DK152302B - BEARING AND AS A BALCONIC DESIGNED BUILDING ELEMENT WITH AN INTERMEDIATE VEGETABLE PARTICLE MATERIAL - Google Patents

Description

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The invention relates to a beam-shaped structural element of the kind specified in the preamble of claim 1.

As a vegetable material, e.g. wood ,, straw, bagasse, cotton sticks, sisal or waste fibers or the like 5 are considered.

U.S. Patent No. 2,717,420 discloses a supporting building element of the aforementioned kind, which is constructed in a similar manner to the usual furniture panels, with the difference that the intermediate layer consists of a series of profile elements of different cross-sectional shapes. Coatings shall consist of sheet metal, veneer or three-layer plywood. The profile elements are designed so that they either have through-holes themselves or cooperate to form such voids when they are used. brought close together on row. In this way, low-weight fillers are formed, but the profile elements used have insufficient breaking strength, because their chips are usually oriented transversely longitudinally.

Accordingly, it is the object of the invention to provide the design of a building element of the aforementioned kind which can be manufactured in a simple manner and exhibit the substantially advantageous properties of a natural wood beam, but which is improved with regard to swelling and shrinkage, and which has a greater carrying capacity. This object is achieved by a building element of the kind mentioned initially, which according to the invention is characterized by the design according to the characterizing part of claim 1.

It has been found that building elements designed in this way exhibit surprisingly high breaking load limits, both with respect to bending load and crack load. This advantage must be attributed to the string pressing of coarse and fine staples, as the orientation of the staples is of great importance. Fine pegs have a long-fiber structure with a length of approx. 3-12 mm. Rough staples are approx.

30 mm long and also exhibits the long fibrous structure.

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The invention avoids the use of flat chips. Beams of the invention, unlike the prior art building elements, are generally homogeneous / with respect to the interlayer. This means that despite the desired orientation, a uniform linking of the different long chips over the entire cross-sectional area has been achieved.

The invention also takes advantage of the fact that uniform materials are glued together and that the extruded intermediate layer itself transfers a significantly greater load capacity when it is glued to the 10 rough or planed natural wood boards. In addition, the weathering resistance of molds is substantially greater than that of natural wood beams, since beams of the invention under weathering do not exhibit any deformation or cracking, and any risk of fungus or rot can be avoided by appropriate treatment of the particles prior to pressing.

Beams of the invention can be stacked both to form partitions and otherwise supporting walls. They are also suitable as support beams, tie-down beams and other structural elements.

A preferred value for the mixing ratio of the coarse 20 to the fine pin chips is given in claim 2. In that case, it is recommended that the various chips be oriented as specified in claim 3. It has been found in practice that a beam satisfying under these conditions, a maximum stiffness and over the full cross-section of the intermediate layer exhibit a homogeneous structure which can be recognized as a mutual interlocking of the pin chips.

In the manufacture of beams whose intermediate layers have a rectangular cross-sectional shape, it is preferable to do the string pressing in a position where the longest edge is vertical. Thus, when a cross-sectional rectangular multilayer beam, in its state of use, is to be erected on its wide side, it is therefore made upright or on its narrow side. This method of manufacture has the advantage that the wood particles to be pressed maintain a uniform density over the length and cross-section. If such a multilayer beam was made lying 3

DK 152302 B

on its broad side, the particles would have to overcome a greater friction at the stationary mandrel of the press if they were to freely enter the lower region of the press cylinder. In addition, voids could be formed in the region below the mandrel.

A further preferred embodiment of the building element according to the invention is given in claim 4. In that case, the design according to claim 5 is recommended.

The invention will be explained in more detail below with reference to some exemplary embodiments and with reference to the drawing, in which fig. 1-5 show cross sections for multilayer beams with rectangular profile and two opposite cover layers, fig. 6-9 cross sections for multilayer beams with coverings on all sides and FIG. 10-11 cross sections through additional beams as additional embodiments.

In the embodiment of FIG. 1 shows a cross section for a multilayer beam, the intermediate layer 1 consisting of a 20 extruded body. How such extruded bodies can be manufactured in larger dimensions is shown in German Publication No. 2,535,989. The intermediate layer 1 has along its longest side surfaces cover layer 2, which consists of natural wood, preferably sawed or planed wooden boards. In the middle layer 1 there is in the middle a through-going cavity 3, which in cross-section has the shape of an oval or oblong hole. However, the distances from the wall of the cavity 3 to the side surfaces of the intermediate layer 1 should be practically equal.

At the narrow end sides of the intermediate layer 1 there is respectively a spring 4 and a groove 5, which are so profiled that the multilayer beams for forming a wall, such as a partition, can be mounted one on top of the other; using the feder-not design.

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In one embodiment, the total width a of the multilayer beam is about 156 mm, the total height b is about 200 mm, while the wall thickness c of the cover layers 2 is approx. 8 mm and the width of the intermediate layer approx. 140 mm. A beam of these dimensions has a bending breaking load of approx. 3020 kp. This and the values set forth below have been ascertained by government material testing institutes.

