CUT-OFF DEVICE FOR CUTTING OFF A WALL OPENING

Description

[0001] The invention relates to a shuttering device according to the preamble of claim 1 and a method according to the preamble of claim 16 for shuttering openings in walls with a shuttering panel of a shuttering device to prevent the escape of fresh concrete.

[0002] It is common practice on construction sites to form or close off the open narrow side of a double wall element of a concrete wall to be constructed, consisting of two spaced-apart precast wall elements, using a formwork panel or a shuttering board before pouring fresh concrete. This shuttering board is held in place by auxiliary structures with iron girders, angle iron, or similar, which are secured to the outer sides of the two precast wall elements by bolted connections, which require external drill holes in the precast wall elements. This procedure is very complex and also requires subsequent sealing of the drill holes created solely for anchoring.

[0003] US 2006 / 174588 A1 discloses a formwork device for forming formwork openings in walls.

[0004] The object of the invention is to provide a formwork device as mentioned above which is improved with regard to its fastening to a wall, and to provide an improved method for attaching such a formwork device.

[0005] The problem is solved by a shuttering device having the features of claim 1.

[0006] Advantageous embodiments of the invention are specified in the dependent claims.

[0007] In the formwork device according to the invention, the fastening device with the tension unit is therefore arranged in an area of ​​the formwork panel in which the formwork panel closes the opening in the wall with its formwork surface. Walls with openings to be formed are any type of wall or ceiling on buildings in the construction or completion of which fresh concrete is used, which, in its flowable state, must be prevented from escaping through such openings. Such walls are, in particular, hollow walls or double wall elements with spaced-apart prefabricated wall elements. An open side between the two prefabricated wall elements at the end of a double wall element represents such an opening to be formed. In this case, a formwork panel of the formwork device forms an end formwork for this opening or the double wall element. The formwork panel then expediently rests against the edges of the two prefabricated wall elements.Openings that require formwork removal are similarly located, for example, at recesses in double-wall elements intended for windows or doors. A recess in a ceiling can also represent such an opening that requires formwork removal. The formwork panel, in its formwork position, then rests against the underside of the ceiling surrounding the recess or opening. Fresh concrete is poured into the opening and, after curing, closes it.

[0008] A wall-side support device represents any fixed structure that can support high forces applied via the tensile unit. Such a wall-side support device can be an integral part of the wall or can be positioned and supported on the wall as a standalone part, in particular without screws or similar fastening devices that would require drilling into the wall. In particular, formwork is installed in such a way that a formwork panel is attached to the outer surfaces of the two prefabricated wall components of a double wall element without support or fastening. This eliminates the need to create drill holes for screws or other fastening devices in these outer surfaces. The formwork panel is attached using simple means to the existing or easily attached support device.The support device can have different designs, always comprising support elements arranged in such a way that the fastening device can be brought into engagement with the tensile unit for transmitting tensile force. The support device is, in particular, a spacer device with steel rods or steel wires that hold two opposing prefabricated wall elements of a double-wall element at the correct distance. Particularly when forming the formwork for an opening in a ceiling, the support device can comprise at least one rod or beam or the like, which is arranged or placed on top of the ceiling and spans the opening.

[0009] A tensile unit of the fastening device is thus located with its section assigned to the support device and attached thereto beyond the formwork panel in the opening to be formed and is embedded in the fresh concrete to be filled and remains at least partially in the hardened fresh concrete.

[0010] Depending on the height of the double-wall element or the length of the opening, which is located, for example, on the narrow side of the double-wall element to be shuttered or on a window or door recess, the formwork device can have only one formwork panel or several formwork panels arranged side by side.

[0011] The fastening device of the formwork panel contains at least one tension unit. The fastening device expediently contains several tension units, with the formwork panel having a panel opening for each tension unit. The formwork panel can also have a number of panel openings that exceeds the number of tension units to be attached. Panel openings not required for formwork can be closed with closure elements such as closure caps.

[0012] Each panel opening is preferably a round through-hole or hole in the formwork panel. The diameter of the panel opening is selected such that the tension unit can preferably be easily inserted through and accommodated therein with some clearance.

[0013] The traction unit can be secured or fixed directly to the formwork panel in a holding engagement. For example, the traction unit can be secured to the rear or outer side of the formwork panel opposite the formwork surface, or to an insert, e.g., a ring-shaped part inserted into the panel opening, particularly with a holding device. Alternatively, the traction unit can also be secured indirectly to the formwork panel in a holding engagement by interposing an additional component.

[0014] The fastening device has a tensioning device that pre-tensions the tension unit in its holding engagement with the formwork panel. A tensioning device can significantly increase the tensile force with which the formwork panel, in its shuttering position, is pressed against the parts of the wall surrounding or bordering the opening. A tensioning device contains a winding device that can cause a particularly mechanical increase in the tension force, expediently by translating a manual actuating force. Accordingly, the pre-tensioning force is significantly increased by the tensioning device, especially when the tension unit is attached manually.

[0015] The traction unit preferably contains at least one, in particular elongated, traction element. According to one embodiment not forming part of the invention, such a traction element is a tension rod. According to the invention, the traction element is a traction cable or a tensioning belt. Furthermore, the traction unit can comprise a combination of at least two traction elements according to the invention.

[0016] According to an embodiment which is not part of the invention, a tension anchor can be combined with a tension cable in such a way that the tension anchor is provided for engagement with the support device and the tension cable connected to the tension anchor runs through the panel opening and is pre-tensioned, for example by means of the tensioning device, in the holding engagement with the formwork panel.

[0017] A traction rope is, in particular, a high-tensile rope such as a high-strength steel rope, synthetic fiber rope, or textile rope. The traction rope is preferably a synthetic fiber rope made of high-modulus polyethylene fibers. Such a synthetic fiber rope is known, for example, under the brand name Dyneema®.

[0018] In a preferred embodiment, the tensioning device comprises a winding device combined with a ratchet mechanism. The winding device is provided for winding the tension element, the tension cable, or the tensioning belt. The ratchet mechanism assists the operator in winding the tensioning cable or tensioning belt onto a winding shaft and keeps the tensioning cable or tensioning belt locked in the tensioned position.

[0019] The winding device expediently includes a fixing device for securing the traction cable to the winding shaft. The fixing device can be used to secure the traction cable to the winding shaft before or during the initial winding process. Such a fixing device comprises, for example, a slotted winding shaft. The traction cable is inserted through the slot in the winding shaft and secured against pulling out, for example, by a clamping piece or a thickened portion formed by a knot in the traction cable.

