Patent Publication Number: US-2023146450-A1

Title: Mould core for a mould for producing hollow concrete bodies, and a moulding device having a mould core of this kind

Description:
DESCRIPTION 
     The present disclosure relates to a mold core for a molding apparatus for producing hollow and/or in particular tubular concrete bodies and a molding apparatus having such a mold core for producing hollow and/or in particular tubular concrete bodies. Furthermore, the present disclosure relates to a sealing element, in particular a strip-shaped sealing element, and/or a longitudinal strip forming such a sealing element for use on such a mold core. 
     BACKGROUND 
     Mold cores for molding apparatuses for the production of hollow and/or tubular concrete bodies have been known in the prior art for a long time. For example, U.S. Pat. No. 1,394,570, published in 1921, shows a generic mold core for use as an inner mold for a molding apparatus for the production of hollow and/or in particular tubular concrete bodies. The mold core of U.S. Pat. No. 1,394,570 has a spreadable and/or expandable core which, in the expanded and/or expanded state, assumes the specified inner shape for the concrete casting process and is designed to be shrinkable and/or contractible for demolding the concrete body. Such expandable mold cores are also regularly referred to as collapsible cores in the prior art. Collapsible cores of this type facilitate demolding of a concrete body formed between an outer wall of the core of the molding apparatus and the collapsible core, in that the collapsible core can be shrunk from the spread set-up state assumed during the concrete pouring process and is thereby lifted off the inner wall of the concrete body. 
     Another generic mold core and/or collapsible core for use as an inner mold for a molding apparatus for producing hollow and/or in particular tubular concrete bodies is described in DE 10 2012 220 814 A1. The collapsible core according to DE 10 2012 220 814 A1 has an substantially cylindrical wall of the core (core mantle), which has an opening extending in the longitudinal direction on one side, on the opposite longitudinal edge sections of which a spreading device arranged inside the wall of the core engages in order to expand the opposite longitudinal edge sections of the wall of the core to spread the collapsible core apart in the tangential direction. In order to seal the opening, which extends in the longitudinal direction, towards the inside of the collapsible core, in particular when the collapsible core is in the expanded set-up state in which the concrete pouring process is carried out, according to DE 10 2012 220 814 A1, a connecting strip, which extends in the longitudinal direction, is provided between the opposite longitudinal edge sections and has at least one elastomeric portion, wherein the connecting strip is shear-resistant connected to the longitudinal edges of the wall of the core. This enables a permanent sealing connection of the two longitudinal edges of the wall of the core, both during the expansion process and during the shrinking process, so that the tightness of the wall of the core that is effective in all positions of the collapsible core can be ensured over the entire circumference. In the arrangement proposed in DE 10 2012 220 814 A1, a very good sealing of the interior of the collapsible core can be provided. However, during the expansion processes when setting up the collapsible core and/or the shrinking processes when removing the formwork from a concrete body, the elastomeric connecting strip is always exposed to alternating bending stresses, which leads to material fatigue that is disadvantageous for the service life, so that wear-related leaks can occur on the connecting strip and/or the connection to the longitudinal edges of the wall of the core can partially or completely tear off. 
     In view of the disadvantages described above, based on the prior art described above, it is an object of the present disclosure to provide a mold core for a molding apparatus for the production of hollow and/or in particular tubular concrete bodies and a molding apparatus having such a mold core for the production of hollow and/or in particular to provide tubular concrete bodies, in which a cost-effective arrangement can be provided that reliably seals the wall of the core inwards, which enables improved service live, is able to reduce material fatigue and/or wear and/or allows easier handling in the event of material fatigue and/or wear. 
     SUMMARY 
     The present disclosure relates to a mold core for a molding apparatus for producing hollow and/or in particular tubular concrete bodies and a molding apparatus having such a mold core for producing hollow and/or in particular tubular concrete bodies. In particular, a mold core for a molding apparatus for the production of hollow and/or in particular tubular concrete bodies according to claim  1  and a molding apparatus comprising such a mold core for the production of hollow and/or in particular tubular concrete bodies according to claim  15  are proposed for achieving the above-mentioned object. Furthermore, a sealing element for use on such a mold core according to claim  13  is proposed. The dependent claims relate to exemplary preferred embodiments. 
     According to an exemplary aspect, a mold core is proposed for use on a molding apparatus for the production of hollow and/or in particular tubular concrete bodies, the mold core comprising: a longitudinally extending core mantle, which particularly preferably has a strip-shaped longitudinal opening extending in the longitudinal direction of the core mantle (preferably at least from one end to the other end of the core mantle) between two longitudinal edges of the core mantle, an expansion device for expanding and/or spreading and/or contracting and/or shrinking the mold core, and/or a sealing element sealing the longitudinal opening of the core mantle. The sealing element is preferably provided as a sealing element that deforms flexibly and/or elastically when the mold core contracts and/or shrinks and, in the shrunken or contracted state of the mold core, in particular by bending and in particular about a longitudinal axis, preferably folds inwards (or outwards), in particular relative to the core mantle. 
     According to particularly expedient examples, the sealing element can be connected to the core mantle so that it can be slidably displaced in the longitudinal direction, in particular, the sealing element can be connected to the two longitudinal edges of the core mantle so that it can be slidably displaced in the longitudinal direction. This has the advantage that the sealing element can be removed easily, efficiently and inexpensively due to the slidably displaceable connection in order to be replaced with another sealing element (spare part) if necessary, e.g. without having to remove the mold core from the molding apparatus. 
     According to particularly expedient examples, the sealing element can be attached to the respective longitudinal edges of the core mantle by a respective detachable connection. This has the advantage that the sealing element can be removed easily, efficiently and inexpensively due to the detachable connection in order to be replaced with another sealing element (spare part) if necessary, e.g. without having to remove the mold core from the molding apparatus. According to particularly expedient examples, the sealing element can be held in particular on the mold core so that it can be pulled out of the mold core in the longitudinal direction. In particular, the sealing element on the mold core can be pulled out of the longitudinal opening of the core mantle in the longitudinal direction and/or be held in a manner allowed to be pulled out from between the longitudinal edges of the core mantle, for example, in particular be pulled out in the longitudinal direction along the longitudinal edges of the core mantle. This has the advantage that the sealing element can be removed easily, efficiently and inexpensively by simply pulling it out in the longitudinal direction of the mold core in order to be replaced with another sealing element (spare part) if necessary, e.g. without having to remove the mold core from the molding apparatus. 
     According to particularly expedient examples, the sealing element can be connected with its longitudinal edges to the respective longitudinal edges of the core mantle (respectively) in a slidably displaceable manner in the longitudinal direction. In particular, respective longitudinal edges of the sealing element facing the longitudinal edges of the core mantle can each be connected to the respective longitudinal edges of the core mantle in a slidably displaceable manner in the longitudinal direction. This has the advantage that the sealing element can be removed easily, efficiently and inexpensively due to the slidably displaceable connection in order to be replaced with another sealing element (spare part) if necessary, e.g. without having to remove the mold core from the molding apparatus. 
