Mold for casting molten metal with coupling mechanism for a shroud, casting device for casting molten metal, and method for casting molten metal - Patents.com

Abstract

The present invention refers to a mold (2) for casting molten metal comprising a mold / shroud coupling mechanism (14) for a shroud (9) of a casting apparatus (1) comprising a funnel (11) mounted on a hollow shaft (10), the mold / shroud coupling mechanism comprising a seat member (15) for receiving the funnel (11) and holding the shroud (9), and a base member (16) secured to an upper surface (8) of the mold and coupled to the seat member (15) by at least one compliant element (17), such that the seat member (15) is separate from the base member (16) and movable relative to the base member (16) upon application of a load to the seat member (15) that deforms the at least one compliant element.

Description

[Technical field]

[0001] The present invention relates to a mold with a mold / shroud coupling mechanism for a shroud of a casting apparatus, a mold assembly and a casting apparatus for casting molten metal with the mold / shroud coupling mechanism, and a method of casting molten metal. The mold / shroud coupling mechanism of the present invention enables automatic and smooth formation of a sealing contact between a nozzle of a ladle and a shroud without the intervention of a human operator or a robot. [Background technology]

[0002] One of the main challenges in the metal casting process is to avoid air entrainment during casting. This can cause defects including air bubbles and oxide films, which can lead to cracks in the casting. To avoid air entrainment, it is known in the art to cast the molten metal with the aid of a shroud, which reduces the reoxidation of the metal when pouring between the ladle and the mold. As shown in FIG. 6, the shroud (10) is, for example, a hollow elongated shaft with a funnel at its proximal end (= inlet), which is inserted into the bore of the mold and whose distal end (= outlet) communicates with the running system of the mold, which is located, for example, below the casting cavity. The critical step in coupling the nozzle (12) of the ladle to the shroud inlet, which is at the level of the funnel, is to form a sealed contact between the two and to maintain the sealed contact during the entire duration of the casting operation.

[0003] A system for casting molten metal is disclosed in European Patent Application No. 3463715B1. This system comprises: a mold including an inlet and a casting cavity having a bore extending between a top surface of the mold and the inlet; - A shroud comprising a funnel and a hollow shaft, the funnel being located outside the mold adjacent the upper surface and the hollow shaft being housed in the bore and movable therein.

[0004] To form a sealing contact between the nozzle and the funnel of the shroud, EP 3463715 B1 proposes a lifting mechanism located on the upper surface of the mould. The lifting mechanism comprises a concentrically arranged first and second collar, the first collar being fixed to the upper surface of the mould and the second collar being rotatably coupled to the upper surface of the mould, supporting the funnel of the shroud. A bayonet system, including a follower engaged in an inclined slot, allows the second collar to be lifted by rotation relative to the upper surface of the mould, thus causing a linear movement of the shroud. The rotation of the bayonet system is performed by an operator, who must administer the angle of rotation of the bayonet to lift the funnel sufficiently to form a sealing contact without damaging the refractory material in contact. The operator must always be close to the nozzle of the ladle, which is not ideal from a security point of view. Furthermore, one operator is needed to centre and align the ladle nozzle over the funnel, and another operator is needed to operate the lifting mechanism via a handle. Once the funnel of the shroud contacts the nozzle, the lift mechanism no longer moves during the entire casting operation, which can be problematic because the flow of molten metal through the shroud can cause vibrations that propagate to the contact area between the nozzle and the funnel, causing wear or cracking of the refractory material.

[0005] It is an object of the present invention to provide a mold that is easy to operate and includes a mold / shroud mating mechanism that requires little human intervention to engage the funnel of the shroud with the nozzle of the ladle to form a sealing contact. It is a further object of the present invention to provide a casting apparatus that is easier and safer to operate than systems known in the prior art.

[0006] It is a further object of the present invention to provide a method of casting molten metal using a mold / shroud combination arrangement of the above type. Summary of the Invention

[0007] These and other objects are achieved by means of the features of the independent claims. Preferred embodiments of the invention are covered by the dependent claims.

[0008] In a first aspect, the present invention provides a mould for casting molten metal, comprising: A casting cavity having a cavity inlet; a housing selected from a filter housing and a diverter housing, the housing having a housing outlet in fluid communication with the cavity inlet and a housing inlet in fluid communication with the bore; • a bore extending between an upper surface of the mold and the housing inlet; ●A mold / shroud coupling mechanism configured to accommodate a shroud of a casting apparatus in a shroud casting position, the shroud being hollow and including a funnel attached to a proximal end of a shaft having a distal end with a shroud outlet, the shroud casting position being when the shaft is accommodated in a bore such that the distal end of the shaft is surrounded by a housing.

[0009] The mold / shroud coupling mechanism is - Base member fixed to the top surface, A seat member configured to receive the funnel and hold the shroud in a shroud casting position.

[0010] The sheet member is coupled to the base member by at least one compliant element such that the sheet member is separate from the base member and movable relative to the base member upon application of a load to the sheet member that deforms the at least one compliant element.

[0011] The compliant element can include one or more resilient elements defining a resilient configuration. The one or more resilient elements can include an elastomeric material at a process temperature extending between the sheet member and the base member, or a spring, preferably a spiral spring. Alternatively, the compliant element can include a free-flowing material enclosed within one or more bags configured to deform when a load is applied to the sheet member.

[0012] In a preferred embodiment, the base member and the sheet member each include a central hole aligned with one another to define a lead toward the bore for the shroud. In the resilient configuration defined above, the mold / shroud coupling mechanism may include at least three resilient elements, preferably at least three spiral springs, extending between the sheet member and the base member, the at least three resilient elements preferably being equally spaced around the circumference of the central hole in the sheet member and the base member.

[0013] In a second aspect, the present invention provides a method for producing a pharmaceutical composition comprising the steps of: a mold according to the present invention; a shroud including a funnel attached to a proximal end of a shaft having a distal end that is hollow and includes a shroud outlet, the shroud being received in a mold with a sheet member receiving the funnel and holding the shroud in a shroud casting position; The mold assembly is such that the shroud casting position is when the shaft is received in the bore such that the distal end of the shaft is inserted through the housing inlet with the shroud outlet enclosed within the housing.

[0014] In a preferred embodiment of the mold assembly, the shroud is fixed to the sheet member with a filler of foundry sand that seals an annular gap between the funnel and the sheet member and defines a seat for the funnel, the sheet member preferably comprising a sleeve that defines the boundary of the annular gap.

[0015] In a third aspect, the present invention provides a method for producing a pharmaceutical composition comprising the steps of: A mold according to the present invention, and a shroud comprising a funnel attached to a proximal end of a shaft, the funnel being hollow and having a distal end with a shroud outlet; A ladle including a nozzle at the base of the ladle for dispensing molten metal from the ladle, the nozzle configured to reversibly and sealingly engage a funnel of a shroud, and the ladle is adapted to be slidably mounted against a mold, e.g. to position the nozzle substantially vertically above the mold / shroud coupling mechanism; and a ladle configured to be displaced such that the nozzle is vertically lowered by application of a load to the sheet member until the nozzle is sealingly engaged with a funnel of the shroud in the shroud casting position; The casting apparatus relates to a shroud casting position when the shaft is received in the bore such that the distal end of the shaft is inserted through the housing inlet with the shroud outlet enclosed within the housing.

[0016] In a gripping configuration of the casting apparatus according to the invention, the casting apparatus includes a ladle / shroud coupling mechanism configured to reversibly grip the shroud to the nozzle, preferably without forming a seal between the funnel and the nozzle, the ladle / shroud coupling mechanism comprising: a funnel adapter secured to a funnel of the shroud, the funnel adapter comprising a retaining means; A nozzle adaptor secured to the base or nozzle of the ladle and configured to engage the retaining means of the funnel adaptor to reversibly lock the shroud to the nozzle in a locked position.

[0017] In a preferred embodiment of the gripping arrangement of the casting apparatus, the retention means of the funnel adaptor comprises a retention peg and the nozzle adaptor comprises a fastening hook configured to reversibly engage, preferably self-engage, with the retention peg; or The retaining means of the funnel adapter includes one or more retaining pegs, and the nozzle adapter is provided with a bayonet coupling element configured to interact with the one or more retaining pegs to reversibly lock the shroud to the nozzle in a locked position.

[0018] In a preferred embodiment of the casting machine gripping arrangement, the funnel adapter is secured to the shroud with an adhesive material.