[0020] In a preferred embodiment, the fixing device comprises a fixing part which is mounted on the winding shaft of the winding device so as to be movable, preferably radially to the winding shaft. The fixing part rests on a first layer of the traction cable placed on the winding shaft. As the winding shaft continues to rotate, the fixing part is covered by a second layer of the traction cable placed on the rotating winding shaft. This second layer and, if applicable, further layers of the traction cable press the fixing part against the winding shaft, thereby clamping the first layer of the traction cable. The fixing part is, for example, strip-shaped. It can, in particular, be arranged by means of two pins at a distance from the circumference of the winding shaft and in a parallel alignment to the axis of rotation of the winding shaft. The two pins are, for example, mounted in radial bores in the winding shaft radially to the axis of rotation.The fixing part is mounted on the pins so that they can move radially relative to the winding shaft, or is mounted with the pins so that they can slide in the bores. The fixing part is held in an outer position by a stop, e.g., on an enlarged head or collar of each pin. The fixing part can be preloaded into its outer position, e.g., by spring force. In the outer position, the fixing part is spaced from the circumference of the winding shaft, forming a gap such that the free end of the traction cable can be inserted through this gap. The fixing part therefore represents, in particular, a clamping part.

[0021] The tension element, tension rope, or tensioning strap can be attached to the support device in a tensile-resistant manner by means of knotting and / or wrapping. Both knotting and wrapping represent an easy-to-manufacture fastening method that can be universally and flexibly attached to the required location on the support device or support element. No special auxiliary devices are required.

[0022] Preferably, the tensioning cable or tensioning belt includes a loop or eyelet at its front or fixing end, which can be secured to the support device. The front end of the tensioning cable is positioned with the loop or eyelet in a looping position that engages behind the support element, such that the free end of the tensioning cable can be inserted through the loop or eyelet and guided outward toward the formwork panel to be attached. In principle, the loop or eyelet can also be attached to a free end of a support element or another part of the support device, thus eliminating the need for a loop.

[0023] According to a preferred embodiment, a sealing bushing or a seal is arranged at the panel opening of the formwork panel through which the tension element extends. Expediently, the sealing bushing or the seal seals the panel opening against the escape of fresh concrete. The sealing bushing can also be a bushing with an inserted seal. The bushing or seal is designed and made of such a material that it seals the tension element and the panel opening even when the tension element does not extend into the panel opening perpendicular to the formwork panel, but runs obliquely or inclined to the formwork panel due to its actual attachment point on the support device, i.e. at an angle to the formwork panel that deviates from 90°.The seal or bushing has a diameter larger than the panel opening so that it can seal even when the tension element is pulled diagonally. When the tension element is pulled diagonally, the tension element can contact the edge of the panel opening in the direction of the diagonal pull, thereby offsetting the bushing or seal radially relative to the panel opening. The diameter of the bushing or seal is adapted to this radial offset and is always sufficient to close the panel opening.

[0024] It is particularly preferred if seals and bushings in different sizes and diameters are available and usable. The seals and bushings can be selected and used to suit the respective sizes of the panel openings in the formwork panels. This ensures universal applicability of the fastening device.

[0025] The seal or bushing preferably protrudes from the formwork surface of the formwork panel. The seal or bushing then forms a particularly cup-shaped depression in the hardened concrete, surrounding a space around a corresponding section of the tension element cast into the concrete. After removing the formwork panel and the bushing or seal, as well as the section of the tension element protruding from the concrete, this depression in the concrete can be filled, for example, with filler.

[0026] The tension cable can have a reinforcement or a sheath at its free end, which is assigned to the tensioning device. The free end of the tension cable is reinforced or surrounded by a sheath in such a way that individual fibers or wires of the tension cable cannot fray at the free end of the tension cable. Plastic fibers of the tension cable can, for example, be welded to a solid end. This makes it easier to insert the tension cable into a bore or opening of a seal or bushing, especially if the diameter of the bore or opening is intended for play-free insertion of the tension cable or if the tension cable is accommodated in the bore or opening with a slight press fit, so that moving the seal relative to the tension cable requires a certain amount of force. Attaching the tension cable to the tensioning device or winding shaft can also be made easier.

[0027] The formwork panel can be connected to a support element on its rear side opposite the formwork surface. Such a support element is, for example, a frame part of a formwork frame supporting the formwork panel. Such a support element expediently contains a recess directed towards the panel opening, through which the tension unit or a tension element runs. The recess in the support element is preferably tubular. An insert, e.g., a sleeve-like insert, is arranged in the recess, the end face of which is preferably arranged at the same level as the formwork surface of the formwork panel and against which the seal rests. The seal can therefore also move and adapt in a radial direction on the insert and the formwork surface when the tension element is pulled diagonally and radially in the opening of the insert during tensioning of the tension cable.

[0028] According to a preferred embodiment, the wall comprises a double wall element with two prefabricated wall components that are spaced apart from one another and are held at a mutual distance by means of a support device that represents a spacer device, with a cavity that lies between them and is to be filled with fresh concrete. The formwork panel rests with its formwork surface in a formwork-forming position against the edges of the two prefabricated wall components that delimit the opening. The opening is formed on the laterally open narrow side of the double wall element or on a recess provided in the double wall element, e.g. for a window or a door. The at least one tension unit holds the formwork panel in its formwork-forming position pre-tensioned against the edges, wherein on the one hand it is supported on the formwork panel and on the other hand it engages between the two prefabricated wall components and is guided along the spacer device orthe support device and / or on the inside of the prefabricated wall elements.

[0029] According to a further embodiment, the wall is a building ceiling containing the opening. The formwork panel, in its shuttering position, is attached to the underside of the building ceiling by means of the at least one tension unit. The support device includes, for example, a beam, a girder, a steel rod, or the like, which is placed on the top side of the ceiling and spans the opening, and to which the tension element is attached. Accordingly, even with such an opening, the tension unit is expediently supported on the wall side by a support element that is an integral part of the support device, is held as a separate element on the support device, or itself forms the support device.

[0030] According to a preferred embodiment, the ratchet mechanism comprises a tensioning lever and a control cam coupled to the tensioning lever. The tensioning lever, in an associated pivoting position, adjusts a locking slide, which selectively blocks the winding shaft, to an unlocked position by means of the control cam. Such unlocking of the winding shaft is achieved when the pull rope or tensioning belt is taut during disassembly of the shuttering device. Operation by means of the tensioning lever requires comparatively low actuation forces.

