(19)
(11)EP 3 450 059 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
29.07.2020 Bulletin 2020/31

(21)Application number: 18190206.5

(22)Date of filing:  22.08.2018
(51)International Patent Classification (IPC): 
B22F 3/105(2006.01)
B33Y 10/00(2015.01)
B33Y 40/00(2020.01)
B29C 64/153(2017.01)
B33Y 30/00(2015.01)

(54)

THREE-DIMENSIONAL SHAPING APPARATUS

VORRICHTUNG ZUR DREIDIMENSIONALEN FORMUNG

APPAREIL DE MISE EN FORME TRIDIMENSIONNELLE


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 05.09.2017 JP 2017170283

(43)Date of publication of application:
06.03.2019 Bulletin 2019/10

(73)Proprietor: Matsuura Machinery Corporation
Fukui City, Fukui (JP)

(72)Inventors:
  • AMAYA, Kouichi
    Fukui City, Fukui (JP)
  • KATO, Toshihiko
    Fukui City, Fukui (JP)
  • MIDORIKAWA, Tetsushi
    Fukui City, Fukui (JP)
  • YOSHIDA, Mitsuyoshi
    Fukui City, Fukui (JP)
  • SHIMIZU, Kazuhiro
    Fukui City, Fukui (JP)

(74)Representative: Lambacher, Michael et al
V. Füner Ebbinghaus Finck Hano Patentanwälte Mariahilfplatz 3
81541 München
81541 München (DE)


(56)References cited: : 
EP-A1- 2 832 528
JP-A- 2017 214 627
JP-A- 2016 056 417
US-A1- 2017 173 879
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    [Technical Field]



    [0001] The technical field of the present invention is that of a three-dimensional shaping apparatus that functions by the steps of lamination of metal powder by traveling of a squeegee, sintering by irradiation of a laser beam or electron beam, and cutting by rotation of a tool, the three-dimensional shaping apparatus being based on a basic construction whereby inert gas is supplied to the transport pathway for metal powder and fumes collected after shaping.

    [Background Art]



    [0002] For a three-dimensional shaping apparatus which uses metal powder as material, lowering an oxygen concentration in a shaping tank and suppressing oxidation of the metal powder is a commonly known technique according to supplying an inert gas that does not react with the metal powder, such as nitrogen gas, neon gas or argon gas, into the shaping tank surrounding a shaping table that is vertically movable and supports an object to be shaped.

    [0003] In such a three-dimensional shaping apparatus, reuse of the metal powder is also a well-known technique according to recovering the fumes and metal powder produced by cutting on the outside of the shaping tank surrounding the shaping table, and to discharging the non-laminating metal powder to the outer side of a chamber that is placed around the periphery of the shaping tank and surrounding the shaping tank and to storing it in a powder tank after passing through a sifter, further transporting it to a powder supply apparatus.

    [0004] However, after the metal powder has been discharged from the shaping tank and chamber, the metal powder to be transported often oxidizes in the transport pathway before reaching the sifter, thereby results an obstacle against reuse of the metal powder.

    [0005] Moreover, during transport of combustible metal powder such as titanium or aluminum, sudden oxidation of the metal powder can result in accidents such as dust explosion, with explosion being particularly likely to occur when the metal powder is located at the highest point of the transport pathway just before falling into the sifter, due to collision between the metal powder particles.

    [0006] In the prior arts, however, no technical consideration has been given to suppressing oxidation of metal powder in the transport pathway for the fumes and metal powder collected from the shaping tank until they reach the sifter, or in the transport pathway for the metal powder collected from the chamber until it reaches the sifter.

    [0007] For example, JP 2016 216773 A and JP 2017 048408 A disclose a construction for supplying nitrogen gas to a fume collector and recovering the nitrogen gas from the fume collector for reuse (see Figs. 1 and 2, paragraph [0025] of JP 2016 216773 A, and Figs. 1 and 2, paragraph [0030] of JP 2017 048408 A).

