LU101168B1

LU101168B1 - Loading lock arrangement

Info

Publication number: LU101168B1
Application number: LU101168A
Authority: LU
Inventors: Moshe Aknin; Max Oberlander
Original assignee: BigRep GmbH
Priority date: 2019-03-29
Filing date: 2019-03-29
Publication date: 2020-09-30
Also published as: WO2020201054A1

Abstract

This disclosure refers to an additive manufacturing apparatus with a lock chamber and an inner chamber as well as a locking method for an additive manufacturing apparatus.

Description

A2019/09005-LU-00 -1- LU101168 Loading Lock arrangement

[0001] The present invention relates to additive manufacturing. In particular, the pre- sent invention relates to a loading lock arrangement for an additive manufacturing ap- paratus.

[0002] In the field of additive manufacturing an additive manufacturing apparatus can be a 3D-printer that deposits material to form a workpiece. An additive manufacturing ap- paratus alternatively can be a post printing processing station being used to process 3D-printed workpieces such as cleaning, detaching support structures, post curing, an- nealing and any other type of heat treatment. Due to reactions of the depositing material with the oxygen in the ambient air it can be of advantage to put the additive manufactur- ing apparatus under a special and controlled atmosphere, (protective gas) e.g. an inert atmosphere. A 3D-printer with a load lock between a processing chamber and a build module is known from EP 3263316 Al.

[0003] If the additive manufacturing apparatus is opened, for example, to insert or ex- tract a workpiece or manipulate the workpiece, the controlled atmosphere may be af- fected or even destroyed with negative influence on other workpieces in the manufac- turing apparatus by the atmosphere of the outside environment. Also, the controlled at- mosphere has to be restored to the needed quality. Features of this quality may be at least one of pressure, gas composition, temperature, etc. Maintaining the controlled at- mosphere is costly.

[0004] It is thus the object of the present application to provide a manufacturing appa- ratus and locking methods according to the appended independent claims to overcome the above inconveniences. Selected embodiments are comprised in the dependent claims. Each of which, alone or in any combination with the other dependent claims, can represent an embodiment of the present application.

[0005] According to one aspect of the present application an additive manufacturing ap- paratus comprises a lock chamber and an inner chamber. The additive manufacturing

A2019/09005-LU-00 -2- LU101168 apparatus further comprises at least one inner door and at least one outer door. The in- ner door is located between the lock chamber and the inner chamber. The outer door is located between the lock chamber and an outside environment. This outside environ- ment may be the room and its atmosphere in which the additive manufacturing appa- ratus is located. The foregoing configuration may have the advantage that a controlled atmosphere within the additive manufacturing apparatus and, in particular, within the inner chamber can be maintained undisturbed from outside influences or the outside environment. The inner chamber may comprise a controlled atmosphere.

[0006] According to a further aspect of the present application an additive manufactur- ing apparatus is a 3D-printer. This may have the advantage that the 3D-printer can pro- duce workpieces in an undisturbed environment of the controlled atmosphere that may not negatively influence the deposited material.

[0007] According to another aspect of the present application the additive manufactur- ing apparatus is an additive manufacturing post processing apparatus (see examples above). This may have the advantage that the printed workpiece can be processed in a controlled environment and the deposited material of the workpiece may be enhanced in quality or at least not negatively affected by the ambient atmosphere while being pro- cessed.

[0008] According to another aspect of the present application the additive manufactur- ing apparatus may comprise at least one lock chamber that can be divided by at least one section door into at least two sections. The at least one section door may divide the at least one inner chamber. This may have the advantage that the size of the at least one inner chamber may be adjusted to the size of a workpiece or tray. For example, in case of a small workpiece ortray has to be taken out of the inner chamber, not the entire inner chamber has to be opened but only the section that is separated by the at least one sec- tion door from the rest of the inner chamber.