     According to particularly expedient examples, the sealing element can be positively (form-fit positive lock) connected to (and/or with) the respective longitudinal edges of the core mantle in the direction transverse to the longitudinal direction of the mold core, particularly preferably in the substantially radial direction of the mold core and/or substantially perpendicular to the radial direction of the mold core relative to the mold core. Particularly preferably, the sealing element can be positively connected to (and/or with) the respective longitudinal edges of the core mantle in substantially all directions transverse to the longitudinal direction of the mold core, particularly preferably in the substantially radial direction of the mold core inwards and/or outwards and/or substantially in both directions perpendicular to the radial direction of the mold core relative to the mold core. This has the advantage that the sealing element can be held in such a way (preferably in a sealing manner) that substantially only the longitudinal direction remains as a translatory degree of freedom. According to particularly expedient examples, the sealing element can have lateral connecting strips which extend in the longitudinal direction and/or are fastened to the side and which can be held slidably displaceably in the longitudinal direction, preferably on the longitudinal edges of the core mantle, in particular on respective fastening strips fastened to the longitudinal edges of the core mantle. 
     According to particularly expedient examples, the connecting strips of the sealing element can have one or more profile groove sections extending in the longitudinal direction, in which preferably respective corresponding profile rail sections of the longitudinal edges, in particular of the fastening strips fastened to the longitudinal edges of the wall of the core, engage in a longitudinally slidably displaceable manner and/or are fitted in a longitudinally slidably displaceable manner. Alternatively or additionally, the connecting strips of the sealing element can have one or more profile rail sections extending in the longitudinal direction, which can preferably engage in the respective corresponding profile groove sections of the longitudinal edges, in particular the fastening strips fastened to the longitudinal edges of the wall of the core, in a longitudinally slidably displaceable manner and/or are fitted in a longitudinally slidably displaceable manner. According to particularly expedient examples, one or more profile groove sections and/or their corresponding one or more profile rail sections can have a T-shape in cross-sectional profile. 
     According to particularly expedient examples, the sealing element can have a flexible and/or elastically bendable connection band which, in particular, preferably can comprise an elastic plastic, in particular an elastomer. According to particularly expedient examples, the connecting band of the sealing element can be arranged between the connecting strips of the sealing element and/or can be connected to the connecting strips on both sides, respectively. According to particularly expedient examples, the connecting band of the sealing element can be attached to the connecting strips by a non-positive connection, particularly preferably by an adhesive connection. According to particularly expedient examples, the connecting strips of the sealing element can each have one or more retaining profile sections, in particular anchor and/or nose profile sections, protruding and/or engaging into the material of the connecting band in the cross-sectional profile. According to particularly expedient examples, at least one of the connecting strips of the sealing element can have, in the cross-sectional profile, a plurality of retaining profile sections which are aligned transversely to one another and/or project into and/or engage in the material of the connecting band. 
     According to a further exemplary aspect, a sealing element (e.g. also available as a spare part) for use on a mold core according to one of the above examples is proposed, with the sealing element or its lateral longitudinal edges (in particular facing the longitudinal edges of the wall of the core) preferably being configured to be connected to the longitudinal edges of the core mantle respectively in a slidably displaceable manner in the longitudinal direction, and particularly preferably to be fastenable to respective longitudinal edges of the core mantle by respective detachable connections. 
     According to particularly expedient examples, the sealing element or its lateral longitudinal edges (in particular facing the longitudinal edges of the core mantle) can be configured to be connected to the core mantle in a longitudinally slidable displaceable manner, particularly preferably, the sealing element can be connected slidably displaceable in the longitudinal direction with respect to the two longitudinal edges of the core mantle. 
     According to particularly expedient examples, the sealing element or its lateral longitudinal edges (in particular facing the longitudinal edges of the core mantle) can be designed to be attached to (and/or with) the respective longitudinal edges of the core mantle by respective detachable connections. According to particularly expedient examples, the sealing element or its lateral longitudinal edges (especially those facing the longitudinal edges of the core mantle) can be configured to be held in particular on the mold core so that it can be pulled out of the mold core in the longitudinal direction. In particular, the sealing element or its lateral longitudinal edges (in particular those facing the longitudinal edges of the core mantle) can be configured to be able to be pulled out of the longitudinal opening of the core mantle of the mold core in the longitudinal direction and/or to be held in a pull-out manner, for example, between the longitudinal edges of the core mantle, in particular to be held to be pulled out respectively at the respective longitudinal edges of the core mantle in the longitudinal direction. 
     According to particularly expedient examples, the sealing element can be configured with its lateral longitudinal edges (in particular facing the longitudinal edges of the core mantle) or its lateral longitudinal edges (in particular facing the longitudinal edges of the core mantle) can be configured to be slidably connected at (and/or with) the respective longitudinal edges of the core mantle in the longitudinal direction. In particular, respective longitudinal edges of the sealing element facing the longitudinal edges of the core mantle can each be configured to be slidably displaceably connected to/with the respective longitudinal edges of the core mantle in the longitudinal direction. 
     According to particularly expedient examples, the sealing element can be configured with its lateral longitudinal edges (in particular facing the longitudinal edges of the core mantle) or its lateral longitudinal edges (in particular facing the longitudinal edges of the core mantle) can be configured to be positively connected in a form-fitting manner at (and/or with) the respective longitudinal edges of the core mantle in the direction transverse to the longitudinal direction of the mold core, particularly preferably in the substantially radial direction of the mold core and/or substantially perpendicular to the radial direction of the mold core relative to the mold core. Particularly preferably, the sealing element can be configured with its lateral longitudinal edges (in particular facing the longitudinal edges of the core mantle) or its lateral longitudinal edges (in particular facing the longitudinal edges of the core mantle) can be configured to be positively connected in a form-fitting manner at (and/or with) the respective longitudinal edges of the core mantle in substantially all directions transverse to the longitudinal direction of the mold core, particularly preferably in the substantially radial direction of the mold core inwards and/or outwards and/or substantially in both directions perpendicular to the radial direction of the mold core relative to the mold core. According to particularly expedient examples, the sealing element can have lateral longitudinally extending connecting strips (e.g. along the longitudinal edges of the sealing element and/or forming the longitudinal edges of the sealing element) and/or laterally fastened connecting strips which are preferably configured to attach to the longitudinal edges of the core mantle, in particular on respective fastening strips fastened to the longitudinal edges of the core mantle, in each case to be slidably held in the longitudinal direction. 
     According to particularly expedient examples, the connecting strips of the sealing element can have one or more profile groove sections extending in the longitudinal direction, in which preferably respective corresponding profile rail sections of the longitudinal edges of the core mantle, in particular of the fastening strips fastened to the longitudinal edges of the core mantle, can engage in a longitudinally slidably displaceable manner and/or are fitted in a longitudinally slidably displaceable manner. Alternatively or additionally, the connecting strips of the sealing element can have one or more profile rail sections extending in the longitudinal direction, which can preferably engage in the respective corresponding profile groove sections of the longitudinal edges of the core mantle, in particular the fastening strips fastened to the longitudinal edges of the core mantle, in a longitudinally slidably displaceable manner and/or are fitted in a longitudinally slidably displaceable manner. According to particularly expedient examples, one or more profile groove sections and/or their corresponding one or more profile rail sections can have a T-shape in cross-sectional profile. 
     According to particularly expedient examples, the sealing element can have a flexible and/or elastically bendable connecting band which, in particular, preferably can comprise an elastic plastic, in particular an elastomer. According to particularly expedient examples, the connecting band of the sealing element can be arranged between the connecting strips of the sealing element and/or can be connected to the connecting strips on both sides. According to particularly expedient examples, the connecting band of the sealing element can be attached to the connecting strips by a non-positive connection, particularly preferably by an adhesive connection. According to particularly expedient examples, the connecting strips of the sealing element can each have one or more retaining profile sections, in particular anchor and/or nose profile sections, protruding and/or engaging into the material of the connecting band in the cross-sectional profile. According to particularly expedient examples, at least one of the connecting strips of the sealing element can have, in the cross-sectional profile, a plurality of retaining profile sections which are aligned transversely to one another and/or project into and/or engage in the material of the connecting band. 
