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(11) | EP 0 532 067 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Duct element and cover arrangement for the duct element to be cast into a wall of concrete |
| (57) A building element of concrete or the like having a through duct element (2; 102)
for a ventilation pipe (7, 8) or the like. The duct element (2; 102) is together with
a sheet metal lid (3; 103) able to be cast into the concrete, the pipes (7, 8) being
insertable into holes (5, 6) in the lid and securely held therein. The lid (3; 103)
has locking means (10; 110a) enabling the lid to be readily fastened to the duct element
(2; 102) by jamming or snap action. |
TECHNICAL FIELD
[0001] The present invention relates to a building element of concrete or the like having a through duct element adapted to accomodate at least one pipe, for instance a ventilation pipe, at least one of the ends of the duct element being closable by a lid which can together with the duct element be cast into the building element.
BACKGROUND PRIOR ART
[0002] In traditional building elements having a through duct eleement, the duct element, which is often of metal, plastic, cardboard or wood, is first cast into the concrete, whereupon the ventilation pipe is introduced into the duct and fixed therein by casting. The fixing of the ventilation pipe by casting will, thus, cause an extra amount of work, which can often be very time-consuming. Alternatively, instead of fixing the pipe within the duct by casting, it is also known, see US-A-4,488,388, to fix the pipe within the duct by means of a tensioning joint of complicated nature.
[0003] WO89/02015 shows a duct element and a lid with pipes fastened therein, the pipes being fastened to the lid by casting before the lid is cast into the building element. That method is very complicated, since it needs special tools to hold the pipes positioned until the concrete has solidified. Besides, it is very difficult to form exactly dimensioned holes in such a concrete lid once it has been cast into the building element.
SUMMARY OF THE INVENTION
[0004] The object of the present invention is, therefore, to accomplish a building element of the kind mentioned by way of introduction, which greatly simplifies the fastening of the pipes within the duct element. This object will be achieved by a building element according to the invention having the characterizing features of Claim 1.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The invention will be described in more detail by reference to the accompanying drawing which illustrates a preferred embodiment of the invention.
[0009] Fig. 3 is a sectional view of a building element according to the invention, where two pipes are mounted within the duct of the building element.
[0012] Fig. 6 is a portion of the sectional view of Fig. 5 shown with a duct element fastened to the lid.
DESCRIPTION OF A PREFERRED EMBODIMENT
[0013] Fig. 2 shows a duct element, known per se, of plastic, sheet metal, cardboard or wood, being used in the present invention for casting into a building element of concrete. The duct element consists in the embodiment shown of a tube 2 of rectangular cross-section having four mutually identical plane sheet metal walls 1. The tube 2 may be manufactured from an elongated sheet which is folded at three positions so as to form said walls 1. The outermost walls 1 of the sheet need not be fastened against each other, since they are held in position by a lid 3, see Fig. 1. According to the invention, the duct element 2 is closed at one or both ends by means of such a lid 3 before the casting of the duct element into the concrete. The lid 3, which is made of sheet metal, has a square-shaped main surface 4, in which through holes 5 and 6 may be made (see Fig. 3), suitably after the duct element 2 with its lid 3 has been cast into the concrete. In each one of said holes a mating ventilation pipe 7 and 8, respectively (see Fig. 3), is adapted to be introduced and held by the lid 3. Alternatively, the holes 5 and 6 may be made in the lid 3 before this and its duct element 2 are cast into the concrete.
[0014] The lid 3 has, on each side, a downwards at 90o folded side wall 9, the main surface 4 of the lid and the downwards folded side walls 9 being so dimensioned that the lid 3 exactly mates over either end of the duct element 2 in order to close the opening thereof.
[0015] In each one of the side walls 9 and also a short distance (corresponding to the thickness of the wall 1) along the main surface 4, a tongue 10 has been cut, extending substantially parallel to the respective side wall 1, the tongue forming a guidance plate when the lid 3 is put on to the duct element 2, such that each wall 1 will be jammed between a side wall 9 and a corresponding guidance plate 10, such that the duct walls 1 will be securely held by the lid 3.