A2019/09005-LU-00 -3- LU101168

[0009] According to another aspect of the present application the additive manufactur- ing apparatus may further comprise one outer door for each section of the inner cham- ber being divided by at least one section door. The regarding section of the inner cham- ber can be accessed by the respective outer door. This may have the advantage, that not the entire controlled atmosphere within the inner chamber may be affected by opening the outer door

[0010] According to another aspect ofthe present application an additive manufacturing apparatus further comprises a tray transport system and at least one tray connected to the tray transport system. This may have the advantage that workpieces can be placed on the at least one tray and thus handling becomes easier and even automatic handling is possible. Also, the transport of the at least one tray within the additive manufacturing apparatus may be automated.

[0011] According to another aspect of the present application the tray of an additive manufacturing apparatus is detachably connected to the tray transport system. This may have the advantage that workpieces on the tray may remain on the tray even when the tray is taken out of the additive manufacturing apparatus. This may have the ad- vantage, that an automated handling of the trays even outside the additive manufactur- ing apparatus is possible. Also, inserting or extracting the at least one tray from the ad- ditive manufacturing apparatus may be automated e.g. with an industrial robot.

[0012] According to another aspect of the present application the tray transport system of an additive manufacturing apparatus may comprise a transport level and a pro- cessing level. In other words, the processing of the workpieces related to the trays takes place on a different level with respect to the level on which the trays are trans- ported or moved by the tray transport system. This may have the advantage that the di- mensions of the additive manufacturing apparatus may be kept compact.

[0013] According to another aspect of the present application the at least one tray of an additive manufacturing apparatus may comprise a movable platform. This movable platform may be vertically movable with respect to the respective tray. This may have

A2019/09005-LU-00 -4.

LU101168 the advantage that a workpiece ma be built by stepwise moving downward the movable platform within the tray.

[0014] According to another aspect of the present application the additive manufactur- ing apparatus may further comprise a gas supply connected to the lock chamber. This may have the advantage that a controlled atmosphere may be restored or maintained even if the at least one outer door is open or was opened.

[0015] According to another aspect ofthe present application an additive manufacturing apparatus may further comprise a gas sensor connected to the lock chamber. This may have the advantage that e.g. a composition and/or pressure and/or temperature of the atmosphere in the lock chamber may be detected. Also, the atmosphere in the lock chamber may be controlled by means of the gas sensor and a control unit via the above gas supply.

[0016] According to another aspect of the present application at least one of the outer or inner doors of the additive manufacturing apparatus comprises at least one hand glove. This may have the advantage that a workpiece on the other side of the door can be han- dled through the door without disturbing the controlled atmosphere on the other side of the door where the workpiece is handled.

[0017] According to another aspect of the present application an additive manufacturing apparatus may further comprise a heating system connected to at least one of the lock chamber and the inner chamber. This may have the advantage that an atmosphere within the lock chamber / the inner chamber may be controlled with regard to its tem- perature. This may have advantages for the quality of the workpiece.

[0018] According to another aspect ofthe present application an additive manufacturing apparatus may comprise a material supply unit and/or a heating unit per tray. This may have the advantage that the additive manufacturing apparatus may be modular and thus highly flexible.

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[0019] Accordingto another aspect of the present application an additive manufacturing apparatus may comprise a tray transport system moving the at least one trayin at least two different directions on a level. This has the advantage that the dimensions of additive | manufacturing apparatus may be kept compact and further the potential openings be- tween the inside of the additive manufacturing apparatus and the outside environment may be minimized.

[0020] According to another aspect of the present application a locking method for an additive manufacturing apparatus comprises the steps of: establishing an equal atmos- phere in a lock chamber as well as in an inner chamber; Opening an inner door: Placing or moving a workpiece or tray from the inner chamber into the lock chamber: Closing the inner door; Opening an outer door. This method may have the advantage that a con- trolled atmosphere in the inner chamber remains undisturbed even when a tray or workpiece is taken out of the inner chamber.