[0031] Conveniently, a separation point or a separation device is formed on the tension element between its tension element head and its rear tension element tensioning section, at which the rear tension element tensioning section can be separated from the front tension element head, which remains in the hardened fill concrete, in order to remove the formwork panel from its shuttering position. A separation point or a separation device can be formed in such a way that, for example, excessive tensile force or shear force causes the tension element to tear off at the separation point. However, the tension element can also have, for example, a screw connection or the like as a separation device, so that the two parts of the tension element to be separated can be separated from each other by a rotating or screwing movement.

[0032] Preferably, a bushing is inserted into the panel opening in the formwork panel, through which the tension element extends. The bushing, e.g., a plastic bushing, guides the tension element and can have other useful features, such as locking the tension element. In principle, however, the tension element can also pass directly through the panel opening.

[0033] If the bushing rests against the outer surface or back of the formwork panel with a collar, it can be supported by this collar to transmit axial forces.

[0034] Furthermore, the bushing can be designed to seal the tension element against the escape of fresh concrete. Alternatively, the bushing can contain a sealing insert that seals the tension element against the escape of fresh concrete.

[0035] The tension element head expediently contains at least one hook that engages or hooks onto the support device. Such a hook can be designed in various ways and can be adapted to a particular support device.

[0036] Furthermore, the tension element head can have an engagement device that spreads apart after insertion of the tension element head into the support device and forms a rear hook on the support device. Thus, the tension element can be inserted into the support device with a small cross-sectional size and assume an enlarged cross-sectional or hooked shape therein.

[0037] The tension element expediently contains a locking profile on its tension element clamping section for locking the tension element to the bushing or to a support device supported on the outside or rear side of the formwork panel, such as a locking disc or the like, which transmits axial force.

[0038] Preferably, the tension element is tensile and rigid, or tensile and flexible. A flexible tension element can self-adjust or bend if the hooking of the tension element head or the fastening of the tension cable or tensioning strap deviates laterally or radially from the longitudinal axis of the panel opening in the formwork panel or the opening of the bushing.

[0039] The object is further achieved by a method according to claim 16.

[0040] This method enables universal formwork using a tension element that is fastened on the one hand in or on the wall in front of a formwork surface of the formwork panel and on the other hand, after passing through the panel opening, is tensioned and fastened directly or indirectly to the formwork panel in the area of ​​the panel opening. The seal or bushing is held on the tension element, which runs through an opening in the seal or bushing, preferably by clamping friction force in such a way that with higher tensile force, the tension element can be pulled through the seal or bushing supported on the formwork panel in the area of ​​the panel opening. The seal or bushing is pulled into its sealing position on the formwork panel or panel opening with a certain tension force.In particular, a traction rope or a tensioning belt can be easily attached to a fastening point on a support device arranged on the wall in a largely arbitrary manner.

[0041] Instead of attaching the seal or a sealing bushing to the tension element after the tension cable has been attached to the attachment point, the tension element can also be pre-configured with a seal or bushing attached before it is attached to the attachment point according to step a).

[0042] In the following, a formwork device is explained in more detail using exemplary embodiments with reference to the drawing. Figures 2 and 3 show an embodiment that is not part of the invention. It shows: Fig. 1 shows a vertical cross-sectional view of a double wall element with two spaced-apart prefabricated wall elements held at a distance from each other by a support device; Fig. 2 shows an isometric view of two double wall elements erected to create a wall, with a formwork panel of a stop-end device attached to the front double wall element; Fig. 3 shows a horizontal cross-sectional view of the double wall element with the formwork board in stop-end position and a tension anchor engaging the support device; Fig. 4 shows an isometric view of a double wall element with a door recess and a window recess prior to stop-end removal; Fig. 5 shows an isometric exploded view - partially broken away and in section - of a double wall element with the stop-end device to be attached thereto; Fig. 6 shows a further isometric view of the double wall element with the stop-end device to be attached thereto. Fig. 5 ; Fig. 7 in an isometric view the fastening device of the formwork panel with a tension cable; Fig. 8 in an isometric view a tensioning device with a winding device for the tension cable having a ratchet mechanism; Fig. 9 in a further isometric view the winding device of the Fig. 8 with tensioning lever actuated in the tensioning direction; Fig. 10 in a plan view, the tension cable having a loop in three positions when attached to an element of the support device; Fig. 11 in a sectional view, a double wall element cast with fresh concrete, with a tension cable cast into the fresh concrete; Fig. 12 in an isometric view, a support element with a formwork panel attached thereto and two winding devices; Fig. 13 in a sectional view, the formwork panel with the support element at the open end of the double wall element; Fig. 14 in an isometric view, the formwork panel of the Fig. 13on a double wall element with two support elements placed next to each other, each with two winding devices; Fig. 15 in an isometric view a U-shaped arrangement of three formwork panels held by three interconnected support elements; Fig. 16 in an isometric view a ceiling of a building with an opening which is shuttered by means of a shuttering device; Fig. 17 in a sectional view the ceiling of the Fig. 16 with the shuttering device forming the opening; and Fig. 18, in an isometric view, a tensioning device with a winding shaft for a traction cable and with a ratchet mechanism coupled to the winding shaft.

[0043] A hollow or double wall element 1 (see Fig. 1 and 4) is manufactured in a known manner as a precast concrete element in a concrete plant and erected at its place of use for constructing a wall or wall on a base slab 2, such as a concrete base slab. The double wall element 1 has two spaced-apart flat concrete wall elements or prefabricated wall parts 3, which are held at a mutual distance by means of a support device 4 with a cavity 5 in between. Such a support device 4 is, for example, a spacer device which contains, for example, a wire bracing and / or reinforcement. The double wall element 1 can be erected at a distance from the base slab 2 in such a way that a floor joint 6 is formed between a joint end face 7 on the lower edge 8 of each of the two prefabricated wall parts 3 and a surface 9 of the base slab 2.

[0044] Before filling the cavity 5 with fresh concrete 5a (see example of the Fig. 4), the two floor joints 6 are sealed on the outside to prevent the fresh concrete poured into the cavity 5 of the double-wall element 1 from escaping. A shuttering device for the external shuttering of each floor joint 6 is described, for example, in DE 10 2014 013 559 A1.

