MOULDING MACHINE WITH A BOLSTER ARRANGEMENT AND METHOD FOR PRODUCING A MOULD

Abstract

 A Machine for producing a portion of a mould comprises a bolster arrangement (140) a flask (121) and an upper compacting system (110). The bolster arrangement (140) comprises a bolster frame (144) and a bolster plate (141). A pattern (131) is positioned on the bolster plate (141) in the bolster frame (144). The bolster frame (144) is positioned on a machine table (172) and the bolster plate (141) is positioned on a stroke device (171). The pattern (131) and the upper compacting system (110) are movable towards each other by a movement of the bolster plate (141) and the bolster frame (144) relative to each other

Description

[0001] The invention relates to a bolster arrangement for supporting a pattern in a moulding machine and a moulding machine with the bolster arrangement. Additionally a method for producing at least a portion or a part of a mould is provided.

[0002] Sand moulds for metal casting are well known in the art. Typically a model, called pattern, resembling the element, which is to be cast, is used for producing sand moulds. Usually, there are two patterns resembling two portions (often halves) of the element to be cast. Each pattern can then be placed into a box (flask) and sand is filled into the box. The sand is then compacted by a pressing tool until a sufficient strength of the compacted sand is achieved. Afterwards, the pattern is removed leaving a negative of the pattern in the compacted sand. Thereby, a first portion of a mould is produced. These steps are repeated for a second portion of a mould. A gating system is included in the mould portions as known in the art.

[0003] Often, the moulding material (e.g. green sand) is compacted by applying a force to the moulding material from the top, the top side being the side at which the sand was filled into the box to cover the pattern. Thereby, the surface to which the force was directly applied to is typically more compacted (harder) than the opposite surface at which the compacting process was limited by the pattern surface. An insufficient compaction of the moulding material at the pattern surface side can lead to unsatisfactory casting results.

[0004] Bolster arrangements for supporting a pattern in a mould producing machine are known in the art. These known bolster arrangements comprise an upper frame and a lower frame, wherein the two frame elements are coupled by a complex external (outside the bolster frames) guiding system. A movement of the known bolster arrangement lower frame towards the upper frame allows a compaction of the moulding material from the bottom, which is the side opposite to the side at which a moulding material was filled into the bolster arrangement. A sand filling frame is used to accommodate necessary moulding material, since such external guiding systems only allow relatively small room for accommodation of moulding material covering the pattern.

[0005] The problem to be solved by the invention is to provide a machine for producing mould portions with reduced complexity while at least maintaining a good quality of the mould portions produced from it.

[0006] This problem is solved by a machine according to claim 1 and a method according to claim 10.

[0007] Disclosed is a bolster arrangement for supporting a pattern in a mould producing machine. The bolster arrangement comprises a bolster frame and a bolster plate. The bolster plate and the bolster frame are movable in a direction relative to each other, such that the bolster plate is movable inside the bolster frame.

[0008] Preferably, the bolster plate is moved while the bolster frame remains in its position. The bolster plate can be lifted.

[0009] The bolster plate is to be understood as any element with a width of at least two times its height.

[0010] The bolster plate and the bolster frame can be moved relative to each other over a distance of at least 100 mm.

[0011] The bolster plate and the bolster frame can also be moved relative to each other over a distance of at least 150 mm or at least 200 mm.

[0012] The bolster arrangement can be configured such that it is capable of receiving a moulding material with a filling height of at least 100 mm, wherein the moulding material can be storable to be compacted by the relative movement.

[0013] Further moulding material can be accommodated by e.g. a flask that can be positioned on the bolster arrangement.

[0014] The bolster arrangement can also be configured such that it is capable of receiving a moulding material with a bolster arrangement related filling height of at least 150 mm or at least 200 mm. The moulding material is thereby storable to be compacted by the relative movement.

[0015] The bolster frame can comprise an opening in a plane perpendicular to the movement direction. The area of the opening of the bolster frame can be equal to the area of the bolster plate in the same plane allowing a deviation of ± 20 % based on the area of the opening of the bolster frame.

