AU2006206830A1

AU2006206830A1 - Device in order to provide an electric connection cavity in a cast concrete floor

Info

Publication number: AU2006206830A1
Application number: AU2006206830A
Authority: AU
Inventors: Staffan Eriksson
Original assignee: Thorsman and Co AB
Current assignee: Thorsman and Co AB
Priority date: 2005-01-18
Filing date: 2006-01-16
Publication date: 2006-07-27
Also published as: EP1841934A1; NO20074013L; SE529513C2; WO2006078208A1; SE0500159L

Description

WO 2006/078208 PCT/SE2006/000059 Device in order to provide an electric connection cavity in a cast concrete floor. Technical Field of the Invention The invention relates to a connection cavity in a cast concrete floor and a 5 device in order to provide the same. Such connection cavities enable connection below the floor level of electrical cables to terminal devices or terminal blocks arranged in the cavity for service lines of different types located under the floor. The connection cavity may be used as a usual so-called floor well, which in such a case is provided with a suitable top plate, where appropriate provided 10 with a suitable cable outlet or as a floor well, which simultaneously offers a stable mechanical attachment for a service post arranged on top of the floor well. Background of the Invention Today, it is common in office premises, computing centres and the like 15 that service cables of different types are located under the floors. Terminal floor boxes or floor wells were used in these installations in order to arrange the distri bution of, e.g., electrical power and data from defined positions on the floor. Cables from the connected equipment are directly connected to terminal devices in the connection cavity or to a terminal unit for power and data that is mounted 20 standing on top of such a floor box. Such a connection cavity is usually arranged by the fact that a box-shaped unit made from galvanized thin sheet, plastic or aluminium to which incoming and outgoing cable ducts are connected, is casted into the floor on the desired location. 25 Usually, the screeded box has two main parts, a lower box-shaped part provided with a bottom part and vertical side walls and an upper frame, which can be vertically adjusted in relation to the bottom part. Because of the fact that the arrangement, during the casting, is exposed to relatively great forces, which could bring the same out of position, it has to be fixed and anchored properly. Therefore, 30 the lower part is usually provided with a flange all around. This is provided with devices for fixation and anchorage, e.g., mounting holes for screws or nails or lashing wire. The box may, e.g., be fixed by means of spacing elements against the mould and be lashed in the concrete reinforcement.

WO 2006/078208 PCT/SE2006/000059 2 A disadvantage of this type of connection cavity is that it may be difficult to arrange a sufficiently mechanical stable fixing of a service post arranged on top of the cavity. 5 Object of the Invention An object of the present invention is to provide an electrical connection cavity in a cast concrete floor without using a box-shaped unit of sheet-metal plate, plastic or the like that will remain in the floor after the casting. An additional object of the present invention is to provide a connection 10 cavity in a concrete floor by the use of a casting body or filler body, which has parts made from a material that easily can be removed after the casting, and which comprises at least one stable substantially planar fixing element made from, e.g., sheet-metal plate or suitable plastic material, arranged between the parts that are removed after the casting. 15 Furthermore, the object of the present invention is to provide a casting body that geometrically corresponds to said connection cavity, which connection cavity consists of an upper connection cavity, arranged above said fixing element, and a lower connection cavity, arranged below said fixing element, and which in said upper connection cavity houses a terminal device or terminal blocks and 20 which in the lower connection cavity houses electrical cables and cable ducts that do not risk being jammed under terminal devices and terminal blocks having been mounted in the connection cavity. Summary of the Invention 25 The above object is attained by the present invention such as it is defined in the independent claim 1. Suitable embodiments of the invention are defined in the dependent claims. Thus, according to the present invention, a device is defined in order to provide an electrical connection cavity in a cast concrete floor, and a mechanical 30 attachment for electrical service posts, characterized in that it comprises a casting body consisting of an upper and a lower part block of a relatively stiff material, which part blocks are arranged to be allowed to be removed after the casting, and a substantially planar fixing element horizontally arranged between the part blocks, which casting body geometrically corresponds to said connection cavity, which WO 2006/078208 PCT/SE2006/000059 3 connection cavity consists of an upper connection cavity, arranged above said fix ing element, and a lower connection cavity, arranged below said fixing element. In accordance with the invention, the advantage is obtained that a con nection cavity in a concrete floor is provided, at the same time as at least one sta 5 ble substantially planar fixing element is cast into the concrete floor and partitions the cavity into an upper connection cavity, arranged above the fixing element, and a lower connection cavity, arranged below the fixing element, in such a way that a terminal device can be arranged in the upper connection cavity and be secured at said fixing element and that cables and cable ducts can be arranged in the lower 10 connection cavity and securely fastened at said fixing element, whereby the cables will not be jammed under the terminal device. According to an advantageous embodiment, the upper and lower part blocks of the casting body may constitute an integrated block, which is cast inte grally on the fixing element. An alternative is that the upper and lower part blocks 15 of the casting body are glued against each other from each side of the fixing ele ment. According to an additional advantageous embodiment, the upper and lower part blocks of the casting body may, after the embedment in the floor, be broken down mechanically by means of a tool. According to an alternative, the 20 upper and lower part blocks of the casting body may, after the embedment in the floor, be broken down by means of a solvent. The advantage of this is that it is not necessary to use a box-shaped unit of sheet-metal plate, plastic or the like, which will remain in the floor after the casting. With such a unit, it is difficult to arrange a sufficiently mechanically stable fixing of a service post. 25 According to an additional advantageous embodiment, a lower surface of the lower part block is convexly shaped. In this way, it is avoided that possible air bubbles will remain under the part block 2 and create undesired cavities in the connection cavity. According to an additional advantageous embodiment, the fixing element 30 is provided with at least one fastening device in order to allow locking of cable ducts and cable troughs against the fixing element. According to an additional advantageous embodiment, the fixing element is provided with at least one recess in order to allow fixing of service posts on top of said lower connection cavity.