[0019] In a preferred embodiment of the gripping configuration, a seat member of the mold / shroud coupling mechanism is configured to receive the funnel adapter and hold the shroud in a shroud casting position. In a preferred embodiment of the gripping configuration, the seat member includes a conical portion centered about a central hole in the seat member. The conical portion is configured to guide the shroud into alignment with the bore when the ladle is lowered vertically with the shroud reversibly locked to the nozzle.

[0020] In a fourth aspect, the present invention provides a method for casting molten metal using a casting device according to the present invention, comprising the steps of: lowering the ladle vertically until the nozzle engaged with the funnel applies a load to the funnel which is resting on the seat member, thus moving the seat member against the compliant element and relative to the base member to form a sealing contact between the nozzle and the shroud in the shroud casting position; allowing molten metal to flow from the ladle to the casting cavity through the nozzle, the shroud, and the housing.

[0021] In one embodiment of a method in which a casting apparatus includes a mold assembly according to the present invention, the method includes lowering the ladle vertically to engage the nozzle with the funnel, and further lowering the nozzle ladle to apply a load to the funnel to form a sealing contact between the nozzle and the shroud.

[0022] In another embodiment of the method applied to a gripping arrangement of a casting apparatus, the method comprises the steps of: Engage the nozzle with the funnel of the shroud, A means for retaining the funnel adapter fixed to the funnel of the shroud, Engage with a nozzle adapter fixed to the base or nozzle of the ladle, gripping the shroud to the nozzle with a ladle / shroud coupling mechanism, for example by locking the shroud to the nozzle in a locked position; Positioning the shroud locked to the nozzle substantially vertically over a mold / shroud mating mechanism; Lowering the shroud vertically with the funnel resting on the sheet material until it reaches the shroud casting position; - Forming a sealing contact between the nozzle and the shroud by further lowering the nozzle ladle to load the funnel.

[0023] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The drawing is as follows. [Brief description of the drawings]

[0024] [Figure 1] 1 illustrates steps of a metal casting method using a casting apparatus according to an embodiment of the present invention. [Diagram 2] 1 illustrates steps of a method of metal casting using a casting apparatus according to an alternative embodiment of the present invention, including a ladle / shroud combination arrangement (140). [Diagram 3] 1 shows a perspective view of one embodiment of a mold / shroud coupling mechanism according to the present invention, the mold / shroud coupling mechanism supporting a shroud housed therein; FIG. [Figure 4] 4 shows a cross-section of the mold / shroud combination of FIG. 3 and the shroud contained therein along line IV-IV of FIG. 3. [Diagram 5] FIG. 1 is a perspective view of a casting apparatus according to the present invention with the ladle nozzle positioned vertically above the funnel of the shroud in a shroud casting position, the funnel being received in a seat member of the mold / shroud coupling mechanism, the ladle not being shown for clarity. [Figure 6] FIG. 6 is a cross-sectional view of the casting apparatus of FIG. 5 with the nozzle reversibly and sealingly engaged with the funnel of the shroud. [Figure 7a] 1 shows a detailed cross-sectional view of the mold / shroud coupling mechanism and nozzle in a casting apparatus according to the present invention as the ladle moves over the mold and aligns the nozzle with the funnel. [Figure 7b] 1 shows a detailed cross-sectional view of the mold / shroud coupling mechanism and nozzle in a casting apparatus according to the present invention as the ladle is lowered to bring the nozzle close to or into contact with the funnel. [Figure 7c] 13 shows a detailed cross-sectional view of the mold / shroud coupling mechanism and nozzle in a casting apparatus according to the present invention as the ladle is further lowered, compressing the compliant elements to form a sealing contact. [Figure 8] 1 illustrates a perspective bottom view of a sheet member of a mold / shroud coupling arrangement according to one embodiment of the present invention; FIG. [Figure 9a] FIG. 2 shows a detailed cross-sectional view of the ladle / shroud coupling mechanism in a casting apparatus according to an embodiment of the present invention prior to gripping the shroud to the nozzle. [Figure 9b] 9 shows a detailed cross-sectional view of the ladle / shroud attachment mechanism in the casting apparatus of FIG. 9a, in which the shroud is non-sealedly attached to the nozzle and holds the shroud vertically above the mold / shroud attachment mechanism. [Figure 9c] 9b shows a detailed cross-sectional view of the ladle / shroud and mold / shroud coupling mechanisms of the casting apparatus of FIG. 9a with the funnel adapter received in a seat member of the mold / shroud coupling mechanism that holds the shroud and the compliant element in a stationary state. [Figure 9d] 9b shows a detailed cross-sectional view of the ladle / shroud and mold / shroud coupling mechanisms in the casting apparatus of FIG. 9a, where the ladle is further lowered vertically with the shroud gripped by the nozzle until the nozzle loads the flexible member, thus forming a sealing contact between the nozzle and the shroud. [Figure 10]FIG. 9b shows a detailed view of the ladle / shroud coupling mechanism in the casting apparatus of FIG. 9a prior to gripping of the shroud to the nozzle in the shroud casting position. [Figure 11] FIG. 11 shows a detailed view of the ladle / shroud attachment mechanism in the casting apparatus of FIG. 10 with the shroud gripped to the nozzle in the shroud casting position. [Figure 12] 11 shows a detailed cross-sectional view of the ladle / shroud coupling mechanism of FIG. 10. [Figure 13] 12 shows a detailed cross-sectional view of the ladle / shroud coupling mechanism of FIG. 11. [Figure 14] FIG. 1 shows a detailed view of a ladle / shroud coupling mechanism in a casting apparatus according to the present invention, in which the shroud is coupled to the nozzle and vertically translates (up or down) the ladle and its coupled shroud above the mold. [Figure 15] FIG. 2 shows a detailed cross-sectional view of the casting apparatus in a shrouded casting position with the ladle / shroud coupling arrangement according to the present invention, with the shroud gripped to the nozzle. [Figure 16] FIG. 16 is a detailed cross-sectional view of the casting apparatus of FIG. 15 in which the shroud is gripped by the nozzle and translated vertically (up or down) over the mold. [Figure 17a] 1 illustrates various embodiments of a compliant element according to the present invention. [Figure 17b] 1 illustrates various embodiments of a compliant element according to the present invention. [Figure 17c] 1 illustrates various embodiments of a compliant element according to the present invention. [Figure 17d] 1 illustrates various embodiments of a compliant element according to the present invention. [Figure 17e] 1 illustrates various embodiments of a compliant element according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] In a first aspect, the present invention relates to a mold (2) for casting molten metal, as shown in Figure 5. The mold (2) comprises one or more casting cavities (3), each having one or more cavity inlets (4), and a housing (6) selected from among a filter housing and a diverter housing. The housing (6) comprises one or more housing outlets (6o) in fluid communication with the one or more cavity inlets (4) of the one or more casting cavities (3). The housing (6) also comprises a housing inlet (6i) in fluid communication with a bore (7) extending vertically between the housing inlet (6i) and a top surface (8) of the mold, opening at an opening. At least a portion of the top surface (8) surrounding the opening is preferably substantially planar, preferably horizontal.

[0026] In Figure 5, the mould (2) comprises an upper part (2a) and a lower part (2b) joined horizontally at a parting line, and a single casting cavity (3). The casting cavity (3) is bottom-fed via two cavity inlets (4). The cavity inlets (4) communicate with two feed channels (5) to a housing (6) which is connected to a bore (7) extending to the top surface (8) of the mould (2). The housing (6) may be a filter housing or a diverter housing. The filter housing may be designed in the same or similar manner as disclosed in EP3463715B1, insofar as it is incorporated herein by reference.

[0027] 15 and 16, the mold (2) comprises several casting cavities, each in fluid communication with a housing (6) via a respective feed channel (5) for conveying molten metal from the housing to the casting cavity. Similarly, the same mold may comprise two or more bores (7) in fluid communication with one or more corresponding housings (6).

[0028] The housing (6) of the mold (2) according to the invention comprises a single housing inlet (6i) and a single or multiple housing outlets (6o). The housing is configured to distribute the flow of molten metal across the housing from the housing inlet (6i) to one or more housing outlets (6o) connected to the casting cavity. The housing (6) is selected between a diverter housing and a filter housing comprising a filter element for filtering and removing impurities in the molten metal flow.