[0016] The bolster plate and the bolster frame can be not coupled by at least one extendable and/or retractable cylinder element, outside the bolster frame.

[0017] An outer surface of the bolster plate can be coupled to an inner surface of the bolster frame for guiding the relative movement.

[0018] At least a portion of the outer surface of the bolster plate can comprise a first guiding structure and/or at least a portion of the inner surface of the bolster frame can comprise a second guiding structure.

[0019] A first guiding structure can be detachably connected to the outer surface of the bolster plate and/or a second guiding structure can be detachably connected to the inner surface of the bolster frame.

[0020] At least one of the first guiding structure and the second guiding structure can comprise a carbide material.

[0021] At least one of the first guiding structure and the second guiding structure can comprise carbon.

[0022] The first guiding structure can be made of a different material than the bolster plate. Additionally or alternatively, the second guiding structure can be made of a different material than the bolster frame.

[0023] Specifically, the material of the first guiding structure can have a higher hardness than the material of the bolster plate. The hardness can be measured according to ISO 6508-1 (Rockwell hardness).

[0024] Additionally or alternatively, the material of the second guiding structure can have a higher hardness than the material of the bolster frame.

[0025] The material of the first guiding structure can have a lower hardness than the material of the second guiding structure. Thereby, wear of the second guiding structure is lower than of the first guiding structure which is advantageous if the first guiding structure can e.g. be replaced more easily than the second guiding structure.

[0026] The bolster arrangement can comprise a sealing member. The sealing member can be configured to seal between the bolster plate and the bolster frame.

[0027] Typically, there is a small gap between the bolster plate and the bolster frame to allow a movement relative to each other. As moulding material, which often has abrasive properties, can enter the gap, wear of the bolster plate and the bolster frame or the first guiding structure and the second guiding structure can be enhanced by moulding material between the bolster plate and the bolster frame. The sealing member can reduce the amount of moulding material that enters the gap and, therefore, reduce wear between the elements.

[0028] The sealing member can be a sealing lip. The sealing member (as sealing lip) can be fixed to the bolster plate.

[0029] A machine for producing a portion of a mould is also disclosed. The machine comprises a bolster arrangement with a bolster frame and a bolster plate. A pattern is positioned on the bolster plate in the bolster frame. The machine further comprises a flask and an upper compacting system. The pattern and the upper compacting system are movable towards each other by a movement of the bolster plate and the bolster frame relative to each other.

[0030] The bolster frame can be positioned on a machine table and/or the bolster plate can be positioned on a stroke device.

[0031] Any herein disclosed bolster arrangement can be used in the machine.

[0032] Preferably, the bolster plate is moved while the bolster frame remains in its position. The bolster plate can be lifted.

[0033] A distance between an upper end of the pattern and a lower end of the flask can be at least 5 mm. The distance can be measured in a direction opposite to the movement direction and the distance can be measured prior to the relative movement of the pattern and the upper compacting system towards each other.

[0034] The upper end of the pattern can be understood as an upper end of a portion of the pattern that shapes the mould geometry that will be present in the later finished casting prepared from the (portion of the) mould. The pattern can e.g. comprise components that form a gating or gas venting system. Such components are necessary for the moulding process but are not related to the shape or geometry of a finished casting produced from the mould (portion). Preferably, such moulding process related components of the pattern (e.g. for a gating or venting system) are preferably not taken into account for the determination of the upper end of the pattern.

[0035] An upper end of the pattern can be (situated or positioned) at most 50 mm higher (above) than a lower end of the flask, preferably in the movement direction, prior to the relative movement of the pattern and the upper compacting system towards each other.

[0036] Especially, the upper end of the pattern can be (situated or positioned) not higher than 30 mm or 15 mm than (above) the lower end of the flask.

[0037] The sum of the maximum height of the pattern and the maximum height of the bolster plate can be smaller than the maximum height of the bolster frame.

