Hohlwanddose

Abstract

The invention relates to a cavity wall box (1) for electrical purposes, comprising a box body (2) with a box base (3) and a tubular side wall (4) extending into the box base in an axial direction (y). At least one clamping element (8) is arranged to be displaceable in the axial direction (y). At least one retaining element (9) for supporting the cavity wall box (1) against a rear wall of the cavity wall is arranged on the clamping element.

Description

[0001] The present invention relates to a cavity wall box for mounting electrical installations in a cavity wall.

[0002] It is known in the art to install electrical systems in walls, cavity walls, or even in thermally insulated walls or facades of buildings. Particularly in cavity walls, but also in other walls or facades, it is common practice to run electrical cables behind the wall or in a cavity behind the cavity wall, with these cables exiting the wall at specific points. Cavity wall boxes are installed in these areas to accommodate switches, sockets, or similar installation elements. For example, a cavity wall consisting of several layers, such as wooden panels or a combination of plasterboard and wooden panels, is installed at a distance in front of a building wall. To install a cavity wall box in such a cavity wall, an opening is created in one of the cavity walls using a suitable tool.A cavity wall box is inserted into such a wall opening, which can then be connected to the installed electrical cables on the back side of the wall.

[0003] For securing such cavity wall boxes, retaining devices are known which can be actuated from the front of the cavity wall box by means of actuators in order to pull the retaining device against the back of the cavity wall and fix the cavity wall box in the wall opening. A disadvantage of such known designs is the complex installation of the retaining devices.

[0004] One object of the invention is to provide a cavity wall box that can be installed easily and quickly. A further object of the invention is to provide a simple method for installing a cavity wall box in a wall opening of a cavity wall.

[0005] A cavity wall box according to the invention is suitable for electrical engineering purposes and comprises a box body with a base and a tubular side wall extending axially into the base. The side wall and the base together enclose an installation space. The side wall extends from a front end to a rear end. The side wall can have different cross-sections between the front and rear ends. At the rear end, the side wall transitions into the base. Opposite the base and surrounded by the front end of the side wall is an installation opening that provides access to the installation space. At least one cutout is arranged in the side wall, which is spanned at least partially by a deformable membrane.A tensioning element is arranged on the membrane, which can be moved axially and / or radially as needed by deforming the membrane. Advantageously, the membrane and the tensioning element together completely close the respective opening. At least one retaining element is also arranged on the tensioning element, which serves to support the cavity wall box against the rear side of a cavity wall.

[0006] For even tensioning of the cavity wall box within the wall opening, several tensioning elements can be used. It is advantageous to have one tensioning element per cutout. Therefore, several cutouts can be arranged in the tubular side wall. These are advantageously evenly distributed around the circumference. If there are two cutouts, they are advantageously located opposite each other. This ensures even tensioning of the cavity wall box via the tensioning elements, or rather the retaining elements, within the wall opening. Each cutout extends (radially) through the tubular side wall. The cutout can be essentially rectangular or have other shapes. The cutout can extend axially over 75–100%, and in particular over 85–100%, of the side wall.This is advantageous in order to provide the clamping element with the largest possible displacement range and thus enable a wide range of applications for the cavity wall box.

[0007] The deformable membrane can be attached to an edge of the cutout, particularly by bonding it to the material. Advantageously, the membrane is attached to the cutout all the way around its edge. The clamping element is arranged on the membrane, and in particular spaced apart from the respective edge of the cutout. Advantageously, the membrane completely surrounds the clamping element around its circumference. The clamping element is preferably bonded to the membrane by bonding it to the material. The clamping element can project beyond the membrane (in its undeformed state) at least radially inwards and / or outwards. Advantageously, the clamping element penetrates the membrane in a radial direction. In this case, the clamping element is accessible from both the outside and the inside of the cavity wall box.

[0008] The placement of the clamping element on the respective membrane allows for axial and / or radial displacement of the clamping element relative to the box body by deforming the membrane. This displacement is facilitated if the membrane comprises a soft, elastic plastic. In a pre-tensioned position and / or a mounting position of the clamping element, as described in more detail below, the membrane can form a tensile stress zone and a compressive stress zone opposite this tensile stress zone relative to the clamping element. Preferably, the tensile stress zone is formed in an area of ​​the membrane facing the installation opening. In one variant of the cavity wall box, the membrane can further comprise two shear stress zones opposite each other relative to the clamping element in the pre-tensioned position and / or the mounting position. The shear stress zones lie axially between the tensile stress zone and the compressive stress zone.The membrane can have different designs depending on the zone in order to better absorb the respective applied stresses. To counteract stress peaks, the membrane can additionally incorporate a stress diversion structure. This can include, for example, reinforcing ribs and / or fold structures and / or membrane bulges extending outwards and / or inwards. Depending on the design, it may be advantageous to position the stress diversion structure in the tensile stress zone and / or the compressive stress zone and / or the shear stress zones.