[0029] Mold / shroud coupling mechanism (14) During casting, the molten metal contained in the ladle (103) is distributed through a nozzle (12) located at the bottom of the ladle (103) and flows from there through the shroud (9), the housing (6) and the feed channel (5) into the cavity (3). The shroud (9) comprises a funnel (11) attached to the proximal end of a shaft (10) which is hollow and has a shroud bore opening into the funnel and ending in a shroud outlet (9o) which opens at the distal end (10d) of the hollow shaft. To maintain the position of the shroud during the casting operation, the mold according to the invention comprises a mold / shroud coupling mechanism (14), an embodiment of which is shown in FIG. As shown in FIG. 6, the mold / shroud coupling mechanism (14) is configured to receive the shroud (9) of the casting apparatus (1) in a shroud casting position defined as the shaft (10) received in the bore (7) and its distal end (10d) inserted into the housing (6) via the housing inlet (6i) such that the shroud outlet (9o) is enclosed by the housing (6). During a casting operation, molten metal flows from the ladle through a nozzle (12) sealingly engaged with a funnel (11) of the shroud (9) in the shroud casting position. The molten metal flows through the shaft (10), enters the housing (6) via the shroud outlet (9o) enclosed therein, and exits the housing outlet (6o) into a feed channel to fill the casting cavity.

[0030] As shown in Figure 6, the mold (2) according to the invention is characterized in that the mold / shroud coupling mechanism (14) comprises a base member (16) fixed to the top surface (8) and a seat member (15) configured to receive the funnel (11) and hold the shroud (9) in a shroud casting position. As shown in Figure 3, the seat member (15) is coupled to the base member (16) by at least one compliant element (17) such that the seat member (15) is separate from the base member (16) when the mold / shroud coupling mechanism (14) is at rest and is movable relative to, and preferably towards, the base member (16) upon application of a load to the seat member (15) that deforms the at least one compliant element (17).

[0031] In the mould / shroud coupling mechanism (14) of the present invention, it is not necessary to manually lift the shroud (9) received on the seat member (15) in order to engage the funnel (11) with the nozzle (12) of the ladle (103). In one embodiment of the present invention, the shroud is coupled to the mould in the casting position, i.e. with the funnel resting on the seat member (15) of the mould / shroud coupling mechanism (14), the hollow shaft housed in the bore (7) and the shroud outlet (9o) in the housing (6). In contrast to the mould / shroud coupling mechanism described in EP 3 463 715 B1, in the rest state, the funnel rests on the seat member (15) maintained at a rest distance (h0) from the base member (16) by the reaction force of the compliant element (17) biased in such a way. The nozzle (12) of the ladle (103) is engaged with the funnel (11) resting on the seat member (15) of the mold / shroud coupling mechanism (14) simply by first moving the ladle over the mold relative to the funnel and then lowering the ladle (103) towards the mold (2) until the nozzle engages the funnel, as illustrated in Figures 7a and 7b. In Figure 7a, the nozzle is aligned with the funnel along the vertical direction and is located away from the funnel. Then, as illustrated in Figure 7b, the ladle is lowered and moved downwards towards the funnel so that the nozzle engages the funnel of the shroud. At this stage, the nozzle and the funnel are not coupled to form a sealing contact. To sealingly engage the nozzle with the funnel and prevent air and molten metal from leaking through the interface between the nozzle and the funnel, the ladle is then lowered further as illustrated in FIG. 7c, so that the nozzle contacts the funnel, which rests on the seat member (15) of the mold / shroud coupling mechanism (14), applying a load and deforming the compliant element (17), thereby moving the seat member (15) towards the base member (16), so that coupling of the nozzle and the funnel can be achieved in a controlled manner.As shown in Fig. 7c, the movement of the seat member (15) relative to the base member (16), driven by the downward translation of the pick-up pan and enabled by the deformation of the flexible member (17), reduces the distance between the seat member (15) and the base member (16) from the rest distance (h0) to the sealing distance (h1) with h1 < h0. The downward movement of the seat member towards the base member, of course, causes the shroud to move axially in the bore of the mold. This means that the downward movement of the seat member (15) towards the base member (16) drives the distal end of the shroud and the shroud outlet (9o) deeper into the housing, so the housing inlet (6i) must allow such movement. In addition to means known in the art, the dynamic seal between the moving shroud and the static housing inlet (6i) can be formed using an expandable sealing material, for example a gasket housed in the housing inlet, as described for a slide gate in WO2013 / 088249A2.

[0032] In Figures 7a and 7b, the nozzle is not in contact with the funnel or is barely in contact with it. Thus, the mold / shroud coupling mechanism (14) is in a stationary state where the seat member (15) is maintained at a fixed stationary distance (h0) from the base member (16) and is supported by the compliant element (17) which is also stationary with respect to gravity. In Figure 7c, the mold / shroud coupling mechanism (14) is in a loaded state where the nozzle is in contact with the funnel and exerts a load thereon, i.e., a downwardly oriented force driven by the downward movement of the ladle. This load applied to the funnel is transferred through the seat member to the compliant element (17), which deforms to reach a deformation or loaded state where the seat member (15) moves to a sealing distance (h1) from the base member (16). The reaction force of the compliant element presses the funnel against the nozzle, thus forming a sealing contact at the interface between the nozzle and the funnel. The presence of the compliant element (17) in the present invention replaces the operator's intervention to manually rotate the bayonet and lift the funnel to engage the nozzle, as in the prior art. In the present invention, lowering the ladle to sealingly engage the nozzle with the funnel of the shroud can be accomplished by the operator commanding the position of the ladle. Furthermore, the operator's actions are not repeatable, and the force applied to the interface between the nozzle and the funnel depends on the force applied to rotate the bayonet. With the compliant member (17), the same force is applied in each casting operation, as it is controlled by the flexibility of the compliant member.

[0033] Another advantage provided by the mold / shroud coupling mechanism (14) in the mold of the present invention is that it allows displacement between the sheet member and the base member, and thus between the shroud held by the sheet member and the mold, absorbing the energy generated by such movement and reducing the wear caused by friction between the moving elements. For example, lowering a ladle along the vertical direction requires a high level of precision by the operator commanding the position of the ladle to avoid shocks when engaging and contacting the nozzle with the funnel, i.e. to gently establish contact between the nozzle and the funnel. In the absence of compliant elements, lowering the ladle too far or too quickly could cause significant stresses, shocks, or even breakage in the refractory material of the nozzle and the funnel, especially at the point of contact with the nozzle. The energy of such shocks is partially absorbed in the present invention thanks to the presence of the mold / shroud coupling mechanism (14) that allows for flexible relative displacement between the sheet member and the base member.

[0034] The mold / shroud connection mechanism (14) in the mold of the present invention preferably also makes it possible to compensate for lateral and / or tilted misalignments between the nozzle and the funnel, i.e. horizontal misalignments between the nozzle and the funnel. A lateral misalignment may occur when the ladle is lowered to engage the nozzle with the funnel of the shroud. In the absence of compliant elements (17) in the mold / shroud connection mechanism (14), as in the previous examples, the lateral misalignment may prevent the formation of a sealing contact between the nozzle and the funnel or may cause significant material stresses to compensate for this misalignment in order to establish a sealing contact. In the present invention, the lateral misalignment is compensated by the mold / shroud connection mechanism (14) thanks to the introduction of compliant elements, thereby reducing material stresses and potential defects in the casting equipment. The same applies in the case of a tilted or angular misalignment (α), as illustrated in FIG. 6.

[0035] Similarly, the mold according to the invention with the mold / shroud coupling mechanism (14) also allows for small displacements of the ladle relative to the mold and for maintaining a sealing contact between the nozzle and the funnel during the casting operation. For example, such displacements result from changes in the distribution of the molten metal flowing through the shroud bore and the mass of molten metal held in the ladle as the ladle gradually empties of molten metal during the casting operation, which causes the ladle to tilt slightly or move vertically or laterally, causing the nozzle to engage the funnel, as illustrated in FIG. 6.

[0036] As illustrated in Figures 3, 4 and 5, the base member (16) and the sheet member (15) of the mold / shroud combination mechanism (14) according to the invention can each be provided with a central hole that is aligned with one another and defines a lead-in towards the bore (7) of the shroud (9). In Figures 3, 4 and 5, the base member (16) has a central hole (20) that is circular and forms a lead-in to the bore (7), as shown in the detailed cross-sectional views of Figures 5 and 4, through which the shroud (9) can penetrate into the bore (7) until it reaches the casting position, i.e., until the funnel of the shroud comes to rest on the sheet member with the shroud outlet in the housing (6). As will be explained below, the shroud can be introduced into the bore by a human operator, as shown in Figure 1(1a), or by lowering the ladle with the shroud attached, as shown in Figures 2(1) and 2(2).