WO 2006/078208 PCT/SE2006/000059 4 According to an additional advantageous embodiment, fastening and spacing elements are arranged against a bottom of the mould against which the floor is to be cast and formed in such a way that it carries said fixing element in order for the concrete, upon the casting, to be able to penetrate under the casting 5 body. Brief Description of the Drawings The invention will now be described closer by means of embodiment examples and reference being made to the accompanying drawings, where 10 Figure 1 shows in perspective an embodiment of the prepared casting body having a number of connected cable ducts and a cable trough, Figure 2 shows in a side view and a view from above an embodiment of the casting body having the included fixing element, Figure 3 schematically shows a side view in section of the embodiment 15 according to Figure 1, Figure 4 shows a vertical section through the cavity provided in the con crete, Figure 5 shows a vertical section through the cavity provided in the con crete and a frame according to a first embodiment mounted in the opening, 20 Figure 6 shows a vertical section through the cavity provided in the con crete and a frame according to a second embodiment mounted in the opening. Detailed Description of the Invention Figure 1 shows in perspective a mounted casting body and connected 25 cable ducts 4 and a cable trough 4', which upon the subsequent casting of the floor and the subsequent machining provides an electrical connection cavity, hav ing an upper connection cavity 22 and a lower connection cavity 16, according to the invention. In a first embodiment, the casting body is composed of an upper and a 30 lower part block 1, 2 of a relatively stiff material, which is easy to machine mechanically or alternatively is easy to dissolve chemically, and an intermediate horizontally arranged, substantially planar fixing element 3. The casting body cor responds geometrically to the intended connection cavity, where the upper part WO 2006/078208 PCT/SE2006/000059 5 block 1 corresponds to the upper connection cavity 22 and the lower part block 2 corresponds to the lower connection cavity 16 (see, among others, Figure 4). Said material may, for example, be EPS (expanded polystyrene) or a similar plastic foam material and the fixing element 3 may be a punched sheet 5 metal material, cf. Figure 2. The upper and lower part blocks 1, 2 may constitute an integrated block that has been cast integrally on the fixing element 3. Another way to provide the casting body is to agglutinate the two part blocks 1, 2 against each other from each side of the fixing element 3. It is also conceivable to divide the fixing element 10 3 into two or more parts and push in the parts in a groove from the side in the block 1,2, which in this case has been provided with a suitable transversal groove for the purpose. The upper planar surface of the part block 1 is arranged in such a way that it will lie in the plane of the finished floor. In the figures, the two part blocks 1,2 are 15 shown having a rectangular (square) cross section but may of course also be of other shapes, e.g., circular. The thickness of the part blocks 1, 2 may of course also be adapted for the purpose. After the casting, the blocks 1, 2 are mechanically machined (broken down into small parts) by means of a suitable tool and removed. Alternatively, the blocks 20 1, 2 may be dissolved by the addition of a suitable solvent, which subsequently is sucked up. In such a way, in the concrete there is provided a connection cavity having, on one hand, a lower connection cavity 16, situated below the fixing ele ment 3, which is connected to ingoing and outgoing cable ducts, and on the other hand an upper connection cavity 22, which lower connection cavity 16 may be 25 utilized as an electrical connection cavity for the connection, below the floor level, of electrical cables to terminal devices or terminal blocks arranged in the upper connection cavity 22. The horizontally arranged planar fixing element 3 extends laterally outside the part blocks 1, 2 and will thus be anchored in the cast concrete. It will be appre 30 coated that, in this way, it is very easy to provide a very stable anchorage of the fixing element 3, which thereby in turn can give very good stability to equipment mounted in the upper connection cavity 22. Upon mounting of the casting body before the casting, the, cable ducts 4 are pressed into the lower part block 2, cf. Figures 3-6, which upon casting seals WO 2006/078208 PCT/SE2006/000059 6 the duct ends against concrete. In the case the blocks 1, 2 after the casting are to be removed by means of a solvent, advantageously the duct ends may first be sealed before they are pressed into the block 2. In the example shown, four fastening and spacing elements 5 have been 5 mounted against the bottom of the mould (not shown) against which the floor is to be cast. This may be effected by means of, for example, nailing or screwing. As is seen in the figures, said elements 5 have a relatively small contact surface against the bottom of the mould. The lower block 2 has such a vertical extension that the concrete, upon 10 the casting, can penetrate under the block 2. The fastening and spacing elements 5 are suitably formed in such a way that the corners of the fixing element 5 can rest on and possibly be fastened against the same. The connected cable ducts 4 as well as the cable trough 4' are pressed into the part block 2 from the side upon the mounting. In order to additionally stabi 15 lize the connection of the cable ducts and a possible cable trough, which join against the block 2 exactly under the fixing element 3, the same is provided with a number of recesses 6 along the outer edge 10 of the same, cf. Figure 2, which enable the locking of the end portions of the ducts and of the cable trough against the bottom side of the fixing element 3 by means of, for example, so-called bundle 20 band or lashing by wire 7, as is shown in Figure 1. Figure 2 shows in a side view and a view from above an embodiment of the casting body having the included fixing element 3. The planar fixing element 3 may, for instance, be made as a punched sheet-metal element. 25 The sheet-metal plate is provided with a central recess 9 and fastening devices 8, e.g., in the form of threaded holes for the fixing of inserts of different types in the connection cavity or in order to present a support for a service post or frame of conventional type arranged in the upper connection cavity 22. This recess 9 as well as the fastening devices 8 will end up inside the exposed connection 30 cavity after the embedment. Correspondingly, the outer edge 10 and the recesses 6 will be positioned inside the concrete, cf. Figures 3-6. In the embodiment illus trated, an additional threaded hole 8' is arranged in the respective corner at the recess 9. This hole is arranged for the co-operation with an adjusting screw, which will be described below.