    [0008] Further, in JP 2017 214627 A, a lamination molding apparatus is described including: a chamber in which an inert gas of a predetermined concentration is filled; a molding table that is arranged in the chamber and capable of moving in a vertical direction; a material feeder for feeding the material powder on the molding table; a powder holding wall that surrounds the molding table and holds the material powder supplied from the material feeder on the molding table; a material recovery bucket for housing an excess material powder discharged outside of the powder holding wall and impurities together; and an impurity removing apparatus for removing the impurities from the material powder containing the impurities in the material recovering bucket, and recycles the material powder from which the impurities are removed by the impurity removing apparatus by returning to the material feeder.

    [0009] In JP 2016 056417 A, a recovering/supplying system is described that recovers non-sintered metal powder and supplies it to a production stage when the metal powder stored in the production stage is selectively sintered to form a predetermined configuration. Therefore, the recovering/supplying system comprises: sucking means sucking the non-sintered metal powder; first separation means for separating the metal powder and spatter from fume and gas; storing means for storing fume; second separation means for separating the metal powder from the spatter; transporting means for transporting the metal powder with air stream; third separation means for separating the metal powder from the air stream; and supply means for supplying the metal powder to the production stage.

    [0010] Still further, EP 2 832 528 A1 refers to a method and associated apparatus for the recovery and regeneration of metal powders in Electron Beam Melting (EBM) applications.

    [0011] In regard to their construction, however, there is no disclosure or suggestion regarding supplying nitrogen gas in the fume transport pathway until it reaches the fume collector, nor furthermore is there any disclosure or suggestion regarding supplying nitrogen gas into the transport pathway for reuse of the metal powder.

    [Summary of Invention]


    [Problem to be solved]



    [0012] It is an object of the present invention to provide a construction for a three-dimensional shaping apparatus that suppresses oxidation of metal powder in the transport pathway for collected metal powder and fumes, as well as dust explosion due to sudden oxidation of the same.

    [Means for solving the Problem]



    [0013] In order to solve the aforementioned problem, the basic construction of the present invention is a three-dimensional shaping apparatus comprising a shaping table that is raised and lowered within a shaping tank, a squeegee that disperses metal powder by movement in the horizontal direction and forms a laminated layer from the metal powder, a sintering device that works based on irradiation of a laser beam or electron beam, and a cutting device that works by rotation of a tool, wherein the three-dimensional shaping apparatus is provided with transport pathways through which metal powder and fumes that have been discharged to an outer side of the shaping tank after cutting with the cutting device, and metal powder that has been discharged to an outer side of a chamber surrounding the shaping tank without forming part of the laminated layer, are transported to a sifter located at the top of a powder tank, and is further provided with a compressor injecting inert gas that does not react with the metal powder at an inlet of each transport pathway, and is provided with a suction device sucking the inert gas at an end of each of the transport pathways, and therefore achieves supply of the inert gas and transport of the metal powder and fumes in the transport pathways all at once, wherein a feedback pathway is provided that is configured to return and supply all or a portion of the inert gas that has been discharged from the suction device to an inlet of one of the transport pathways and/or a highest point of one of the transport pathways, wherein the feedback pathway is directly connected to the inlet and/or the highest point of the one of the transport pathways.

    [Advantageous Effects of Invention]



    [0014] According to the present invention which is based on this basic construction, it is possible to suppress oxidation within the transport pathway for collected metal powder, and also dust explosion due to its sudden oxidation, thereby achieving reuse of purified metal powder under safe conditions.

    [Brief Description of Drawings]



    [0015] 

    Fig. 1 is a schematic diagram denoting the construction of Example 1

    Fig. 2 is a schematic diagram denoting the construction of Example 2.

    Fig. 3 is a schematic diagram denoting the basic construction described above.


    [Description of Embodiments]



    [0016] According to the basic construction, as denoted in Fig. 3, the metal powder and fumes that have passed through the cutting step are discharged to the outer side of the shaping tank 1, and metal powder that is not forming the laminated layer in the chamber 2 that is surrounding the shaping tank 1, is discharged to the outer side of the chamber 2.

    [0017] The metal powder and fumes that have been discharged from the shaping tank 1 are thus collected by a collector 21, and fall down into the transport pathway 4 after having passed through a falling pipe 14.

    [0018] Similarly, the metal powder that has been discharged from the chamber 2 is collected by the collector 21, and all of it falls down into the transport pathway 4 after having passed through a falling pipe 22.

