Multipart ceramic support element

Abstract

The invention relates to a multipart ceramic support element (1) for spacing ceramic bases (80) of an oven shelf (100), comprising an upper part (2) and a lower part (3). The upper part (2) can be releasably connected to the lower part (3) for the purpose of fixing a shelf base (80) between the upper part (2) and the lower part (3) in an axial direction by means of a locking connection, wherein the locking connection is formed by a pin (7), which is provided on one part (2) and which comprises one or more locking noses (11) that protrude from the pin (7), and an opening (12), which is provided on the respective other part (3), and the pin (7) can be plugged into the opening (12) and can be rotated in the opening (12) without a simultaneous movement into the opening (12) or in the opposite direction such that each of the one or more locking noses (11) can be locked in a locking receiving area (31) formed by the part (3) which has the opening (12).

Description

[0001] Multi-part ceramic support element

[0002] The invention relates to a multi-part ceramic support element for spacing ceramic shelves of a furnace shelf.

[0003] Multi-part ceramic support elements for spacing ceramic shelves are known from the prior art. For example, WO 2007 / 132276 A1 discloses ceramic support elements with an upper part and a lower part. A pin with an external thread is arranged on the upper part, which is screwed to an internal thread provided in an opening on the lower part. A plate stand or a fire plate is firmly screwed in between the upper and lower parts to serve as a shelf. Another multi-part ceramic support element is disclosed in DE 102008022159 B4, in which an upper part and a lower part can be detachably connected axially by means of a screw connection for the purpose of fixing a shelf between the upper part and the lower part. DE 102004023076 A1 discloses a device for connecting coaxial pipes, in particular for shelving systems.Further prior art can be found in DE 102018114817 A1 and DE 102014115098 A1.

[0004] In general, a disadvantage of screwed ceramic support elements is that, due to the material properties of the high-temperature-resistant ceramic materials used for the support elements and shelves, a secure, force-locking connection cannot be achieved by applying preload. In any case, the screw connection must not be tightened sufficiently due to the risk of breakage of the ceramic material, which, however, promotes loosening of the screw connection. As has been shown in practice, loosening of the screw connection can also be caused by vibrations and, in general, by movements during robot-assisted, automated handling of a shelf with an attached support element. Furthermore, thermal stress during use in the furnace can also lead to loosening of the screw connection.

[0005] This poses a major problem in the automated handling, loading, and unloading of kiln racks. Loose screw connections are always accompanied by local changes in the spacing and position of shelves in the kiln rack, meaning that the usually precisely defined gripping and depositing positions of gripper arms in automated production processes no longer fit and can even lead to damage to the kiln rack. This can lead to malfunctions in automated production processes, the rectification of which is disadvantageously associated with time and expense.

[0006] Based on this, the object of the invention is to provide a multi-part ceramic support element for the spacing of standard shelves of a ceramic kiln shelf, which overcomes the above-mentioned disadvantages of the support elements known in the prior art, ensures trouble-free operation even in automated production processes and is characterized by a simple design and a long service life even at the highest kiln temperatures.

[0007] The object of the present invention is achieved by a multi-part ceramic support element according to independent claim 1. Preferred embodiments are evident from the subclaims.

[0008] According to the invention, a multi-part ceramic support element for spacing ceramic shelves of a furnace shelf is shown. The multi-part ceramic support element consists of one or more ceramic materials, i.e., it contains no non-ceramic material. The multi-part ceramic support element comprises an upper part and a lower part for the purpose of fixing a shelf between the upper part and the lower part. The upper part and the lower part are preferably manufactured by a casting process, in particular by an injection molding process.

[0009] The terms "upper part" and "lower part" refer to the relative arrangement of the two parts in a typically horizontal working position of a fixed shelf in an oven rack, with the upper part being arranged at least partially above the fixed shelf and the lower part being arranged at least partially below the fixed shelf.

[0010] In the support element according to the invention, the upper and lower parts can be detachably connected axially by means of a locking connection. The locking connection is formed by a pin provided on one part (e.g. upper part) with one or more locking lugs projecting from the pin and an opening provided on the other part (e.g. lower part), wherein the pin can be inserted into the opening and rotated in the opening without simultaneously moving into the opening or in the opposite direction such that the one or more locking lugs can each be locked in a locking receptacle formed by the part having the opening. The locking connection prevents movement of the pin out of the opening.

