Method for manufacturing a curable, slab-like light-conducting body, mold for carrying out the method and a light-conducting body produced in accordance with the method

Abstract

A method for manufacturing a curable light-conducting body (21) in a casting method, in particular for the manufacture of light-conducting bodies (21) of a curable concrete material (36, 56), wherein a light-conducting mat (1) is embedded in a curable casting material (36, 56), and a casting mold (27) with a recessed mold cavity (18) open at the top is filled with the not-yet-cured casting material (36, 56), wherein, in a first method step, a plurality of molding punches (32) moveably arranged in the mold cavity (18) of the casting mold (27) are moved to at least the plane of the upper edge (43) of the mold cavity (18), 1. in a second method step, the space between the molding punches (32) in the mold cavity (18) is filled with a curable casting material (36), 2. in a fifth method step, the light-conducting mat (1) to be embedded in the casting material (36, 56) is placed on the end sides (61) of the molding punches (32) raised in the mold cavity (18), 3. and that, in a sixth method step, the light-conducting mat (1) is pressed into the casting material (36, 56) wherein, with the pressing movement of the light-conducting mat (1) into the casting material (36, 56), the molding punches (32) are approximately synchronously moved downwards out of the bottom surface of the mold cavity (18).

Claims

1. A method for manufacturing a curable light-conducting body in a casting method, wherein a) in a first method step, a mold cavity of a casting mold is filled with a curable casting material, b) in a second method step, a light-conducting mat to be embedded in the casting material is fixed on an underside of a molding punch to be pressed into the casting mold, c) in a third method step, the molding punch moves into the mold cavity with the light-conducting mat fixed at its underside and thereby presses the light-conducting mat into the casting material.

2. A casting mold for carrying out the method according to claim 1, comprising a retaining profile is-arranged at the underside of the molding punch which, as a negative mold, is complementary to a bottom-side profile of the light-conducting mat.

3. The method according to claim 1, wherein the light-conducting mat comprises light-conducting elements having circumferentially rounded edges.

4. The method according to claim 1, wherein the light-conducting mat comprises rounded profile channels.

5. The method according to claim 3, wherein the casting mold comprises an elastically deformable bottom, so that when end-side edges of the light-conducting elements are set and abut on the bottom, the bottom bulges out in a convex manner.

6. The method according to claim 5, wherein, due to the elastically deformable bottom, light emitting end faces of the light-conducting elements remain free of sand and cement substrates during a curing process and afterwards slightly protrude from a cured slab and can thus be more easily further processed.

7. The casting mold according to claim 2, wherein the casting mold comprises a bottom having a soft, elastic surface.

8. The casting mold according to claim 2, wherein a number of slots are present in the molding punch, through which displaced casting material is drained.

Description

(1) In the drawings;

(2) FIG. 1 shows a top view of a light-conducting body of a concrete material;

(3) FIG. 2 shows a top view of a casting mold platen for the production of a concrete paving stone of FIG. 1;

(4) FIG. 3 shows a perspective partial view of a light-conducting mat;

(5) FIG. 4 shows a sectional view of the light-conducting mat of FIG. 4 at the position of a light-conducting element;

(6) FIG. 5 shows a partial sectional view of the top portion of the hermetic press while showing the anchoring of the steel counter mold arranged in the top portion in the light-conducting elements;

(7) FIG. 6 shows a schematic view of the molding punches moving in slots of the bottom of the casting mold platen 17, formed as a metal plate 42, in the vertical direction;

(8) FIG. 7 shows a refined view with respect to FIG. 10 showing a perspective view of the casting mold platen with molding punches arranged therein in a raised state;

(9) FIG. 8 shows a sectional view of the plate segment of a hermetic press in the initial state;

(10) FIG. 9 shows the same sectional view as FIG. 12 during pouring of facing concrete into the mold cavity;

(11) FIG. 10 shows the method progressing with respect to FIG. 13 showing that the facing concrete is also compacted by the press and a vibrating plate in the mold cavity;

(12) FIG. 11 shows the method step progressed with respect to FIG. 14 which shows that the core concrete is now being poured on top of the compacted facing concrete;

(13) FIG. 12 shows how the breakage-prone light-conducting mat is pressed by a top plunger on the molding punches preceding them as templates in the core concrete;

(14) FIG. 13 shows the method progressing with respect to FIG. 16 showing the process of pressing the light-conducting mat into the mold cavity;