[0021] According to another aspect of the present application a locking method for an additive manufacturing apparatus comprises the steps of: Closing an inner door; Open- ing an outer door; Placing or moving a workpiece or tray into a lock chamber: Closing the outer door; Establishing an equal atmosphere in the lock chamber as well as in an inner chamber; Opening the inner door; Placing or moving the workpiece or tray into the inner chamber; Closing the inner door. This method may have the advantage that a controlled atmosphere in the inner chamber remains undisturbed even when a tray or workpiece is placed into the inner chamber.

[0022] According to another aspect of the present application a locking method for an additive manufacturing apparatus further comprises moving the workpiece or tray from a processing level to a transport level and/or vice-versa. This may have the ad- vantage that the dimensions of the additive manufacturing apparatus may be kept com- pact. Further, the method may be carried out in a more flexible manner.

[0023] According to another aspect of the present application a locking method for an additive manufacturing apparatus further comprises analyzing the atmosphere within

A2019/09005-LU-00 -6- LU101168 at least one of the lock chamber and the inner chamber. This may have the advantage that the atmosphere in the lock chamber / inner chamber may be adjusted according to the results of the analysis.

[0024] According to another aspect of the present application a locking method for an additive manufacturing apparatus further comprises heating the atmosphere within at least one of the lock chamber and the inner chamber. This may have the advantage that the quality of the workpiece(s) processed by the additive manufacturing apparatus may be enhanced.

[0025] According to another aspect of the present application a locking method for an additive manufacturing apparatus further comprises dividing the lock chamber into at least two sections. This may have the advantage that the lock chamber may be adapted to a size of atray or workpiece and thus an controlled atmosphere within the lock cham- ber may not entirely go lost.

[0026] Each of the above aspects is to be considered an invention on its own. The aspects can be combined freely with each other and each feature not described as being de- pendent on another feature may also be freely combined with each other. The features of the disclosed method may be incorporated into the aspects concerning the additive manufacturing machine and vice versa. Terms of direction and/or orientation like "up- per”, "lower" and "horizontal" refer to an additive manufacturing machine in its usual position of usage on a horizontal and even plane.

BRIEF DESCRIPTION OF THE FIGURES

[0027] Further advantages and features of the present disclosure will be apparent from the appended figures. The figures are of merely informing purpose and not of limiting character. The figures schematically describes embodiments of the present applica- tion. Hence, the appended figures cannot be considered limiting for e.g. the dimensions of the present disclosure.

A2019/09005-LU-00 -7- LU101168 | [0028] Figure 1 shows a schematic view and locking sequence of an additive manufac- turing apparatus.

[0029] Figure 2 shows a schematic view and locking sequence of another manufactur- ing apparatus.

[0030] Figure 3 shows a schematic view and locking sequence of another manufactur- ing apparatus.

[0031] Referring to figure 1 an additive manufacturing apparatus 10 is depicted. The ad- ditive manufacturing apparatus 10 comprising an inner door 20, a lock chamber 30, an outer door 40, an inner chamber 50, a tray transport system 60, a tray 70, gas sensors 90 and 95 as well as a gas supply 80.

[0032] The outer door 40 separates the lock chamber 30 from an outside environmentE. The inner door 20 separates the lock chamber 30 from the inner chamber 50. The gas sensors 90 and 95 are adapted to detect or analyze the atmosphere within the lock chamber 30 and the inner chamber 50. The gas supply 80 may supply gas to the lock chamber 30. There may be an optional gas supply for the inner chamber 50 as well (not shown). The tray transport system 60 reaches from the outside environment E through the lock chamber 30 into the inner chamber 50. A tray 70 is connected to the tray transport system 60, The tray 70 comprises a movable platform 75 that can move up and down (vertically) within the tray 70. Also, the tray 70 can be lifted by the tray transport system 60 from a transport level Tto a processing level P.