     According to a further exemplary aspect, a molding apparatus for the production of hollow and/or in particular tubular concrete bodies is also proposed, comprising an outer mold and an inner mold which is preferably arranged and/or can be arranged in the outer mold and which preferably has a mold core according to one of the above aspects and/or examples. 
     Further preferred examples of the mold core and/or sealing element are described below, which can be combined with the above aspects and expedient examples. 
     The sealing element is preferably provided as a sealing element that deforms flexibly and/or elastically when the mold core contracts and/or shrinks and, in the shrunken or contracted state of the mold core, preferably folds inwards (or outwards), in particular relative to the core mantle, in particular by bending, in particular about a longitudinal axis. 
     According to particularly expedient examples, one or more guide elements can be arranged on the side of the sealing element facing the interior of the mold core. According to particularly expedient examples, the expansion device can be configured to bring the mold core from the expanded or spread state into the contracted or shrunken state in at least two successive shrinking processes. In particular, the expansion device can preferably be configured to bring the mold core from the expanded or spread state into the contracted or shrunk state in at least two consecutive shrinking processes in that at least one driver section of the expansion device comes into contact with at least one entrainment section of the one or more guide elements of the sealing element in the transition from a first shrinking process of the at least two consecutive performed shrinking processes to a second shrinking process of the at least two successively performed shrinking processes, in particular for guiding the sealing element in (or during) the second shrinking process (and possibly in or during further shrinking processes). The formulation of the two or more shrinking processes means in particular that the expansion device already partially shrinks or contracts the mold core in a first shrinking process and in at least one further shrinking process further shrinks or contracts the mold core from the partially shrunken or partially contracted state in order to bring the mold core in the last of the at least two shrinkage processes into the contracted or shrunken state. This does not rule out that the shrinking processes can continuously merge into one another, with the transition from the first to at least one further second shrinking process being recognizable in that, after partial shrinkage or contraction of the mold core has already taken place, at least one driver section of the expansion device comes into contact with at least one entrainment section of the one or more guide elements of the sealing element in the transition from the first to the second shrinking process. In particular, this means that the at least one driver section of the expansion device is not yet in contact or nor does it come into contact with the at least one driver section of the one or more guide elements in the first shrinking process, but only after the shrinkage or contraction of the mold core has already partially taken place. This has the advantage that no tensile forces are exerted on the sealing element in the first shrinking process, but the sealing element can be advantageously guided in the subsequent second shrinking process. This prevents excessive wear of the sealing element due to the avoidance of tensile forces acting on the sealing element. 
     According to particularly expedient examples, the expansion device can also be configured to engage, in the transition from the first to the second shrinking process, on/with the one or more guide elements and/or to come into contact or driving contact element with the one or more guide elements, and to guide the sealing element in the second shrinking process, in particular with engagement and/or contact on the one or more guide members. This has the advantage that no tensile forces are exerted on the sealing element in the first shrinking process, but the sealing element can be advantageously guided in the subsequent second shrinking process. This prevents excessive wear of the sealing element due to the avoidance of tensile forces acting on the sealing element. 
     According to particularly expedient examples, one or more guide elements of the sealing element can each have a spacer sleeve, in particular a respective spacer sleeve with one of the at least one entrainment sections, with the respective entrainment section of the spacer sleeve preferably being spaced from the side of the sealing element facing the interior of the mold core. According to particularly expedient examples, the at least one driver section of the expansion device can preferably be moved inward relative to the mold core during contraction or shrinkage of the mold core and/or preferably come into contact with the at least one driver section of the respective spacer sleeve of the guide elements in the transition from the first to the second shrinking process, and/or the at least one driver section of the expansion device can preferably guide and/or take along (pull) the one or more guide elements of the sealing element in the second shrinking process. This has the advantage that no tensile forces are exerted on the sealing element in the first shrinking process, but the sealing element can be advantageously guided in the subsequent second shrinking process. This prevents excessive wear of the sealing element due to the avoidance of tensile forces acting on the sealing element. 
     According to particularly expedient examples, the expansion device can comprise a shaped element which, in the expanded or spread state of the mold core, bears against the side of the sealing element facing the interior of the mold core and/or is moved inward relative to the mold core when the mold core contracts or shrinks. According to particularly expedient examples, the shaped element can have the at least one driver section of the expansion device. According to particularly expedient examples, the shaped element can be a shaped sheet metal extending in the longitudinal direction of the mold core, and the at least one driver section of the expansion device can be formed by a respective borehole in the shaped sheet metal, through which the respective spacer sleeve of the guide element or of the one or more guide elements can extend. According to particularly expedient examples, the at least one entrainment section of the respective spacer sleeve of the guide element or of the one or more guide elements can be arranged on the side of the shaped sheet metal facing away from the sealing element. According to particularly expedient examples, the entrainment section of the respective spacer sleeve of the guide element or of the one or more guide elements can be at a distance from the side of the sealing element facing the interior of the mold core, which distance is preferably greater than the sheet metal thickness of the shaped sheet. According to particularly expedient examples, one or more guide elements can each have a stamping section on the side facing the sealing element, which preferably engages and/or is fitted into a groove section of the sealing element, the groove section of the sealing element particularly preferably having substantially a T-shape in cross-sectional profile. According to particularly expedient examples, the stamping section can engage and/or be fitted in a direction transverse to the longitudinal direction of the mold core in a positively connected manner in the groove section of the sealing element, particularly preferably in the radial direction of the mold core and/or substantially perpendicular to the radial direction of the mold core. According to particularly expedient examples, the stamping section of the respective guide element can engage in the groove section of the sealing element in a slidably displaceable manner in the longitudinal direction of the mold core. According to particularly expedient examples, the sealing element can have a connecting band on which a guide strip which has the groove section and extends in the longitudinal direction of the mold core is preferably arranged. 
     According to a further exemplary aspect, a sealing element (e.g. also available as a spare part) for use on a mold core according to one of the above examples is proposed, with the sealing element preferably being able to be fastened to the respective longitudinal edges of the longitudinal opening of the core mantle by a detachable connection. Furthermore, one or more guide elements can be arranged on the side of the sealing element that faces the interior of the mold core (in the fastened state). According to particularly expedient examples, the sealing element or the one or more guide elements can be configured and/or designed in such a way that at least one driver section of the expansion device comes or can come into contact with at least one entrainment section of the one or more guide elements of the sealing element (in the fastened state) in the transition from a first shrinking process of the at least two shrinking processes carried out in succession to a second shrinking process of the at least two in succession performed shrinking processes, in particular for guiding the sealing element in (or during) the second shrinking process (and possibly in or during further shrinking processes). The sealing element preferably has a connecting band on which a guide strip, which has the groove section and extends in the longitudinal direction of the mold core, is preferably arranged. Further examples of the sealing element are described above and/or below. 
     According to a further exemplary aspect, a molding apparatus for the production of hollow and/or in particular tubular concrete bodies is also proposed, comprising an outer mold and an inner mold which is preferably arranged and/or can be arranged in the outer mold and which preferably has a mold core according to one of the above aspects and/or examples. 