    [0019] The metal powder and fumes that have fallen down into the transport pathway 4, are separated by the sifter 5 after having passed through the transport pathway 4, and the metal powder alone is received into the shaping tank 1 and reused.

    [0020] In this basic construction, as denoted in Fig. 3, supply devices for inert gas 8 are respectively provided at the inlet 40, i.e. the transport starting point, of each transport pathway 4.

    [0021] The inert gas may be not only an inherently inert gas such as neon or argon, i.e. an inert gas in the strict sense, but also one that is an inert gas in the wider sense of not reacting with metals, such as nitrogen gas.

    [0022] However nitrogen gas is used in almost all three-dimensional shaping apparatuses with consideration for economic cost.

    [0023] Supplying such an inert gas suppresses oxidation of the metal powder either alone or in combination with fumes, in the transport pathway 4 until it reaches the sifter 5, achieving the purified metal powder to be reused.

    [0024] Moreover, dust explosion due to sudden oxidation of combustible metal powder such as titanium and aluminum is also suppressed, achieving the metal powder to be reused under safe conditions.

    [0025] Flow of gas is consequently indispensable for transport of the metal powder and fumes until reaching the sifter 5.

    [0026] In order to elicit such a flow of gas, it is common to employ a construction in which a differential pressure is generated in the transport pathway 4, or a construction in which a state of flow is generated by a rotating screw.

    [0027] In this basic construction, a compressor 8 that injects inert gas is employed as the supply device for inert gas 8.

    [0028] For this embodiment, the supply of inert gas and transport of the metal powder and fumes based on flow of the inert gas is carried out all at once.

    [0029] Instead of the embodiment by injection described above, transport of the metal powder and fumes in the transport pathway 4 can also be accomplished by a suction device 9 that operates in tandem with the supply device for inert gas 8, by generating negative pressure necessary for transport at the end location of the transport pathway 4 for the fumes and metal powder.

    [0030] While using such the embodiment by suction in tandem with the embodiment by injection will achieve more reliable transport, if a larger degree of suction is set, it will be possible for transport to be carried out without tandem operation with the embodiment by injection.

    [0031] The metal powder that has been separated by the sifter 5 and stored in the shaping tank 1 is transported to a powder supply apparatus 7 that supplies metal powder to the squeegee 32 via the other transport pathway 4.

    [0032] As denoted in Fig. 3, in this basic construction, the transport pathway 4 for transport from the powder tank 6 to the powder supply apparatus 7 that supplies metal powder to the squeegee 32 is provided, and communication between the transport pathway 4 and the suction device 9 achieves all or a portion of the inert gas discharged from the suction device 9 to be supplied to the transport pathway 4.

    [0033] By providing this additional transport pathway 4, the inert gas can be very efficiently reused.

    [0034] As denoted by the dotted lines in Fig. 3, this basic construction employs a feedback pathway 41 that returns and supplies all or a portion of the inert gas that has been discharged from the suction device 9 to the inlet 40 of the transport pathway 4 and/or the highest point of the transport pathway 4.

    [0035] Although Fig. 3 denotes the feedback pathway 41 connected to both the inlet 40 of the transport pathway 4 and the highest point of the transport pathway 4, a feedback pathway 41 connected to only one of them may of course be used instead.

    [0036] An embodiment that returns to the inlet 40 of each transport pathway 4 achieves efficient reuse of the inert gas, while an embodiment with feedback to the highest point makes it possible to efficiently suppress dust explosion by collision between the combustible metal powder particles at that location.

    [0037] Examples of the present invention will now be described.

    [Example 1]



    [0038] For Example 1, as denoted in Fig. 1, the outlet 11 of the shaping tank 1 for inert gas that has been supplied into the shaping tank 1 communicates with the inlets 40 of each transport pathway 4, so that the shaping tank 1 corresponds to the supply device for inert gas 8.

    [0039] According to this Example 1, inert gas that has been supplied into the chamber 2 is reused by the transport pathway 4 for metal powder and fumes that have been collected, achieving efficient reuse of the inert gas.