[0038] The sum of the maximum height of the pattern and the maximum height of the bolster plate can also be not more than 50 mm higher than the maximum height of the bolster frame.

[0039] It is preferred, that the sum of the maximum height of the pattern and the maximum height of the bolster plate is not more than 30 mm or 15 mm higher than the maximum height of the bolster frame.

[0040] The bolster arrangement and the flask can be configured to receive at least 70 wt.-% of a moulding material, from which moulding material a portion of a mould is to be produced at least partially in the flask. The portion of the mould can also mainly be produced in the flask.

[0041] The bolster arrangement and the flask can also be configured to receive at least 80 wt.-% or at least 90 wt.-% of the moulding material.

[0042] The bolster frame can be positioned on a machine table and the bolster plate can be positioned on a stroke device. The machine table and the stroke device can be movable relative to each other over a distance of at least 100 mm.

[0043] The stroke device can be moved (lifted) relative to the machine table and the bolster frame in order to compact the moulding material.

[0044] The bolster plate can be lifted by the stroke device while the bolster frame rests on the machine table, preferably while the bolster frame and the flask rests on the rest on the machine table

[0045] The machine table and the stroke device can also be movable relative to each other over a distance of at least 150 mm or at least 200 mm.

[0046] The bolster arrangement and the flask can be configured to receive a moulding material with a filling height of at least 200 mm the moulding material storable to be compacted by the relative movement.

[0047] The bolster arrangement and the flask can also be configured to receive a moulding material with a filling height of at least 300 mm or at least 400 mm.

[0048] The bolster arrangement and the flask can be configured to receive or can receive a moulding material with a filling height, which filling height is at least 1.5 times or at least 2.0 times a (maximum) height of the flask.

[0049] The bolster arrangement and the flask can also be configured to receive or can receive a moulding material with a filling height, which filling height is not more than 4.0 times or not more than 2.5 times a (maximum) height of the flask.

[0050] The height of moulding material inside the bolster arrangement and the flask can be used to determine the filling height of moulding material, i.e. moulding material that extends over the upper end of the flask or below the lower end of the bolster arrangement is not taken into account for the determination of the filling height inside the flask and bolster arrangement.

[0051] For example, if the flask has a (maximum) height of 1 m, the filling height of moulding material inside the bolster arrangement and flask can be between 1.5 m and 4.0 m. In this case the filling height of moulding material inside the bolster arrangement and flask can also be between 2.0 m and 2.5 m.

[0052] Also disclosed is a method of producing a portion of a mould. A bolster arrangement is provided. The bolster arrangement comprises a bolster frame and a bolster plate. A pattern is positioned on the bolster plate. A moulding material covering the pattern is provided. The moulding material is compacted by moving the pattern relative to the bolster frame. Thereby, a portion of a mould is produced.

[0053] After a maximum movement of the pattern relative to the bolster frame or after the compacting step, an upper end of the bolster plate can be substantially at the same height as a lower end of a flask positioned on the bolster arrangement.

[0054] The upper end of the bolster plate may be at the same height ±50 mm or ±10 mm as the lower end of a flask.

[0055] After a maximum movement of the pattern relative to the bolster frame or after the compacting step, an upper end of the bolster plate may not be inside or may not be below a lower end of a flask positioned on the bolster arrangement.

[0056] Any herein disclosed bolster arrangement can be used within the method. Additionally or alternatively, any machine disclosed herein can be used within the method.

[0057] Preferably, the pattern is moved while the bolster frame remains in its position. The pattern can be lifted.

[0058] The relative movement of the pattern and the bolster frame can cover a distance of at least 100 mm.

[0059] The relative movement of the pattern and the bolster frame can also cover a distance of at least 150 mm or at least 200 mm.

[0060] The method can comprise a flask. The flask can be positioned at least partially on the bolster frame. The flask and the bolster arrangement can accommodate at least 70 wt.-% of the moulding material before compaction.

[0061] The flask and the bolster arrangement can also accommodate at least 80 wt.-% or at least 90 wt.-% of the moulding material before compaction.