(15) FIG. 14 shows the finished light-conducting body of cured concrete material;

(16) FIG. 15 is a perspective view of a pressing plate of the embodiment of the method of FIG. 16;

(17) FIG. 16 schematically shows a sectional view of a casting mold with a section of the pressing plate of FIG. 15;

(18) FIG. 17 shows a perspective view of the anchoring of the light-conducting mat at the bottom of the casting mold;

(19) FIG. 18 shows an embodiment, modified with respect to FIG. 17, wherein an additional retaining profile is arranged at the bottom of the casting mold;

(20) FIG. 19 shows the perspective view of a pressing plate for use in the method of FIG. 20;

(21) FIG. 20 schematically shows a sectional view of the further method, showing a metal negative mold and its anchoring in the mold cavity of the casting mold;

(22) FIG. 21 shows the perspective view of the negative mold consisting of metal and its anchoring at the bottom of the casting mold;

(23) FIG. 22 shows an embodiment modified with respect to FIG. 21 in which the negative mold is additionally anchored on a bottom-side retaining profile in the casting mold;

(24) FIG. 23 shows a perspective view of a molding punch with a light-conducting mat attached at its underside;

(25) FIG. 24 shows the arrangement according to FIG. 23 in a section view; and

(26) FIG. 25 shows a section of the casting mold, showing that the light-conducting mat shown in FIG. 24 is pressed into the casting material at the underside of the molding punch.

(27) FIG. 1 shows the configuration of a light-conducting body as an exemplary embodiment, as a concrete slab in road traffic. It could also be used, however, as a facade plate for interior and exterior spaces.

(28) When it is used as a facade plate, one or more heat insulating layers can also be arranged on the light-producing back side.

(29) The concrete-stone-like, slab-like light-conducting body 21 shown there, is installed embedded in a road surface, and the light emitting end faces of light-conducting elements 4 embedded therein are visible in the top surface 22 of the light-conducting body 21. They emit light visible from above, which is produced on the back side of the light-conducting body 21.

(30) FIG. 2 shows the top view of the mold cavity 18 of a casting mold platen 17 which is part of a multiple mold of a press 23 preferably formed as a round table press.

(31) A plurality of slots 19 are arranged in the bottom of the mold cavity 18 in the manner of a grid, wherein the type, size and distribution of the slots corresponds to the light-conducting elements 4 to be used therewith later.

(32) FIGS. 3 and 4 show a light-conducting mat as described in our own POT application WO 2016/150454 A1 in the associated FIGS. 8 and 9, the description thereof being incorporated herewith by reference. Generally, it can be said that the light-conducting mat 1 is of a transparent, light-conducting plastic material, wherein the light emitting light-conducting elements 4 comprise side surfaces 7 at which transverse webs 3 are attached which connect the light-conducting elements 4 extending in parallel and arranged at a spacing with respect to each other.

(33) It is also possible to remove the transverse webs 3 to avoid interference with the subsequent pressing method (see FIG. 12).

(34) Longitudinal webs 2 are provided in the transverse direction to the transverse webs 3, which are preferably formed as profile channels 10 and in which light rods 12 are snap fitted.

(35) Each light channel 5 is thus filled by a light rod 12 which is formed as a rail section and is snap engaged behind two opposed snap-in tabs 9 on the bottom side 8 of the light-conducting element 4.

(36) The numbers shown on the right in FIG. 4 are indications in millimeters referring to the height of the elements individually shown there.

(37) Since the light channel 5 also consists of a transparent, light-conducting plastic material, it emits the light in the arrow direction 13 into the light-conducting elements 4, and the light is ultimately emitted in the arrow direction 15 from the end faces 6 of the light-conducting elements 4.

(38) These end faces 6 are the light-emitting surfaces in the light-conducting body 21 in FIG. 1.

(39) It goes without saying that the invention is not limited to plate-like light-conducting elements 4. They can have any profile shape, i.e. they can be corrugated, round-profiled, circular, cylindrical or any other shape. They can also be formed as hollow sections or as a solid material.

(40) The only thing that is crucial to the present invention is that the molding punches 32 to be described later in the bottom portion 33 of a press are adapted to the dimension and profiling of the light-conducting elements 4.