     Further aspects and their advantages, as well as advantages and more specific implementation options of the aspects and features described above, are described in the following descriptions and explanations relating to the attached figures, but these are in no way to be understood as limiting. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG.  1    shows an exemplary perspective view of a molding apparatus for producing tubular concrete bodies according to an exemplary embodiment of the present disclosure; 
         FIG.  2    shows an exemplary plan view of the exemplary molding apparatus of  FIG.  1   ; 
         FIG.  3    shows an exemplary cross-sectional view of the exemplary molding apparatus of  FIG.  1    (section A-A of  FIG.  2   ); 
         FIG.  4    shows an exemplary perspective view of a mold core of a molding apparatus for the production of tubular concrete bodies according to an exemplary embodiment of the present disclosure; 
         FIG.  5    shows an exemplary plan view of the exemplary mold core of  FIG.  4   ; 
         FIG.  6    shows an exemplary longitudinal sectional view of the exemplary mold core according to  FIG.  3    (section  8 - 8  according to  FIG.  5   ); 
         FIG.  7    shows an exemplary perspective view of an exemplary expansion device of a mold core of a molding apparatus for manufacturing tubular concrete bodies according to an exemplary embodiment of the present disclosure; 
         FIG.  8    shows an example front view of the example expansion device of  FIG.  7   ; 
         FIG.  9    shows an exemplary top view of the exemplary expansion device according to  FIG.  7   ; 
         FIG.  10    shows an exemplary longitudinal side view of the exemplary expansion device of  FIG.  7   ; 
         FIG.  11    shows an exemplary cross-sectional view of the exemplary expansion device of  FIG.  7    (section C-C of  FIG.  10   ); 
         FIG.  12 A  shows an exemplary profile view of a sealing element for use on a mold core according to an exemplary embodiment of the present disclosure; 
         FIG.  12 B  shows an exemplary profile view of a sealing element for use on a mold core according to another exemplary embodiment of the present disclosure; 
         FIG.  12 C  shows an exemplary profile view of a sealing element for use on a mold core according to another exemplary embodiment of the present disclosure; and 
         FIG.  12 D  shows an exemplary profile view of a sealing member for use on a mold core according to another exemplary embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE FIGURES AND PREFERRED EXAMPLES 
     Preferred examples and/or examples of the present disclosure are described in detail below with reference to the attached figures. Identical and/or similar elements in the figures can be denoted by the same reference numbers, but sometimes also by different reference numbers. It should be emphasized that the present disclosure is in no way limited and/or restricted to the examples described below and their design features, but also includes modifications of the examples, in particular those that are obtained by modifications of the features of the examples described and/or by combination of one or more of the features of the examples described are included within the scope of the independent claims. 
       FIG.  1    shows an exemplary perspective view of a molding apparatus  1000  for producing tubular concrete bodies according to an exemplary embodiment of the present disclosure.  FIG.  2    shows an example top view of the example molding apparatus  1000  of  FIG.  1   .  FIG.  3    shows an example cross-sectional view of the example molding apparatus  1000  of  FIG.  1    (section A-A of  FIG.  2   ). For example, the molding apparatus  1000  is herein configured to produce cylindrical concrete pipes that have a substantially circular cross section with a wall thickness that is substantially constant over the circumference (i.e., for example, with substantially coaxial circular inner and outer cross-sectional shapes). However, further exemplary embodiments with other inner and/or outer shapes can be provided, in which hollow and/or tubular concrete bodies can be produced, the outer and/or inner shape of which deviates from the circular shape in cross-section, e.g. with oval, elliptical, angular (possibly with rounded corners) cross-sectional shapes outside and/or inside and/or with inside and/or outside shape centers deviating from the coaxial arrangement. 
     The molding apparatus  1000  of the exemplary embodiment according to  FIGS.  1 ,  2  and  3    comprises, by way of example, a stand section  100  on which an outer mold  200  comprising two outer mold sections  210  and  220  is arranged. In this case, both outer mold sections  210  and  220  are formed, purely by way of example, substantially as semi-hollow cylindrical elements which, when put together, form the outer mold  200 , which is in the form of a hollow cylinder, for example. In further examples, the outer mold can be composed of two or more identical and/or differently shaped outer mold sections. The outer mold sections  210  and  220  of the outer mold  200  of the example according to  FIGS.  1  and  2    are arranged on respective carriage sections  211  and  221 , for example. By means of the carriage sections  211  and  221 , which are slidably displaceably mounted on rails  110  and  120 , which are arranged, for example, on the stand section  100 , the outer mold sections  210  and  220  can be moved apart and/or away from each other, for example, for demoulding a concrete body B produced in the molding apparatus  1000  from the set-up state shown in  FIG.  1    to be moved to release the concrete body inside. In the set-up process, e.g. before the next concrete pouring process, the outer mold sections  210  and  220  can be moved towards one another and/or brought together again in order to be assembled and/or fastened to one another in the set-up state shown as an example in  FIG.  1   . In the set-up state, the inner wall of the outer mold sections  210  and  220  forms, for example, substantially a cylinder shape (hollow cylinder inner wall), which at least partially forms the outer wall of the concrete body to be produced. 
     The molding apparatus  1000  of the embodiment according to  FIGS.  1 ,  2  and  3    further includes a mold core  300  forming the inner mold. The mold core  300  and/or its outer shape substantially forms a (vertical) cylindrical shape, which at least partially forms the inner wall of the concrete body B to be produced. During the concrete pouring process, in the set-up state of the molding apparatus  1000  according to  FIG.  1   , concrete can be poured into the gap formed between the outer mold  200  and the mold core  300  in order to form the concrete body B to be produced (see, for example,  FIGS.  2  and  3   ). By way of example, the molding apparatus  1000  is used to form substantially cylindrical concrete pipes in an upright position. The mold core  300  of the molding apparatus  1000  is exemplary embodied as a collapsible core, for example, which has an expansion device  400  (spreading and/or shrinking device) arranged in the exemplary hollow-cylindrical interior of the mold core  300  (see  FIG.  2   , not shown in  FIGS.  1  and  3   ). The expansion device  400  extends, for example, in the interior of the mold core  300 , in particular, for example, in the longitudinal direction of the mold core  300 , i.e. in the present example vertically in the case of the mold core  300  standing as an example in  FIG.  1   . The longitudinal direction of the mold core is defined here, for example, by the longitudinal direction of the hollow and/or tubular concrete bodies or concrete pipes to be produced. The expansion device  400  is configured, for example, to spread (expand) the mold core  300  to form the set-up state for the concrete casting process and/or to shrink (contract) the mold core  300  to demould the concrete body B. 
     However, it should be pointed out that in the present example, substantially cylindrical concrete pipes can be cast in an upright position only by way of example. However, further examples are possible in which the outer shape and/or the inner shape, i.e. e.g. the inner mold core, of the molding apparatus deviate from the cylindrical shape and/or the substantially circular cross-section. For example, it is possible to produce concrete pipes with an oval cross-section or a square (triangular, square, pentagonal and with more corners) cross-section, if necessary with rounded corners, in which case the outer shape and/or the mold core in cross-section can be adapted to the desired shape of the produced concrete body is adjusted. Thus, examples with mold cores with an oval cross section or angular cross section, possibly with rounded corners, are also possible. Consequently, further examples with other inner and/or outer shapes can be provided, in which hollow and/or tubular concrete bodies can be produced, the outer and/or inner shape of which deviates from the circular shape in cross section, e.g. with oval, elliptical, angular (possibly with rounded corners) cross-sectional shapes outside and/or inside and/or with inside and/or outside shape centers deviating from the coaxial arrangement. Here, the cross-sectional shape of the inner wall of the outer mold and/or the cross-sectional shape of the outer wall of the mold core or the inner shape can deviate from the circular shape. Furthermore, it is possible to provide external and/or internal shapes whose cross-sectional shape and/or cross-sectional size may change in the longitudinal direction. In further examples, the outer mold  200  can, for example, comprise a cover element, possibly a circular and/or ring-shaped cover element, which covers the concrete body B hardening in the mold after the casting process from above, and/or a clamping device, which fastens the outer mold  200  and the inner mold and/or the mold core  300  in the set-up state for the casting process. In this example, the expansion device  400  is controlled hydraulically, for example, and/or can be actuated hydraulically, whereby in further examples, in addition to one or more hydraulic mechanisms, other mechanisms can also be used additionally or alternatively, e.g. using a mechanical, hydraulic, pneumatic and/or electrical and/or or electromagnetic control. 