[0062] The moulding material described herein can be sand, especially green sand.

[0063] Preferably, the machine for producing a portion of a mould does not comprise a (sand) filling frame.

[0064] It is preferred that the machine for producing a portion of a mould does not comprise a (sand) filling frame on the top of the flask.

[0065] The machine for producing a portion of a mould may not comprise a (sand) filling frame between the flask and the upper compacting system.

[0066] Preferably, not more than 50 mm, more preferably not more than 10 mm, of moulding material extends over the upper end of the flask prior to compaction of the moulding material.

[0067] Embodiments of the invention are described in more detail with regard to the drawings. The description of the embodiments is not to be construed as to limit the scope defined by the claims. Same reference signs of the figures describe same elements.

Figure 1a

shows a mould producing machine 100 with a bolster arrangement 140.

Figure 1b

shows the machine 100 of Figure 1a.

Figure 1c

shows the machine 100 of Figures 1a and 1b.

Figure 2

shows a bolster arrangement 140.

Figure 3

shows a lower compacting system 170 comprising a machine table 172 and a stroke device 171.

[0068] Figure 1a depicts a mould producing machine 100 in two different states, which different states are separated by a vertical line in the middle of Figure 1a. The left side of Figure 1a shows the machine 100 in a state prior to compacting a moulding material 122 and the right side of Figure 1a shows the machine 100 in a state after compacting the moulding material 122 in order to obtain compacted moulding material 123.

[0069] The machine 100 of Figure 1a comprises an upper compacting system 110, a flask 121, a bolster arrangement 140 and a lower compacting system 170.

[0070] The lower compacting system 170 comprises a machine table 172 and a stroke device 171.

[0071] The bolster arrangement 140 is positioned on top of the lower compacting system 170 and comprises a bolster plate 141 and a bolster frame 144. Specifically, the bolster frame is positioned on the machine table 172 and the bolster plate is positioned on the stroke device 171.

[0072] Preferably, the stroke device 171 of the lower compacting system 170 is located outside (not surrounded by) the bolster frame 144, when the stroke device 171 is in a lower position.

[0073] It is preferred that an upper surface of the stroke device 171, onto which surface the bolster plate 141 can be positioned, is located in the same plane ±50 mm (perpendicular to the plane), especially ±20 mm (perpendicular to the plane), as the upper surface of the machine table 172, onto which surface the bolster frame 144 can be positioned, when the stroke device 171 is in a lower position.

[0074] In the lower position of the stroke device 171 moulding material in the bolster frame 144 and the flask can be (fully) uncompacted. In an upper position of the stroke device 171 moulding material in the flask 121 can be (fully) compacted.

[0075] The bolster plate 141 can be connected to the stroke device 171 via a hook like locking element 173, 174. The locking element 173, 174 can engage with a respective connecting element 146, 147 of the bolster plate 141.

[0076] The bolster plate 141 can also be connected to the stroke device 171 via a magnetic force or a vacuum acting between the bolster plate 141 and the stroke device 171.

[0077] The bolster plate 141 comprises a first guiding structure 142 that extends on an outer surface, especially an outer rim, of the bolster plate and the bolster frame 144 comprises a second guiding structure 143 that extends on an inner surface, especially an inner rim, of the bolster frame 144.

[0078] The first and the second guiding structure 142, 143 can comprise a metal, for example a metal comprising carbide, specifically tungsten carbide. The first and the second guiding structure 142, 143 can be connected to the bolster plate 141 and the bolster frame 144, respectively, such that the first and the second guiding structure 142, 143 can be removed. The connection can be achieved via screws.

[0079] The first and the second guiding structure 142, 143 are coupled such that a movement of the bolster plate 141 relative to the bolster frame 144 is guided by the first and the second guiding structure 142, 143. Especially, the movement of the bolster frame 144 relative to the bolster plate 141 can be such, that the first guiding structure 142 of the bolster plate 141 slides along the second guiding structure 143 of the bolster frame 144 or vice versa.