[0037] In one embodiment, in which the shroud is in the casting position before the ladle is lowered to establish contact between the nozzle and the funnel (see Figs. 1(1a) and (1) and Fig. 7a), the seat member (15) is formed by a sleeve (21) with arms (18) distributed around the circumference of the sleeve and extending radially outward therefrom, as illustrated in Figs. 3 and 4. The sleeve (21) forms a lead-through for leading the shroud (9) to the casting position. In the rest state, the sleeve is aligned concentrically with the central hole (20) of the base member (16). As shown in Figs. 4 and 7a, in order to fix the funnel in the mold (2), the space between the lead-through of the sleeve and the funnel can be filled with a filler (22), preferably made of molding sand, which forms a seat against which the shoulder (23) of the funnel (11) rests when the shroud (9) is in the casting position.

[0038] The sand fill (22) may contain organic binders such as furan, alkali-phenolic binders, etc. Other binders may also be used, such as inorganic binders or clay minerals. The fill defines a seat for the conical shoulder (23) of the funnel, and at the same time provides a seal and secures the shroud to the mold (2).

[0039] In its cast position in the shroud, the funnel is preferably flush with the upper rim of the sleeve, as illustrated in FIG. 4, or alternatively may be submerged within the sleeve (21) below the upper rim.

[0040] A preferred embodiment of the mold / shroud coupling mechanism (14) of the present invention is depicted in Figure 3. It comprises a seat member (15) configured to receive and hold the funnel (11). The seat member is coupled to a base member (16) by a flexible member (17) in the form of a spiral spring (17s). The seat member (15) has three radially outwardly extending arms (18) equally spaced from each other at a radial distance relative to the axis of symmetry of the drive-through. Those skilled in the art will appreciate that the seat member may have any other shape, for example it may be disc-shaped, and the number of outwardly extending arms may vary.

[0041] The base member (16) is preferably rigidly fixed to the upper surface (8) of the mold (2). For example, the base member can be bonded with adhesives (organic or mineral) or fastening means such as screws, rivets, etc. This ensures that the central hole (20) of the base member remains concentric with the bore (7) during the entire casting operation. The base member also comprises three radially outwardly extending arms (18) equally spaced from one another at a radial distance relative to the axis of symmetry of the central hole (20) and aligned with corresponding opposing arms of the seat member (15). The compliant element (17) is formed by three spiral springs (17s) sandwiched between the seat member and the base member.

[0042] Referring to Figure 3, three spiral springs (17s) extend vertically between three pairs of opposing arms (18) of the seat member (15) and the base member (16). The spiral springs (17s) are evenly distributed around the circumference of the seat member (15) and the base member (16). The arms (18) are provided with centering pins (19) for centering and holding the spiral springs in place, as illustrated in the detailed views of Figures 4 and 8, the centering pins (19) of the seat member (15) and the centering pins (19) of the base member (16) extend in opposite directions, and one centering pin (19) of the base member (16) and a correspondingly positioned centering pin (19) of the seat member (15) are aligned with each other so as to engage one end of the spiral springs (17s) on either side, respectively. In this arrangement, the seat member (15) is supported in a movable manner on the base member by three spiral springs (17s).

[0043] When the shroud (9) with the funnel (11) resting on the seat member (15) is in the casting position, the spiral spring (17s) is in a rest state such that there is a vertical rest distance (h0) between the seat member (15) and the base member (16) (see Figures 4 and 7b).

[0044] When casting metal into the casting cavity (3), the ladle is centered above the mold (2), such that the nozzle (12) of the ladle is aligned with the funnel (11). Subsequently, the ladle (103) suspended by the crane is lowered and the nozzle (12) engages with the funnel (11), thereby exerting a downwardly oriented force that vertically displaces the sheet member (15) towards the base member (16). This vertical displacement is enabled by the deformation of the compliant element (17) (here by the compression of a spiral spring).

[0045] Compliant element (17) In the mold according to the invention, the sheet member (15) is coupled to the base member (16) by at least one compliant element (17), such that the sheet member (15) is separated from the base member (16) and is movable relative to the base member (16) when a load is applied to the sheet member (15) that deforms at least one compliant element (17). In particular, when the ladle is lowered and the nozzle (12) presses against the funnel (11) of the shroud received by the sheet member (15), or when a load or force is applied that is vertically and downwardly oriented, the compliant element (17) moves from a rest state, as illustrated in Figure 7b, where the vertical rest distance (h0) separates the sheet member (15) from the base member (16), to a loaded or deformed state, as illustrated in Figure 7c, where the vertical distance separating the sheet member (15) from the base member (16) is a sealing distance (h1) with h1 < h0. This means that the sheet member (15) moves towards or approaches the base member (16) along the vertical direction when the nozzle applies a vertically and downwardly oriented force to the shroud funnel.

[0046] In addition, the compliant element (17) of the mold / shroud coupling mechanism (14) according to the invention can be configured to allow for lateral displacement of the sheet member (15) relative to the base member (16), i.e., relative displacement between the sheet member and the base member along a horizontal direction orthogonal to the vertical direction.

[0047] In the mold / shroud coupling mechanism (14) of the present invention, the compliant element (17) can be at least partially elastic, and as a result, in a deformed or loaded state, it opposes a reaction force that tends to at least partially restore the stationary state of the mold / shroud coupling mechanism (14). This includes compliant elements (17) that exhibit an elastic behavior (such as a helical spring (17s) made of steel) having an elastic modulus (E') and a loss modulus (E"), or a viscoelastic behavior. For example, when applying a load vertically and downwardly oriented by the nozzle of the ladle onto a funnel received in the seat member to drive the seat element (15) downward from the base element (16) to a sealing distance (d1), the reaction force of the loaded compliant element (17) tends to drive the seat element (15) at least partially towards the initial stationary distance (d0) from the base element (i.e., to a distance h such that h1 < h ≦ h0) when the load is released. Such elastic elements are preferred because they are suitable for maintaining a sealed contact between the funnel and the nozzle during casting even when the nozzle moves slightly up and down due to vibrations during casting. Generally speaking, an elastic compliant element is thus more suitable for use when the nozzle sealedly engaged with the funnel of the shroud moves or vibrates during the casting operation.

[0048] Alternatively, the compliant element (17) can exhibit a purely plastic or viscous behavior, and as a result, it cannot even partially recover its original shape when the load is released. For example, this is the case for a compliant element configured to deform substantially plastically when a load is applied. This can also be the case for a flexible bag or container containing a free-flowing material such as particulate material (e.g., sand), which can absorb energy opposing the viscous flow against the load applied to the shroud and the seat element by the nozzle.

[0049] The mold / shroud coupling mechanism (14) can include one or more compliant elements (17) that extend between the sheet member (15) and the base member (16) and vertically separate the sheet member and the base member from one another. Preferably, the one or more compliant elements (17) include one or more resilient elements that include an elastomeric material or a spring at process temperatures, preferably a spiral spring (17s) as illustrated in FIG.

[0050] In a first embodiment shown in Figure 17a, the elastic element is configured to stretch when moving from a rest state of the elastic element to a deformed or loaded state, which correspond to the rest or loaded state of the mold / shroud coupling mechanism, respectively. This is referred to as a "tension elastic element." The tension elastic element is preferably an expandable spring as illustrated in Figure 17a.

[0051] In a second embodiment shown in Figures 17b to 17d, the elastic element is configured to compress when moving from a rest state of the elastic element to a deformed or loaded state, which respectively correspond to the rest or loaded state of the mold / shroud coupling mechanism. This is referred to as a "compressible elastic element". The compressible elastic element is preferably a compressible spring, preferably a spiral spring (see Figure 17b), a compressible hydraulic or pneumatic piston (see Figure 17c), or a compressible elastomeric or generally viscoelastic element (see Figure 17d).

[0052] In a third embodiment shown in Figure 17e, the elastic member is configured to bend when moving from the rest state of the elastic element to the deformed state. This is referred to as a "flexed elastic element". The flexed elastic element may preferably comprise a curved blade or rod, preferably made of steel or a fibre reinforced composite material attached at one or two points, as illustrated in Figure 17e.