[0011] A "pin" in the sense of the present invention is understood to mean an element protruding from one part, which, due to its geometric shape, is suitable for insertion into an opening provided on the other part to create a releasable locking connection. The pin is typically elongated.

[0012] An "opening" in the sense of the present invention is understood to mean a cavity formed by the other part which has a shape such that the pin can be at least partially inserted into the cavity.

[0013] According to an advantageous embodiment, the part having the opening is designed in the shape of a sleeve. In accordance with the common understanding of the term "sleeve," this is understood to mean a hollow body with a cylindrical outer shape.

[0014] For the purposes of the invention, "axial" or "axial direction" refers to the direction in which the pin can be moved into the opening, or the opposite direction in which the pin can be moved out of the opening. Thus, "axial" corresponds to the assembly or disassembly direction of the multi-part support element. The term "radial" refers to a direction perpendicular to the axial direction.

[0015] According to the invention, in the multi-part support element, the upper and lower parts can be releasably connected axially by means of a locking connection. This creates an axial connection between the upper and lower parts by locking, so that the upper and lower parts cannot be released in the axial direction when locked, i.e. the pin cannot be moved out of the opening. For this purpose, the pin has one or more locking lugs, which can each be locked into a locking recess by turning the pin within the opening. This requires that the pin can be at least partially inserted into the opening, i.e. the opening must have a shape such that the pin with one or more locking lugs can be at least partially inserted into the opening and the one or more locking lugs are arranged within the opening. Preferably, the opening has a shape corresponding to the pin and the one or more locking lugs in sections.It is essential that the opening has a shape in sections such that the pin inserted into the opening can be rotated within the opening such that the one or more locking lugs can each be locked in a locking receptacle formed by the part having the opening. According to the invention, the pin can be rotated about an axis of rotation arranged in the axial direction, preferably in both directions of rotation. According to the invention, the pin can be rotated within the opening such that no simultaneous movement of the pin in the axial direction occurs, i.e. a forced movement of the pin into or out of the opening does not occur when the pin is rotated. The locking connection according to the invention thus differs fundamentally from a rotary connection which is designed as a bayonet connection or screw connection.Therefore, when the pin rotates within the opening, no (positive) guidance is provided for the one or more locking lugs. It is advantageous if the pin can be rotated within the opening in such a way that the one or more locking lugs are only moved in a plane perpendicular to the axial direction.

[0016] According to an advantageous embodiment, the opening is designed such that, starting from a side at which the pin is inserted into the opening, it has a (radial) cross-sectional area in a first region that corresponds to a (radial) cross-sectional area of ​​the pin with the one or more locking lugs. Accordingly, the opening is not hollow-cylindrical, but has different diameters at the same axial height, with at least one diameter being smaller than the combined diameter of the pin and the one or more locking lugs at an axial height of the pin at which the one or more locking lugs are located, such that the pin cannot be rotated in the opening when the one or more locking lugs are located in the first region.Adjacent to the first region is a second region of the opening with a hollow-cylindrical cross-sectional area, wherein the second region has a (single) diameter that corresponds at least to the combined diameter of the pin and the one or more locking lugs at an axial height of the pin at which the one or more locking lugs are located, so that the pin can be rotated in the opening when the one or more locking lugs are located in the second region. In this embodiment, it is particularly advantageous if the locking receptacles are delimited in the axial direction by radially inwardly projecting shoulders.The support element according to the invention thus advantageously enables a detachable snap-in connection between the upper and lower parts for securing a shelf. The snap-in connection ensures a reliable and secure connection between the upper and lower parts without the risk of changing the distance between the upper and lower parts, as is typically the case with a screw or bayonet connection. Disruptions to automated production processes due to an undefined height or changes in the position of shelves can thus be prevented.

[0017] The upper and lower parts of the support element according to the invention can be easily and automatically connected in the axial direction, for example, by means of a gripper arm, whereby only the pin needs to be rotated within the opening by a predetermined angle, for example. This is another important advantage of the invention.

[0018] According to an advantageous embodiment, the pin has a plurality of locking lugs, each of which can be locked into a separate locking receptacle. A separate locking receptacle can be provided for each locking lug. However, it is also possible to provide a common locking receptacle for one or more locking lugs.