[0080] The first and/or the second guiding structure 142, 143 can have a length (height) in the z-axis of at least 100 mm and/or a width in the z-axis of at least 5 mm.

[0081] Due to the described guiding (sliding) of the first and the second guiding structure 142, 143 on each other, these structures can be wear parts.

[0082] The bolster plate 141 further comprises a recess 145 (as can best be seen in Figure 2). The recess 145 is configured to receive a pattern 131 on a pattern plate 132. Preferably, the bolster plate 141 and the pattern plate 132 with the pattern 131 are connected via a positive-locking connection.

[0083] The pattern 131 on the pattern plate 132 can also be connected to the bolster plate 141 via at least one screw.

[0084] The connection between the pattern 131 on the pattern plate 132 and the bolster plate 141 can be a positive-locking connection or a frictional connection.

[0085] The flask 121 is positioned on the bolster frame 144.

[0086] The upper compacting system 110 comprises an upper compacting system frame 112 and several upper compacting elements 111. The upper compacting elements 111 are retractable or extendable in the z-axis.

[0087] A moulding material 122 is accommodated by the flask 121 and the bolster arrangement 140 and covers the pattern 131.

[0088] For compacting the moulding material 122 the machine table 172, and thereby the bolster frame 144 and the flask 121, is moved towards the upper compacting system 110 until the flask 121 contacts the upper compacting system frame 112.

[0089] At the same time, the stroke device 171 can be moved towards the upper compacting system 110.

[0090] After the flask 121 is brought in contact with the upper compacting system frame 112, as described above, an enhanced mechanical stability of the machine 100 including the lower compacting system 170, the bolster arrangement 140, the flask 121 and the upper compacting system 110 is achieved. A (further) movement of the stroke device 171 towards the upper compacting system 110 causes the bolster plate 141, guided by the bolster frame 144, to be moved towards the upper compacting system 110. By this movement of the bolster plate 141, the pattern 131 on the pattern plate 132 and the moulding material 122 is moved towards the upper compacting system 110 until the moulding material 122 contacts the upper compacting system elements 111. A further moving of the bolster plate 141 in this direction causes the moulding material 122 to be compacted while the compacting system elements 111 can retract partially.

[0091] The upper compacting system elements 111 can be several independently retractable or extendable cylinders or a flat surface.

[0092] After compacting the moulding material 122 to a desired degree, compacted moulding material 123 is mainly formed or obtained in the flask 121.

[0093] The machine table 172 and the stroke device 171 can be moved to their initial positions and a portion of a mould is obtained in the flask 121 comprising the compacted moulding material 123 with a negative of the geometry of the pattern 131.

[0094] Preferably, the upper compacting system elements 111 are (passively) retracted only during a movement of the stroke device 171 towards the upper compacting system 110. It is preferred that the upper compacting system elements 111 are extended into their unretracted position (before the upper compacting system elements 111 are retracted) after the flask 121 has been removed from the bolster frame 144.

[0095] With reference to Figure 1b several geometric details of the machine 100 shown in Figure 1a can be best understood.

[0096] The height h_bf of the bolster frame 144 corresponds to its extension in the z-axis. The maximum height h_bf of the bolster frame 144 corresponds to the extension in the z-axis of a portion of the bolster frame 144 with the largest value of the height h_bf of all portions of the bolster frame 144.

[0097] The height h_p of the pattern 131 corresponds to its extension in the z-axis. The maximum height h_p of the pattern 131 corresponds to the extension in the z-axis of a portion of the pattern 131 with the largest value of the height h_p of all portions of the pattern 131.

[0098] Especially, the maximum height h_p of the pattern 131 corresponds to the extension in the z-axis of a portion of the pattern 131 with the largest value of the height h_p of all portions of the pattern 131 that shape the mould geometry that will be present in the later finished casting prepared from the mould portion as described above.

[0099] The height h_bp of the bolster plate 141 corresponds to its extension in the z-axis. The maximum height h_bp of the bolster plate 141 corresponds to the extension in the z-axis of a portion of the bolster plate 141 with the largest value of the height h_bf of all portions of the bolster plate 141.