(41) For manufacture, a hermetic press is preferred which works as a clocked round table press. A number of mold cavities 18 are arranged in the area of a plurality of juxtaposed casting mold platens 17 (see FIG. 2). One light-conducting body 21 is produced in each mold cavity.

(42) The press 26 essentially consists of a round table circulating in a clocked manner, at the periphery of which a number of devices are arranged, such as a feeding unit, the control panel and further functional elements, such as a vibrator, brush tools and the like.

(43) The mold cavity 18 arranged in the casting mold platen 17 is of an approximate box shape, as shown in FIG. 7, and a plurality of slots 19 perforate the bottom 28 of the casting mold 27, through which the molding punches 32 of a lower mold, to be described later, pass.

(44) As already explained, the type, profiling and the mutual spacing of the slots 19 arranged in a grid correspond to the type, the profiling and the grid-like distribution of the light-conducting elements 4 in the light-conducting mat 1.

(45) FIG. 5 shows a portion of a method sequence to be described later in more detail with reference to FIGS. 8 to 14.

(46) Namely, it is important that the method sequence described in FIGS. 5 and 6 uses a steel pressing plate 29 in the upper mold 47 comprising a plurality of short retaining profiles 30 engaging in the associated light channels 5 of the light-conducting mat in a manner that is as backlash-free as possible to thus enable guiding of the breakage-prone light-conducting mat 1 at the upper steel pressing plate 29.

(47) FIG. 7, in combination with FIG. 8, shows the type and arrangement of molding punches 32 arranged in the lower mold 46, which are arranged to be movable in the arrow directions 31 in the slots 19 in the bottom 28 of the casting mold 27.

(48) This can be derived from the perspective view of FIG. 7. The molding punches 32, extending through the bottom 28 in a grid-like manner, are thus shown in their raised positions, A partial section of such a press is shown in FIG. 8, where it can be seen that the molding punches 32 arranged in a grid-like manner, which extend through the slots 19 in the bottom 28 of the casting mold 27 are fixed on a common pressure plate 37 which is driven on a plunger 38 in the lower mold 46 in a raisable and lowerable manner.

(49) Since the press has an outer and an inner side, the inner side is shown at 44 and the outer side is shown at 45.

(50) The top edge of the casting mold 27 is formed by a metal plate 42.

(51) FIG. 9 now shows that in the area of a filling device 39, the relatively low-viscosity facing concrete 36 is poured via tubes 40 as a first casting material in the arrow direction 41 into the mold cavity 18. Herein, the molding punches 32 are maintained in their raised position in the mold cavity 18 so that the relatively low-viscosity facing concrete 36 flows around the molding punches 32.

(52) In accordance with FIG. 10, this is followed by uniform smoothing of the facing concrete 36 in the casting mold 27 by providing a pressing plate 59 with vibrating punches 52 protruding in a comb-like manner in an upper mold 47, which are moved between the still raised molding punches 32 downwards into the mold cavity 18 in the arrow direction 49 in a manner that precisely fills the gaps, and are placed upon and compact the facing concrete as the first casting material 36.

(53) During this, the plunger 38 in the lower mold 46 remains in the locked position.

(54) After the compacting is complete, the end faces of the molding punches 32 are cleaned with a brushing tool 54, and an abrasive tool 53 is also used.

(55) The vibrating punches 52 provided with prong-like protrusions are part of a vibrating plate 51.

(56) After the smoothing of the facing concrete as a first casting material 36 is complete, this is followed by pouring the very viscous (earth-moist) core concrete as the second casting material 56.

(57) To do this, the core concrete, as the second casting material 56, is fed in a feeding unit 58 via a conveyor 55 and filled into the mold cavity 18 in the arrow direction 57. Again, brushing tools 54 and abrasive tools 53 are used to achieve advantageous surface properties.

(58) This is followed, in FIG. 12, by the actual process of pressing-in the light-conducting mat 1, which has meanwhile been attached at the underside of a pressing plate 59 in a positionally secure manner.

(59) Positional securing is carried out using centering tabs 62 arranged at the underside of each pressing plate 59 which engage in the associated recesses which form the light channels 5 in the light-conducting mat 1 in an interlocking manner. This ensures that the light-conducting mat 1 is held at the underside of the pressing plate 59 in a positionally secure manner. Additional retaining means, such as the application of a vacuum, can also be used.

(60) Then, by moving the plunger 48 in the arrow direction 49, each light emitting end face 6 of the light-conducting elements 4 is placed on the end faces 61 of the molding punches 32 in the lower mold and held by the application of a weak pressing force in the arrow direction 49.