[0019] According to a further advantageous embodiment, the ceramic support element has at least two locking receptacles, wherein the two locking receptacles are arranged such that a locking lug can be locked by one of the two locking receptacles by rotating the pin in one or the other direction of rotation, in particular by a respective identical angle of rotation, for example 90°. This embodiment has the particular advantage that the direction of rotation does not have to be predetermined, which could cause problems depending on the orientation of the part providing the opening. Rather, locking can be achieved even if it is not precisely defined in which direction the pin must be rotated for locking.

[0020] According to a further advantageous embodiment, the part providing the opening, which is in the form of a sleeve, has an end face designed to bear against the shelf base. This enables particularly simple fixing of the shelf base. In this case in particular, it is advantageous if the part having the pin has a plate-shaped region with a bottom side facing the opening and a top side facing away from it, wherein the pin protrudes from the bottom side of the plate-shaped region. It is particularly advantageous if the lower plate surface of the plate-shaped region is essentially flat and is designed to bear against the shelf base. This also enables particularly simple fixing of the shelf base.

[0021] In principle, it is arbitrary which parts of the support element form the tenon and the opening. It is advantageous if the part with the tenon is the upper part and the part with the opening is the lower part. The lower part, which is particularly sleeve-shaped and allows for easy adjustment of the axial dimension, allows for easy adjustment of the distance between the shelves.

[0022] According to a further advantageous embodiment, one or more locking lugs are each locked into a locking receptacle with axial play and / or radial play. According to the invention, axial or radial play means that the locking lug can move freely within the locking receptacle over a certain length in the axial direction or in the radial direction.

[0023] According to a further advantageous embodiment, the multi-part ceramic support element has an anti-twist device for fixing a rotational position of the pin in which the one or more locking lugs are locked. This advantageously prevents unwanted rotation of the pin to release the locking connection. Advantageously, the anti-twist device is formed by one or more plug pins, each of which is received in a pin receptacle formed by the upper and lower parts at least in sections and in a fit with the plug pin. Thus, the pin receptacle is formed at least in sections partly by the upper part and partly by the lower part. In other words, part of the pin receptacle in the longitudinal direction of its extension is formed by the upper part and another part by the lower part. The plug pin can thus fix orblock because it is partially surrounded by the upper part and partially by the lower part in its pin receptacle. The pin receptacle advantageously extends in the axial direction. The plug pin and the corresponding pin receptacle can have any (radial) cross-sectional shape. If the upper and lower parts are manufactured using a casting process, the cross-sectional shape of the pin receptacle can be designed as desired. For example, the plug pin has a circular, rectangular or triangular shape in its radial cross-section. The pin receptacle has a corresponding cross-section, for example, a circular, rectangular or triangular shape. It is particularly advantageous if the one or more plug pins each sit on a locking lug. Each plug pin can therefore be easily inserted into and removed from a pin receptacle, whereby it is not necessary to fix the pin in the pin receptacle.

[0024] In principle, the design of the locking lugs and locking receptacles is arbitrary, as long as it is ensured that the upper and lower parts are firmly connected in the axial direction when locked. Advantageously, the one or more locking lugs are each designed in the form of a radially outwardly projecting shoulder, and the one or more locking receptacles are each designed in the form of a radially inwardly projecting shoulder, which enables a particularly simple design.

[0025] Furthermore, the invention relates to an oven shelf element comprising a shelf with at least one bore and at least one multi-part support element according to the present invention, wherein the shelf is fixed between the upper part and the lower part by the support element extending through the bore. Advantageously, a support element is arranged in each corner area of ​​a shelf, for example, a rectangular one.

[0026] Furthermore, the invention relates to an oven shelf with a lower shelf and at least one upper shelf, wherein the lower shelf is fixed in at least one support element according to the invention between the upper part and the lower part, and the at least one upper shelf is fixed in at least one support element according to the invention between the upper part and the lower part, wherein the lower part of the at least one support element that fixes the upper shelf rests exclusively on the upper part of the support element that fixes the lower shelf. In this way, the forces are advantageously transmitted exclusively between the support elements. The shelves themselves are not loaded, which is a major advantage.