[0009] As described above, at least one retaining element for supporting the cavity wall box against the rear wall of a cavity wall is arranged on the clamping element, particularly on one of its outer sides. For secure fastening of the cavity wall box, the retaining element can be made of a high-strength plastic. This high-strength plastic can be a composite material. Depending on the application, however, the retaining element can also be integrally integrated with the clamping element and made of the same material. For a wide range of applications, such as cavity wall walls of varying thicknesses, several retaining elements can be arranged axially one behind the other on the clamping element. In this case, it is advantageous for the multiple retaining elements to be integrally connected to each other via a base. The base can be made of the same material as the multiple retaining elements.Furthermore, one or more retaining elements, as well as the base if present, can be bonded to the clamping element. In an undeformed state of the membrane, at least one retaining element advantageously protrudes from a mounting contour of the cavity wall box. The mounting contour essentially corresponds to the inner contour of the wall opening or an outer contour of the box wall. The inner contour of the wall opening and the outer contour of the box wall differ only minimally by a gap for installation.

[0010] In one variant of the cavity wall box, at least one rib can be arranged on the membrane. The rib(s) advantageously connect the clamping element to the box body initially. The rib(s) can be located on the inside of the membrane (facing the installation space) and / or on the outside of the membrane. During manufacturing, the rib(s) can be used to position the clamping element. In injection molding, and particularly in two-component or three-component injection molding, the rib can, for example, act as a material bridge to distribute the material of the box body and the clamping element within the cavity wall box being molded. Upon initial deflection of the clamping element, at least one rib can break to prevent a negative impact on the deflection.For this purpose, the bridge can have at least one predetermined breaking point, which is designed in such a way that it breaks when the clamping element is moved.

[0011] Depending on the application, the cavity wall box can have at least one additional actuator per clamping element. This actuator, such as a screw or similar device, allows the clamping element to be moved axially and advantageously fixed in the displaced position (especially in the pre-tensioned position). In this way, the at least one retaining element mounted on the clamping element can additionally secure the cavity wall box to the cavity wall from the rear. For this purpose, the actuator can be operatively connected to both the box body and the clamping element when installed. The box body can have a receiving element for the actuator, which can, for example, have an opening for it. This opening can be a slotted hole, preferably a through-hole.Furthermore, the at least one clamping element can have a functional connection element, particularly on its inner side, for functional connection with the actuator. The functional connection element advantageously also has an opening in the axial direction for the actuator. The opening of the functional connection element can have an internal thread into which an external thread of the actuator can engage. The opening of the receiving element and the opening of the functional connection element are advantageously aligned coaxially with each other (in the undeformed state of the diaphragm). The actuator can, for example, be a screw which, in the assembled state, rests against the front of the receiving element and engages with the internal thread of the opening of the functional connection element via the external thread of the actuator. The screw, or...The actuator, when assembled, extends through the (through) opening of the receiving element into the opening of the working connection element, where it is screwed in. By actuating the actuator, the clamping element can be moved and fixed axially towards the front end of the tubular side wall. With the actuator installed, the clamping element cannot be moved radially, or only to a limited extent.

[0012] For disassembly, it is therefore necessary or at least advisable to first remove the actuator. The clamping element can then be deflected radially inwards, and the cavity wall box can be removed from the wall opening (after releasing the undercut between the retaining element(s) and the cavity wall). For simplified disassembly, the clamping element(s), particularly on its inner side, can have a tool interface. This interface allows the insertion of a tool to deflect the clamping element radially inwards. This deflection is also achieved by deformation of the diaphragm. The radial inward deflection allows the clamping element and the retaining element to be temporarily moved into the mounting contour of the cavity wall box, thus releasing the undercut.

[0013] For cost-effective manufacturing, the cavity wall box can be produced in one piece, or integrally. In its initial state before installation or after manufacturing, the cavity wall box can have at least one clamping element and / or at least one retaining element and / or the membrane formed integrally with the box body. Manufacturing via injection molding is advantageous in this case. All materials of the cavity wall box are injection-molded materials, including, in particular, the material of the box body, the soft-elastic material of the membrane, and the high-strength material of the retaining element(s).