(61) The two plungers 48, 38 now perform a common (synchronous) downwards movement in the arrow directions 49, 60 so that the molding punches 32 move through the core concrete 56 and at the same time form the preceding templates for the following light-conducting elements 4 having the same profile and number.

(62) The light-conducting elements 4 are thus no longer obliged to perform their own displacement work in the core concrete 56 and are therefore protected against breakage.

(63) FIG. 13 shows the final state of the pressing process in which the light-conducting mat with its light-conducting elements 4 has arrived at the bottom of the mold cavity 18 and, at the same time, has also penetrated the facing concrete 36.

(64) Then the pressing plate 59 is moved downwards in the arrow direction 49in an embodiment not shown in any more detaila high pressure can then also be exerted on the core concrete by a suitable pressing tool (see FIG. 14) to thus compact the spaces between the light-conducting elements 4.

(65) Then, in accordance with FIG. 14, the finished light-conducting body 21 is removed from the mold and is stored for the subsequent curing process.

(66) The vibrating process for vibrating the facing concrete described with reference to FIG. 10 ensures that the facing concrete is uniformly distributed over the entire bottom 28 of the mold cavity 18. It is thus ensured that, in the final product, the viewing side will always have the same thickness. Before this, however, the surface of the metal plate and the casting mold protruding from the mold is cleaned by means of a rotating brush and a sponge.

(67) Precisely dosed amounts of a very dry concrete are then introduced also in the method step according to FIG. 11 via the conveyor 55 into the mold cavity 18. Then, the metal plate 42 and the molding punches 32 protruding from the mold are cleaned by means of a rotating brush 54 and a sponge.

(68) It has been explained with reference to FIG. 12 that the light-conducting mat 1 is held at the underside of the pressing plate 59 in a positionally secure manner. In a preferred embodiment, this step is performed using an arm robot, wherein the light-conducting mat 1 consisting of an injection-molded material is attached by slightly lowering the plunger 48 and the simultaneous application of a vacuum acting on the light-conducting mat 1.

(69) In any case, it is important that the molding punch has the same recesses as the light-conducting mat 1 at the underside. The underside of the light-conducting mat is that side in which the LED elements 20 provide the lighting and on which the cables are routed.

(70) This ensures that the light-conducting mat does not break even when a very high pressure is applied.

(71) A special working station is not necessary for fixing the light-conducting mat at the underside of the pressing plate 59. While the light-conducting mat 1 is being pressed into the core concrete in accordance with FIGS. 12 and 13, only a small pressure is applied by the plunger 48 in the arrow direction 49 which now ensures that the lower, light-emitting end faces 6 of the light-conducting elements 4 are placed on the end faces 61 of the molding punches 32 in a full and flush manner. This is followed by the previously described synchronous movement of the two plungers 38, 48 in the arrow directions 49, 60.

(72) When the molding punches 32 are moved out of the bottom of the mold cavity there is now the advantage that the moisture of the facing concrete penetrates the core concrete without damaging the injection molded part and a curing process takes place between the facing concrete and the core concrete. The resulting strength of the concrete material produced in this manner is thus the same as that of a normal concrete slab not penetrated by light-conducting elements.

(73) The last pressing process described above as an additional working step can thus be dispensed with since the molding punches moving out of the mold cavity 18 now ensure uniform distribution of the facing concrete with simultaneous curing of the core concrete 56.

(74) After raising of the pressing plate 59 in the upper mold 47, the product is finished. The next light-conducting mat 1 is inserted into the pressing apparatus immediately thereafter and fixed by means of a vacuum.

(75) To remove the finished light-conducting body 21 from the mold, the finished slab is pressed out of the metal mold via plungers not shown in any more detail, with a light pressure in the downward direction, wherein the finished light-conducting body is placed on another base plate and is transferred by a fully automatic system for further processing (drying, sandblasting, impregnating and packaging).

(76) FIGS. 15 and 16 show the method steps for carrying out the method according to the subject matter of independent claim 11.

(77) FIG. 15 shows, in a perspective view, a pressing plate 59 perforated by a number of slots 19 which extend through the entire cross-section of the pressing plate 59.

(78) The pressing plate 59 is shown in cross-section in FIG. 16, and it can be seen that the width and the profile of the slots 19 approximately correspond to the profile of the light-conducting elements 4 of the light-conducting mat 1.

