The present invention relates to a cover grating for a drainage channel or a similar hollow body, whereby the cover grating is manufactured in a single piece from metal sheet and more particularly metal sheet strip, that can be fitted in the ground with at least two webs running along the underside of the cover grating and inlet slots formed in the cover grating between these webs and comprising transverse webs resulting from the slot formation extending along the underside of the cover grating.
Cover gratings of this kind are known from the prior art and are predominantly used to cover rain channels, floor drains, inspection shafts or similar hollow bodies that can be built into the ground. They are preferably inset on the upper edge or in a rebate formed into the upper edge of the hollow object. Cover gratings of this nature may be subjected to various levels of loading, depending on where they are fitted. Thus there are cover gratings that are designed only for loading by pedestrians and cover gratings that will also withstand heavy traffic driving across them.
As a matter of principle, however, manufacturers are interested in producing cover gratings of the type described above to be as stable and durable as possible at the lowest possible cost.
Thus DE 24 233 05 A1 discloses a cover grating with longitudinal webs and inlet slots running transversely to these. To increase the loadbearing capacity of the cover grating, the longitudinal webs are formed as loadbearing webs rolled into a closed profile. This reduces the span of the cover grating between the two loadbearing webs and makes it possible for a thinner sheet metal to be used for gratings of the same loadbearing capacity. In addition to these longitudinal webs, the design of the inlet slots creates angles that are oriented essentially normal to the longitudinal webs in the form of transverse webs. These transverse webs additionally contribute to the load distribution, especially in the transverse direction.
The sheet metal cover gratings described above, however, have the disadvantage that, despite the use of longitudinal webs, the load distribution, particularly in the transverse direction, is unsatisfactory and therefore the sheet thickness of the sheet metal to be used cannot be further reduced. In addition to this, the covet gratings described above have the disadvantage that they only have a low degree of connection stiffness, especially where the bearing faces have been damaged.
This problem is dealt with by DE 37 13 971 A1 and others. It discloses a cover grating formed from sheet metal for channels, having transverse inlet slots to accept surface water, bounded at their ends by curved parts. The webs remaining between the inlet slots that are required to absorb the loading are, to the extent that they run straight, stiffened by flanges folded downwards. The cover comprises two longitudinal webs at right angles to these transverse webs to distribute the load in the longitudinal direction. To ensure that the transverse webs are held in their end regions, i.e. by the bends, a bead on which the transverse webs are supported is provided in this area on the longitudinal webs.
U.S. Pat. No. 5,024,550 discloses a completely different development. It discloses a cover manufactured from several individual pieces. This comprises two individual longitudinal webs connected by transverse webs arranged at right angles to this. The transverse webs engage in receiving slots formed on the longitudinal webs and are secured against slipping out by spot welds.
The covers known from the prior art, however, have the disadvantage of a very complex manufacturing method and, in part, an unsatisfactory static load bearing capacity.
The problem to be solved by the present invention therefore is to provide a cover grating for a drainage channel or a similar hollow body to be built in the ground, that has a better load distribution by comparison with the prior art with at least equivalent or simplified manufacturability.
This problem is solved by a cover grating according to claim 1.
More particularly, this problem is solved by a cover grating for a drainage channel or a similar hollow body to be built into the ground, wherein the cover grating is manufactured as a single piece and more particularly a sheet metal strip and comprises two longitudinal webs running along its underside and inlet slots formed in the cover grating between these longitudinal webs, with transverse webs running along the underside of the cover grating resulting from this formation and wherein the transverse webs comprise at least one supporting section or receiving projection in the end regions which at least partially engages in a receiving section or receiving slot in the longitudinal web formed to complement it.
When the cover grating is loaded from the top side, the transverse webs resulting from the forming process and assigned to the inlet slots act as the primary load distribution elements. Since the transverse webs engage through their supporting sections formed in their end regions in the receiving sections formed to complement them in the longitudinal webs, traffic loads in particular can be distributed from the transverse webs securely into the longitudinal webs.
Furthermore, the cover grating is preferably made from one sheet and in addition to this each longitudinal web is formed integrally, and more particularly folded, with the cover grating. It is in particular this forming of the cover grating from one sheet that makes inexpensive manufacture of the cover according to the invention mentioned above possible.
The supporting sections in the transverse webs preferably have a shorter web height than do those on the longitudinal webs. In this way, there is sufficient material available in the longitudinal webs to permit vertical load distribution through the supporting sections in the transverse webs vertically downwards into the longitudinal webs.