[0014] The present invention also relates to a method for mounting a cavity wall box in the wall opening. The method may comprise the following process steps: The process step involves providing a cavity wall box with a cutout in one side wall of the box, which is at least partially spanned by a deformable membrane and with a clamping element arranged on the membrane on which one or more retaining elements for supporting the cavity wall box against a rear wall of the cavity wall are arranged. This cavity wall box can further correspond to a previously described variant of a cavity wall box.

[0015] The next step involves inserting the provided cavity wall box into the opening in the cavity wall. The cavity wall box can be inserted into the opening with its base first until one edge of the box rests against the cavity wall. This edge may protrude from the front edge of the cavity wall. Typically, the edge is positioned at the installation opening and at least partially surrounds it. As described above, one or more retaining elements may protrude from the mounting contour when the membrane is undeformed. When inserting the cavity wall box into the opening, the retaining element can advantageously shift radially into the mounting contour temporarily and, if necessary, protrude again from the mounting contour after passing through the cavity wall. This is made possible by a corresponding deformation of the membrane.The deformation of the membrane in the radial direction can be initiated by the contact of the at least one retaining element with the wall opening. Due to the deformation of the membrane, the at least one retaining element temporarily shifts into the mounting contour.

[0016] The process step involves applying an assembly force to the clamping element to deform the membrane and displace the clamping element axially away from the installation opening of the cavity wall box until at least one designated retaining element is positioned axially behind the back wall of the cavity wall. The clamping element is thereby moved into an installation position. The designated retaining element is the retaining element positioned in such a way as to achieve a sufficient preload force with which it clamps the cavity wall box in the wall opening of the cavity wall (in a preloaded position). The assembly force is advantageously applied axially towards the bottom of the box. If only one retaining element is present, it corresponds to the designated retaining element.In this case, the pretensioning position of the single (designated) retaining element is tailored to the application, such as the thickness of the cavity wall. If multiple retaining elements are present, any one of them can correspond to the designated retaining element for the specific application. In the installation position, the tensioning element typically remains in place only when the installation force is applied. In the installation position, the membrane has a tensile stress zone and a compressive stress zone opposite this zone relative to the tensioning element. The tensile stress zone is located in an area of ​​the membrane facing the installation opening. Furthermore, the membrane may comprise two shear stress zones opposite each other relative to the tensioning element.

[0017] The process step involves releasing the mounting force and holding the cavity wall box in the wall opening by the remaining deformation of the membrane, which exerts a preload force on the clamping element, so that the at least one holding element is tensioned against the back of the cavity wall wall.

[0018] In the event that the clamping element in the mounting position has a distance in the axial direction to the back of the cavity wall box, the clamping element can undergo an additional (area-specific) repositioning in the axial direction and in the direction of the installation opening until the at least one designated retaining element rests against the back of the cavity wall wall.

[0019] When at least one designated retaining element rests against the back of the cavity wall, the remaining deformation of the membrane exerts a preload force on the tensioning element in the preloaded position, or rather on the designated retaining element, which holds the cavity wall box in the wall opening. In this preloaded position, the membrane still forms the tensile stress zone, the compressive stress zone, and the shear stress zones. However, in contrast to the mounting position, the applied stresses in the respective zones are lower.

[0020] The mounting force can therefore be greater than or equal to the preload force. Equivalently, the clamping element can be closer to the can bottom in the mounting position than in the preload position. In rare cases, however, the mounting position can also correspond to the preload position. In this case, the clamping element is deflected by the mounting force only as far as necessary, i.e., only until the designated retaining element rests just behind the back wall of the cavity.

[0021] Following these steps, the cavity wall box is already pre-tensioned in the wall opening. However, a more secure installation is achieved by additionally fastening the clamping element, or at least one retaining element. For this purpose, the process can further include the step of fixing the clamping element using an actuator. The actuator advantageously fixes the position of the clamping element relative to the box body. For this purpose, the clamping element can have a functional connection element for operative connection with the actuator, as described in more detail above. The (fixed) actuator preferably limits displacement of the actuator in both the axial and radial directions.

[0022] For disassembly, the actuator can first be released so that the clamping element can again be moved axially. Then, the elastic preload on the membrane can be released. This can be done using a tool that engages with a tool interface on the clamping element. The tool interface serves to insert a tool to deflect the clamping element radially inwards. This radial inward deflection allows the clamping element and at least one retaining element to be temporarily moved into a mounting contour of the cavity wall box, and the cavity wall box to be removed from the wall opening.