(79) The light-conducting mat 1, with its bottom side, is placed on the bottom 28 of the casting mold 27 and anchored there.

(80) Then the casting material 66 is poured in until an overfill 67 has been created above the light-conducting elements 4 in the casting mold 27.

(81) Then the pressing plate 59 is moved downwards in the arrow direction 63 so that the light-conducting elements 4 partially penetrate the slots 19 of the pressing plate 59, which is not absolutely necessary, however, to achieve the desired result.

(82) It can also be provided that the underside of the pressing plate 59 is only lowered into the casting mold 27 by the amount of the overfill 67 and the light-conducting elements 4 do not penetrate into the slots 19.

(83) In this case, the slots 19 only serve for draining the displaced overfill 67 to the outside, with the additional possibility of extracting water.

(84) The present is preferably a single-layer concrete method, and the filling level of the casting mold 27 is 10 percent higher than the height of the finished slab.

(85) Subsequently, the pressing plate 59, with its slots 19, is pressed into the mold cavity 18. It can also be additionally vibrated to better compact the concrete.

(86) The concrete overlying the light conductors in the area of the overfill 67 is not compressed. Then, the non-compressed concrete is removed (precisely above the light conductors) and the slab is finished.

(87) In accordance with the exemplary embodiments yet to be described it may also be provided that the bottom 28 of the casting mold 27 is not rigid but elastically deformable.

(88) In a further development of the independent method claim 11 in accordance with FIGS. 15 and 16, it can be additionally provided according to FIGS. 17 and 18 that the light-conducting mat 1 is not just simply placed on the bottom 28 of the casting mold 27 but that a bottom-side profile 28 is provided which is complementary to the profile of the light-conducting mat 1 to be engaged therewith.

(89) In accordance with FIGS. 17 and 18, the light-conducting mat 1 is thus always placed and fixed on the bottom 28 of the casting mold 27 in a manner that is positionally secure and secure against displacement.

(90) The retaining profile 68 preferably consists of a metal or plastic material.

(91) When designing this retaining profile 68 it is important that all profile parts are formed in such a manner that they engage with the associated profile recesses of the light-conducting mat to be fitted in an interlocking manner and thus provide for sealing against the ingress of cement slurries.

(92) Thus, it can be seen from FIG. 18, for example, that the channels 65 for the insertion of cables into the embedded light-conducting mat 1 and further negative molds 69 are present which seal off the profile channel 10 of the light-conducting element 4 in an interlocking manner.

(93) In accordance with the subject matter of independent method claim 15, in a further development of the invention, it is suggested that it is not the light-conducting mat 1 that is placed and anchored in the mold cavity 18 of the casting mold 27 at the bottom, but a placeholder is placed in the mold instead, which is only removed from the casting material after the slab-like casting material is cured.

(94) For this purpose, the exemplary embodiment according to FIGS. 19 to 22 provides that a negative mold 70 preferably of metal sections, is present which exactly corresponds to the profile of the light-conducting mat 1.

(95) Parts of the slab 71 are therefore also present which correspond to the later light-conducting elements 4 of the light-conducting mat 1. All other placeholders are also present so that when the slab has cured it becomes possible to remove the negative mold 70 from the cured slab material and to then insert the light-conducting mat 1 into the cavities thus created.

(96) For this purpose, FIG. 21 shows such a negative mold 70 consisting of metal sections which, in its profile shape, exactly corresponds to the light-conducting mat 1 to be inserted later.

(97) Therefore, hollow sections 72 are also present which are provided for the later insertion of the channels 10 of the light-conducting mat 1, and all other parts are also present, such as a hollow section 73 for the later routing of a cable channel of the light-conducting mat 1 and the like.

(98) FIG. 21 shows that such a negative mold 70 can be anchored directly at the bottom 28 of the casting mold 27.

(99) FIG. 22, however, as a modification of the exemplary embodiment in accordance with FIG. 21, shows that a bottom-side retaining profile 68, on which the negative mold 70 is fitted and fixed can be provided in addition to the positional securing of the negative mold 70.

(100) This thus always ensures positionally secure fixing of the negative mold 70 at the bottom 28 of the casting mold 27.