[0033] On the left side in fig. 1 indicated with A the tray 70 is lifted by the transport system 60 into the processing level P and located within the inner chamber 50. The inner cham- ber 50 comprises a controlled atmosphere. This controlled atmosphere may be aninert atmosphere. Also, the lock chamber 30 and/or the inner chamber 50 may be heated or the atmosphere within at least one of the chambers may be heated. In the depicted fig. 1 the additive manufacturing apparatus 10 is a 3D-printer. In the case of a 3D-printer, at least one workpiece is built up on the movable platform 75 while the tray 70 is located on

A2019/09005-LU-00 -8- LU101168 | the processing level P. As the at least one workpiece on the movable platform 75 is built | up layer by layer, the movable platform 75 moves downwards, however, the tray 70 re- mains on the processing level P.

[0034] In case the at least one workpiece on the movable platform 75, respectively on the tray 70 is completed, the transport system 60 moves the tray 70 downwards from the processing level P onto the transport level T. On the transport level T, the tray transport system 60 moves the tray 70 towards the inner door 20 to the left in fig. 1. As long as there is an unwanted difference in the composition of the atmosphere in the in- ner chamber 50 and the lock chamber 30, the inner door 20 remains closed. The atmos- phere in the lock chamber 30 can be determined by means of the gas sensor 90 con- nected to the lock chamber 30, By means of the gas sensor 90 the composition of the at- mosphere within the lock chamber 30 may be determined. If the composition is not within a certain but freely selectable range of the composition in the inner chamber 50, gas may be supplied to the lock chamber 30 by means of the gas supply 80. If the com- position or quality of the atmosphere in the lock chamber 30 is in an admissible range, the inner door 20 opens and the tray 70 passes from the inner chamber 50 into the lock chamber 30. Subsequently, the inner door 20 closes (see B in fig.1).

[0035] The atmosphere within the lock chamber 30 may be saved or recovered by pump- ing at least part of it out of the lock chamber 30 e.g. via the gas supply 80 prior to opening the outer door 40. This can help save cost since maintaining the atmosphere within the additive manufacturing apparatus 10 is costly. On the other hand, the outer door 40 can simply be opened to the outside environment E and the controlled atmosphere is lost to the outside environment E. The transport system 60 then can move the tray 70 through the outer door 40 into the outside environment E and thus outside the additive manufac- turing apparatus 10. Alternatively, the tray 70 may remain within the lock chamber 30 (maybe moved bythe transportation system 60 towards the outer door 40 but still within the lock chamber 30). In this case, the tray 70 may be taken out of the lock chamber 30 manually or automated (e.g. by means of a robot).

A2019/09005-LU-00 -9. LU101168

[0036] In case a tray 70 is to be placed inside the inner chamber 50, the tray 70 is con- nected with the transport system 60 outside the lock chamber 30 (in the outside envi- ronment E) or in the lock chamber 30 while the outer door 40 is open. The tray transport system 60 then transports the tray 70 into the lock chamber 30 (if not already placed there) and the outer door 40 closes. Subsequently, the atmosphere within the lock chamber 30 is adjusted such as to match the controlled atmosphere within the inner chamber 50 (e.g. to be within a certain range) by means of the gas sensor 90 and the gas supply 80. The atmosphere within the lock chamber 30 can be detected or analysed by means of the gas sensor 90 and the atmosphere within the inner chamber 50 can be de- tected or analysed by means of the gas sensor 90. The controlled atmosphere within the lock chamber 30 and/or the inner chamber 50 may be e.g. analysed for its composition and/or temperature.

[0037] If the atmosphere within th e lock chamber 30 matches the atmosphereinthein- ner chamber 50 (e.g. in an admissible range), the inner door 20 opens and the transport system 60 transports the tray 70 through the inner door 20. The tray transport system 60 further lifts the tray 70 onto the processing level P. When the tray 70 is on the pro- cessing level P, the processing can commence (e.g. printing at least one workpiece in thetray 70). Whenthe tray is entirely located within the inner chamber 50, the inner door 20 can be closed. This is not absolutely necessary since there is the same atmosphere within the inner chamber 50 and the lock chamber 30 but if another tray is to be trans- ported, the inner door 20 has to be closed. Also, it may be preferable to close the inner door 20 such as to prevent material falling down from the processing level P to enter the lock chamber 30.