[0045] Before the cavity 5 is filled, a shuttering device 11 is attached to an open narrow side 10a of the double wall element 1 as the final shuttering of an opening 10 between the two opposing prefabricated wall elements 3 ( Fig. 1 to 3 ). The opening 10 on this open narrow side 10a is therefore closed by means of a concrete surface 5b formed by the precast concrete 5a ( Fig. 11 ). The wall to be formed by at least one double wall element 1 thereby receives an end closed by the precast concrete 5a.

[0046] The formwork device 11 or the final formwork contains a formwork panel 12, which is formed, for example, by a formwork board and is placed with a front formwork surface 13 on the edges 14 of the two prefabricated wall elements 3, so that the opening 10 on the lateral narrow side 10a is formed and sealed against the escape of fresh concrete 5a filled into the cavity 5.

[0047] A fastening device 15 is provided, which holds the formwork panel 12 in its shuttering position pre-tensioned against the edges 14 of the two prefabricated wall elements 3. The fastening device 15 extends between the two prefabricated wall elements 3 and engages or engages behind at least one, e.g., rod-shaped support element 16 of the support device 4, such as a wire strut. The support device 4 or the spacer device (in Fig. 2The wall element 16 (not shown) can be formed with different support elements 16, such as the wire struts shown and arranged as examples. The fastening device 15 can also be supported on the inner surfaces 17 of the two prefabricated wall elements 3 (not shown), which then also form parts of the support device 4.

[0048] In any case, the formwork panel 12 is preferably fastened without support to the outer surfaces 18 of the two prefabricated wall elements 3, so that, for example, no drill holes for screws or the like need to be made there.

[0049] The fastening device 15 contains at least one tension unit 19, which has at least one elongated tension element 19a, such as a tension anchor 19b. The formwork panel 12 contains a particularly round panel or board opening 20, e.g., in the form of a bore, into which a bushing 21 is inserted. The bushing 21 expediently contains a collar 22, which rests against the rear outer surface or panel back 23 of the formwork panel 12, opposite the formwork surface 13.

[0050] The tension element 19a extends through a central bushing opening 21a of the bushing 21 and also through the panel opening 20 in the formwork panel 12. The tension element 19a or the tension anchor 19b is in tensile force-supporting engagement with a front tension element head 24 on at least one support element 16 of the support device 4. The tension element 19a has a rear tension element tensioning section 25 that engages the formwork panel 12, so that the tension element 19a can pre-tension the formwork panel 12 into its shuttering position. The tension element 19a has a locking profile 26 on its tension element clamping section 25, by means of which the tension element 19a can be brought into an axial force-transmitting locking position on an associated locking structure in the bushing 21, wherein the bushing 21 is axially supported via its collar 22 on the formwork panel 12 or on the panel rear side 23.When the tension element 19a is inserted, the tension element clamping section 25 can also extend to the rear side 23 of the formwork panel 12, so that locking can also take place, for example, on a perforated locking disc or the like, which is arranged on the rear side 23 and surrounds the panel opening 20, so that the tension element clamping section 25 can be engaged thereon. The handling of the tension element 19a or the application of tensile force takes place at a rear end 27 of the tension element 19a, which is formed, for example, with a ring for manual handling or has another design that enables handling by means of a handling device or by means of a clamping device.

[0051] The tension element 19a is constructed with sufficient tensile strength to transmit the clamping and tensile forces and can be made either rigid or flexible depending on the material selection and design. The tension element 19a is made, for example, of a metal or a high-tensile plastic.

[0052] The bushing 21 has a seal 28, which acts as a sealing insert to seal the tension element 19a in the bushing opening 21a of the bushing 21 against the escape of fresh concrete. The bushing 21 can also be formed as a seal itself or contain a molded-on seal, and it can also seal the panel opening 20 in the formwork panel 12. Furthermore, the bushing 21 can allow a certain positional adjustment of the tension element 19a in the radial direction, e.g., through a certain flexibility of the bushing 21 at its bushing opening 21a, for example, due to the design and / or material of the bushing 21.

[0053] The tension element 19a can have a separation point or a separation device between its tension element head 24 and its tension element tensioning section 25, at which the tension element 19a can be separated. A separation device can include, for example, a screw connection or a detachable coupling. The formwork panel 12 can then be easily removed from its demolding position with the rear section of the tension element 19a containing the tension element tensioning section 25. At least the front tension element head 24 of the tension element 19a remains in the hardened concrete.

[0054] The bushing 21 is expediently arranged in the panel opening 20 of the formwork panel 12 such that it projects beyond the front formwork surface 13. This annular and in particular conical front section 29 of the bushing 21 then forms a cup-shaped depression 30 in the hardened concrete 5a (see Fig. 11), which surrounds a free space around an associated section of the tension element 19a cast into the concrete 5a. After removing the formwork panel 12 and the bushing 21, as well as the section of the tension element 19a protruding from the concrete 5a, this recess 30 in the concrete can be filled, e.g., with filler.

[0055] To remove the formwork panel 12, the rear section of the tension element 19a can be severed in an alternative procedure, e.g., using a cutting device such as a saw. Furthermore, the collar 22 of the bushing 21 is removed, for example, using a drill or countersunk drill. The formwork panel 12 can then be pulled off the bushing 21, or the bushing 21 is removed with the formwork panel 12. The tension element 19a can then be severed in the recess 30.

[0056] The tension element head 24 can have different designs, such as one or more hooks or even several hooks or bars that can spread apart and engage behind at least one support element 16 of the support device 4 after the tension element 19a has first been guided with its tension element head 24 between the support elements 16 and engages behind at least one support element 16 in a force-supporting manner when retracted.

[0057] In a modified version (see Fig. 5 to 11), the shuttering device 1 contains a formwork panel 12, which is supported with its panel rear side 23 on at least one support element 31 of a frame formwork 32. The frame formwork 32 contains, for example, two opposing longitudinal frame parts 33 and frame cross parts 34 connecting the two longitudinal frame parts 33. The support element 31 can be such a frame cross part 34 or an additional part of the frame formwork 32. The formwork panel 12 is expediently attached to the entire frame formwork 32. The support element 31 has, in particular, a cylindrical recess 35 centrally between the two longitudinal frame parts 33 ( Fig. 7), which is formed, for example, by a bearing sleeve 36 fastened in the support element 31, which can also be, for example, a tube, which extends between a front wall 37 of the support element 31, against which the formwork panel 12 rests, and an opposite rear wall 38 of the support element 31. The panel opening 20 of the formwork panel 12 is arranged substantially concentrically to the recess 35 of the support element 31 and, in particular, has a diameter that largely corresponds to or is identical to the diameter of the recess 35.