[0016] Each side wall 9 has in its free end an outwardly bent flange 11 intended to improve the fastening capability of the lid into the concrete. Also, each side wall 9 has two inwardly bent locking ears 12 adapted to protrude into the walls of the duct element 2 when the lid is drawn thereon so as to improve the fastening between the lid and the duct element. In order to still improve this fastening, two tongues 13 has been cut in each wall 1 in register with the locking ears 12, so that these will urge the tongues 13 inwardly (see Fig. 3) so as to lock the lid 3 against the duct element 2.
[0017] The length of the duct element 2 can by varied by cutting it into a desired length along perforations 14, see Fig. 2.
[0018] Fig. 3 shows a building element 15 of concrete 16. The building element 15 may for instance be a floor or a wall element of a building, not shown. Simultaneously with the casting of the building element 15 in a casting form, not shown, the duct element 2 with a lid 3 in one of its ends, or, as is shown in Fig. 3, in its both ends. The two lids are both of the kind being shown in Fig. 1. When the concrete has set, the holes 5 and 6 are cut in the main surface 4 of the lid 3, such that the ventilation pipes 7 and 8 can be drawn therethrough and thus be held securely by the lid. No extra work has to be done in order to fasten the pipes 7 and 8 in the duct element 2.
[0019] Figs. 4 - 5 show an alternative embodiment of the sheet metal lid 3 of Fig. 1, here generally depicted at 103, and having a main surface 104. A central portion 110 of each side wall 109 of the lid 103 is folded downwards at 90o, a central, outwardly bent, rectangular locking lip 110a being cut out and hammered out in each such portion 110. Similarly to the lid 3 of Fig. 1, each side wall 109 has in its free end an outwardly bent flange 111 to improve the fastening into the concrete. This embodiment of the lid 103 does not need any locking ears of the type shown at 12 in Fig. 1.
[0020] The duct element 102 to be fastened against the lid 103 has, in each side wall 101 thereof, a centrally located U-formed tongue 113 cut out in the side wall 101, see Fig. 6. When drawing the lid 103 on to the duct element 102, the portion of the side wall 101 located above the tongue 113 will first be urged outwardly by the locking lip 110a, and will then snap in above the locking lip to rest against the edges of the locking lip, see Fig. 6, to thereby accomplish a snap action locking between the lid 103 and the duct element 102. In this position the locking lip 110a will urge the tongue 113 outwardly, as is seen in Fig. 6.
[0021] It will be seen that, in the embodiment of Figs. 4-6, the pair of tongues 13 of Fig. 2 have been replaced by one single, centrally disposed locking tongue 113.
[0022] Similarly to Fig. 3, holes (not shown) can be cut through the lid 103, in which necessary pipes can be fitted snugly and thus be held securely in position by the lid 103.
[0024] When casting the duct element 2 (102) and its lid 3 (103) into the building element, the main surface 4 (104) of the lid must be orientated in register with the main surface 17 of the building element. During a subsequent painting of the building element 15, the lid 3 (103) can be painted simultaneously, such that the lid will be invisible on the painted building element.
1. A building element (15) of concrete or the like having a through duct element (2;
102) adapted to accomodate at least one pipe (7, 8), for instance a ventilation pipe,
at least one of the ends of the duct element being closable by a lid (3; 103) which
can together with the duct element be cast into the building element (15), characterized in that the lid (3; 103) is made of hard plastic or sheet metal, so that holes (5,
6) can be cut therethrough after the duct element (2; 102) and its lid has been cast
into the building element (15), said holes (5, 6) being dimensioned to mate with said
pipes (7, 8), so that these can be fitted snugly in a respective one of said holes
and thus be held in position by the lid, the lid having locking means (10; 110a) enabling
the lid (3; 103) to be readily fastened to the duct element by jamming or snap action.
2. Building element according to Claim 1, characterized in that the lid (3; 103) has a plane exterior main surface (4; 104) in register with
a main surface (17) of the building element (15).
3. Building element according to any preceding Claim, characterized in that the duct element (2; 102) is made of sheet metal, cardboard, plastic or wood.
4. Building element according to any preceding Claim, characterized in that the lid (3; 103) has downwardly bent side walls (9; 109) which are provided
with locking means (10, 12; 110a) adapted to lock against the walls (1; 101) of the
duct element.
5. Building element according to any preceding Claim, characterized in that the lid (3; 103) has sidewardly directed flanges (11; 111) in order to improve
the fastening capability of the lid in the concrete.