[0038] Fig. 2 depicts another additive manufacturing apparatus 10 comprising an inner chamber 50 and three lock chambers 31, 32 and 33 that are separable from each other by two sectional doors 100 and 105. The sectional doors 100 and 105 may be opened or closed optionally as needed and/or desired. A tray transport system 60 (here depicted indashed lines due to visibility reasons) reaches from each lock chambers 31, 32, 33 into the inner chamber 50, interconnects the lock chambers 31, 32, 33 and also passes

A2019/09005-LU-00 -10- | LU101168 through an outer door 40 into an outside environment E outside the additive manufac- turing apparatus 10. Inner doors 21, 22 and 23 separate the inner chamber 50 from the three lock chambers 31, 32 and 33. There also can be only a single inner door 20 that opens up to the three lock chambers 31,32 and 33 (see below).

[0039] In step A of fig. 2 a tray 70 is located in the inner chamber 50. All inner doors 20 to 22 are closed to keep possible material within the inner chamber 50. There is essentially the same atmosphere in the inner chamber 50 and all lock chambers 31to 33. In step B the inner door 20 is opened and the tray 70 is moved by the tray transport system 60 into the lock chamber 31. The tray 70 is then moved through the lock chamber 32 by the transport system 60 into lock chamber 33 (not shown). The sectional doors 100 and 105 may be open or just open up to let the tray 70 pass through. However, when the tray 70 reached lock chamber 33 sectional door 105 closes and seals off lock chamber 33 from lock chamber 32. Also, inner door 22 is closed such that lock chamber 33 is isolated.

[0040] Then in step C outer door opens up and the tray transport system 60 moves the tray 70 outside the additive manufacturing apparatus 10 into the outside environment E. The tray may also remain within the lock chamber 33 after the outer door 40 opened to be picked up manually or automated, as described above with respect to fig. 1. The de- picted sequence is arbitrary. Tray 70 may be located behind inner doors 21 or 22 and moved from there into the respective lock chamber 32 or 33. Also, the tray 70 may oc- cupy two or three lock chambers. In fig. 2 a tray 70 having essentially 1/3 of the inner chamber 50 is depicted. However, the tray may be 2/3 or as large as essentially the en- tire inner chamber 50 (see below). As a consequence, inner doors 20 to 22 open up mod- ularly to allow the different possible sizes of trays 70 to pass into the lock chambers. Of course, the sectional doors 100 and 105 are correspondingly opened or closed.

[0041] If the tray is to be placed from the outside environment E into the additive manu- facturing apparatus 10, the method is essentially the above but vice versa. The tray 70 is placed on the tray transport system 60 and then moved into the lock chamber 33. Then the outer door 40 is closed and an atmosphere within the lock chamber 33 is controlled in order to match the atmosphere within the other lock chambers 31 and 33 as well as

A2019/09005-LU-00 -11- LU101168 the inner chamber 50. Once the atmosphere within the lock chamber 33 is within an ad- missible range (see above fig. 1) the sectional door 105 opens and the tray 70 may be moved into lock chambers 31 or 32 and from there into the inner chamber 50. Also, tray 70 may be moved directly from lock chamber 33 via inner door 22 into the inner chamber

50. The above regarding the different sizes of trays 70 also applies here. In case there is atray of the size of essentially the entire inner chamber 50, all inner doors 20 to 22 have to be opened and both sectional doors 100 and 105 stay open. In this case allinner doors 20 to 22 are closed when the tray 70 is located in the lock chambers 31 to 33 and then outer door 40 opens. This means that all locking chambers 31to 33 are exposed to the atmosphere of the outside environment E.