[0053] Alternatively, the compliant element (17) comprises a free-flowing material enclosed in one or more bags or flexible containers configured to viscously deform when a load is applied to the sheet member (15). The compliant element can also include a disposable element configured to break or shatter by plastic deformation when the nozzle applies a load to the funnel.

[0054] Preferably, the mold / shroud coupling mechanism (14) comprises at least three elastic elements, preferably at least three spiral springs (17s), extending between the sheet member (15) and the base member (16), as illustrated in Figures 3, 4 and 5, the at least three elastic elements being preferably equally spaced around the circumference of the central hole of the sheet member (15) and the base member (16). Preferably, the at least three spiral springs, preferably equally spaced, extend between the sheet member and the base member at a distance to the lead-in for the hollow shaft of the shroud at that circumference. This design has the advantage that the spiral springs are not overly heated by the molten metal flowing through the shroud bore from the funnel to the hollow shaft of the shroud during the casting process.

[0055] Mold Assembly In another aspect, the present invention relates to a mold assembly comprising a mold (2) according to the present invention as described above and a shroud (9) in a casting position, the funnel resting on a sheet member (15). The shroud is hollow and comprises a funnel (11) attached to a proximal end of a shaft (10) having a distal end (10d) with a shroud outlet (9o). The shroud casting position is defined as the position where the shaft (10) is received in the bore (7) and the distal end (10d) of the shaft is inserted through the housing inlet (6i) with the shroud outlet (9o) surrounded by the housing (6).

[0056] Preferably, the funnel is located outside the mold, i.e., above and adjacent to the mold top surface (8), and the shaft (10) is received within the bore (7) and is movable up and down therein. The shaft is elongated and extends along a vertical direction so that the molten metal may flow therethrough driven by gravity. The shroud outlet (9o) may comprise one or more openings within the housing (6) for distributing the molten metal.

[0057] In the shrouded casting position as shown in FIG. 5, the hollow shaft extends through the bore (7) and into the housing (6). Molten metal is delivered to the casting cavity (3) through a shroud line that extends from the ladle to the casting cavity including the nozzle, the shroud, the housing, and the feed channel (5). The shroud line is substantially airtight and prevents reoxidation of the metal by protecting it from the atmosphere. The hollow shaft (10) delivers molten metal to the casting cavity (3) through the inlet (4) through the housing (6) and through the feed channel (5). The bore (7), which extends substantially perpendicular to the top surface (8) of the mold (2), is sized to receive the shroud (9) so that there is substantially no gap between them while allowing linear movement of the shroud (9) within the bore (7). In fluid communication with the casting cavity (3) is an open feeder sleeve (13) that extends between the casting cavity (3) and the top surface (8) of the mold (2).

[0058] The shroud (9) is made of a refractory material, for example fused silica. Alternatively, the shroud can be made of other materials, such as alumina graphite materials. Preferably, the proximal end of the shroud (9) forming the funnel (11) has a conical shape with an inclined shoulder (23) that rests on the sheet member (15). In one embodiment, the shoulder rests on a filler (22) that fills the space between the sleeve of the sheet member (15) and the funnel, as can be seen from the cross-sectional view in FIG. 4. Alternatively, the shroud shoulder rests directly on the sheet element, as shown in FIG. 9c, FIG. 9d, FIG. 12, and FIG. 13.

[0059] In a preferred embodiment of the mold assembly according to the invention, the shroud (9) is preferably fixed to the seat member (15) with a filling of foundry sand (22) which seals the annular gap between the funnel (11) and the seat member (15) and defines a seat for the funnel (11), the seat member (15) preferably comprising a sleeve (21) which defines the boundary of the annular gap, as illustrated in FIG. 4.

[0060] In a preferred embodiment of the invention, a gasket is placed at the mouth of the funnel (11) and allows an essentially tight engagement between the nozzle (12) and the funnel (11). The gasket can be formed, for example, by plasticized clay or by an expansive material.

[0061] Casting Equipment In another aspect, the invention relates to a casting apparatus including a mold (2) according to the invention, a shroud (9), and a ladle (103) with a nozzle (12) at the base of the ladle (103) for dispensing molten metal from the ladle (103). The nozzle (12) is configured to reversibly and sealingly engage the funnel (11) of the shroud (9). The ladle (103) is configured to be displaced relative to the mold (2), for example, to position the nozzle (12) substantially vertically above the mold / shroud coupling mechanism (14) and to vertically lower the nozzle (12) by applying a load to the seat member (15) until it is sealingly engaged with the funnel (11) of the shroud (9) in the shroud casting position. The casting apparatus may include a gasket, preferably located in the funnel. In the casting apparatus, the shroud (9) may be secured to the sheet member, preferably with a filler (22), or may be detachable and removable from the sheet member (15).

[0062] As can also be seen from FIG. 6, the nozzle of the ladle preferably has a hemispherical shape and the funnel (11) is correspondingly shaped. The funnel and the nozzle are preferably complementary in shape, for example forming a mating spherical cap or otherwise curved surface, so that tilting of the ladle can be tolerated within certain limits. If the compliant element (17) comprises an elastic element such as a spiral spring, the reaction force of the compliant element also ensures that the nozzle (12) and the funnel (11) remain in sealing engagement with each other during casting. The reaction force exerted by the compliant element ensures that the nozzle and the funnel are held in sealing engagement with each other while sufficient pressure is always maintained on the sealing surfaces or gaskets in the funnel. The compliant element may also compensate for tilting or up and down vibrations of the ladle that may occur due to the fact that the center of gravity of the ladle may change during casting, i.e. while the ladle is emptying.

[0063] The funnel and nozzle are preferably configured such that the nozzle is self-centering within the funnel. For example, the surface of the funnel configured to receive the nozzle may have a conical shape as depicted in Figures 3 and 4, so that when the ladle (103) is lowered vertically to engage the nozzle with the funnel with the nozzle not perfectly aligned with the funnel, the nozzle (12) can slide on the conical surface and exert a force on the seat member (15) to displace it along the horizontal direction and restore alignment between the nozzle and the funnel, and ultimately, the sealing engagement of the nozzle within the funnel.

[0064] Ladle / shroud connection mechanism (140) A preferred embodiment of a casting apparatus according to the present invention includes a ladle / shroud coupling mechanism (140) configured to reversibly grip the shroud (9) to the nozzle (12), preferably without forming a seal between the funnel (11) and the nozzle (12).

[0065] As illustrated in Figures 2 and 9a, this allows the ladle to be moved with the shroud suspended thereon, which is advantageous if the shroud can be reused for several castings in succession, for example as illustrated in Figure 2. If a series of subsequent castings are to be made with the same ladle and shroud (9), the shroud can be disengaged from the bore of the first mould, for example after completing the casting of the metal in the first mould by lifting the ladle up (see Figure 2 - step 4). The ladle is then translated horizontally to position the shroud over the bore of the second mould (see Figure 2 - step 5). The ladle is then lowered downwards (see Figure 2 - step 1) until the shroud reaches the casting position (see Figure 2 - step 2), and the subsequent casting can be made into the second mould. This operation can be repeated as long as the shroud remains in casting condition. The used shroud can then be removed (see FIG. 2-step 1b) and a new shroud can be fitted to the ladle (see FIG. 2-step 1a). This ladle / shroud coupling mechanism allows the same shroud to be used repeatedly several times for multiple castings. It also reduces the operator's workload, since the coupling between the ladle, shroud and mould can be performed only by the operator commanding the ladle positioning system. Between two castings with the same shroud, the shroud heated by the previous casting in one mould does not need to be manipulated by the operator to position it in the casting position in the subsequent mould, thus improving safety.

[0066] As shown in Figure 9a, the ladle / shroud coupling mechanism (140) comprises a funnel adapter (140f) fixed to the funnel of the shroud (9) and equipped with a retaining means. The funnel adapter (140f) is generally made of metal and is fixed to the shoulder of the shroud with an adhesive filler (113) such as cement. The ladle / shroud coupling mechanism (140) also comprises a nozzle adapter (140n) fixed to the base or nozzle (12) of the ladle (103) and configured to engage with the retaining means of the funnel adapter (140f) to reversibly lock the shroud (9) to the nozzle (12) in a locked position. The unlocked and locked positions of the ladle / shroud coupling mechanism (140) are depicted in Figures 10 and 11, respectively. The base of the ladle is the lowest part of the ladle that is in use. A nozzle adaptor (140n) is preferably attached to the base of the bottom pour ladle.