WO 2006/078208 PCT/SE2006/000059 7 The fastening devices 8 in the sheet-metal plate may, in alternative embodiments, be made as through holes for the co-operation with, e.g., a self-tap ping screw, or punched and profiled recesses for the co-operation with, e.g., a screw of the body-screw type or the like. 5 When a connection cavity is provided according to prior art by means of embedment of a box-shaped unit made from galvanized thin sheet, plastic, alu minium or the like, obviously it will be very difficult to arrange anchor points inside the connection cavity that have sufficient stability for equipment mounted on top of the connection cavity. The box-shaped unit is simply too weak. 10 According to the invention, the fixing elements 3, for example made from sheet-metal plate, may be given a thickness of several millimetres. Said fixing elements are then anchored laterally in the cast concrete, which means that they will be able to present fastening devices 8 having very good stability to the equip ment, e.g., a service post, mounted on the floor on top of the connection cavity. 15 The side view in Figure 2 also shows that the lower surface 2' of the part block 2 has been given a convex design. When the concrete is vibrated upon the casting, possible air bubbles rise upward. By virtue of the given design of the lower surface 2', it is avoided that the air bubbles will remain under the block and create unde sired cavities in the lower connection cavity 16. 20 Figure 3 schematically shows a side view in section of the embodiment according to Figure 1. The free duct end 15 of a cable duct 4 and a cable trough 4' are shown pressed-in from the side in the lower part block 2, as has been described above. The part block 2 below the fixing element 3 has suitably, as is shown in the figure, a somewhat greater lateral extension than the part block 1. In 25 this way, the duct ends 15 will not, after exposure of the connection cavity, inter fere with equipment mounted in the lower connection cavity 16. Figure 4 shows a vertical section through the provided connection cavity, having an upper connection cavity 22 arranged above the fixing element 3, and a lower connection cavity 16 arranged below the fixing element 3. On top of the con-. 30 crete, the floor has been provided with a suitable coating 14. Figure 5 shows a vertical section through the provided connection cavity in the concrete and a frame 17 according to a first embodiment mounted in the upper connection cavity 22.