    [0040] In the case of Example 1 described above, by providing the outlet 11 for inert gas at the top of the shaping tank 1 and the outlet 12 for oxygen at the bottom of the shaping tank 1, efficient separation of oxygen that has infiltrated into the shaping tank 1 may be achieved, and the inert gas discharged from the shaping tank 1 can be reused as highly concentrated inert gas.

    [Example 2]



    [0041] According to Example 2, as denoted in Fig. 2, an oxygen densitometer 61 is situated inside the powder tank 6, and a controller 62 is installed that adjusts the feed rate of the inert gas according to the oxygen concentration measured by the oxygen densitometer 61.

    [0042] In this Example 2, the concentration of inert gas supplied to each transport pathway 4 can be adjusted according to the oxygen concentration in the shaping tank 1, and a suitable metal powder feed rate can be maintained.

    [Example 3]



    [0043] For Example 3, as denoted in Fig. 3, the pipes of metal forming each of the transport pathways 4 are grounded.

    [0044] In this Example 3, by setting an electric potential of the grounded pipes to zero, electrification of the metal powder in each of the transport pathways 4 is prevented, achieving oxidation of the metal powder due to electrification to be further suppressed, while also achieving accidents such as explosion of metal powder dust to be suppressed.

    [Industrial Applicability]



    [0045] According to the present invention, it is possible to reuse purified metal powder that has been discharged and collected from a shaping tank and chamber, in a state with suppressed oxidation, and the present invention is therefore applicable to three-dimensional shaping apparatuses having a wide range of structures.

    [Reference Signs List]



    [0046] 

    1: Shaping tank

    10: Three-dimensional shaped product

    11: Top outlet of shaping tank

    12: Bottom outlet of shaping tank

    13: Collector

    14: Falling pipe

    15: Pipe for communicating between inert gas outlet and transport pathway

    2: Chamber

    21: Collector

    22: Falling pipe

    31: Shaping table

    32: Squeegee

    4: Transport pathway

    40: Inlet of transport pathway

    41: Feedback pathway

    5: Sifter

    6: Powder tank

    61: Oxygen densitometer

    62: Controller

    7: Powder supply apparatus

    8: Supply device for inert gas and compressor

    9: Suction device




    Claims

    1. A three-dimensional shaping apparatus comprising a shaping table (31) that is raised and lowered within a shaping tank (1), a squeegee (32) that disperses metal powder by movement in the horizontal direction and forms a laminated layer from the metal powder, a sintering device that works based on irradiation of a laser beam or electron beam, and a cutting device that works by rotation of a tool, wherein the three-dimensional shaping apparatus is provided with transport pathways (4) through which metal powder and fumes that have been discharged to an outer side of the shaping tank (1) after cutting with the cutting device, and metal powder that has been discharged to an outer side of a chamber (2) surrounding the shaping tank (1) without forming part of the laminated layer, are transported to a sifter (5) located at the top of a powder tank (6), and is provided with a compressor (8) injecting inert gas that does not react with the metal powder at an inlet (40) of each transport pathway (4), and is provided with a suction device (9) sucking the inert gas at an end of each of the transport pathways (4), and therefore achieves supply of the inert gas and transport of the metal powder and fumes in the transport pathways (4) all at once, wherein a feedback pathway (41) is provided that is configured to return and supply all or a portion of the inert gas that has been discharged from the suction device (9) to an inlet (40) of one of the transport pathways (4) and/or a highest point of one of the transport pathways (4), wherein the feedback pathway (41) is directly connected to the inlet (40) and/or the highest point of the one of the transport pathways (4).
     
    2. The three-dimensional shaping apparatus according to claim 1, wherein beneath end of a falling pipe (14) into which the metal powder and the fumes discharged from the shaping tank (1) fall, and beneath end of a falling pipe (22) into which the metal powder discharged from the chamber (2) falls are communicated to the transport pathways (4).
     
    3. The three-dimensional shaping apparatus according to any one of claims 1, 2, wherein an outlet (11) of the shaping tank (1) for inert gas that has been supplied into the shaping tank (1) communicates with the inlets (40) of the transport pathways (4), so that the shaping tank (1) corresponds to a supply device (8) for the inert gas.
     