       FIG.  4    shows an exemplary perspective view of a mold core  300  of a molding apparatus  1000  for producing hollow and/or in particular tubular concrete bodies according to an example of the present disclosure. By way of example, the mold core  300  in the molding apparatus  1000  according to  FIGS.  1  to  3    can be used. Analogously to  FIG.  2   , the mold core  300  has the expansion device  400  on the inside, for example. The mold core  300  comprises, for example, a substantially cylindrical core mantle  310  (can also be referred to as a form mantle or wall of the core), which has a strip-shaped opening (longitudinal opening) that extends, for example, on one side in the longitudinal direction of the mold core  300 , from one end to the other end of the mold core  300  and/or over the entire length of the mold core, on which opening, for example, a sealing and/or closing strip-shaped sealing element  500  is arranged. By way of example, the strip-shaped sealing element  500  extends (preferably at least) substantially from one end to the other end of the mold core  300 , in particular in the longitudinal direction of the mold core, and/or by way of example (preferably at least) over the entire length of the mold core  300  along the longitudinal opening of the core mantle  310 , especially in the longitudinal direction of the mold core. The strip-shaped sealing element  500  has on its longitudinal edges, for example, connecting strips  511  and  512  extending in the longitudinal direction, which connect the sealing element  500  to the respective longitudinal edges  311  and  312  of the strip-shaped longitudinal opening of the core mantle  310  and/or attach them sealingly. For example,  FIG.  4    shows the mold core  300  in the spreaded and/or expanded state, in which the core mantle  310  is expanded, for example in such a way that the longitudinal edges  311  and  312  of the strip-shaped longitudinal opening of the core mantle  310  are pushed apart, in particular controlled and/or driven by, for example the expansion device  400 . In  FIG.  4   , fastening elements  321  to  324  on the underside of the mold core  300  are shown merely by way of example, with which the mold core  300  can be fastened in a standing position on and/or at the stand section  100  of the molding apparatus  1000  between the outer mold sections  210  and  220  of the outer mold  200 . 
       FIG.  5    shows an exemplary plan view of the example of the mold core  300  according to  FIG.  4   . Here, in particular, the exemplary expansion device  400  arranged inside the mold core  300  is shown (e.g. analogously to  FIG.  2   ). The expansion device  400  is operated hydraulically, for example, and is configured, for example, to spread and/or expand the mold core  300 , e.g. by the longitudinal edges  311  and  312  of the core mantle  310  being pushed apart by an expansion mechanism of the expansion device  400 , for example hydraulically controlled, or by expansion of the core mantle  310 . Conversely, the expansion device  400  is configured, for example, to shrink and/or contract the mold core  300  in that the longitudinal edges  311  and  312  are moved towards one another and/or towards onto one another by the expansion mechanism of the expansion device  400 , for example hydraulically controlled, or by contracting the core mantle  310 .  FIG.  5    shows, by way of example, the expanded and/or spread state of the mold core  300 , with the longitudinal edges  312  and  312  of the strip-shaped longitudinal opening of the core mantle  310  being pushed apart, for example. The sealing element  500  is arranged between the longitudinal edges  311  and  312  of the longitudinal opening of the core mantle  310 , for example, wherein the sealing element  500  seals the mold core  300  from the outside against the ingress of liquid, and, on the longitudinal sides of the sealing element  500 , the connecting strips  511  and  512 , for example, connect the sealing element  500  with the respective longitudinal edges  311  and  312  of the longitudinal opening of the core mantle  310  in a sealed manner. An exemplary expansion mechanism of the expansion device  400  and its exemplary mode of operation according to an example is shown in  FIGS.  6  to  11    in more detail. 
       FIG.  6    shows an exemplary longitudinal cross-sectional view of the exemplary mold core  300  of  FIG.  3    (section B-B of  FIG.  5   ).  FIG.  6    shows, by way of example, the expansion device  400  inside the mold core  300 , the expansion device  400  extending, by way of example, in the longitudinal direction from one end of the mold core  300  to the other end. By way of example, the expansion device  400  comprises two hydraulically actuated expansion mechanisms  400 A and  400 B of exemplarily identical construction at different positions inside the mold core  300 . In further examples, only one or more than two expansion mechanisms can also be provided, e.g. also depending on the length of the mold core. The expansion mechanisms  400 A and  400 B are each configured, for example, to move the sword element  410  of the expansion device  400 , which extends for example in the longitudinal direction, in the radial direction of the substantially cylindrical core mantle  310 , for example. The further exemplary mode of operation of the expansion device  400  and/or expansion mechanisms  400 A and  400 B is described in the following purely by way of example using an example. 
       FIG.  7    shows an exemplary perspective view of an exemplary expansion device  400  of a mold core  300  of a molding apparatus  1000  for the production of hollow and/or in particular tubular concrete bodies according to an embodiment of the present disclosure. As previously described, by way of example, expansion device  400  includes two hydraulically actuable expansion mechanisms  400 A and  400 B. In further examples, only one or more than two expansion mechanisms can also be provided, e.g. also depending on the length of the mold core. 
       FIG.  8    shows an exemplary front view of the exemplary expansion device  400  according to  FIG.  7   , in particular, for example, in the spreaded and/or expanded state.  FIG.  9    shows an exemplary top view of the exemplary expansion device  400  according to  FIG.  7   .  FIG.  10    shows an exemplary longitudinal side view of the exemplary expansion device  400  according to  FIG.  7   . The expansion device  400  comprises, by way of example, two fastening strips  421  and  422  which extend parallel to one another in the longitudinal direction and which, for example, can be fastened and/or are fastened to the parallel extending longitudinal edges  311  and  312  of the strip-shaped longitudinal opening of the core mantle  310  in a parallel arrangement (see e.g.  FIGS.  4  and  5   ). The expansion mechanisms  400 A and  400 B are each fastened and/or screw-connected to the fastening strips  421  and  422  on both sides in the longitudinal direction one behind the other, for example, via respective screw connections S 1  and S 2 . The fastening strips  421  and  422  serve in the example only as an example as fasteners for fastening the expansion device  400  to the core mantle  310  or to the longitudinal edges  311  and  312  of the core mantle  310  and also only as an example for fastening or connecting the sealing element  500  or the connecting strips  511  and  512  of the sealing element  500  at/with the longitudinal edges  311  and  312  of the strip-shaped longitudinal opening of the core mantle  310  (see e.g.  FIG.  5   ). 