[0023] The described embodiments of the cavity wall box can serve to carry out the method according to the invention. The previously described embodiments of the cavity wall box also disclose correspondingly designed versions of the method for mounting a cavity wall box in a wall opening of a cavity wall and vice versa. The listed method steps are not exhaustive and can also be carried out in a different order (if appropriate).

[0024] Aspects of the invention are explained in more detail with reference to the exemplary embodiments shown in the following figures and the accompanying description. The figures show: Fig. 1 A variant of a cavity wall box according to the invention in a perspective view; Fig. 2 The variant of the cavity wall box according to Fig. 1 in a side view; Fig. 3 The variant of the cavity wall box according to Fig. 1 in a front view; Fig. 4 The variant of the cavity wall box according to Fig. 3 in a sectional view AA from the side; Fig. 5 The variant of the cavity wall box according to Fig. 3 in a sectional view BB from the side.

[0025] Fig. 1, Fig. 2, Fig. 3, Fig. 4 to Fig. Figure 5 shows a cavity wall box 1 according to the invention in various views. The cavity wall box 1 depicted comprises a box body 2 with a box base 3 and a tubular side wall 4 extending axially from a front end to a rear end. Opposite the box base 3 and surrounded by the front end of the side wall 4 is an installation opening 5 through which an installation space 6 is accessible. A rim 23 also projects radially outwards from the side wall 4 at its front end. Two opposing cutouts are arranged in the side wall 4 of the box body 2. However, a different number of cutouts is also conceivable. A deformable membrane 7 spans at least part of each cutout.A clamping element 8 is also arranged on the membrane 7, which is axially displaceable along the side wall 4 by deformation of the membrane 7. The membrane 7 clearly surrounds the respective clamping element 8. On the outer side 18 of the cavity wall box 1, several retaining elements 9 are located on the respective clamping element 8 for supporting the cavity wall box 1 against a rear wall of a cavity wall. The several retaining elements 9 are arranged axially one behind the other on the at least one clamping element 8. The retaining elements 9 can be integrally connected to one another via a common base 16.

[0026] When the cavity wall box 1 is installed in a wall opening, the membrane 7 can be deformed radially inwards. Furthermore, the clamping element 8 attached to the membrane 7 can be displaced axially by deformation. For this purpose, the membrane 7 can have a tensile stress zone 10 and a compressive stress zone 11 opposite this zone in relation to the clamping element 8, both in the previously described installation position and in the pre-tensioned position. The membrane can also comprise two shear stress zones 12 opposite each other in relation to the clamping element 8. Zones 10, 11, and 12 are nevertheless numbered with reference numbers in the undeformed states of the membrane 7 shown here (see figure). Fig. 2 and Fig. 5) To counteract stress peaks, the membrane 7 can have one or more stress diversion structures 13. Depending on the design, it may be advantageous to arrange the stress diversion structure(s) 13 in the tensile stress zone 10 and / or the compressive stress zone 11 and / or the shear stress zones 13. The stress diversion structure(s) 13 are located in the cavity wall box 1 described here. Fig. 2 and Fig. 5 is merely an example and schematically indicated by dashed lines.

[0027] In Fig. Figure 4 shows the membrane 7 and the clamping element 8 in a sectional view. The can body 2 can be seen having a receiving element 20 for the actuator 22 on the inner side 17 at the front end of the side wall 4. Furthermore, the clamping element 8 has an operative connecting element 21 on its inner side 17 for operative connection with the actuator. Both the receiving element 20 and the operative connecting element 21 each have an opening for the actuator 22, which are arranged coaxially to each other. The actuator 22 can, for example, be a screw which, in the assembled state, rests against the receiving element 20 and engages with the operative connecting element 21 by means of a thread. By actuating the actuator 22, the clamping element 8 can be moved axially towards the tubular side wall 4 and fixed in place. Tool interfaces 19 are also arranged on the clamping elements 8 below the operative connecting element 21.The tool interfaces 19 serve to radially deflect the clamping element 8 into the installation space 6 during disassembly.