[0058] An insert part 39 is received in the recess 35, which has a central cylindrical through-opening 40 and is formed, for example, as a hollow cylinder or as a part similar to a hollow cylinder, which, for example, has a plurality of circumferential ribs. The insert part 39 is arranged in the recess 35 essentially free of radial play. A front end 41 of the insert part 39 is arranged in the panel opening 20 of the formwork panel 12 such that its front side 42 is flush with the formwork surface 13 or is recessed therein. A rear end 43 of the insert part 39 is arranged flush with the rear wall 38 of the support element 31.

[0059] A traction unit 19 of the fastening device 15 has a traction cable 44, which, on the one hand, can be or is secured with its front end 45 to the support device 4, which extends through the through-opening 40 of the insert part 39, and which, on the other hand, can be or is connected to a tensioning device 46 of the fastening device 15, which is supported on the rear wall 38 of the support element 31 and on the rear end 43 of the insert part 31. Thus, the traction cable 44 connected to the tensioning device 46 is supported indirectly on the formwork panel 12 via the support element 31.

[0060] The tension cable 44 extends through a seal 47, which is arranged at the front end 41 of the insert part 39, is supported on the insert part 39, and protrudes from the formwork panel 12. The seal 47 has a sealing body 48 in the manner of a sealing bushing. The sealing body 48 contains a central sealing opening 49, in which the tension cable 44 is precisely received and, in particular, is held slightly clamped, so that a relative displacement of the seal 47 with respect to the tension cable 44 is possible with appropriate tensile force. The sealing body 48, which is preferably rotationally symmetrical with respect to the central sealing opening 49, has a front end face 50, a conical annular circumferential surface 51, and a rear contact surface 52, with which the sealing body 48 rests against the insert part 39. The sealing body 48 can have an annular groove 53 open towards the contact surface 52, so that the contact surface 52 is formed as an annular surface.The sealing body 48 is preferably made of a plastic such as PVC.

[0061] The tensioning device 46 has a winding device 54, by means of which the tension cable 44 is wound and held under pretension, so that the formwork panel 12 is pressed against the edges 14 of the prefabricated wall elements 3 by means of tensioning force. The winding device 54 has a winding shaft 55 coupled to a ratchet mechanism 56. A winding shaft base body 57 of the tensioning device 46 or the winding device 54, which supports the winding shaft 55, rests against the support element 31.

[0062] For shuttering an opening 10 on a double wall element 1, which is located, for example, on a lateral end narrow side 10a ( Fig. 2 and Fig. 4 ) or which, for example, delimits a door recess 10b or a window recess 10c in the double wall element 1 (see Fig. 4), the tension cable 44 is fastened to a support element 16 of the support device 4 arranged between the two prefabricated wall elements 3. The fastening of the tension cable 44 takes place at a fastening point which is assigned to a panel opening 20 of the formwork panel 12 to be attached in such a way that the tension cable 44, in its tensioned position, is preferably aligned approximately perpendicular to the formwork panel 12 or at a small angle to the perpendicular to the formwork panel 12, starting from its fastening point.

[0063] The traction cable 44 is preferably attached to the support device 4 in a tension-resistant manner by means of a loop 58 (see Fig. 10). The traction cable 44 has a loop 59 or an eyelet at its fixing or front end 45, which can be secured to the support device 4. The front end 45 of the traction cable 44 is positioned with the loop 59 in a looping position engaging behind the support element 16 in such a way that the opposite free end 60 of the traction cable 44 can be inserted through the loop 59 and guided outwards in the direction of the formwork panel 12 to be attached. By pulling on the free end 60 of the traction cable 44, the loop 59 is firmly attached to the traction cable 44 and wraps around the support element 16, so that the traction cable 44 is lashed to the support element 16 in the looping position and is thus fixed. The figures show the fastening of the traction cable 44 to the support device 4 or to an element 16 in a schematic and simplified representation by means of the loop 59.In principle, the loop 59 can also be attached to a free end of a support element 16 or another part of the support device 4, so that a looping is not necessary (see e.g. . Figs. 16 and 17 ). Furthermore, the traction cable 44 can be attached to the support device 4 by means of a knot.

[0064] The free end 60 of the tension cable 44 is reinforced or enclosed by a sheath 61 in such a way that individual fibers or wires of the tension cable 44 cannot fray at the free end 60 of the tension cable 44. Plastic fibers of the tension cable 44 can, for example, be welded to a fixed end. The seal 47 is placed or pushed onto the tension cable 44 at the free end 60 before the tension cable 44 is guided with its free end 60 through the panel opening 20 in the formwork panel 12, which, in an assembly position, is positioned close to the opening 10 in the wall, and through the support element 16 in the support element 31. The seal 47 is then applied to the component surrounding the panel opening 20 or the formwork surface 13, so that the seal 47 can be displaced radially to the panel opening 20 to the extent that the tension cable 44 can move radially in the panel opening 20, thereby ensuring a seal.However, the seal 47 can also be inserted into the panel opening 20 and thus assumes a defined position relative to the panel opening 20. On the other hand, the seal 47 can also already be attached or inserted to or in the panel opening 20 before the pull cable 44 is inserted through the seal 47. Furthermore, the seal 47 can be placed onto the insert part 39 and, in particular, locked thereto.

[0065] The formwork panel 12 is placed against the prefabricated wall elements 3 defining the opening 10. The free end 60 of the tension cable 44 is positioned on the winding shaft 55 of the provided tensioning device 46 such that it is wound up by rotation of the winding shaft 55. The tension cable 44 is wound onto the winding shaft 55 by means of the ratchet mechanism 56 until the required tension of the tension cable 44 is reached.

[0066] Of course, the clamping device 46 can also be attached and supported directly on the rear side 23 of the formwork panel 12.