[0027] Preferably, all shelves, ie, the lower shelf and one or more upper shelves arranged one above the other, are supported by at least one, preferably three or four multi-part support elements according to the invention. The shelves can each be plate-shaped or designed as plate stands. The support elements and the shelves, as well as the furnace shelf elements and the furnace shelf, consist of one or more ceramic materials, such as silicon carbide or mullite, but do not contain any non-ceramic material.

[0028] The invention will now be explained in more detail with reference to the drawings. The drawings are schematic representations and not to scale. The drawings do not limit the invention in any way. They show:

[0029] Fig. 1 is a perspective view of an embodiment of the oven shelf according to the invention,

[0030] Fig. 2 is a perspective view of the upper and lower parts of an embodiment of the support element of the oven shelf of Fig. 1 before assembly,

[0031] Fig. 3A is a perspective view of an oven shelf element of the oven shelf of Fig. 1 before assembly of the upper part and lower part of Fig. 2,

[0032] Fig. 3B is a perspective view of the oven shelf element of Fig. 3A after assembly of the upper and lower parts,

[0033] Fig. 4A is a perspective view of the upper part and a section of the lower part of Fig. 2 before locking,

[0034] Fig. 4B is a view analogous to Fig. 4A of the upper and lower parts after locking without a locking pin,

[0035] Fig. 4C is a view analogous to Fig. 4A of the upper and lower parts after locking with a locking pin,

[0036] Fig. 5 shows a cross section through two adjacent shelves of the oven shelf of Fig. 1 .

[0037] Fig. 1 shows a perspective view of an embodiment of the kiln shelf according to the invention, designated overall by the reference numeral 100. The kiln shelf 100 comprises a plurality of plate-shaped kiln shelf elements 90 which are stacked one above the other in the vertical direction. Each kiln shelf element 90 comprises a rectangular shelf 80 made of a ceramic material, which is designed in the form of a flat plate and is provided with a support element 1 made of a ceramic material in each of its four corner regions. The four support elements 1 fix a respective shelf 80. When the kiln shelf elements 90 are stacked, the support elements 1 serve as supporting spacers for spacing one shelf 80 from an immediately adjacent shelf 80. In particular, the support elements 1 ensure a precise distance between two immediately adjacent shelves 80 and a precise position orPositioning of each shelf 80 relative to the immediately adjacent shelf 80 is achieved. Preferably, the stacked shelves 80 are arranged parallel, typically horizontally in the working position, which is achieved in the case of flat shelves 80 by identical dimensioning of the axial extension of the parts of the support elements 1 located between the shelves 80.

[0038] The shelves 80 of the kiln rack 100 are used for loading with firing material for storage and transport of firing material through a kiln. The kiln rack 100, loaded with firing material on the various levels, can be transported into and out of a kiln, which is well known to those skilled in the art, so it need not be discussed in detail here.

[0039] In the kiln shelf 100, the kiln shelf elements 90 are stacked one on top of the other solely by weight, without being fixed to one another. In Fig. 1, the stacking of one shelf 80 on top of another is schematically illustrated by arrows. The assembly / disassembly of the kiln shelf 100 by stacking / unstacking kiln shelf elements 90, as well as the loading / unloading of the shelves 80 with firing material, is advantageously carried out in an automated manner (robot-assisted) by gripper arms. It is understood that precise positioning of the shelves 80 in the kiln shelf 100 is required for the usually precisely defined gripping positions of the gripper arms.

[0040] Fig. 2 shows a perspective view of an embodiment of the upper part 2 and lower part 3 of the support element 1 according to the invention prior to assembly on a shelf 80. In Fig. 2, the arrow indicates the assembly direction (axial direction) of the upper part 2 and lower part 3; a radial direction is defined perpendicular to this. Both the upper part 2 and the lower part 3 are manufactured using a casting process, in particular an injection molding process. The upper part 2 comprises a centrally arranged pin 7 and a plate-shaped extension 4 with a plate upper side 5 and a plate lower side 6. The pin 7 projects from the plate lower side 6. The plate lower side 6 has a lower plate surface 9 surrounding the pin 7. A centrally arranged centering collar 8 is located on the plate upper side 5. The plate upper side 5 has an upper plate surface 10 surrounding the centering collar 8. In the embodiment shown in Fig.In the embodiment shown in Figure 2, the lower plate surface 9 and the upper plate surface 10 of the plate-shaped extension 4 are each flat.