In the embodiment of FIG. 2, the ratio of the wall thickness of the cover layer 2 to the thickness of the intermediate layer 1 is greater. In this case again, for example, the wall thickness of the cover layer 2 is dimensioned to 20 mm, while the other dimensions remain the same. The carrying capacity of this beam is correspondingly higher than that of FIG. 1, assuming retained goal 15 for the intermediate layer 1 without the costs having been correspondingly higher.

In general, it can be assumed as recommended that the ratio of the thickness of the cover layer 2 to the thickness of the target layer 1 is chosen between 1: 6 and 1:25. Of course, in special cases where there may be other loads, these conditions can be underestimated or exceeded. For particularly high-load beams, a thickness of the slab layer 2 of the order of 20 mm can preferably be assumed.

In the FIG. 3 and 4, the narrow sides 25 of the intermediate layer 1 are covered by the covering layers 2. The beam or carrier in the drawing is preferably shown in the loading position.

In the embodiment of FIG. 3, the cover layer 2 is relatively thin-walled, e.g. formed with a thickness of 8 mm, while the height of the intermediate layer 1 is again approx. 200 mm. In the embodiment of FIG. 4, on the other hand, the cover layer 2 is again thickened, e.g. 20 mm, with the height of the intermediate layer 1. maintained. 4 shows a bending breaking load of 5200 kp at 3000 mm in length.

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FIG. 5 shows a frame for element construction, in which the covering layers 2 are adhered to the wide side surfaces of the intermediate layer 1, thereby also being able to serve with its outer surfaces as visible surfaces or smooth substrates for veneer, wallpaper or the like.

The 6-9 embodiments are based on the fact that all outer surfaces of the intermediate layer 1 are enclosed by cover layers 2.7, The cover layers 2 cover the narrow areas, while the cover layers 7 cover the wider areas of the intermediate layer 1. These cover layers 2.7 also exist. of natural wood boards.

In the embodiment of FIG. 6, the wall thickness of the individual cover layers may be 8 mm, while the outer dimensions of the intermediate layer may correspond to those of FIG. 1, namely 140 x 200 mm. In the embodiment of FIG. 7, the cover layer is new, for example 20 mm. Such 15 beams are particularly suitable as roof supports and the like.

The FIG. 8 and 9 are based on intermediate layers 1 of square cross-section, with the through cavity 3 correspondingly having a circular cross-section. In the example shown in Fig. 8, the wall thickness is again set to 8 ram, while the side surfaces of the intermediate layer 1 have a width of about 145 mm. In the case of retaining inner dimensions, the wall thickness of the cover layers 2 in the embodiment of FIG. 9 is selected for 20 mm. The FIG. 9, at a clamp length of 3000 mm, it has been found to have a bending breaking load of 7300 kp and a column breaking 25 of 32000 kp.

In the FIG. 8-9, examples of the beams are shown in their operating position so that the load affects them in a vertical direction. The lateral cover layer 7 is, in these embodiments, clamped between the upper and lower cover layer 2. In addition, the corners 6 of the intermediate layer 1 in the FIG. Examples 8 and 9 are chamfered. By the latter measure, it is achieved that the adhesion of the covering layers 2.7 to the intermediate layer 7 can be carried out undisturbed, without thereby reducing the carrier or beam's sustainability.

Claims (5)

6 DK 152302B The intermediate layer 1 is in all the beams shown in the figures composed of staple mixed with binder and can e.g. consist of 50% rough shavings and 50% fine shavings. The strength of the beams thus becomes optimal when the pin chips at the string pressing for approx. two-thirds are oriented in the longitudinal direction of the beam, which can be achieved by the nature and manner of the chip mixture, introduction into the press chamber and by the pressure determination in accordance with previous proposals. It should be noted here that the proportion of other chip types, such as flat shavings, must be reduced to the inevitable minimum. In FIG. 10, a beam is provided with spring 4 and groove 5, where the covering layers 2a, 2b and 2c have spacings 8 and are provided with bevels 9. In this way, walls with a high bearing capacity can be obtained. FIG. 11 shows the direct connection between two intermediate layers 1, the free outer surfaces of which are adhered to the cover layer 2. Such a multi-layered beam can be manufactured at low pressing costs to achieve particularly high load-bearing capacity. Claims. 20 1. A structural member as a beam, consisting of an intermediate layer (1) of disintegrated vegetable material mixed with binders, which occupies most of the volume of the beam and on which at least two exterior surfaces are adhered (2, 7) of natural wood, characterized in that (a) the intermediate layer (1) consists of a extruded body, the main volume of which consists of a mixture of coarser and finer pin chips whose chips are oriented mainly in the longitudinal direction of the beam; and (b) the cover layers (2.7) consist of natural wood boards. The building element according to claim 1, characterized in that the mixing ratio between the coarse and the fine pins is approximately approx. 50:50. Building element according to claim 1 or 2, characterized in that approx. 2/3 of the pins are oriented in the longitudinal direction of the beam and the others across it. Building element according to one or more of claims 1-3, characterized in that all the outer surfaces of the intermediate layer (1) are adhered to the covering layer (2,7) of natural wood boards (Figs. 6-9). Building element according to claim 4, characterized in that the vertical cover layers (7) in the load condition are 10 interposed between the horizontal cover layers (2).