[0100] The filling height h_fill1 of the moulding material 122 in the bolster arrangement 140 before compaction of the moulding material 122 is the height of the moulding material 122 in the z-axis (movement direction) that extends until a plane that is perpendicular to the z-axis, which plane is defined by the upper end (in the z-axis) of the bolster frame 144.

[0101] In the example of Figure 1b the filling height h_fill1 of the moulding material 122 in the bolster arrangement 140 is equal to the height h_bf of the bolster frame 144 minus the height h_bp of the bolster plate 141.

[0102] The distance d_fp1 can be determined between an upper end of the pattern 131 and a lower end of the flask 121.

[0103] In Figure 1c the machine 100 of Figures 1a and 1b is shown. The pattern 131 includes two cylindrical elements 190, 190' that extend in the direction of the z-axis above the upper end of the bolster frame 144.

[0104] The extension of the cylindrical elements 190, 190' above the upper end of the bolster frame 144 and inside the flask 121 can be determined as d_fp2. The extension of an element 190, 190' of the pattern 131 above the upper end of the bolster frame 144 can be measured in relation to the lower end of the flask 121. Typically, the height of an element 190, 190' of the pattern 131 that extends above the lower end of the flask 121 is relatively small (smaller than 50 mm).

[0105] Such an element 190, 190' of the pattern 131 can be used for creating a gating or venting system in the mould (portion) after compaction. This can be seen on the right side of Figure 1c that shows the machine 100 after compaction of the moulding material 122, wherein the element 190' of the pattern 131 (slightly) extends above the upper end of the flask 121. After removing the pattern 131 and cutting the upper surface of the compacted moulding material 123, a channel that is accessible from the top surface of the compacted moulding material 123 is created. The channel can be used to pour liquid metal into the mould or to allow gas (steam) to exit the mould.

[0106] This channel is not directly related to the shape or geometry of a finished casting produced from the mould and any element 190, 190' of the pattern 131 that causes such channel in the compacted moulding material 123 is preferably not to be understood as being part of the pattern 131.

[0107] Additionally, a filling height h_fill2 of the moulding material 122 in the flask 121 and the bolster arrangement 140 is shown in Figure 1c. The filling height h_fill2 comprises moulding material 122 in the bolster arrangement 140 and in the flask 121 up to the upper end of the flask 121.

[0108] A sealing member 195 is positioned such that it seals between the bolster frame 144 and the bolster plate 141.

[0109] E.g. when the bolster plate 141 is lifted towards the upper compacting system 110, a small amount of moulding material 122 can enter a gap between the bolster frame 144 and the bolster plate 141. As moulding material 122 typically has abrasive properties, a further lifting of the bolster plate 141 can damage the surface of the bolster frame 144 and the bolster plate 141 or the first guiding structure 142 and the second guiding structure 143.

[0110] The sealing member 195 can be a sealing lip that can be fixed to the bolster plate 141.

[0111] By using the sealing member 195, the amount of moulding material 122 that enters the gap between the bolster plate 141 and the bolster frame 144 can be reduced compared to the amount of moulding material 122 that enters the gap without the sealing member 195.

[0112] Figure 2 depicts a bolster arrangement 140, usable in machine 100 of Figures 1a and 1b, in more detail.

[0113] The opening 149 of the bolster frame 144 can be seen.

[0114] Figure 3 depicts an upper compacting system 110 and a lower compacting system 170, both usable in machine 100 of Figures 1a and 1b, in more detail.

Claims

1. Machine for producing a portion of a mould, the machine (100) comprising:

(a) a bolster arrangement (140), having a bolster frame (144) and a bolster plate (141), wherein a pattern (131) is positioned on the bolster plate (141) in the bolster frame (144), and wherein the bolster frame (144) is positioned on a machine table (172) and the bolster plate (141) is positioned on a stroke device (171);

(b) a flask (121); and

(c) an upper compacting system (110);

(d) wherein the pattern (131) and the upper compacting system (110) are movable towards each other by a movement of the bolster plate (141) and the bolster frame (144) relative to each other.