[0041] The pin 7, which is essentially cylindrical in its outer shape, has two locking lugs 11 immediately adjacent to its free end. The locking lugs 11 are each designed as radially (outwardly) projecting extensions and, in the exemplary embodiment, are arranged opposite one another at the same axial height on the pin 7. The diameter (radial dimension) of the two locking lugs 11 is increased relative to the diameter of the pin 7. The two locking lugs 11 do not extend around the entire circumference of the pin 7, but are only formed in certain regions, so that an area with the reduced diameter of the pin 7 remains between the locking lugs 11. Correspondingly, the two locking lugs 11 do not extend along the entire axial length of the pin 7, but are only formed in certain regions, so that the reduced diameter of the pin 7 is also present towards the plate-shaped extension 4.The pin 7 has no screw thread.

[0042] The lower part 3 shown in Fig. 2 is designed as a hollow body with a through-opening 12, which is bordered by a lateral surface 19. The lower part 3, designed here, for example, in the form of a sleeve, has a lower part upper side 13 with an upper lower part surface 16 and a lower part lower side 14 with a lower lower part surface 15. The two lower part surfaces 15, 16 are formed by the terminal end faces of the sleeve and are each flat.

[0043] As can be seen in Fig. 2, the through opening 12 has a cross-sectional area in an upper region 17 directly adjacent to the upper side 13 of the lower part, which is adapted to the cross-sectional area of ​​the upper part 2 in the region of the pin 7 and the two locking lugs 11, so that the pin 7 with locking lugs 11 can be inserted into the opening 12. The cross-sectional area is the area in a radial plane. In the upper region 17, the cross-sectional area is therefore not circular, but the outer surface 19 has two opposing bulges 20 for the locking lugs 11. Immediately adjacent to the upper region 17, the opening 12 has a lower region 18 with a circular cross-sectional area, corresponding to a hollow cylindrical outer surface 19, the diameter of which corresponds at least to the radial dimension of the pin 7 and locking lugs 11 (see Figures 4A to 4C).Accordingly, the pin 7 with locking lugs 11 can be inserted into the upper region 17 of the opening 12, but cannot be rotated in the upper region 17 about an axis of rotation parallel to the assembly direction (i.e. axially). This is prevented by the regions of reduced diameter between the bulges 20. If the locking lugs 11 reach the lower region 18 of the opening 12 with an enlarged diameter as a result of continued insertion of the pin 7 into the opening 12, the pin 7 can be rotated about an axis of rotation parallel to the assembly direction, so that locking of the pin 7 is possible (see Figures 4A to 4C). The through-opening 12 does not have an internal thread. It is understood that the pin 7 can have a greater or lesser number of locking lugs 11.

[0044] As can also be clearly seen in Fig. 2, the support element 1 has an anti-twist device for fixing a rotational position of the pin 7, in which the two locking lugs 11 are locked. Specifically, this is formed by a plug pin 21 (see Fig. 3B) made of a ceramic material, which is inserted into a corresponding pin receptacle 22 designed to fit the plug pin 21. The plug pin 21 and the pin receptacle 22 are arranged in the axial direction. The plug pin 21 here has, for example, a circular cross-sectional area in the radial direction. The pin receptacle 22 correspondingly has a circular cross-sectional area in the radial direction. It would also be conceivable for the cross-sectional areas of the plug pin 21 and the pin receptacle 22 to have a different cross-sectional shape, for example rectangular or triangular.

[0045] In the area of ​​the plate-shaped projection 4, the pin receptacle 22, which is open on the upper side 5 of the plate, is formed only by the upper part 2. However, at the level of the pin 7, the pin receptacle 22 is composed of an upper-part pin receptacle section 23 and a lower-part pin receptacle section 24, which complement each other to form the pin receptacle 22 when the pin 7 is in a specific rotational position relative to the lower part 3, in which the locking lugs 11 are locked. This rotational position is fixed by the plug pin 21. In this embodiment, the upper-part pin receptacle section 23 and the lower-part pin receptacle section 24 each contribute half to the pin receptacle 22. The upper-part pin receptacle section 23 and the lower-part pin receptacle section 24 open at a locking lug 11, so that the plug pin 21 inserted into the pin receptacle 22 can sit on the locking lug 11.It is understood that the support element 1 can also have a plurality of such plug pins 21 to form an anti-twist device, each of which is received in a corresponding pin receptacle 22.