[0042] Here, the advantage of the configuration depicted in fig. 2 is that there is only a single and small outer door 40 which renders the sealing of lock chambers 31to 33 and the inner chamber 50 from the outside environment E rather simple and there are only afew moving parts. The tray transport system 60 moves the tray(s) 70 on a certain level (e.g. levelTinfig.1) in two different directions. In fig.2 one direction is sideways from the inner chamber 50 into the locking chambers 31to 33 and the other direction is along the locking chambers 31to 33 and in this example perpendicular to the sideways movement.

[0043] Fig. 3 depicts another additive manufacturing apparatus 10, similar to the additive manufacturing apparatus of fig. 2. The difference between the additive manufacturing apparatuses of fig.2 and fig. 3 is that the tray transport system 60 (here also depicted in dashed lines due to visibility reasons) moves the tray(s) 70 essentially sideways from the inner chamber 50 to the locking chambers 31to 32. Here, there is not only one outer door 40 but three. Each locking chamber 31to 32 has its own outer door 40. Also, the tray transport system 60 can move trays 70 between the locking chambers 31to 33, however, this is optionally.

[0044] In fig. 3 different sizes of trays 70 (as already mentioned above) are depicted. Here, one tray 70 has the size of essentially 1/3 of the inner chamber 50 and the other tray 70 has essentially the size of 2/3 of the inner chamber 50. Of course, the tray 70 may

A2019/09005-LU-00 -12- LU101168 have the size of essentially the entire inner chamber 50 and thus the size of both de- picted trays in fig. 3 combined.

[0045] Corresponding to the disclosure of fig. 2, moving the trays 70 in fig. 3 is depicted with steps À to C. In step A of fig. 3 trays 70 are located within the inner chamber 50. In step B the tray transport system 60 moves the both trays 70 at the same time or inde- pendently from each other from the inner chamber 50 to the locking chambers 31 to 33, In case of fig. 3 the sectional door 100 is opened such that the 2/3-tray 70 fits into the locking chambers 31 and 32. Also, in fig. 3 there is only one inner door 20 that spans all three locking chambers 31 to 33. However, there can be respective inner doors for each locking chamber, as described regarding fig. 2.

[0046] When one or both trays 70 are located in the locking chambers 31 to 33, inner door 20 closes and seals off the inner chamber 50 from the locking chambers 31 to 33. Then one or more of the outer doors 40 open and the tray transport system 60 moves the tray(s) 70 into the outside environment E. Here as well, the tray(s) may be picked up manually or automatically directly from the regarding lock chamber.

[0047] If one or more trays are to be placed from the outside environment E into the in- ner chamber 50 the above steps of fig.3 essentially apply in the opposite sense (mutatis mutandis to fig. 2). There may be also the different levels of fig. 1 in the additive manufac- turing apparatus of fig. 3.

[0048] The handling of the atmosphere (gas sensors, gas supply, etc.) in the lock cham- ber 30 of fig. 1 may also applied mutatis mutandis to chambers 31 to 33 in figs. 2 and 3 if needed and/or desired. The tray transport system 60 in figs. 2 and 3 may also handle the tray(s) 70 on the different levels as depicted in fig. 13 if needed and/or desired. The addi- tive manufacturing apparatuses depicted in figs 2 and 3 may be operated with any pos- sible number or size of trays different from the depicted examples. The sectional doors 100 and 105 serve to seal of one or more locking chambers from one another in case one or more of the locking chambers are opened to the outside environment E and the at- mosphere in the other locking chamber(s) should remain undisturbed by the opening. Also, with the sectional doors 100 and 105 the handling of different tray sizes is possible.

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[0049] The above disclosure describes possible and different additive manufacturing apparatuses. However, it is to be noted that the invention is not limited to these additive manufacturing apparatuses but there may be combinations of the additive manufactur- ing apparatuses as described above. Further, there may be variations that may be car- ried out using the common knowledge of the skilled person.