[0067] The Fig. 12 shows a shuttering device 1 with a narrow, elongated formwork panel 12, which is attached to only one elongated formwork support 62 of approximately the same length. The formwork support 62 has a front wall 63 ( Fig. 13) with two flange sections 64 against which the formwork panel 12 rests and is fastened, for example, by screw connections 65. Two opposing side walls 66 carry a rear head region 67 which has a rear wall 68 for attaching the tensioning device 46. The head region 67 has a connecting device 69 which is formed, for example, as an undercut longitudinal groove 70 countersunk in the rear wall 68. The tensioning device 46 is supported on the rear wall 68. Recesses 71 and 72 are formed in the front wall 63 and in the longitudinal groove 70, which are each congruent with one another and with an associated panel opening 20, so that the tension cable 44 can extend straight through to the tensioning device 46. The recesses 71 and 72 are, for example, bores or elongated holes. The formwork support 62 can also have a largely open front wall 63, which essentially consists only of the two flange sections 64.

[0068] Two formwork beams 62, which are adjacent to each other in the longitudinal direction (see Fig. 14 and 15 ), are firmly connected to one another by means of a coupling part 74 that can be secured by screws 73. The coupling part 74 is a flat strip with two bent legs 75 on the edge, which rests on the rear wall 68 and laterally surrounds the head area 67 with the legs 75 in a centered manner. One of two screws 73 is received with its screw head, which represents a sliding block, in the longitudinal groove 70 of one of the two formwork supports 62, inserted through a hole in the coupling part 74, and clamped by a lock nut 76, such as a wing nut.

[0069] A shuttering device 1 (see Fig. 15 ) for a door recess 10b or a window recess 10c in a double wall element 1 ( Fig. 4) contains such a formwork panel 12 supported by a formwork support 62 in a central or horizontal arrangement and two lateral formwork panels 12, which are supported, for example, by two formwork supports 62 coupled together and which are each coupled to the central formwork panel 12 via an angle coupling part 77 in a right-angled orientation. The angle coupling part 77 is fastened to the respective longitudinal groove 70 in accordance with the coupling part 74 described above. The formwork device 1 of the Fig. 15 can be fixed to the support device 4 of the double wall element 1 by means of the tension cables 44 and the tensioning devices 46.

[0070] A shuttering device 1 for shuttering an opening 10 in a ceiling 78 of a building or the like ( Figs. 16 and 17) has a formwork panel 12 arranged on the ceiling underside 79 such that it closes off the opening 10 downwards. The support device 4 contains, for example, two support elements 16 in the form of two beams, in particular with a rectangular cross-section, which are placed on the ceiling top side 80 and span the opening 10. Two tension cables 44 are attached to each beam, for example, with a respective loop 59 through which the beam extends. Each tension cable 44 extends through a panel opening 20 (not shown) sealed by the seal 47 and is pre-tensioned on the rear side 23 of the formwork panel 12, in this shuttering position, the underside of the formwork panel 12, by means of a respective tensioning device 46. The support elements 16 or the beams do not require any attachment to the ceiling top side 80.Instead of the supports placed on the ceiling top 80, support elements 16 such as reinforcing bars or the like can also be provided on the ceiling 78, which are already fixedly arranged and are accessible in or on the opening 10 for fastening the respective traction cable 44.

[0071] The ratchet mechanism 56 of the tensioning device 46 (see Fig. 6 to 9and 18) has two ratchet wheels 81. The winding shaft 55 is rotatably mounted in bores on two spaced-apart legs 82 of the winding shaft base body 57. The two ratchet wheels 81 are arranged on the winding shaft 55 outside the two legs 82 and are connected to the winding shaft 55 in a rotationally fixed manner. A tensioning lever 83 is attached to a U-shaped bearing part 84, for example, which has two side cheeks 85 that are pivotally mounted on shaft journals 86 of the winding shaft 55 outside the two ratchet wheels 81. A slide 87 is slidably mounted in two slots 88 arranged in the two side walls 85 of the bearing part 84 in radial alignment with the winding shaft 55, and is preloaded against the two ratchet wheels 81 by means of a compression spring 89 supported on the bearing part 84. The slide 87 has two drivers 90 preloaded into a driving engagement with the two ratchet wheels 81.

[0072] A locking slide 91 is mounted on the two legs 82 of the winding shaft base body 57 in radial alignment with the winding shaft 55. The locking slide 91 is slidably received in slots 92, which are arranged parallel or inclined to a base surface 93 of the winding shaft base body 57 and in radial alignment with the winding shaft 55. In the Fig. 6 to 8 In the clamping position of the clamping device 46 shown, the winding shaft 55 is aligned horizontally and the winding shaft base body 57 is supported in a vertical orientation on the rear wall 38 of the support element 31. In this arrangement, the locking slide 91 is arranged below the winding shaft 55. The locking slide 91 is pretensioned against the ratchet wheels 81 by means of a compression spring 94, which is supported on the winding shaft base body 57. The locking slide 91 has two pawls 95, which, in locking engagement with the ratchet wheels 81, lock the winding shaft 55 against rotation in the unwinding direction.

[0073] The tensioning of the traction cable 44 fixed to the winding shaft 5 takes place from an initial position of the tensioning lever 83. Such an exemplary initial position is shown in the Fig. 7 and 8shown. The tensioning lever 83 is pivoted into a position parallel to the formwork panel 12, in which it is arranged essentially vertically. The locking slide 91, via its pawls 95, which are in locking engagement with the ratchet wheels 81, holds the winding shaft 55 locked against rotation in the unwinding direction. The slide 87, mounted on the bearing part 84 of the tensioning lever 83, is pretensioned against the ratchet wheels 81, so that its two drivers 90 are in driving engagement with the ratchet wheels 81. When the tensioning lever 83 is pivoted, the ratchet wheels 81 and the winding shaft 55 are rotated, and the traction cable 44 is wound onto the winding shaft 55. The pawls 95 slide or ratchet over the ratchet wheels 81, whereby the spring-loaded locking slide 91 executes a corresponding reciprocating compensating movement in the slots 92. The tensioning lever 83 is pivoted by, for example, approximately 90° (into the position of the Fig. 9). When the tensioning lever 83 is pivoted back, the pawls 95 of the locking slide 91 are in locking engagement with the ratchet wheels 81, so that the winding shaft 55 is locked against rotation in the unwinding direction, and the drivers 90 of the slide 87 slide or ratchet over the ratchet wheels 81. By pivoting the tensioning lever 83 back and forth, the winding shaft 55 is rotated step by step and the traction cable 44 is wound onto the winding shaft 55 and tensioned.