    4. The three-dimensional shaping apparatus according to claim 3, wherein the outlet (11) for inert gas is provided at a top of the shaping tank (1) and an outlet (12) for oxygen is provided at a bottom of the shaping tank (1).
     
    5. The three-dimensional shaping apparatus according to any one of claims 1, 2, 3, 4, wherein an oxygen densitometer (61) is situated inside the powder tank (6), and a controller (62) is installed that adjusts the feed rate of the inert gas according to the oxygen concentration measured by the oxygen densitometer (61).
     
    6. The three-dimensional shaping apparatus according to any one of claims 1, 2, 3, 4, 5, wherein pipes of metal forming each of the transport pathways (4) are grounded.
     


    Ansprüche

    1. Dreidimensionale Formungsvorrichtung umfassend einen Formungstisch (31), der innerhalb eines Formungstanks (1) angehoben und abgesenkt wird, eine Rakel (32), die durch eine Bewegung in der horizontalen Richtung Metallpulver verteilt und aus dem Metallpulver eine geschichtete Lage bildet, eine Sintervorrichtung, die basierend auf einer Bestrahlung eines Laserstrahlenbündels oder Elektronenstrahlenbündels arbeitet, und eine Schneidvorrichtung, die durch eine Drehung eines Werkzeugs arbeitet, wobei die dreidimensionale Formungsvorrichtung mit Transportpfaden (4) versehen ist, durch die Metallpulver und Dämpfe, die nach einem Schneiden mit der Schneidvorrichtung zu einer Außenseite des Formungstanks (1) abgeführt worden sind, und Metallpulver, das zu einer Außenseite einer den Formungstank (1) umgebenden Kammer (2) abgeführt worden ist, ohne einen Teil der geschichteten Lage zu bilden, zu einem Sichter (5) transportiert werden, der sich an der Oberseite eines Pulvertanks (6) befindet, und mit einem Kompressor (8) versehen ist, der Inertgas, das nicht mit dem Metallpulver reagiert, an einem Einlass (40) jedes Transportpfads (4) injiziert, und mit einer Saugvorrichtung (9) versehen ist, die das Inertgas an einem Ende von jedem der Transportpfade (4) ansaugt, und deshalb eine Zufuhr des Inertgases und einen Transport des Metallpulvers und der Dämpfe in den Transportpfaden (4) alles auf einmal erreicht, wobei ein Rückführpfad (41) vorgesehen ist, der dazu konfiguriert ist, alles oder einen Teil des Inertgases, das von der Saugvorrichtung (9) abgeführt worden ist, zu einem Einlass (40) von einem der Transportwege (4) und/oder einem höchsten Punkt von einem der Transportwege (4) zurückzuführen und zuzuführen, wobei der Rückführpfad (41) direkt mit dem Einlass (40) und/oder dem höchsten Punkt des einen der Transportpfade (4) verbunden ist.
     
    2. Dreidimensionale Formungsvorrichtung nach Anspruch 1, wobei ein unteres Ende eines Fallrohrs (14), in das das Metallpulver und die Dämpfe, die von dem Formungstank (1) abgeführt wurden, fallen, und ein unteres Ende eines Fallrohrs (22), in das das Metallpulver, das von der Kammer (2) abgeführt wurde, fällt, mit den Transportpfaden (4) in Verbindung stehen.
     
    3. Dreidimensionale Formungsvorrichtung nach einem der Ansprüche 1, 2, wobei ein Auslass (11) des Formungstanks (1) für Inertgas, das in den Formungstank (1) zugeführt worden ist, mit den Einlässen (40) der Transportpfade (4) in Verbindung steht, so dass der Formungstank (1) einer Zuführvorrichtung (8) für das Inertgas entspricht.
     
    4. Dreidimensionale Formungsvorrichtung nach Anspruch 3, wobei der Auslass (11) für Inertgas an einer Oberseite des Formungstanks (1) vorgesehen ist und ein Auslass (12) für Sauerstoff an einer Unterseite des Formungstanks (1) vorgesehen ist.
     