A2019/09005-LU-00 -14- LU101168 Reference sign list additive manufacturing apparatus inner door 21 inner door 22 inner door lock chamber 31 section 32 section 33 section 40 outer door 50 inner chamber 60 tray transport system 70 tray 75 movable platform 80 gas supply 90 gas sensor 95 gas sensor 100 sectional door 105 sectional door T transport level P processing level E outside environment

Claims

| A2019/09005-LU-00 -15- LU101168 Claims

1. Additive manufacturing apparatus (10) comprising at least one inner chamber (50), at least one lock chamber (30), at least one inner door (20, 21, 22), and at least one outer door (40), wherein the inner door (20, 21, 22) is located between the lock chamber (30) and the inner chamber (50), and the outer door (40) is located between the lock chamber and an outside environment (E).

2. Additive manufacturing apparatus (10) according to claim 1, wherein the additive manufacturing apparatus (10) is a 3D-printer.

3. Additive manufacturing apparatus according to claim 1, wherein the additive manufacturing apparatus (10) is an additive manufacturing post processing apparatus.

4. Additive manufacturing apparatus (10) according to any of the preceding claims, wherein the at least one lock chamber (30) is dividable by at least one section door (100,105) into at least two sections (31, 32, 33).

5. Additive manufacturing apparatus (10) according to claim 4, further comprising one outer door (40) for each section (31, 32, 33).

6. Additive manufacturing apparatus (10) according to any of the preceding claims, further comprising a tray transport system (60) and at least one tray (70) connected to the tray transport system.

7. Additive manufacturing apparatus (10) according to claim 6, wherein the tray (70) is detachably connected to the tray transport system (60).

8. Additive manufacturing apparatus (10) according to claims 6 or 7, wherein the tray transport system (60) comprises a transport level (T) and a processing level (P).

9. Additive manufacturing apparatus (10) according to any of claims 6 to 8, wherein the at least one tray (70) comprises a movable platform (75).

| A2019/09005-LU-00 -16- LU101168

10. Additive manufacturing apparatus (10) according to any of the preceding claims, further comprising a gas supply (80) connected to the lock chamber (30).

1. Additive manufacturing apparatus (10) according to any of the preceding claims, further comprising a gas sensor (90) connected to the lock chamber (30).

12. Additive manufacturing apparatus (10) according to any of the preceding claims, wherein at least one of the outer (40) or inner door (20) comprises at least one hand glove.

13. Additive manufacturing apparatus (10) according to any of the preceding claims, further comprising a heating system connected to at least one of the lock chamber (30) and the inner chamber (50).

14. Additive manufacturing apparatus (10) according to any of claims 6 to 13, further comprising a material supply unit and/or a heating unit per tray.

15. Additive manufacturing apparatus (10) according to any of claims 6 to 14, wherein the tray transport system (60) moves the at least one tray (70) in at least two different directions on a level (P, T).

16. Locking method for an additive manufacturing apparatus (10), in particular an additive manufacturing apparatus according to one of the claims 1 to 15, comprisingthe steps of: Establishing an equal atmosphere in a lock chamber (30) as well as in an inner chamber (50); e Opening an inner door (20); e Moving a workpiece or tray (70) from the inner chamber in the lock chamber; e Closing the inner door (20); e Opening an outer door (40); e Placing the workpiece or tray in an outside environment (E).

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17. Locking method for an additive manufacturing apparatus (10), in particular an additive manufacturing apparatus according to one of the claims 1 to 15, comprising the steps of: e Closing an inner door (20); e Opening an outer door (40); e Moving a workpiece or tray (70) in a lock chamber (30) from an outside environment (E); e Closing the outer door; e Establishing an equal atmosphere in the lock chamber as well as in an inner chamber (50); e Openingthe inner door; e Moving the workpiece or tray in the inner chamber: e Closingthe inner door;

18. Locking method according to claims 16 or 17, further comprising moving the workpiece or tray (70) from a processing level (P) to a transport level (T) and/or vice versa.

19. Locking method according to any of claims 16 to 18, further comprising dividing the lock chamber (30) into at least two sections.