(101) According to FIG. 20, after fixing the negative mold 70 at the bottom 28 of the casting mold 27, the pressing plate 59 is now moved downwards in the arrow direction 63, and the slots 19 are dimensioned such that they at least partially overlap the slab portions 71 of the negative mold 70 and thus penetrate the slots 19.

(102) The curable substance 66 is then compressed, resulting in the cured slab-like parts, from which the negative mold 70 is then removed, and the light-conducting mat 1 is then inserted in the thus created cavities in the cured slab part.

(103) As already mentioned in the general description, a so-called expendable mold can be used, wherein the negative mold 70 is not of metal material, but is formed as a wax pattern, for example, and is also enclosed in the casting material in the described manner.

(104) After curing is complete, the cured slab undergoes heat treatment for a short time until the wax drips out of the cavities and the light-conducting mat 1 can be inserted and anchored in the now freed cavities.

(105) FIGS. 23 to 25 describe a method sequence in accordance with independent claim 17, where it can be seen that suitable negative molds 29 for the releasable attachment of profile parts of the light-conducting mat 1 are arranged at the underside of a molding punch 24. The light-conducting mat is thus anchored on the negative mold 69 and, according to FIG. 24, the thus equipped molding punch 74 is lowered into the casting mold 27 shown in FIG. 25, which has already been filled with the not yet cured casting material 66.

(106) A displacement effect occurs during lowering and when the light-conducting mat 1 penetrates the casting material 66, so that displaced casting material and any surplus water have to be extracted and removed.

(107) In such a method it is advantageous for the circumferential edges of the light-conducting elements 4 to be rounded because this leads to an improved displacement effect of the casting material.

(108) To simplify the description; it has been omitted to show that a number of slots can be present in the molding punch 74 through which the displaced casting material drains.

(109) Incidentally, it can also be provided that the profile channels 10 of the light-conducting mat and all other parts are suitably rounded to enable better penetration into the casting material 66.

(110) Furthermore, it is preferred for the bottom 28 of the casting mold 27 to be formed so that it is elastically deformable; because it is then able to bulge out elastically in a convex manner when the end-side edges of the light-conducting elements 4 are placed and abut on the bottom 28 thus resulting in a displacement effect because grains of sand and cement slurries deposited on the end faces of the light-conducting elements 4 are thus displaced.

(111) The elastic configuration of the bottom 28 also ensures that the light-emitting end faces 6 of the light-conducting elements 4 remain free of sand and cement substrates during the curing process and slightly protrude from the cured slab and can thus be more easily further processed.

(112) Regardless of which method of manufacture is used, it is always possible to press the parts to be produced with oversize and to reduce the surface by means of postprocessing, such as grinding, sandblasting etc. to a point where the finished height results after processing.

(113) When the part is pressed with oversize, i.e. the filling level is about 20 percent higher than the finished height, pressing is conducted to an oversize of about 10 percent, and these 10 percent are then ground off.

(114) This is also possible, of course, with a pressing plate that is not provided with holes (recesses such as in the injection casting mold), which means that the plate is simply planar.

LEGEND OF THE DRAWINGS

(115) 1 light-conducting mat 2 longitudinal web 3 transverse web 4 light-conducting element 5 light channel 6 end face (of 4) 7 side surface 8 bottom surface 9 snap-in tab 10 profile channel 11 12 light rod 13 arrow direction 14 arrow direction 15 arrow direction 16 arrow direction 17 casting mold platen 18 mold cavity 19 slot 20 LED element 21 light-conducting body 22 top side 23 end face (of 32) 24 round table 25 side wall (of 27) 26 front and rear wall (of 27) 27 casting mold 28 bottom (of 27) 29 pressing plate (upper part) 30 retaining profile (of 29) 31 arrow direction 32 molding punch (lower part) 33 lower part 34 end face (of 21) 35 upper mold 36 first casting material (facing concrete) 37 pressure plate 38 plunger 39 filling device 40 tube 41 arrow direction 42 metal plate 43 top edge (of 42) 44 inside 45 outside 46 lower mold 47 upper mold 48 plunger (of 47) 49 arrow direction 50 recess 51 vibrating plate 52 vibrating punch 53 abrasive tool 54 brushing tool 55 conveyor 56 second casting material (core concrete) 57 arrow direction 58 feeding unit 59 pressing plate 60 arrow direction 61 end face (of 32) 62 centering tab 63 arrow direction 64 side wall 65 channel for cables in 1 66 casting material