[0074] To release the tension on the traction cable 44 and to unwind the traction cable 44 from the winding shaft 55, the locking slide 91 is released from its locking engagement on the ratchet wheels 81. For this purpose, the locking slide 91 is moved away from the winding shaft 55, e.g., by manual engagement in its slots 92. Alternatively, the locking slide 91 can be actuated or moved by moving the tensioning lever 83. For this purpose, the two side cheeks 85 of the bearing part 84 are rounded in a semi-disk shape in the area of ​​the shaft journals 86 and each have a peripheral edge 96 ( Fig. 8 ), whose radial distance from the rotational axis 97 of the winding shaft 55 varies over the circumference. Thus, in the upwardly pivoted initial position of the tensioning lever 83 ( Fig. 7 and 8) the radial distance of the circumferential edge 96 at the point opposite the pawl 95 is less than the distance of the pawl 95 from the axis of rotation 97 of the winding shaft 55 in its engaged position on the ratchet wheel 81. Thus, the circumferential edge 96 is without contact with the pawl 95. The radial distance R 1 of the circumferential edge 96 remains constant over a circumferential angle α of, for example, approximately 100° (see Fig. 9) constant, so that when the tensioning lever 83 is pivoted downwards by approximately 90°, the locking slide 91 cannot yet be actuated beyond this pivoting neutral range of the peripheral edge 96. Following this pivoting neutral range, the radial distance of the peripheral edge 96 increases and, from a pivoting angle of, for example, approximately 110°, in a pivoting control range of the peripheral edge 96, has an increased radial distance R 2 from the axis of rotation 97 with respect to the locking pawl 95. In this pivoting control range, the peripheral edge 96 represents a control cam 98 which, in engagement with the locking pawl 95, moves the locking slide 91 from its locked position into a release position. The locking of the winding shaft 55 is thus released and the tension of the pull cable 44 is released and can be unwound from the rotating winding shaft 55.

[0075] Before being tensioned by the tensioning device 46, the traction cable 44 can be attached to the winding shaft 55 by wrapping it several times around the winding shaft 55 and securing it thereto by frictional force while the winding shaft 55 is rotated. The winding shaft 55 can also have a slot (not shown) that radially penetrates the winding shaft 55 and through which the traction cable 44 is inserted one or more times to achieve improved fixation.

[0076] Preferably, the winding device 54 contains a fixing device 99 (see Fig. 18), which fixes the traction cable 44 to the winding shaft 55 or at least supports its fixation. One embodiment of the fixing device 99 contains a fixing part 100, e.g. in the form of a strip, which is arranged by means of two pins 101 at a distance from the circumference of the winding shaft 55 and in a parallel alignment to the axis of rotation 97. The two pins 101 are mounted in bores in the winding shaft 55 radially to the axis of rotation 97. The fixing part 100 is movable on the pins 101 radially to the winding shaft 55. The fixing part 100 is held in an outer position on a stop, e.g. on the collar of the pins 101. The fixing part 100 can be preloaded into its outer position, e.g. by spring force. In the outer position, the fixing part 100 is spaced from the circumference of the winding shaft 55 to form a gap 102 so that the traction cable 44 can be inserted with its free end 60 through this gap 102.

[0077] The tension cable 44, which is fed through a recess 103 in the winding shaft base body 57, rests on the winding shaft 55 and extends through the gap 102. As the winding shaft 55 rotates by means of the tension lever 83, the tension cable 44 initially wraps around the winding shaft 55 in a first layer and, upon further rotation, simply wraps in a second layer and then repeatedly wraps in several layers onto the fixing part 100. The tension of the tension cable 44 presses the fixing part 100 against the winding shaft 55. The fixing part 100 thus clamps the tension cable 44 to the winding shaft 55. The fixing of the tension cable 44 to the winding shaft 55 is thus achieved by the clamping force of the fixing part 100 and by the frictional force of the tension cable 44 wrapping around the winding shaft 55.

[0078] The pull cable 44 can also be inserted through the gap 102 several times to achieve an initial fixation of the pull cable 44 to the winding shaft 55. In this case, the pull cable 44 can wrap around the fixing part 100 and / or at least one pin 101.

[0079] During disassembly of the shuttering device, the slide 87 of the ratchet mechanism 56 is manually pulled out of its engagement position on the ratchet wheels 81, so that the tensioning lever 83 can be pivoted downwards far enough that the control cam 98 can push the locking slide 91 out of its engagement position on the ratchet wheels 81. When the formwork panel 12 is removed from its dismantling position, the winding shaft 55 can be rotated by the pull cable 44 cast into the concrete on the wall, whereby the pull cable 44 unwinds.

[0080] A tensioning belt is used in a similar way to the traction cable 44. List of reference symbols 1 Double wall element 23 Back of board 2 base plate 24 Tension element head 3 Prefabricated wall element 25 Tension element tensioning section 4 Support device 26 Locking profiling 5 cavity 27 rear end 5a Fresh concrete 28 seal 5b concrete surface 29 front section 6 floor joint 30 Deepening 7 Joint front side 31 Support element 8 lower edge 32 frame formwork 9 surface 33 Longitudinal frame part 10 opening 34 Frame cross member 10a narrow side 35 recess 10b door recess 36 bearing sleeve 10c Window recess 37 front wall 11 Final formwork 38 back wall 12 Formwork panel 39 Insert part 13 Formwork area 40 passage opening 14 edge 41 front end 15 Fastening device 42 front side 16 Support element 43 rear end 17 inner surface 44 pull rope 18 exterior surface 45 front end 19 Tractor unit 46 clamping device 19a Tension element 47 seal 19b Tie rods 48 Sealing body 20 Table opening 49 Sealing opening 21 socket 50 frontal surface 21a Socket opening 51 Ring circumferential surface 22 collar 52 contact surface 53 Nut 79 Ceiling underside 54 Changing facility 80 Ceiling top 55 winding shaft 81 ratchet wheel 56 Ratchet mechanism 82 leg 57 Winding shaft base body 83 clamping lever 58 Wrap-around 84 Bearing part 59 loop 85 sidewall 60 free end 86 Shaft journal 61 Covering 87 slider 62 Formwork beams 88 slot 63 front wall 89 compression spring 64 Flange section 90 Driver 65 screw connection 91 gate valve 66 side wall 92 slot 67 Head area 93 Base area 68 back wall 94 compression spring 69 Connecting device 95 pawl 70 Longitudinal groove 96 peripheral edge 71 recess 97 axis of rotation 72 recess 98 Control curve 73 screw 99 Fixing device 74 Coupling part 100 Fixing part 75 leg 101 cones 76 wing screw 102 gap 77 Angle coupling part 103 recess 78 Ceiling