[0028] In Fig. Figure 5 shows the membrane 7 and the clamping element 8 visible from the installation space 6. Visible on the membrane 7 are webs 14, which initially connect the clamping element 8 and the box body 2. Each web 14 has at least one predetermined breaking point 15, which is preferably designed to break when the clamping element 8 is initially moved. LIST OF REFERENCE MARKS 1 cavity wall box 2 can bodies 3 can bottoms 4 side wall 5 Installation opening 6 Installation space 7 Membran 8 clamping elements 9 retaining element 10 Tensile stress zone 11 Compressive stress zone 12 Shear stress zone 13 Voltage diversion structure 14 Bridge 15 Breakaway point 16 sockets 17 Inside 18 Outside 19 Tool interface 20 recording element 21 Functional connecting element 22 Actuator 23 Rand

Claims

A cavity wall box (1) for electrical purposes comprising: a. a box body (2) with i. a box base (3) and a tubular side wall (4) extending into the base and extending in an axial direction (y); ii. an installation opening (5) opposite the box base (3) and surrounded by the side wall (4); and iii. at least one cutout arranged in the side wall (4); b. a deformable membrane (7) spanning at least part of the respective cutout; c. a clamping element (8) arranged on the membrane (7), which is displaceable in the axial direction by deformation of the membrane (7); and d. at least one retaining element (9) arranged on the clamping element (8) for supporting the cavity wall box (1) against a rear side of a cavity wall wall. Cavity wall box (1) according to claim 1, characterized in that the membrane (7) surrounds the clamping element (8). Cavity wall box (1) according to one of the preceding claims, characterized in that the membrane (7) in a mounted state of the cavity wall box (1) forms a tensile stress zone (10) and a compressive stress zone (11) opposite this in relation to the clamping element (8) in the wall opening. Cavity wall box (1) according to claim 3, characterized in that the tensile stress zone (10) is arranged in an area of ​​the membrane (7) facing the installation opening (5). Cavity wall box (1) according to one of the preceding claims, characterized in that the membrane (7) in a mounted state of the cavity wall box (1) comprises two shear stress zones (12) opposite each other in relation to the clamping element (8). Cavity wall box (1) according to one of the preceding claims, characterized in that the membrane (7) has a stress diversion structure (13) which in particular comprises reinforcing ribs and / or fold structures and / or membrane protrusions. Cavity wall box (1) according to claim 5 and 6, characterized in that the stress diversion structure (13) is arranged in the tensile stress zone (10) and / or the compressive stress zone (11) and / or the shear stress zones (12). Cavity wall box (1) according to one of the preceding patent claims, characterized in that the membrane (7) comprises a soft elastic plastic. Cavity wall box (1) according to one of the preceding claims, characterized in that at least one web (14) is arranged on the membrane (7) which initially connects the clamping element (8) and the box body (2) together, wherein the web (14) in particular has at least one predetermined breaking point (15) which is designed such that it breaks when the clamping element (8) is moved. Cavity wall box (1) according to one of the preceding claims, characterized in that the at least one retaining element (9) comprises a high-strength plastic. Cavity wall box (1) according to one of the preceding claims, characterized in that several retaining elements (9) are arranged one behind the other in an axial direction on the at least one clamping element (8). Cavity wall box (1) according to claim 11, characterized in that the several retaining elements (9) are integrally connected to each other via a base (16) comprising the same material as the several retaining elements (9). Cavity wall box (1) according to one of the preceding claims, characterized in that the at least one clamping element (8), in particular on an inner side (17), comprises an operative connecting element (21) for an actuating element (22) for fixing the clamping element (8). Cavity wall box (1) according to one of the preceding claims, characterized in that the at least one clamping element (8), in particular on an inside (17), has a tool interface (19) for radially deflecting the clamping element (8) into an installation space (6) of the cavity wall box (1). A method for mounting a cavity wall box (1) in a wall opening of a cavity wall, the method comprising the following process steps: a. Providing a cavity wall box (1) with a cutout arranged in a side wall of the cavity wall box (1), which is spanned at least partially by a deformable membrane (7) and with a clamping element (8) arranged on the membrane (7) on which one or more retaining elements (9) for supporting the cavity wall box (1) against a rear wall of the cavity wall are arranged; b. Inserting the cavity wall box (1) into the wall opening of the cavity wall; c. Applying an installation force to the clamping element (8) to deform the membrane (8) and displacing the clamping element (8) by the installation force in the axial direction away from an installation opening (5) of the cavity wall box (1) until a designated retaining element (9) is arranged behind the rear wall of the cavity wall; d.The applied mounting force is released and the cavity wall box (1) is held in the wall opening by the remaining deformation of the membrane (7), which exerts a preload force on the clamping element (8), so that the designated holding element (9) is tensioned against the back of the cavity wall wall. Method for mounting a cavity wall box (1) according to claim 15, the method further comprising the method step of fixing the clamping element by means of an actuator. Method for mounting a cavity wall box (1) according to claim 15 or 16, the method further comprising the method step that, when the mounting force is applied, the clamping element (8) and the designated retaining element (9) arranged thereon are displaced in a radial direction into a contour of the wall opening by contact with the wall opening.

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