[0067] The funnel adapter (140f) and the nozzle adapter (140n) are complementary to each other and are configured to releasably and loosely engage each other in the locked position. One important aspect of the ladle / shroud coupling mechanism (140) according to the present invention is that the funnel adapter (140f) and the nozzle adapter (140n) are configured to loosely engage each other in the locked position. This means that the funnel adapter and the nozzle adapter engage each other in the locked position with sufficient play relative to each other so that they can articulate to some extent relative to each other within certain limits. This design allows for relative movement of the shroud and the ladle when the shroud is attached to the ladle, such that the risk of damage to the shroud during, for example, insertion into the bore of the mold is significantly reduced. In the locked position, preferably, no sealing contact is formed between the nozzle and the funnel.

[0068] In a preferred embodiment of the ladle / shroud coupling mechanism depicted in Figures 10 and 11, the holding means of the funnel adapter (140f) comprises a holding peg (109) and the nozzle adapter (140n) comprises a fastening hook (107) configured to reversibly engage with the holding peg (109), preferably self-engaging with the holding peg (109). The self-engaging fastening hook allows the shroud to be easily gripped to the ladle. For example, this allows the ladle to be used to pick up the shroud held in casting position in the first mold (2) according to the invention, as illustrated in Figure 10, by lowering the ladle so as to engage the holding means of the funnel adapter with the nozzle adapter, as illustrated in Figures 11 and 15, and then the ladle can be lifted to remove the shroud from the bore, as illustrated in Figures 14 and 16.

[0069] 12, the funnel adapter (140f) may be a sleeve-like element having a truncated bearing surface (114) that rests on a beveled edge (115) in a central bore (25) of a seat member (15) that forms a seat for the funnel adapter (140f). The funnel adapter (140f) rests loosely on the seat member (15) and is held only by gravity, i.e., the weight of the shroud (9) which is suspended from the funnel adapter (140f).

[0070] Extending radially outward on the outer periphery of the funnel adapter (140f) are three or four retention pegs (109) which may be engaged by fastening hooks (107) attached to a nozzle adapter (140n) which is attached to the ladle base plate (105).

[0071] The nozzle adapter (140n) is designed as a socket that surrounds the nozzle (12). At the side attached to the ladle (103), also called the proximal side, the first coupling member (11) comprises a bayonet ring (106) that engages with the ladle base plate (105). The nozzle adapter (140n) is removably connected to the ladle (103). At the other end of the nozzle adapter (140n), also called the distal end, the nozzle adapter (140n) comprises a number of studs (111) on which the fastening hooks (107) are rotatably attached.

[0072] During lowering of the nozzle (12) into the funnel (11), the nozzle adapter (140n) and the funnel adapter (140f) are engaged with each other. The coupling and locking of the nozzle adapter and the funnel adapter can be achieved in different ways. The fastening hook (107) can be self-engaging. The inclined surface (112) of the fastening hook (107) slides over the retaining peg (109) so that the fastening hook (107) captures the retaining peg (109).

[0073] Alternatively, the funnel adapter (140f) can be rotated such that the retaining peg (109) is disposed between the fastening hooks (107) when the ladle (103) is lowered, and then locking of the retaining peg (109) in the fastening hooks (107) is achieved when the funnel adapter (140f) is rotated, for example, counterclockwise.

[0074] Once coupled as shown in FIG. 13, the ladle (103) with the shroud (9) hanging thereon can be lifted for insertion into a second mold for a second casting using the same shroud.

[0075] In another embodiment of the ladle / shroud coupling mechanism (140), the retention means of the funnel adapter (140f) includes one or more retention pegs (109), and the nozzle adapter (140n) is provided with a bayonet coupling element configured to interact with the one or more retention pegs to reversibly lock the shroud (9) to the nozzle (12) in a locked position.

[0076] The nozzle adapter (140n) may be in the form of a sleeve-like member that may be configured as a bayonet coupling element at one and / or both ends. The nozzle adapter (140n) may surround the nozzle and may be releasably attached to the ladle base plate (105), as illustrated in Figures 12 and 13. For example, at one end, the nozzle adapter (140n) may be configured as a bayonet ring (106) that engages with a corresponding structure on the ladle base plate.

[0077] In a particularly preferred embodiment of the ladle / shroud coupling mechanism according to the invention, the funnel adapter and / or the nozzle adapter are rotatable about a longitudinal axis to enable at least disengagement of the funnel adapter and the nozzle adapter by rotating either the funnel adapter or the nozzle adapter about said longitudinal axis.

[0078] In the casting apparatus according to the present invention, the seat member (15) of the mold / shroud connection mechanism (14) is configured to receive the funnel adapter (140f) and hold the shroud (9) in the shroud casting position.

[0079] The funnel adapter (140f) is preferably fixed to the shroud (9) with an adhesive material (113), as represented in Figures 12 and 13. Preferably, the proximal end of the shroud in the region of the funnel may have the shape of a cone, the shoulder (23) of which is held in the adhesive material (113), which is preferably, for example, a filling or packing material of the foundry sand of the funnel adapter, which may contain an organic binder. The funnel adapter may be designed as a sleeve-like element. The funnel adapter preferably surrounds the adhesive material (113).

[0080] The funnel adapter (140f) may be configured to be received in a centrally located manner in the sheet member (15) on the mold (2), and thus may include a truncated bearing surface.

[0081] Preferably, the casting apparatus according to the invention allows the coupling of the ladle and the shroud in situ, i.e. while the shroud is inserted in the mold. Thus, a separate mounting stand for the ladle is not required. With this system, it is possible to insert the shroud into the mold using a separate crane. Once the shroud is inserted in the mold, the ladle can be located above the mold with the nozzle centered on the funnel of the shroud. When lowering the ladle, the nozzle can be engaged with the funnel of the shroud. While engaging the nozzle of the ladle with the funnel, the funnel adapter and the shroud adapter can be locked together such that the ladle and the shroud are loosely locked together.

[0082] Those skilled in the art will appreciate that the downwardly directed force when lowering the ladle nozzle into the funnel will move the sheet member toward the base member against the reaction force of the compliant elements, preferably against the spring tension of at least one spring, so that the coupling of the nozzle and the funnel can be effected in a controlled manner. The downward movement of the sheet member toward the base member will, of course, cause the shroud to move axially within the bore of the mold. For example, if the distal end of the shroud extends into the housing of the mold, the downward movement of the sheet member toward the base member will drive the distal end of the shroud deeper into the housing where at least one shroud outlet (9o) communicates with the runner system of the mold, i.e., the casting cavity via the feed channel (5).

[0083] In the existing technology, the so-called Harrison process proposed by Harrison Steel Castings Company involves mounting a fused silica shroud under the nozzle of a bottom-pour ladle. The mold is provided with side risers to receive the shroud. Beneath the side risers is a pouring well that flows into the casting cavity. With the shroud mounted, the ladle is aligned over the mold and then lowered to insert the shroud into the side risers. The stopper rod is then moved to an open position so that the molten metal in the ladle flows through the nozzle and the shroud into the mold. Once the mold is filled, the stopper is closed. The ladle is raised until the shroud clears the mold and then moved to the next mold to repeat the process. To mount the shroud under the nozzle of the bottom-pour ladle, the ladle is first secured to a mounting stand and then the shroud is fixedly attached to a shroud holder assembly that is connected to the ladle base plate.

[0084] One drawback of this rigid and fixed attachment of the shroud to the nozzle is that cleaning of the nozzle by oxygen lancing is nearly impossible. Because the material selected for the shroud is fused silica, inserting the shroud into the side risers of the mold while attaching it to the bottom of the ladle is a difficult and critical operation since even a slight tilt of the shroud can result in the destruction of the shroud.

[0085] In the present invention, the previous disadvantages are avoided by loosely gripping the shroud to the ladle and providing compliant elements to allow relative displacement between the seat and base members of the mold / shroud coupling mechanism (14). This reduces the risk of destroying the shroud when inserting it into the mold, and therefore provides a safer system for handling the shroud in order to obtain multiple castings with one shroud and one pour heat.

[0086] To further enhance the security of engagement of the shroud gripped to the ladle in the bore of the mold, the seat member (15) preferably includes a conical portion centered about a central hole of the seat member and configured to guide the shroud (9) into alignment with the bore (7) when the ladle (103) is lowered vertically with the shroud (9) reversibly locked to the nozzle (12).