[0046] Reference is now made to Figs. 3A and 3B, which illustrate, using perspective views, an embodiment of the oven shelf element 90 according to the invention of the oven shelf 100 of Fig. 1 before the assembly of the upper part 2 and lower part 3 to a shelf 80 (Fig. 3A) and after assembly to a shelf 80 (Fig. 3B). For the sake of simplicity, only one corner region of the shelf 80 is shown, although it is understood that the support element 1 can be mounted to the other corner regions of the shelf 80 in a corresponding manner.

[0047] The shelf 80 has, in the corner area, a circular opening 25, for example, whose diameter corresponds to the diameter of the pin 7 and the locking lugs 11, so that the pin 7 can be inserted through the opening 25. The shelf 80 has a shelf top 27 with an upper shelf surface 29 and a shelf bottom 26 with a lower shelf surface 28. As shown in Fig. 3A, the lower part 3 is positioned at the opening 25 on the shelf bottom 26 so that the opening 12 is aligned with the opening 25, with the upper lower part surface 16 coming into contact with the lower shelf surface 28. The upper lower part surface 16 (end face of the sleeve) therefore serves as the contact surface of the lower part 3.The pin 7 is inserted through the through-hole 25 and into the opening 12, which is indicated by an arrow in Figure 3A, whereby the lower plate surface 9 comes to rest against the upper shelf surface 29. The lower plate surface 9 therefore serves as the bearing surface of the upper part 2. By rotating the pin 7 through a predetermined angle of rotation, here for example 90°, the pin 7 can be locked in the opening 12. This is illustrated by an arrow in Fig. 3B. In the locked position, to secure the rotational position of the upper part 2 or pin 7 relative to the lower part 3, a plug pin 21 is inserted into the pin receptacle 22 designed as a bore. The shelf 80 is fixed between the upper part 2 or plate-shaped extension 4 and the lower part 3.

[0048] As shown in Figure 1, the oven shelf elements 90, which are produced by mounting four support elements 1 each on a shelf 80, can be stacked, wherein the distance between immediately adjacent shelves 80 is determined by the support elements 1, specifically the axial dimension of the areas of the support elements 1 located between the shelves 80. If two immediately adjacent shelves 80 are considered, the lower part 3 of each support element 1 of the upper shelf 80 sits with its lower lower part surface 15 exclusively on the upper plate surface 10 of an upper part 2 of the lower shelf 80 located below it. The centering collar 8 of a respective upper part 2 is suitable for being received in the downwardly open opening 12 of the lower part 3 located above it, i.e. the opening 12 engages around the centering collar 8 in order to secure the upper part 2 against lateral slipping.

[0049] In Figs. 4A to 4C, the locking of the pin 7 and the formation of the anti-twist device in the locked position are illustrated using perspective views of the upper part 2 and a section of the lower part 3 of Fig. 2.

[0050] As already explained, the opening 12 comprises an upper region 17 and a lower region 18. In the upper region 17, the opening 12 has a cross-sectional area that is adapted to the cross-sectional area of ​​the upper part 2 in the region of the pin 7 and the two locking lugs 11, such that the pin 7 with locking lugs 11 can be inserted into the opening 12. In the lower region 18, the opening 12 has a hollow cylindrical outer surface 19, the diameter of which corresponds at least to the summed radial dimension of the pin 7 and locking lugs 11, such that the pin with locking lugs 11 can be rotated. The widened lower region 18 results in radially inwardly projecting shoulders 30, by means of which the respective locking receptacles 31 for the locking lugs 11 are limited upwards in the axial direction.