     The expansion mechanism of expansion device  400  shown in  FIG.  8    (and analogously, by way of example, expansion mechanisms  400 A and  400 B of exemplary identical construction) includes, for example, a hydraulic cylinder  430 , the hydraulically controllable piston  431  of which, for example, has a lever element  440  that extends transversely to piston  431  and transversely to the longitudinal direction of expansion device  400  and is connected, in particular, for example, via a screw connection S 3 . On the side of hydraulic cylinder  430  facing away from lever element  440 , the hydraulic cylinder  430  and/or a carrier element  470  carrying the hydraulic cylinder  430  is connected, for example, to the sword element  410  extending transversely to the axis of the hydraulic cylinder  430 . At both end sections  441  and  442  of the lever element  440  and/or at both opposite sides of the lifting element  440 , the push rod elements  451  and  452  are fastened, for example. For example, the push rod elements  451  and  452  are connected at both ends via swivel joints L 11  and L 12  and they can be rotatably mounted and/or pivotally mounted and/or rotatably held at the swivel joints L 11  and L 12  about a respective axis of rotation that is aligned substantially perpendicular to the push rod elements  451  and  451  and/or parallel to the longitudinal direction of the expansion device  400 . The push rod elements  451  and  452  extend, for example, parallel to one another and parallel to the piston  431  of the hydraulic cylinder  430  and/or parallel to the axis of the hydraulic cylinder  430 , which is aligned transversely to the longitudinal direction of the expansion device  400 . For example, the push rod elements  451  and  452  are connected to the ends facing away from the lever element  440  and/or on the side facing away from the lever element  440  to respective fastening sections  461  and  462 , wherein the fastening sections  461  and  462  are exemplarily respectively connected to the fastening strips  421  and  422  and/or or are fastened to them oppositely via the screw connections S 1  and S 2 . Furthermore, by way of example, respective spacer elements  481  and  482  are fastened to the fastening sections  461  and  462  via pivot joints L 31  and L 32 , the respective other ends of the spacer elements  481  and  482  being fastened to the sword element  410  on transversely opposite sides of the sword element  410  via respective pivot joints L 41  and L 42  to the sword element  410 . For example, the spacer elements  481  and  482  are each mounted on the pivot joints L 31 , L 32 , L 41  and L 42  such that they can rotate and/or pivot and/or about a respective axis of rotation that is substantially perpendicular to the push rod elements  451  and  452  and/or parallel to the longitudinal direction of the expansion device  400 . The spacer elements  481  and  482  are, for example, always aligned with their own longitudinal direction transverse to the longitudinal direction of the expansion device  400 . It should be mentioned at this point that the longitudinal direction of the expansion device  400  in  FIG.  8    is arranged, for example, perpendicular to the plane of the drawing. Here, the spacer elements  481  and  482  can be pivoted with respect to one another due to the rotatable mounting on the joints L 31 , L 32 , L 41  and L 42  and can also be pivoted relative to the connecting rods  451  and  452  at the same time. 
     In the exemplary spreaded position of expansion device  400  (spreaded and/or expanded state) shown in  FIG.  8   , the spacer elements  481  and  482  are, for example, aligned with their own longitudinal direction parallel and/or axially to one another and, for example, transversely to the push rods  451  and  452 . Due to the alignment axially to one another, the joints L 31  to L 41  and/or L 32  to L 42  (and thus the joints L 31  to L 32 ) on both sides of the expansion mechanism  400  are at a maximum distance from one another. Thus, the opposing fastening sections  461  and  462  in the state shown in  FIG.  7    are, for example, at a maximum distance from one another and the fastening strips  421  and  422  (and thus also the longitudinal edges  311  and  312  of the core mantle  310  fastened to them) are pushed apart at a maximum distance. This leads to the core mantle  310  being spreaded and/or expanded. In order to shrink and/or contract the mold core  300 , e.g. for the demolding process, the hydraulic cylinder  430  can be actuated to retract the piston  431  so that the sword element  410  is moved towards the lever element  440 , i.e. in particular in the inward direction relative to the mold core  300 . This also leads to a movement of the sword element  410  relative to the fastening sections  461  and  462  and/or the fastening strips  421  and  422 , so that the spacer elements  481  and  482  can be pivoted against each other and relative to the fastening sections  461  and  462  and the sword element  410 . Due to the pivoting of the spacer elements  481  and  482 , the distance between the attachment sections  461  and  462  is reduced compared to the spreaded position shown in  FIG.  8   , so that the attachment strips  421  and  422  connected to the attachment sections  461  and  462  and/or the longitudinal edges  311  and  312  attached thereto of the core mantle  310  are contracted and the distance between the longitudinal edges  311  and  312  of the core mantle  310  is reduced over the entire length of the core mantle  310 . This leads to the desired shrinkage of the mold core  300  in order to facilitate demoulding of the concrete body B. 
       FIG.  8    also shows the fastening of the exemplary sealing element  500  by way of example. The sealing element  500  is fastened to the respective fastening strips  421  and  422  by connection of the connecting strips  511  and  512  of the sealing element  500  and/or is connected to them in a sealing manner. The fastening strips  421  and  422  serve in the example only as an example as fasteners for fastening the expansion device  400  to the core mantle  310  or to the longitudinal edges  311  and  312  of the core mantle  310  and also only as an example for fastening or connecting the sealing element  500  or the connecting strips  511  and  512  of the sealing element  500  at/with the longitudinal edges  311  and  312  of the strip-shaped longitudinal opening of the core mantle  310  (see e.g.  FIG.  5   ). In particular, the profiles of the connecting strips  511  and  512  of the sealing element  500  have, for example, longitudinally running groove sections  511   a  and  512   a  which, for example, have a T-shape in cross-sectional profile (see e.g. also  FIGS.  12 A to  12 D ). The fastening strips  421  and  422  have, for example, corresponding profile rails  421   a  and  422   a  extending in the longitudinal direction, which are designed to engage in the respective groove sections  511   a  and  512   a  of the connecting strips  511  and  512  of the sealing element  500  and/or to be slided in into them in the longitudinal direction, so that the profile rails  421   a  and  422   a,  which have a T-shape, for example, are fastened to the groove sections  511   a  and  512   a  and/or to the connecting strips  511  and  512  of the sealing element  500  and/or are connected to them in a sealing manner. The connecting strips  511  and  512  of the sealing element  500  as well as the profile rails  421   a  and  422   a  of the fastening strips  421  and  422  extend, for example, in the longitudinal direction parallel to the longitudinal edges  311  and  312  of the core mantle  310  and can preferably be displaced in relation to one another in the longitudinal direction, but they are preferably positively connected in the transverse direction and/or transversely to the longitudinal direction. In particular, the connecting strips  511  and  512  of the sealing element  500  are each connected to the fastening strips  421  and  422  so that they can be slidably displaced in the longitudinal direction, for example, with the movement transverse to the longitudinal direction being blocked in a form-fitting manner (i.e. for example only one remaining degree of translatory freedom). This has the advantage that the sealing element  500  can be replaced easily and inexpensively, e.g. when signs of wear occur, by the sealing element  500  being held on the fastening strips  421  and  422  so that it can be pulled out in the longitudinal direction. For example, the sealing element  500  can advantageously simply be slidably pulled out of the longitudinal opening of the core mantle  310  in the longitudinal direction and a sealing element  500  of the same construction and/or a sealing element having analogous connecting strips  511  and  512  can be slidably inserted in the longitudinal direction. 