Claims

1. Shuttering device for shuttering of openings (10) in walls with a shuttering panel (12) against the escape of fresh concrete (5a) and with a fastening device (15), which holds the shuttering panel (12) in its shuttering position at an opening (10) against the escape of fresh concrete (5a) filling the opening (10), wherein the fastening device (15) comprises a traction unit (19) - which extends through a panel opening (20) of the shuttering panel (12) and can extend into the opening (10), and - wherein the traction unit (19) is, on the one hand, supportable against a wall-side support device (4) and, on the other hand, fixed directly or indirectly to the shuttering panel (12) in a holding engagement, wherein the fastening device (15) comprises a tensioning device (25, 26; 46) which pretensions the traction unit (19) in its holding engagement on the shuttering panel (12), characterized in that the traction unit (19) - comprises at least one traction element formed by a traction cable (44) or a tensioning strap, or - is a combination of at least two of the above-mentioned traction elements, and the tensioning device (46) comprises a winding device (54) for winding the traction cable (44) or the tensioning strap.

2. Shuttering device according to claim 1, characterized in that the winding device (54) is combined with a ratchet mechanism (56).

3. Shuttering device according to claim 1 or 2, characterized in that the winding device (54) comprises a fixing device (99) for fixing the traction cable (44) to a winding shaft (55) of the winding device (54).

4. Shuttering device according to claim 3, characterized in that the fixing device (99) comprises a fixing part (100) that is mounted on the winding shaft (55) of the winding device (54) so as to be movable radially to the winding shaft (55), rests on a first layer of the traction cable (44) laid on the winding shaft (55), and is covered by a second layer of the traction cable (44) placed on the rotated winding shaft (55), pressing it against the winding shaft (55)5. Shuttering device according to one of claims 1 to 4, characterized in that the traction element, the traction cable (44) or the tensioning strap can be attached to the support device (4) in a traction-resistant manner by means of knotting and / or wrapping (58).

6. Shuttering device according to one of claims 1 to 5, characterized in that the traction cable (44) or the tensioning strap comprises a loop (59) or an eyelet at its front or fixing end (45) which can be fixed to the support device (4).

7. Shuttering device according to one of claims 1 to 6, characterized in that the traction cable (44) has a sheath (61) which surrounds its free end (60) which can be tensioned by the tensioning device (46).

8. Shuttering device according to one of claims 1 to 7, characterized in that a seal (47) is arranged at the panel opening (20) of the shuttering panel (12), through which the traction element (19a) extends and which seals the panel opening (20) against the escape of fresh concrete (5a).

9. Shuttering device according to claim 8, characterized in that the seal (47) projects from the shuttering surface (13) of the shuttering panel (12).

10. Shuttering device according to one of claims 1 to 9, characterized in that the shuttering panel (12) is connected on its panel rear side opposite the shuttering surface (13) to a carrier element (31) which has a recess (35) aligned towards the panel opening (20), through which the traction unit (19) passes.

11. Shuttering device according to claim 10, characterized in that the recess (35) in the carrier element (31) is formed in a tubular manner and that a sleeve-like insert part (39) is arranged in the recess (35), the end face (42) of which is arranged at the same level as the shuttering surface (13) and against which the seal (47) bears.

12. Shuttering device according to one of claims 1 to 11, characterized in that the wall comprises a double wall element (1) with two spaced-apart prefabricated wall parts (3), which are held at a distance from one another by means of the support device (4) constituting a spacing device with a cavity (5) located between them and to be filled with fresh concrete (5a), the shuttering panel (12) bearing with its shuttering surface (13) against the edges (14), delimiting the opening (10), of the two prefabricated wall elements (3) in a calendered manner, wherein the opening (10) is formed on the laterally open narrow side of the double wall element (1) or on a recess (10b, 10c) provided in the double wall element (1) for a window or a door, and wherein the at least one traction unit (19) holds the shuttering panel (12) in its shuttering position pretensioned against the edges (14) and, on the one hand, is supported on the shuttering panel (12) and, on the other hand, engages between the two prefabricated wall parts (3) and is supported on the spacer device or the support device (4) and / or on the inside of the prefabricated wall elements (3).

13. Shuttering device according to one of claims 1 to 11, characterized in that the wall is a structural ceiling (78) containing the opening (10) and in that the shuttering panel (12) is attached to the underside (79) of the structural ceiling (78) in the shuttering position by means of the at least one traction unit (19).

14. Shuttering device according to one of claims 1 to 13, characterized in that the traction unit (19) is supported on the wall side on a supporting element (16) which - is a fixed part of the support device (4) or - is held as a separate element on the support device (4) or - itself forms the support device (4).

15. Shuttering device according to one of claims 2 to 14, characterized in that the ratchet mechanism (56) has a tensioning lever (83) and a control cam (98) coupled to the tensioning lever (83), and in that the tensioning lever (83), by means of the control cam (98) in an associated pivot position, moves a locking slide (91), which selectively blocks the winding shaft (55), into an unlocking position.

16. Method for shuttering openings (10) in walls with a shuttering panel (12) of a shuttering device, which is formed according to one of claims 1 to 15, against the escape of fresh concrete (5a), characterized in that a) a traction cable (44) or a tensioning strap is fastened as a traction element of a fastening device at a fastening point on a support device (4) arranged on the wall side, b) a seal (47) or a sealing bushing (21) is slipped onto the traction element and is held by means of a clamping friction force at a distance from the fastening point, which is greater than the distance between the fastening point and a panel opening (20) of the shuttering panel (12), which is subsequently attached in the shuttering position and at which the seal (47) or the bushing (21) is positioned for the passage of the traction element, c) the traction element is inserted through the panel opening (20) of the shuttering panel (12) arranged at a distance in front of the opening (10) to be shuttered in the assembly position, d) the shuttering panel (12) is brought into its shuttering position, e) the seal (47) or the bushing (21) is positioned at the panel opening (20) - either during the passage of the traction element through the panel opening (20) in accordance with step c), - or when tensioning the traction element through clamping force-driven engagement of the seal (47) or the bushing (21) at the panel opening (20), and f) the traction element is tensioned by a tensioning device (46) containing a winding device (54) and is fixed directly or indirectly in holding engagement with the shuttering panel (12).