[0051] Fig. 4A shows a situation in which the pin 7 has been inserted into the opening 12. The locking lugs 11 are already located in the lower region 18 of the opening 12, but are not yet locked, i.e. the pin 7 has not yet been rotated. Fig. 4B shows a later situation in which the upper part 2 or pin 7 has been rotated by a predetermined angle of rotation, here for example 90°. This is illustrated by an arrow. The locking lugs 11 were inserted into the locking receptacles 31 by turning the pin 7, the locking lugs 11 being blocked by the shoulders 30 in the axial direction upwards (in the direction in which the pin 7 moves out of the opening 12). As a result, the upper part 2 is locked to the lower part 3 in the axial direction. In Fig. 2B it is indicated that in the locked rotational position a plug pin 21 can be inserted into the pin receptacle 22. In Fig.4C shows an even later situation in which the plug pin 21 is inserted into the pin receptacle 22.

[0052] In general, the locking lugs 11 are not preloaded in the locking receptacles 31. Rather, it is even preferred if the locking lugs 11 are received in the locking receptacles 31 with axial and / or radial play. Accordingly, in a support element 1 mounted on a shelf base 80, a locking lug 11 advantageously has a small axial gap 32 to the shoulder 30 (axial play) and / or a small radial gap 33 to the outer surface 19 (radial play). This allows assembly tolerances and different thermal expansions of the ceramic materials used in the furnace shelf element 90 to be compensated.

[0053] It would also be conceivable for only a single locking lug 11 to be arranged on the pin 7, which can be selectively locked in one of two locking receptacles 31, which are arranged such that the locking lug 11 locks in one locking receptacle when the pin 7 is rotated in one direction of rotation and locks in the other locking receptacle 31 when the pin 7 is rotated in the other direction of rotation. This has the advantage that the locking lug can always be locked in a locking receptacle regardless of the direction of rotation.

[0054] Fig. 5 shows a cross-section through two oven shelf elements 90 of the oven shelf 100 of Fig. 1. It is clearly visible that the lower part 3 of the support element 1 of the upper shelf 80 rests with its lower lower part surface 15 exclusively on the upper plate surface 10 of the upper part 2 of the lower shelf 80 located below it. The centering collar 8 of the upper part 2 is received in the opening 12 of the lower part 3 located above it. The plug pin 21 arranged in the bore sits on a locking lug 11.

[0055] The oven shelf 100 shown in Fig. 1 can be easily assembled and disassembled. To disassemble a support element 1 from a shelf 80, the plug pin 21 must be removed from the pin receptacle 22, followed by rotating the upper part 2 relative to the lower part 3 in the opposite direction to that used for locking, so that the locking lugs 11 disengage from the shoulders 30 and the pin 7 can be removed from the opening 12.

[0056] The support elements 1 and the shelves 80 are made of a high-temperature-resistant ceramic material, such as silicon carbide or mullite. As can be seen from the above description of the invention, the invention shows a novel, multi-part ceramic support element in which the upper and lower parts can be detachably connected axially by a snap-in connection to fix a shelf. The disadvantages of a screw connection, in particular the risk of changing the spacing and position of shelves, can be advantageously avoided. This is particularly important in automated production processes such as those typical in industrial environments, where malfunctions due to inappropriate gripping and depositing positions of robot gripper arms must be avoided.

[0057] List of reference symbols:

[0058] 1 support element

[0059] 2 top

[0060] 3 Lower part

[0061] 4 plate-shaped approach

[0062] 5 Plate top

[0063] 6 Plate bottom

[0064] 7 cones

[0065] 8 Centering collar

[0066] 9 lower plate surface

[0067] 10 upper plate surface

[0068] 11 locking lug

[0069] 12 Opening

[0070] 13 Bottom top

[0071] 14 Bottom part

[0072] 15 lower sub-area

[0073] 16 upper lower part area

[0074] 17 upper area

[0075] 18 lower area

[0076] 19 Shell surface

[0077] 20 bulge

[0078] 21 pin

[0079] 22 pin holder

[0080] 23 Upper part pin receiving section

[0081] 24 Lower part pin receiving section

[0082] 25 Breakthrough

[0083] 26 Shelf bottom

[0084] 27 Shelf top

[0085] 28 lower shelf area

[0086] 29 upper shelf area

[0087] 30 paragraph

[0088] 31 locking mount

[0089] 32 axial gap

[0090] 33 radial gap shelf

[0091] Oven shelf element

[0092] Oven shelf

Claims

Patent claims 1 . Multi-part ceramic support element (1) for spacing ceramic shelves (80) of a furnace shelf (100), comprising an upper part (2) and a lower part (3), wherein the upper part (2) is axially detachably connectable to the lower part (3) for the purpose of fixing a shelf (80) between the upper part (2) and the lower part (3) by means of a locking connection, wherein the locking connection is formed by a pin (7) provided on one part (2) with one or more locking lugs (11) projecting from the pin (7) and an opening (12) provided on the respective other part (3), wherein the pin (7) can be inserted into the opening (12) and can be rotated in the opening (12) without simultaneously moving into the opening (12) or in the opposite direction such that the one or more locking lugs (11) are each in a position opposite to the part having the opening (12). (3) shaped locking receptacle (31).

