 96, until a desired amount of cleaning agent is received/present in the wiping member 52. For this purpose, the wiping member 52 may, for example, be moved to the illustrated position C and may there be treated by means of a fluid stream. The fluid stream supply device 96 may, for example, comprise a fluid stream thermoregulation device (not shown) to set the temperature of the fluid stream. The temperature of the fluid stream may, for example, be set to between 25 to 200? C.

[0109] In order to determine the amount of cleaning agent received in the wiping member 52, the 3D printer 10 may for example further comprise a sensor device 110 having one or more sensors 112, which may be configured to determine the amount of cleaning agent received in the wiping member 52. Capacitive sensors, electrolytic sensors or resistive sensors may, for example, be used as sensors 112. As shown in FIG. 2, the sensor 112 may, for example, be located in the wiping member conditioning station. The sensor 112 may, for example, be arranged in a way to scan the wiping member 52 when the wiping member is treated by the fluid stream supply device 96. It is thereby possible to supply the wiping member 52 with a fluid stream until the desired amount of cleaning agent received in the wiping member is achieved. Alternatively or in addition thereto, a sensor may, for example, be integrated in the wiping member 52. Alternatively or in addition thereto, a sensor may, for example, also be arranged following or behind the fluid stream supply device 96, i.e. in FIGS. 1 and 2 on the left-hand side of the fluid stream supply device 96. In addition, a sensor may, for example, be arranged on/in the coating device cleaning station 70 alternatively or in addition thereto.

[0110] The 3D printer may, for example, further comprise a control C which is, for example, connected to the sensor device 110 and the sensor 112, respectively, the driving device 54, the conditioning station 90, the fluid stream supply device 96, the drive 84 and/or the sensor 82. The control may, for example, be configured to prompt an adjustment of a residual amount of cleaning agent in the wiping member 52 based on a value received from the sensor 112, which is representative of the amount of cleaning agent received in the wiping member 52.

[0111] For this purpose, the control may, for example, carry out the movement of the wiping member between the positions A, B, and C by driving/controlling the driving device 54. For example, when the sensor detects in position C that the residual amount is too low, the wiping member 52 may be moved to the roller 76 again, in order to be infiltrated by it with cleaning agent once again. Alternatively, the control C may, for example, stop the fluid stream when the wiping member is located in position C and it is detected that the wiping member comprises the preferred residual amount of cleaning agent. It may, for example, be preferred that the wiping member is first infiltrated with a sufficient amount of cleaning agent and is then conditioned in a way that another infiltration is not necessary.

[0112] The coating device cleaning device 50 may, for example, further comprise a sensor 170 which is configured to detect a circulation position of the carrier structure 56 and thus a position of the wiping member 52. For this purpose, a sensor target 172 may be arranged on/attached to the carrier structure 56. Alternatively or in addition thereto, the wiping member 54 itself may, for example, comprise a sensor target 172 of this type.

[0113] The coating device cleaning device 50 shown herein may, for example, further comprise an optional housing 130 in which the cleaning station 70 and the conditioning station 90 are received and arranged, respectively; in this context, an optional fixing device 150 may, for example, be connected to the housing or may be arranged thereon, in order to fix the housing or the cleaning station 70 and the conditioning station 90 in a desired position.

[0114] As shown in FIG. 3, the output region 36 may, for example, comprise an elongate output slot 40 and/or at least one elongate stroking surface which may be configured to stroke construction material output from the container 32, to thereby level and/or compress the output construction material. The coating device 30 may, for example, be configured as a bidirectional coating device which is able to apply a layer in both directions onto a construction field (i.e., during a journey to the left and to the right and/or during a journey and a return journey across the construction field), for which purpose the coating device may be provided with two elongate stroking surfaces which here may be formed by two bar-shaped stroking members 38a and 38b or rather by their respective lower side. The two stroking members 38a, 38b may, for example, be arranged in a transverse direction of the coating device (in which direction the coating device can be moved horizontally across a construction field) on opposed sides of the output slot 40, and may delimit the same in a transverse direction. It should be understood that the coating device may, for example, also be configured as a unidirectional coating device having, for example, merely one stroking surface and/or one stroking member. It is also possible to realize the coating device, for example, without stroking surface/stroking member.

[0115] As further illustrated by FIG. 3, the wiping member 52 may underlap the output region 36 in the transverse direction thereof for example entirely, i.e. both the output slot 40 and the two stroking surfaces which may be formed by the lower side of the respective stroking member 38a, 38b facing the construction field.

[0116] FIGS. 1 and 2 illustrate, amongst others, a state or a position A which is a lowered position, where the wiping member is, in addition, oriented in a downward direction, to clean the wiping member at the cleaning station and infiltrate it with cleaning agent. FIG. 3 illustrates a state in which the wiping member is in an elevated position and oriented upward (cf. the state or the position D in FIGS. 1 and 2) to clean the output region.

[0117] In normal operation of the 3D printer 10, the wiping member may be moved into any lowered position and may be oriented in a downward direction, so that the coating device 30 may be moved into and across the cleaning position without collision. If the coating device 30 or its output region 36 is to be cleaned, it may be moved to a position above the cleaning device 50 and may be stopped. Then, the drive 54 may be turned on or one of the two disks/deflection pulleys 58, 60 may be rotated/moved (for example by the control C), so that the wiping member 52 in which an appropriate amount of cleaning agent is received or which is infiltrated with an appropriate amount of cleaning agent moves from its lowered position upward. A desired cleaning effect may be achieved by an appropriate movement pattern of the wiping member 52 or the carrier structure 56 relative to the coating device. For example, the carrier structure 56 may be moved permanently in one direction or the carrier structure 56 may be moved alternately to the left and to the right, when the wiping member is in the elevated position D oriented upward. After the output region 36 having been cleaned sufficiently, the wiping member may be moved downward again, to enable the wiping member 52 to be cleaned and supplied with new cleaning agent and to enable the coating device 30 to be moved across the cleaning position without collision. An intermediate cleaning and infiltration with new cleaning agent of the wiping member during a cleaning process of the coating device is also possible.

[0118] The previous description of specific exemplary embodiments of this invention has been presented for the purpose of illustration and description. It is not intended to be exhaustive or to limit the invention to the exact forms disclosed, and it is to be understood that various modifications and variations are possible in the light of the teaching disclosed above. The exemplary embodiments have been chosen and described to explain certain principles of the invention and their practical application, to hereby enable those skilled in the art to manufacture and use various exemplary embodiments of this invention as well as various alternatives and modifications thereof. It is intended that the scope of protection of the invention shall be defined by the attached claims and their equivalents.