     The sealing element  500  is configured, for example, to seal off the interior of the mold core  300  during the concrete pouring process and to prevent liquid from penetrating into the interior of the mold core  300 . For this purpose, the sealing element  500  has, for example, a connecting band  520  which is arranged between the connecting strips  511  and  512  and is connected to the connecting strips  511  and  512 , which connecting band  520  is, for example, flexible and/or preferably elastically bendable (particularly preferably bendable or deformable about a longitudinal axis of the sealing element  500 ). For example, the connecting band  520  can consist of an elastically bendable or elastically formable material, such as an elastic plastic, and/or can comprise a section consisting of an elastically bendable material, such as an elastic plastic. In preferred examples, the connecting band  520  comprises an elastomer and/or the connecting band  520  consists of an elastomer. 
     In the expanded state shown as an example in  FIG.  8   , the round shape of the elastic connecting band  520  (see, e.g. also  FIG.  5   ) is specified, for example, by a shaped plate  490  (shaped plate), with the shaped plate  490  being attached (in particular on the side facing away from the lever element  440  and/or from the hydraulic cylinder  430 ) to the sword element  410  (see e.g. also  FIG.  6   ). When the sword element  410  is pulled inwards during the shrinking of the mold core  300  by the expansion device  400 , the shaped sheet metal  490  also lifts off of the elastic connecting band  520  of the sealing element  500  and is pulled inwards, for example. In addition (as described further above by way of example), the longitudinal edges  311  and  312  of the wall of the core  310  are pushed towards each other, for example, so that the connecting strips  511  and  512  of the sealing element  500  are also pushed towards each other, for example. When the mold core  300  shrinks, this also leads, for example, to a bending of the elastic connecting band  520  of the sealing element  500  folding inwards. The outward bending of the elastic connecting band  520  of the sealing element  500  is prevented in this process (e.g. when demoulding a hardened concrete body) by the inner surface of the hardened concrete body B lying against the sealing element  500  on the outside. This results in the technical advantage that the sealing element  500  and/or the flexibly and/or elastically bendable connecting band  520  of the sealing element  500  is not initially pulled inwards, but rather is bent inwards, with the advantageous avoidance of tensile forces acting on the connecting band  520 , by the pushing together of the longitudinal edges  311  and  312  of the core mantle  310 . Due to the avoidance of tensile forces acting on the sealing element  500 , this advantageously leads to less stress acting on the sealing element  500  and/or the flexibly and/or elastically bendable connecting band  520  of the sealing element  500  and thus to an improvement in the wear behavior and/or to the advantageous avoidance of above-average signs of wear on the sealing element  500  and/or on the connecting band  520  of the sealing element  500 . Should the sealing element  500  nevertheless be worn out after repeated use and/or after a large number of casting processes and/or shrinkage processes, e.g. due to cracking, it can still quickly, efficiently, inexpensively and easily replaced according to the above description. Overall, there is a significant improvement in the service life of the molding apparatus  1000  due to the reduced wear of the sealing element  500  on the one hand and the simpler and/or quicker possibility of replacing the sealing element  500  on the other. 
       FIG.  11    shows an example cross-sectional view of the example expansion device  400  of  FIG.  7    (section C-C of  FIG.  10   ). The illustration is analogous to  FIG.  8    by the plan view of the expansion mechanism  400 B. However, as an example, bores  421   b  and  422   b  are also shown on the fastening strips  421  and  422 , to which the fastening strips  421  and  422  (and thus the expansion device  400 ) can be fastened to fastening strips on the longitudinal edges  311  and  312  of the core mantle  310 . Additionally, an example guide member  600 D is shown in  FIG.  11   . Such guide elements  600 A to  600 E are, for example, held one behind the other at several positions in the center of the guide plate  490  in the longitudinal direction (see also  FIGS.  6  and  7   ), in particular at the respective bores in the shaped plate  490  (see  FIG.  11   ). The guide element  600 D has, for example, on the side of the shaped sheet metal  490  facing the sealing element  500 , a stamping section  601  which is fastened, for example, with a screw  602  extending through the respective bore of the shaped sheet metal  490 . For example, the screw  602  extends further through a spacer sleeve  603 , which also extends through the respective bore of the shaped sheet  490 , wherein the spacer sleeve  603  has, on the side of the shaped sheet  490  facing away from the sealing element  500 , for example, a driver section  603   a  with an enlarged diameter. The sealing element  500  has, for example, on the side facing the interior of the mold core  300 , for example, a profile strip  530  extending in the longitudinal direction in the middle, which is fastened, for example, to the connecting band  520  of the sealing element  500 . The profile strip  530  has, for example, a receiving groove  530   a,  which is opened inwards toward the interior of the mold core, for the stamping sections  610  of the guide elements  600 A to  600 E (see also  FIG.  12   ). The receiving groove  530   a  of the profile strip  530  has, for example, a T-shape in cross-sectional profile (see also  FIG.  12   , for example), which is adapted, for example, to the cross-sectional profile of the stamping section  601  of the guide elements  600 A to  600 E. In the process of shrinking the mold core  300 , when the sword element  410  and thus also the shaped sheet  490  are pulled radially into the interior of the mold core  300 , the shaped sheet  490  moves inwards and lifts off the connecting band  520  of the sealing element  500 . Here, the shaped sheet  490  moves a preset stroke distance inwards (upward in  FIG.  10   ), for example, which is preset with the length of the spacer sleeve  603  and/or the screw length of the screw  602 , until the upper side of the shaped sheet  490  comes into contact with the driver section  603   a  of the spacer sleeve  603  and takes the spacer sleeve  603  and/or the driver section  603   a  of the spacer sleeve  603  with it, so that, after the movement of the exemplary preset stroke distance (without tensile forces acting on the sealing element  500 ), the guide elements  600 A to  600 E carried along by the shaped sheet metal  490  via the stamp sections  601  inserted in the profile strip  530 , thereby guiding the sealing element  500  and/or its inward bending during the shrinking process. 
     According to the above examples, the expansion device is configured, for example, to carry out the shrinking process in two steps and/or as two-staged shrinking, in particular with preferably a single continuous lifting movement of the mechanism driving both shrinking steps, herein for example by the hydraulic cylinder  430 . For example, in the first step (e.g. first stage of the continuous shrinking process), the sword element  410  and thus also the shaped sheet metal  490  are pulled radially into the interior of the mold core  300 , with the shaped sheet metal  490  moving inwards and being lifted off of the connecting band  520  of the sealing element  500 , for example without tensile force in this first step being exerted on the sealing member  500 . If the continuous lifting movement is continued by the single and/or the same drive (e.g. the hydraulic cylinders), the upper side of the shaped sheet metal  490  comes into contact with the driver section  603   a  of the spacer sleeve  603  (transition to the second step and/or to the second stage of the continuous shrinking process), for example, and the shaped sheet metal  490  then, for example, takes the spacer sleeve  603  and/or the driver section  603   a  of the spacer sleeve  603  with it in the second step, so that in the second step, for example, the sealing element  500  is now also carried along during the shrinking movement of the mold core  300  driven by the same drive mechanism. As a result, this example has the technical advantage that the sealing element  500  and/or the flexible and/or elastically bendable connecting band  520  of the sealing element  500  is not initially pulled inwards, but rather is bent inward, with the advantageous avoidance of tensile forces acting on the connecting band  520 , due to the pushing together of the longitudinal edges  311  and  312  of the core mantel  310 , wherein the bending of the sealing element  500  also is advantageously guided, for example, by the guide elements  600 A to  600 E and being held in the shrunken state. 