The support section on the end region of the transverse webs is preferably a cut-out support section. Cut-out means here that only a part of the end region of the transverse web engages precisely in the support section on the longitudinal web, while another part, namely the cut-out part butts up against a side wall of the longitudinal web and does not engage in the longitudinal web through the support section or its receiving section. In this way the longitudinal web is fixed horizontally, at least in the direction of the transverse web. This means that it is also possible to give the transverse web a greater web height than the longitudinal web as a result of which the load distribution in particular is improved as in the case of the transverse web designed here as a single span beam, the component height, especially in the central region of the transverse bearer, has a decisive influence on the load dissipation characteristics.
The support section is preferably formed such that it at least in part fully penetrates the longitudinal web and projects beyond one outer side of the longitudinal web, wherein it then comprises a fastening fold or a similar fastening element on the projecting support section. In this way, the longitudinal web is also fixed outwards in a horizontal direction, i.e. in a direction facing away from the transverse web, in particular in its interaction with a cut-out support section described above. This thus results in a very stiff, yet simple to fabricate, cover grating. In additional to the horizontal stiffening, the design described above with a fastening fold or similar fastening element, or the design with the cut-out support section leads, in terms of structural strength, to the transverse web being constrained in the longitudinal web. In this way the load distribution, especially in the vertical direction, is additionally improved.
In place of the fastening fold, any other type of fastening known from the prior art may be used for the projecting support section. A suitable expansion, flanging, necking of the support section, a spot weld, etc. are some of the methods that could be proposed.
Further embodiments of the invention are described by the dependent claims.
The invention will be described more closely in below on the basis of a number of embodiment examples that are illustrated in more detail in the drawings. Where:
The same references will be used below for identical parts and parts having an identical effect, whereby the references used thus far to distinguish the same components will be used.
Cover grating 1 also comprises several inlet slots 8 which may be used, in particular, for the drainage of surface water, etc. As a matter of principle, it should be mentioned here that the designation ‘inlet slot’ should be taken to refer to practically any inlet opening that essentially extends between the two longitudinal webs 4 of cover grating 1.
The inlet slots 8 are made by stamping and forming from the metal sheet 32 and each comprise two transverse webs 6 that each run parallel to the inlet slots 8 along the underside 3 of the cover grating 1. In this embodiment, the inlet slots have been formed by a cut 34 into the sheet 32 in the region of the transverse webs 4 and subsequent folding towards the underside 3. All methods familiar from the prior art may be applied here as long as inlet slots are created with transverse webs during the forming process.
The longitudinal webs 4 comprise receiving sections 9 in an axis with the transverse webs 6 that are formed in a complementary fashion to the support sections 12 formed at the end regions 7 of the transverse web 6 in such a way that said support sections can engage in the receiving sections 9. Load distribution through the transverse webs 6 into the longitudinal webs 4 is made safely and effectively possible in this way. Furthermore, the engagement of the support sections 12 also permits force application in the (relative to the cover grating 1) horizontal direction, from the transverse webs 6 into the longitudinal webs 4 and vice versa, which leads to a cover grating 1 with particular torsional stiffness. It is clearly visible here, in particular in conjunction with
Thus
In
Thus
The drainage channel 20 here comprises a rebated bearing region 21 to which a vertical beating face 22 is integrally connected. These two bearing faces or regions 21, 22, here essentially arranged at right angles to one another, secure the position of the covet grating 1, as soon as this is placed on or in the drainage channel 20.
In this embodiment a receiving section, in which a support section 12 formed on the transverse web 6 of the cover grating 1 engages, is for its part formed on the multiply folded longitudinal web 4. The receiving section 9 or the support section 12 are formed here in such a way that the support section 12 fully penetrates a region of the transverse web 6 through the receiving section 9 so that it forms a projecting support section 11. This projecting support section 11 can then, as already described for the preceding embodiments, be locked against being removed from the receiving section 9 by means of a fastening fold (not shown or a similar fastening).
1 Cover grating
5 Upper side
7 End region
8 Inlet slot
9 Receiving section or receiving slot
10 Support area
11 Projecting support section or receiving projection
12 Support section or receiving projection
13 Cutout region
15 Fastening fold
16 Inner side
18 Outer side
20 Drainage channel
21 Bearing area
22 Vertical bearing face
32 Sheet metal strip or sheet metal
36 Locking element
hQ Height of transverse web
hF Height of support section
Number | Date | Country | Kind |
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10 2006 051 160.3 | Oct 2006 | DE | national |
The present application is a national phase of International Application No. PCT/EP2007/001874 filed May 3, 2007, which claims the priority of German Patent Application No. DE 10-2006-051 160.3, filed Oct. 30, 2006.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP07/01874 | 3/5/2007 | WO | 00 | 8/26/2009 |