2. Multi-part ceramic support element (1) according to claim 1, in which the part (3) having the opening (12) is designed in the form of a sleeve and in particular has an end face (16) serving to bear against the shelf base (80).

3. Multi-part ceramic support element (1) according to claim 1 or 2, wherein the part (2) having the pin (7) has a plate-shaped region (4) with a plate underside (6) facing the opening (12) and a plate upper side (5) facing away therefrom, wherein the pin (7) projects from the plate underside (6).

4. Multi-part ceramic support element (1) according to claim 3, wherein the plate underside (6) is substantially flat and is intended to bear against the shelf base (80).

5. Multi-part ceramic support element (1) according to claim 3 or 4, wherein the plate upper side (5) has a centering collar (8) which is intended to be received by the lower part (3) of a further support element (1).

6. Multi-part ceramic support element (1) according to one of claims 1 to 5, in which the part having the pin (7) is the upper part (2) and the part having the opening (12) is the lower part (3).

7. Multi-part ceramic support element (1) according to one of claims 1 to 6, in which the opening (12) is designed such that, starting from a side on which the pin (7) is inserted into the opening (12), it has a cross-sectional area in a first region (17) corresponding to the cross-sectional area of ​​the pin (7) and the one or more locking lugs (11), so that the pin (7) is not rotatable in the first region (17), and in a second region (18) adjoining the first region (17) has a hollow cylindrical cross-sectional area with a diameter which corresponds at least to the summed diameter of the pin (7) and the one or more locking lugs (11), so that the pin (7) is rotatable in the second region (18).

8. Multi-part ceramic support element (1) according to one of claims 1 to 7, in which the one or more locking lugs (11) are each designed in the form of a radially outwardly projecting shoulder and the one or more locking receptacles (31) are each designed in the form of a radially inwardly projecting shoulder (30).

9. Multi-part ceramic support element (1) according to one of claims 1 to 8, in which the one or more locking lugs (11) are each locked with axial play and / or radial play in a locking receptacle (31).

10. Multi-part ceramic support element (1) according to one of claims 1 to 9, which has at least two locking receptacles (31), wherein the two locking receptacles (31) are arranged such that a locking lug (11) can be locked by one of the two locking receptacles (31) by rotating the pin (7) in one or the other direction of rotation, in particular by a respective equal angle of rotation, for example 90°. 1 1. Multi-part ceramic support element (1) according to one of claims 1 to 10, which has an anti-rotation device for fixing a rotational position of the pin (7) in which the one or more locking lugs (1 1) are locked.

12. Multi-part ceramic support element (1) according to claim 11, in which the anti-twist device is formed by one or more plug pins (21), which are each received in a pin receptacle (22) which is formed at least in sections by the upper and lower parts (2, 3) together and in a fit with the plug pin (21).

13. Multi-part ceramic support element (1) according to claim 12, wherein the one or more plug pins (21) each rest on a locking lug (11).

14. Oven shelf element (90), comprising a shelf (80) with at least one opening (25) and at least one multi-part support element (1) according to one of the claims 1 to 13, wherein the shelf (80) is fixed between the upper part (2) and the lower part (3).

15. Oven shelf (100), comprising a lower shelf (80) and at least one upper shelf (80), wherein the lower shelf (80) is in at least one support element (1 ) according to one of claims 1 to 13 is fixed between the upper part (2) and the lower part (3) and the at least one upper shelf (80) is fixed in at least one support element (1 ) according to one of claims 1 to 13 between the upper part (2) and the lower part (3), wherein the lower part (3) of the at least one support element (1) which fixes the upper shelf (80) rests exclusively on the upper part (2) of the support element (1) which fixes the lower shelf (80).

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