[0087] Methods without ladle / shroud coupling mechanism (140) The invention also relates to a method for casting molten metal using a casting device according to the invention.

[0088] In a first embodiment of the method illustrated in Figure 1, the casting apparatus does not include a ladle / shroud coupling mechanism (140) and the shroud is inserted into the bore (7) at the casting position before the ladle approaches the mold. As represented in step 1a of Figure 1, a casting apparatus is provided that includes a mold (2) and a shroud (9) inserted therein to reach the casting position. Preferably, when the mold is installed for use, the axis of symmetry of the mold's bore is vertical and the shroud is installed in the bore by translating it along the vertical direction. The shroud (9) can be inserted into the mold (2) by an operator or using one or more dedicated tools or robots, as illustrated in Figure 1(1a). As illustrated in Figure 5, the shaft (7) is inserted into the bore (7) of the mold until the shroud is attached in a casting position defined as the shaft (10) housed in the bore (7), its distal end (10d) inserted through the housing inlet (6i) and the shroud outlet (9o) enclosed in the housing (6). In the shroud casting position, the longitudinal axis of the hollow shaft (10) is preferably vertical. The shroud (9) is held in the shroud casting position by a seat member (15) on which the funnel (11) rests.

[0089] In one example of the invention, the funnel of the shroud comprises a shoulder for seating the funnel on the seat member (15), the funnel is received directly on the seat member (15), and the shroud is releasably maintained in the shroud casting position under the force of gravity. In another example, a filler (22) is provided between the funnel and the seat member (15). The shroud (9) is fixed to the seat member (15) by the filler (22), which seals the annular gap between the funnel (11) and the seat member (15) and defines a seat for the funnel (11). Preferably, the seat member (15) comprises a sleeve (21) that defines the boundaries of the annular gap, and the filler (22) can be applied to the sleeve (21) before receiving and seating the funnel on the filler (22). The filler should then be allowed to dry until the funnel is fixed to the seat member (15).

[0090] After step 1a of FIG. 1, the mold assembly is ready to receive molten metal. As illustrated in step 1 of FIG. 1 and in the detailed view of FIG. 7a, the ladle filled with molten metal (103) is moved, for example by a crane, onto the first mold with the shroud until the nozzle at the base of the ladle is vertically aligned with the mold / shroud coupling mechanism (14) and the bore (7). The ladle (103) is then lowered until the nozzle (12) engages the funnel of the shroud (9), as illustrated in FIG. 7b. Before contacting the funnel with the nozzle and applying a load to the funnel, the mold / shroud coupling mechanism (14) and compliant element are in a stationary state with the seat and base members separated by a stationary distance h0 measured along the vertical direction.

[0091] Next, the method further vertically lowers the ladle (103) until the nozzle (12) engaged with the funnel (11) applies a load to the funnel placed on the sheet member (15), and thus moves the sheet member (15) relative to the base member (16) against the compliant element (17), forming a sealing contact between the nozzle (12) and the shroud (9) in the shroud casting position. This is illustrated in step 2 of FIG. 1 and the detailed view of FIG. 7c, where the mold / shroud coupling mechanism (14) and the compliant element are in a loaded state where the sheet member and the base member are separated by a sealing distance h1 < h0 measured along the vertical direction.

[0092] After establishing the sealing contact between the nozzle (12) and the funnel (11), the casting of the molten metal can be started. The nozzle is opened, thereby enabling the molten metal to flow from the ladle (103) through the nozzle (12), the shroud (9), and the housing (6) of the first mold into the casting cavity (3). As illustrated in step 3 of FIG. 1, when the casting cavity is full, the nozzle can be closed to stop the flow of the molten metal.

[0093] As illustrated in step 4 of FIG. 1, after the casting is completed, the ladle is vertically lifted to disengage the nozzle from the funnel of the shroud, thus removing the load on the sheet member (15) from the nozzle. The shroud remains inserted in the first mold with the funnel held by the sheet member and the shaft received in the bore (7), without being gripped by the ladle. If the compliant element does not include an elastic element, the mold / shroud coupling mechanism (14) and the compliant element remain in the loaded state and the shroud does not move when the ladle is lifted. If the compliant element includes an elastic element, the mold / shroud coupling mechanism (14) and the compliant element can at least partially return to a stationary state when the ladle is lifted, and the shroud held by the sheet member can correspondingly slide upward within the bore.

[0094] The ladle is then available for a subsequent casting into the second mold, preferably another pour using the same heat, as illustrated in FIG. 1-step 5, where the ladle is translated horizontally over the second mold to perform the next casting according to the method of the present invention, where the ladle does not include the ladle / shroud coupling mechanism (140).

[0095] A method using a ladle / shroud coupling mechanism (140) In a second embodiment of the method according to the invention, a casting apparatus is provided with a ladle / shroud coupling mechanism (140). Such a method is illustrated in Fig. 2. For casting, a first and a second mold (2), a shroud (9) with a funnel adapter (140f) fixed thereto, and a ladle with a nozzle adapter (140n) fixed to the ladle base or nozzle are provided. There are at least two ways to initialize a cast using a casting apparatus with a ladle / shroud coupling mechanism (140).

[0096] In a first method of initializing the cast, illustrated in FIG. 2-Step 1a, the shroud is clamped to the ladle prior to inserting the shroud into the first mold. For example, this can be accomplished by engaging the funnel (11) of the shroud (9) over the nozzle (12) and A holding means for the funnel adapter (140f) fixed to the funnel of the shroud (9), Engage with a nozzle adapter (140n) fixed to the base of the ladle (103) or the nozzle (12), For example, this can be accomplished by an operator lifting the shroud (9) toward the base of the ladle to grip the shroud (9) to the nozzle (12) using the ladle / shroud coupling mechanism (140) by locking the shroud (9) to the nozzle (12) in a locked position.

[0097] Alternatively, the ladle can be displaced over the storage location of the shroud (9) and the shroud can be picked up by lowering the ladle with the nozzle vertically aligned with the funnel until the nozzle engages the funnel and the ladle / shroud coupling mechanism (140) is used to grasp the shroud (9) to the nozzle (12).

[0098] Once the shroud is gripped onto the ladle, the ladle As illustrated in step 1 of FIG. 2 and in FIG. 9b, the shroud (9) locked substantially vertically to the nozzle (12) is positioned on the mold / shroud coupling mechanism (14), and then As illustrated in Figure 9c and Figure 2-Step 2, with the funnel (11) resting on the sheet member (15), the ladle can be moved vertically down until the shroud (9) reaches the shroud casting position.

[0099] Preferably, the funnel rests on the sheet member (15) via a funnel adapter (140f), i.e., the funnel adapter (140f) is fixed to the funnel and is configured to be received in the sheet member (15) of the mold / shroud coupling mechanism (14) as illustrated in FIG. 9c, with a conical portion of the sheet member (15) mating with a corresponding conical portion of the funnel adapter (140f).

[0100] Sealing contact between the nozzle (12) and the shroud (9) in the shroud casting position is formed by further lowering the ladle (103) vertically until the nozzle (12) engaged with the funnel (11) loads the funnel resting on the seat member (15), thus moving the seat member (15) against the compliant element (17) and relative to the base member (16). This is illustrated in step 2 of Figure 2 and Figure 9d.

[0101] In a second method of initializing the cast, the shroud (9) is inserted into the first mold in the casting position before being gripped by the ladle. The gripping of the shroud is performed by lowering the nozzle towards the funnel, as illustrated in Figures 2(2a) and (2), 10 and 12, and a sealing contact is made as the nozzle is driven further down against the resistance provided by the compliant element (17). Preferably, the ladle and the shroud are loosely, but not releasably, locked together before the sealing contact is made.

[0102] In a second method of initializing the cast, illustrated in Figure 2-Step 2a, a sealing contact between the nozzle (12) and the shroud (9) in the shroud casting position is formed after gripping the shroud to the ladle. This is achieved by further lowering the ladle (103) vertically until the nozzle (12) engaged with the funnel (11) loads the funnel resting on the seat member (15), thus moving the seat member (15) against the compliant element (17) and relative to the base member (16), as illustrated in Figure 2-Step 2 and Figure 9d.

[0103] After establishing sealing contact between the nozzle (12) and the funnel (11) according to the first or second method of initializing casting, the nozzle is opened, thereby allowing molten metal to flow from the ladle (103) through the nozzle (12), the shroud (9), and the first mold housing (6) into the casting cavity (3). Once casting is completed or the casting cavity is full, as illustrated in step 3 of Figure 2, the nozzle can be closed to stop the flow of molten metal.