    5. Dreidimensionale Formungsvorrichtung nach einem der Ansprüche 1, 2, 3, 4, wobei sich ein Sauerstoff-Densitometer (61) innen in dem Pulvertank (6) befindet, und eine Steuereinrichtung (62) installiert ist, die die Zuführrate des Inertgases gemäß der durch das Sauerstoff-Densitometer (61) gemessenen Sauerstoffkonzentration justiert.
     
    6. Dreidimensionale Formungsvorrichtung nach einem der Ansprüche 1, 2, 3, 4, 5, wobei Metallrohre, die jeden der Transportpfade (4) bilden, geerdet sind.
     


    Revendications

    1. Appareil de façonnage en trois dimensions comprenant une table de façonnage (31) qui est levée et baissée dans un réservoir de façonnage (1), un racloir (32) qui disperse une poudre métallique par un mouvement dans la direction horizontale et forme une couche stratifiée à partir de la poudre métallique, un dispositif de frittage qui fonctionne sur la base d'un rayonnement d'un faisceau laser ou d'un faisceau électronique, et un dispositif de découpe qui fonctionne par la rotation d'un outil, dans lequel l'appareil de façonnage en trois dimensions est doté de chemins de transport (4) à travers lesquels une poudre métallique et des fumées qui ont été évacuées vers un côté extérieur du réservoir de façonnage (1) après la découpe avec le dispositif de découpe, et une poudre métallique qui a été évacuée vers un côté extérieur d'une chambre (2) entourant le réservoir de façonnage (1) sans faire partie de la couche stratifiée, sont transportées vers un tamis (5) situé dans le haut d'un réservoir de poudre (6), et est doté d'un compresseur (8) injectant un gaz inerte qui ne réagit pas avec la poudre métallique à une entrée (40) de chaque chemin de transport (4), et est doté d'un dispositif d'aspiration (9) aspirant le gaz inerte à une extrémité de chacun des chemins de transport (4), et donc réalise une alimentation du gaz inerte et le transport de la poudre métallique et des fumées dans les chemins de transport (4) d'un seul coup, dans lequel un chemin de retour (41) est ménagé et est configuré afin de renvoyer et d'alimenter tout ou une partie du gaz inerte qui a été déchargé du dispositif d'aspiration (9) vers une entrée (40) d'un des chemins de transport (4) et/ou un point le plus élevé d'un des chemins de transport (4), dans lequel le chemin de retour (41) est directement raccordé à l'entrée (40) et/ou au point le plus élevé de l'un des chemins de transport (4).
     
    2. Appareil de façonnage en trois dimensions selon la revendication 1, dans lequel l'extrémité inférieure d'un tuyau tombant (14) dans lequel tombent la poudre métallique et les fumées déchargées du réservoir de façonnage (1), et l'extrémité inférieure d'un tuyau tombant (22) dans lequel tombe la poudre métallique déchargée de la chambre (2) communiquent avec les chemins de transport (4).
     
    3. Appareil de façonnage en trois dimensions selon l'une quelconque des revendications 1, 2, dans lequel une sortie (11) du réservoir de façonnage (1) pour un gaz inerte qui a été fourni dans le réservoir de façonnage (1) communique avec les entrées (40) des chemins de transport (4), de sorte que le réservoir de façonnage (1) corresponde à un dispositif d'alimentation (8) pour le gaz inerte.
     
    4. Appareil de façonnage en trois dimensions selon la revendication 3, dans lequel la sortie (11) pour un gaz inerte est ménagée en haut du réservoir de façonnage (1) et une sortie (12) pour l'oxygène est ménagée dans le bas du réservoir de façonnage (1).
     
    5. Appareil de façonnage en trois dimensions selon l'une quelconque des revendications 1, 2, 3, 4, dans lequel un densimètre d'oxygène (61) est situé à l'intérieur du réservoir de poudre (6), et un système de commande (62) est installé qui règle le débit du gaz inerte selon la concentration d'oxygène mesurée par le densimètre d'oxygène (61).
     
    6. Appareil de façonnage en trois dimensions selon l'une quelconque des revendications 1, 2, 3, 4, 5, dans lequel des tuyaux de métal formant chacun des chemins de transport (4) sont mis à la terre.
     




    Drawing











    Cited references

    REFERENCES CITED IN THE DESCRIPTION



    This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

    Patent documents cited in the description