     Due to the avoidance of tensile forces acting on the sealing element  500 , despite the advantageous guidance by the guide elements  600 A to  600 E, there is advantageously less stress on the sealing element  500  and/or the flexibly and/or elastically bendable connecting band  520  of the sealing element  500 , and thus an improvement in the wear behavior and/or an advantageous avoidance of above-average wear and tear on the sealing element  500  and/or on the connecting band  520  of the sealing element  500  is achieved. Should the sealing element  500  nevertheless wear out after repeated use and/or after a large number of casting processes and/or shrinkage processes, e.g. due to cracking, it can still be replaced quickly, efficiently, inexpensively and easily according to the above description, wherein in this case, the stamp sections  601  of the guide elements  600 A to  600 E are also pushed in into the receiving groove  530   a  of the profile strip  530  (guide strip) of the sealing element  500  when the sealing element  500  is pushed in in the axial direction. Overall, there is a significant improvement in the service life of the forming device  1000  due to the lower wear of the sealing element  500  on the one hand and the simpler and/or faster possibility of replacing the sealing element  500  with simultaneous excellent guidance of the bending process on the other. 
       FIG.  12 A  shows an exemplary profile view of a sealing member  500  for use on a mold core  300  according to an exemplary embodiment of the present disclosure. The sealing element  500  is preferably in the form of a strip, with the longitudinal edges of strip-shaped sealing element  500  being provided, for example, with connecting strips  511  and  512 , which are arranged opposite one another on the flexibly and/or elastically bendable (preferably strip-shaped) connecting band  520  arranged between connecting strips  511  and  512  of the sealing element  500 , e.g. by an adhesive connection or at least supported by an adhesive connection. By way of example, the connecting strips  511  and  512  have the receiving grooves  511   a  and  512   a,  which are open laterally to the outside, for receiving the rail profiles  421   a  and  422   a  of the fastening strips  421  and  422  for sealing attachment to the mold core  300  and/or the core mantle  310 . The receiving grooves  511   a  and  512   a  have, for example, a T-shape in the cross-sectional profile. In the middle, the sealing element  500  also has, for example, a profile strip  530  extending in the longitudinal direction, which is fastened to the connecting band  520  of the sealing element  500 , for example. The profile strip  530  has, for example, an outwardly open receiving groove  530   a  for receiving the above-described stamping sections  610  of the guide elements  600 A to  600 E. 
     For example, the profile strip  530  is embedded in the connecting band  520  of the sealing element  500  in such a way that the outside of the profile strip  530  terminates with the outside of the connecting band  520  of the sealing element  500  and does not and/or does not substantially protrude beyond it. Here, the profile strip  530  can be connected to the connecting band  520  of the sealing element  500  by a non-positive connection (e.g. an adhesive connection) or at least supported by a non-positive connection. In addition, the profile strip  530  has, for example, laterally protruding profile webs  530   b  in order to strengthen the connection between the profile strip  530  and the connecting band  520  and to avoid and/or prevent the connection from tearing off during repeated bending movements of the connecting band  520 . To strengthen the connection of the connecting band  520  to the connecting strips  511  and  512  and in particular to reduce the risk of tearing off in the edge area of the connecting band  520 , the connecting strips  511  and  512  can also have profile sections protruding into the material of the connecting band  520  (possibly similar to the profile webs  530   b  of the profile strip  530 ). This improves the longevity of the connection of the connecting band  520  to the connecting strips  511  and  512  over the entire length of the sealing element  500  and thus avoids partial tearing off at the edges even if the sealing element  500  is used multiple times in shrinking and/or expansion processes on the mold core  300 . 
       FIG.  12 B  shows an exemplary profile view of a sealing member  500  for use on a mold core  300  according to another exemplary embodiment of the present disclosure. The features from  FIG.  12 A  are taken up here by way of example. To strengthen the connection of the connecting band  520  to the connecting strips  511  and  512  and in particular to reduce the risk of tearing off in the edge area of the connecting band  520 , the connecting strips  511  and  512  have, for example, respective anchor profile sections  511   b  and  512   b  protruding into the material of the connecting band  520 . This improves the longevity of the connection of the connecting band  520  to the connecting strips  511  and  512  over the entire length of the sealing element  500  and thus avoids partial tearing off at the edges even if the sealing element  500  is used multiple times in shrinking and/or expansion processes on the mold core  300   
       FIG.  12 C  shows an exemplary profile view of a sealing element  500  for use on a mold core  300  according to another exemplary embodiment of the present disclosure. The features from  FIG.  12 B  are taken up here by way of example, the profile strip  530  being dispensed with by way of example (elements  600 A to  600 E can then be omitted in the expansion device). To strengthen the connection of the connecting band  520  to the connecting strips  511  and  512  and in particular to reduce the risk of tearing off in the edge area of the connecting web band  520 , the connecting strips  511  and  512  again have, for example, respective anchor profile sections  511   b  and  512   b  protruding into the material of the connecting band  520 . In addition, the connecting strips  511  and  512  have, for example, respective nose profile sections  511   c  and  512   c  protruding into the material of the connecting band  520 , which protrude transversely to the anchor profile sections  511   b  and  512   b  into the material of the connecting band  520 , for example. This improves the longevity of the connection of the connecting band  520  with the connecting strips  511  and  512  over the entire length of the sealing element  500  even more and thus leads to an improved avoidance of partial tearing off at the edges, even if the sealing element  500  is used several times in shrinking and/or expansion processes on the mold core  300 . 
       FIG.  12 D  shows an exemplary profile view of a sealing member  500  for use on a mold core  300  according to another exemplary embodiment of the present disclosure. The features from  FIG.  12 C  are taken up here by way of example, the profile strip  530  being provided analogously to  FIG.  12 A  by way of example. 
     In examples, the sealing elements are preferably designed such that their cross-sectional width is substantially at least four times, in particular at least five times greater than the cross-sectional height of the connecting band, particularly preferably at least eight times greater than the cross-sectional height of the connecting band. In the above examples, the cross-sectional width is substantially ten times greater than the cross-sectional height of the connecting band. 
     In the above examples, an expansion device  400  and a sealing element  500  were shown on the mold core  300  in each case. However, in further examples it is also possible to provide a mold core with a core mantle (wall of the core) with a plurality of longitudinal openings and a plurality of sealing elements sealing the respective longitudinal openings. For example, in the case of an oval shroud shape, both opposite sides of the shroud can be provided with a respective expansion device and/or a respective sealing element. In the case of angular core mantle cross-sections (triangular, square, pentagonal, . . . , polygonal; e.g. with rounded corners), several and/or all sides between two corners of the wall of the core cross-section can be provided with appropriate expansion devices and/or sealing elements. Examples of the present disclosure have been described and proposed above, so that with regard to the disadvantages of the known prior art, mold cores according to the disclosure for molding apparatuses for the production of hollow and/or in particular tubular concrete bodies and accessories and spare parts (e.g. the sealing elements described) for such mold cores can be proposed and/or provided, in which a cost-effective arrangement that reliably seals the core mantle inwards can be provided, which also enables improved service life, is able to reduce material fatigue and/or wear and/or allow for easier handling in the event of material fatigue and/or wear and tear. It should be pointed out again that only examples and/or examples of the present disclosure and their advantages have been described in detail above with reference to the attached figures. It should be emphasized again that the present disclosure is in no way limited and/or limited to the above-described embodiments and their embodiment features and/or their described combinations, but also includes modifications of the embodiments, in particular those that are made possible by modifications of the features of described examples and/or by combination and/or partial combination of one or more of the features of the described examples are included within the scope of the independent claims.