2. Machine of claim 1, wherein an upper surface of the stroke device (171) is located in the same plane ±50 mm as the upper surface of the machine table (172), when the stroke device (171) is in a lower position.

3. Machine of any one of claims 1 or 2, wherein the stroke device (171) is located outside the bolster frame (144), when the stroke device (171) is in a lower position.

4. Machine of any one of claims 1 to 3, wherein the flask (121) is positioned on the bolster frame (144).

5. Machine of any one of claims 1 to 4, wherein no filling frame is positioned on the top of the flask (121).

6. Machine of any one of claims 1 to 5, wherein a distance (d_fp1) between an upper end of the pattern (131), preferably an upper end of a mould geometry shaping portion of the pattern (131), and a lower end of the flask (121) is at least 5 mm, the distance (d_fp1) in a direction opposite to the movement direction and the distance prior to the relative movement of the pattern (131) and the upper compacting system (110) towards each other.

7. Machine of any one of claims 1 to 6, wherein the sum of the maximum height (h_p) of the pattern (131) and the maximum height (h_bp) of the bolster plate (141) is not more than 50 mm, preferably not more than 30 mm, more preferably not more than 15 mm, higher than the maximum height (h_bf) of the bolster frame (144).

8. Machine of any one of claims 1 to 7, wherein the bolster arrangement (140) and the flask (121) are configured to receive a moulding material (122) with a filling height (h_fill2) of at least 200 mm, preferably at least 300 mm, more preferably at least 400 mm, the moulding material (122) storable to be compacted by the relative movement.

9. Machine of any one of claims 1 to 8, wherein the bolster arrangement (140) and the flask (121) are configured to receive a moulding material (122) with a filling height (h_fill2), which filling height (h_fill2) is at least 1.5 times, preferably 2.0 times, a height (h_f) of the flask (121), preferably the filling height (h_fill2) is not more than 4.0 times, more preferably not more than 2.5 times, the height (h_f) of the flask (121).

10. Method of producing a portion of a mould, wherein

(a) a bolster arrangement (140) is provided, the bolster arrangement (140) having a bolster frame (144) and a bolster plate (141), and

(b) a pattern (131) is positioned on the bolster plate (141);

the method further comprising:

(c) providing a moulding material (122) covering the pattern (131),

(d) compacting the moulding material (122) by moving the pattern (131) relative to the bolster frame (144), thereby producing a portion of a mould.

11. Method of claim 10, wherein an upper end of the bolster plate (141) is not inside a flask (121) or not below a lower end of the flask (121) after the compacting step.

12. Method of any one of claims 10 or 11, wherein the bolster frame (144) is positioned on a machine table (172) and the bolster plate (141) is positioned on a stroke device (171), wherein the bolster plate (141) is lifted by the stroke device (171) during the compacting step, preferably the bolster plate (141) is lifted by the stroke device (171) during the compacting step and the bolster frame (144) is lifted by the machine table (172) prior and/or during the compacting step.

13. Method of any one of claims 10 to 12, wherein the relative movement of the pattern (131) and the bolster frame (144) covers a distance of at least 100 mm, preferably at least 150 mm, more preferably at least 200 mm.

14. Method of any one of claims 10 to 13, wherein after a maximum movement of the pattern (131) relative to the bolster frame (144) or after the compacting step an upper end of the bolster plate (141) is substantially at the same height as a lower end of a flask (121) positioned on the bolster arrangement (140), preferably an upper end of the bolster plate (141) is at the same height ±50 mm, preferably ±10 mm, as a lower end of a flask (121).

15. Method of any one of claims 10 to 14, wherein after a maximum movement of the pattern (131) relative to the bolster frame (144) or after the compacting step an upper end of the bolster plate (141) is not inside or below a lower end of a flask (121) positioned on the bolster arrangement (140).

Drawing