[0104] As illustrated in step 4 of FIG. 2, when casting is completed, the ladle with the shroud gripped thereon is lifted vertically, the shroud is disengaged from the first mold, and the nozzle is unloaded from the seat member (15).

[0105] The ladle with the shroud attached is then available for a subsequent casting into the second mold with the same heat, as illustrated in step 5 of FIG. 2, where the ladle is translated horizontally onto the second mold to perform the next casting according to the present method, which includes the ladle / shroud attachment mechanism (140). Alternatively, at the end of the series of castings, or if the shroud is degraded, no further castings are performed and the ladle, with the shroud still gripped, is transported to a disassembly location of the facility where the shroud is separated from the ladle. The shroud (9) and nozzle (12) are unlocked by disengaging the retention means of the funnel adapter (140f) from the nozzle adapter (140n), and the funnel and funnel adapter (140f) are preferably removed, so that the funnel adapter (140f) can later be reused and secured to another shroud. A new shroud can be used to continue casting with a new series of molds.

[0106] List of Reference Numbers 1 Casting equipment 2. Mold 2a Top of the mold 2b Lower part of mold 3 Casting Cavity 4 Cavity entrance 5. Supply Channels 6. Housing 6i Housing entrance 6o Housing Exit 7 Bore 8 Top of mold 9. Shroud 9o Shroud Exit 10 Shroud Shaft 11 Funnel 12 Nozzles 13 Feeder sleeve 14 Mold / shroud connection mechanism 15 Sheet material 16 Base material 17 Compliant Elements 17s Spiral Spring 18 Arm 19 Centering pin 20 Center hole of base member 21 Sleeve 22 Filling 23 Shoulder 103 Ladle 105 Ladle Base Plate 106 Bayonet Ring 107 Fastening hook 109 Retaining Peg 111 Stud 112 Slope 113 Adhesive materials 114 Bearing surface 115 Sloped Edge 140f funnel adapter 140n nozzle adapter

Claims

1. A mold (2) for casting molten metal, comprising: ● A casting cavity (3) having a cavity inlet (4); ● A housing (6) selected from a filter housing and a diverter housing, having a housing outlet (6o) in fluid communication with the cavity inlet (4) and a housing inlet (6i) in fluid communication with a bore (7); ● A bore (7) extending between the upper surface (8) of the mold and the housing inlet (6i); ● A mold / shroud coupling mechanism (14) configured to receive a shroud (9) of a casting apparatus (1) in a shroud casting position, the shroud including a funnel (11) attached to the proximal end of a shaft (10) that is hollow and has a distal end (10d) with a shroud outlet (9o), the shroud casting position being when the distal end (10d) is inserted into the housing inlet (6i) and the shaft (10) is received in the bore (7) such that the shroud outlet (9o) is surrounded by the housing (6); The mold / shroud coupling mechanism (14) comprising: ○ A base member (16) fixed to the upper surface (8); ○ A seat member (15) configured to receive the funnel (11) and hold the shroud (9) in the shroud casting position; And the seat member (15) being coupled to the base member (16) by at least one compliant element (17), such that the seat member (15) is movable relative to the base member (16) when a load is applied to the seat member (15) that separates the seat member (15) from the base member (16) and deforms the at least one compliant element (17), the compliant element (17) including one or more elastic elements including a spring extending between the seat member (15) and the base member (16). A mold (2) characterized by this.

2. The base member (16) and the seat member (15) each comprise a central hole aligned with each other so as to define a lead-in towards the bore (7) for the shroud (9), and the mold / shroud coupling mechanism (14) comprises at least three elastic elements extending between the seat member (15) and the base member (16), and the at least three elastic elements are preferably arranged equidistantly around the circumference of the central holes of the seat member (15) and the base member (16). The mold (2) according to claim 1.

3. A mold assembly, ● The mold (2) according to claim 1 or 2, and ● The shroud (9) according to claim 1, wherein the seat member (15) is received in the mold (2) in a state of receiving the funnel (11) and holding the shroud (9) in the shroud casting position. The shroud (9) according to claim 1. A mold assembly comprising.

4. The shroud (9) seals an annular gap between the funnel (11) and the seat member (15) and is fixed to the seat member (15) with a filling (22) of foundry sand that defines a seat for the funnel (11). The mold assembly according to claim 3.

5. A casting apparatus, ● The mold (2) according to any one of claims 1 or 2, and ● The shroud (9) according to claim 1, ● A ladle (103) comprising a nozzle (12) provided at the base of the ladle (103) for distributing molten metal from the ladle, the nozzle (12) being configured to reversibly and sealingly engage the funnel (11) of the shroud (9), and the ladle (103) being, for example, ○ Positioned substantially vertically above the mold / shroud coupling mechanism (14) such that the nozzle (12) is, and ○ The nozzle (12) is configured to be displaced vertically until it is sealingly engaged with the funnel (11) of the shroud (9) in the shroud casting position by applying the load to the seat member (15). A casting apparatus comprising a ladle (103).

6. Preferably, a ladle / shroud coupling mechanism (140) is provided that is configured to reversibly grip the shroud (9) to the nozzle (12) without forming a seal between the funnel (11) and the nozzle (12), and the ladle / shroud coupling mechanism (140) comprises ○ a funnel adapter (140f) fixed to the funnel of the shroud (9) and comprising holding means; ○ a nozzle adapter (140n) fixed to the base of the ladle (103) or the nozzle (12) and engaging with the holding means of the funnel adapter (140f) to reversibly lock the shroud (9) to the nozzle (12) in a locked position, the casting apparatus according to claim 5.

7. The casting apparatus according to claim 6, wherein the holding means of the funnel adapter (140f) includes a holding peg (109), and the nozzle adapter (140n) includes a fastening hook (107) configured to reversibly engage with the holding peg (109), and preferably, the holding peg (109) is configured to self-engage.

8. The casting apparatus according to claim 6, wherein the holding means of the funnel adapter (140f) includes one or more holding pegs (109), and the nozzle adapter (140n) includes a bayonet coupling element configured to interact with the one or more holding pegs to reversibly lock the shroud (9) to the nozzle (12) in the locked position.

9. The casting apparatus according to claim 6, wherein the funnel adapter (140f) is fixed to the shroud (9) with an adhesive material (113).

10. The casting apparatus according to claim 6, wherein the mold (2) is as described in claim 3, the sheet member (15) includes a conical portion disposed around the central hole of the sheet member, and the conical portion is configured to align and guide the shroud with the bore (7) when the ladle (103) is lowered vertically with the shroud (9) reversibly locked to the nozzle (12).

11. A method for casting molten metal using the casting apparatus according to claim 5, comprising ● Lowering the ladle (103) vertically until the nozzle (12) engaged with the funnel (11) applies a load to the funnel placed on the sheet member (15), and thus moving the sheet member (15) relative to the base member (16) against the compliant element (17) to form a sealed contact between the nozzle (12) and the shroud (9) at the shroud casting position. ● Allowing the molten metal to flow from the ladle (103) to the casting cavity (3) through the nozzle (12), the shroud (9), and the housing (6). A method comprising these steps.

12. The casting apparatus comprises the mold assembly according to claim 4, engaging the nozzle (12) with the funnel (11) by lowering the ladle (103) vertically, and further lowering the ladle (103) of the nozzle (12) to apply the load to the funnel (11) to form the sealed contact between the nozzle (12) and the shroud (9). The method according to claim 11, including these steps.

13. The casting apparatus is as described in claim 6, ● Engaging the nozzle (12) with the funnel (11) of the shroud (9), ○ Engaging the holding means of the funnel adapter (140f) fixed to the funnel of the shroud (9) with, ○ The nozzle adapter (140n) fixed to the base of the ladle (103) or the nozzle (12), For example, gripping the shroud (9) to the nozzle (12) using the ladle / shroud coupling mechanism (140) by locking the shroud (9) to the nozzle (12) in a locked position. ● Positioning the shroud (9) locked to the nozzle (12) substantially vertically above the mold / shroud coupling mechanism (14). ● Lowering the shroud (9) vertically until it reaches the shroud casting position while the funnel (11) is stationary on the sheet member (15). ● Further lowering the ladle (103) of the nozzle (12) to apply the load to the funnel (11) to form the sealed contact between the nozzle (12) and the shroud (9). The method according to claim 11, including these steps.

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