WO 2006/078208 PCT/SE2006/000059 8 After exposure of the connection cavity, a frame 17 of previously known type may be mounted in the upper connection cavity 22 in the concrete for height adjustment in relation to possible flooring 14 on top of the concrete. In this frame 17, if desired, subsequently a cover (not shown) for the connection cavity may be 5 mounted in a known way. In this case, the frame 17 is provided with a flange 18, which abuts against the upper floor surface. In order to keep the frame 17 in place, fixing screws 19 are utilized, which co-operate with the threaded holes 8. Figure 6 shows a vertical section through the provided connection cavity in the concrete and a frame 20 according to a second embodiment mounted in the 10 upper connection cavity 22. In this case, the frame 20 has no flange that abuts against the upper surface of the floor. In order to adjust the height of the frame 20 in this case, in the threaded holes 8', it is possible to mount adjusting screws 21 having a screw head that has a greater diameter than a co-operating and coaxial hole in the frame 20. In this way, the screw recess will be accessible from above 15 and the edge of the frame can be adjusted in relation to the upper surface of the floor. When the adjustment is finished, the frame 20 is locked in position by means of the screws 19.

Claims

1. Device in order to provide an electrical connection cavity in a cast con crete floor, and a mechanical attachment for electrical service posts, character 5 ized in that it comprises a casting body consisting of an upper and a lower part block of a relatively stiff material, which part block are arranged to be allowed to be removed after the casting, and a substantially planar fixing element horizontally arranged between the part blocks, which casting body geometrically corresponds to said connection cavity, which connection cavity consists of an upper connection 10 cavity, arranged above said fixing element, and a lower connection cavity, arranged below said fixing element.

2. Device according to claim 1, characterized in that the upper and lower part blocks of the casting body may constitute an integrated block, which is cast 15 integrally on the fixing element.

3. Device according to claim 1, characterized in that the upper and lower part blocks of the casting body may be glued against each other from each side of the fixing element. 20

4. Device according to any one of claims 1-3, characterized in that the upper and lower part blocks of the casting body may, after the embedment in the floor, be broken down mechanically by means of a tool. 25

5. Device according to any one of claims 1-3, characterized in that the upper and lower part blocks of the casting body may, after the embedment in the floor, be broken down by means of a solvent.

6. Device according to any one of the preceding claims, characterized in 30 that a lower surface of the lower part block is convexly formed.

7. Device according to any one of the preceding claims, characterized in that the fixing element is provided with at least one fastening device in order to allow locking of cable ducts and cable troughs against the fixing element. WO 2006/078208 PCT/SE2006/000059 10

8. Device according to any one of the preceding claims, characterized in that the fixing element is provided with at least one recess in order to allow fixing of service posts on top of said lower connection cavity. 5

9. Device according to any one of the preceding claims, characterized in that fastening and spacing elements are arranged against a bottom of the mould against which the floor is to be cast and is formed in such a way that it carries said fixing elements in order for the concrete, upon the casting, to be able to penetrate io under the casting body.