US 3390504 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
y 1968 G. J. VAN ELTEN 3,390,504
' B IL G 5 Filed June 29, 1965 2 Sheets-Sheet 1 July 2, 1968 e. .1. VAN ELTEN 3,390,504
ARMOURED EDGE FOR BUILDING SLABS Filed June 23, 1965 2 Sheets-Sheet 2 United States Patent Claims. cl. 52-588) ABSTRACT OF THE DISCLOSURE A building slab of wood wool and a mineral binder in which the edges of the slab are armoured with a U-shaped sheet metal edge, the center portion of the U-shaped edge extending laterally on the edge from one side of the slab to the other and a first and second flange integrally joined to the center portion of the U-shaped member, at the respective opposite ends of the center portion, one of the flanges having an inwardly bent end seated in and in engagement with a groove on one side of the slab and the other flange having an inwardly bent portion for engagement into and seating in a groove extending longitudinally along the center portion adjacent to the second shaped portion on the center portion extending longitudinally along the center portion adjacent to the second flange which, when bent downwardly engages the bent end of the second flange, and seats the bent end in, the groove extending longitudinally along the opposite side of the slabs.
The present invention relates to a building slab, and more particularly to a light weight building slab consisting of a long-fibrous insulative material such as wood wool and a mineral binding agent, the lateral edges of which are enclosed by metal channel-section members.
It is known in the art to armour building slabs which are used, for instance, to line ceilings, floors, roofs, walls etc. along their edges. This protects their edges against damage and strengthens their static capacity. When the building slabs are installed in horizontal or inclined positions the armouring renders them more resistant against bending strain so that the slabs may be installed in larger sizes, or, where they are self-supported, may take up heavier weights.
The armouring frequently consists of sheet metal strips of U-shaped cross section, the flanks of which form flanges engaging with the upper and lower surfaces of the building slab. In order to avoid loosening of the armouring from the building slab the two flanges are at their longitudinal edges internally bent and imbedded in grooves extending parallel to the abutting faces of two adjoining slabs. The U-shaped armouring strip is pushed or clamped into its grooves subsequent to the manufacture of the building slab. Due to the bending of greater building slabs during the pushing of the U-shaped armouring strip into the grooves of the slab damage to the edges of the building slab is likely to occur. Also slab parts of a slightly higher thickness are raising difficultiesfor the fastening of the U-shaped armouring strip to the building slab.
Further, it has been known to increase the bending resistance of the U-shaped sheet metal strips serving as connecting elements of the slabs in that the flanges of the "ice sheet metal strips are folded in a plurality of layers. It is further known to bend the middle part of the armouring strip parallel to the edges like the letter S. This S-shaped portion works as rib and groove with the next building slab together.
It is one object of the invention to provide for an increased length of building slabs to be armoured with an U-shaped armouring strip.
It is a further object of the invention to increase the bending resistance of the building slab and thus to achieve a larger span width of the slab.
To achieve this, a S-shaped bending portion of the armoured strip is put along an edge of the building slab. Preferably the armoured strip shows before the clamping to the edge of the slab not yet a fully backward bent S-shape. This open portion of the armoured strip is laid over the groove extending parallel to the abutting face of the slab and then is pushed down with the internally bent parts of the flange into the groove. This avoids the abovementioned disadvantages.
The S-shaped bending portion is situated near to one edge of the building slab. This results in more iron cross section near the flange of the armouring which increases the resistance moment of the armouring.
It is a further object of the invention, to provide for a layer of waterproof material upon the slab, which is clamped into the grooves by the internally bent flanges. If the S-shaped bending portion is made in a way that the armouring strip runs straight ahead from the S-shaped bending portion to the flange of the strip a waterproof roof construction results.
In the following specification the invention will be further described with reference to the embodiments shown in the accompanying drawings, in which:
FIG. 1 is a cross section of the abutting point of two building slabs;
FIG. 2 is a cross section of a building slab and of an armouring strip in the position in which it is laterally applied against the slab prior to being pressed into the slab;
FIG. 3 is a cross section of a building slab with pressedin armouring strips and a roof covering rigidly clamped by these strips;
FIG. 4 is a cross section of the abutting point of two inclined building slabs with reinforced marginal portions laid on beams of the roof;
FIG. 5 is a cross section of the abutting point of two building slabs with reinforced marginal portions and laid-in insulation strip;
FIG. 6 is a partial cross section of a pile of building slabs in accordance with FIG. 5.
Wit-h reference to FIG. 1, the two building slabs 1 and 2, consisting of wood wool and a binding agent, are at their abutting point provided with armouring strips 3 and 4 respectively, which may be made, for instance, of galvanized steel plates and in their upper portions are provided, by S-type bending, with a rib 5, 6 and a groove 7, 8 each.
When the building slabs are laid, rib 5 engages with groove 7, and rib 6 with groove 8. Above the S-type shaping, the two armouring strips 3 and 4 are continued in the shape of flanges 18 which, owing to multiple folding of the sheet metal, are formed of a plurality of layers. The
external edges 13 and 14 of flanges 18 are downwards bent by 90 and engage with grooves 9 and of the building slabs 1 and 2. At their lower ends, the armouring strips 3 and 4 are in a similar manner continued by a plurality of layers, which form flanges 17. The flanges 18 are mounted in excavations 11 and 12 at the upper Side of building slabs 1 and 2, these excavations being of such depth that the flanges 18 are in alignment with the surfaces and 16 of building slabs 1 and 2. The part of the material of the two armouring strips 3 and 4 contained in the ribs 5 and 6 and in the grooves 7 and 8 is a good distance from the line of bending neutrality of their center parts and therefore essentially contributes to the resistance moment of the armouring strips 3, 4.
In FIG. 2, the appliance of the armouring strips to the building slabs is shown, by way of example, with respect to slab 2. The flange 18 of armouring strip 4 is at first bent by an angle smaller than 180 so that its outside edge does not yet engage with groove 10 of building slab 2. The armouring strip 4 may therefore be laterally laid against building slab 2 without any difficulty, and the outside edge 14', being rectangularly bent in upward direction, may be pushed into the corresponding groove 16' at the lower side of the building slab 2. After the whole of armouring strip 4 has been caused to be adjacent to the slab, rib 5 is completely pressed together, for instance by hydraulically operated clamping jaws 19 or by press wheels, which causes the inturned outside edge 14 of flange 18 to be resiliently pressed into groove 10 of building slab 1. The pressing can be eflectuated without difficulty by a suitable construction of the clamping jaws. As a result, the armouring strip 4 is given a springy and firm adhesion to the smooth edges of building slab 2, which is not in any way damaged by the application of the armouring strip 4, nor is the galvanized layer of strip 4 itself.
In the same manner, armouring strip 3 is connected with building slab 1 so that, upon fastening of the two armouring strips 3, 4, the abutting point of the slabs 1 and 2 receives its final shape shown in FIG. 1.
The building slab 21 shown in FIG. 3 is provided with a waterproof covering 20, such as tar paper, a foil of plastic material or the like, which is laid on the surface of the slab before rib 5 is pressed together. When entering groove 10, the inturned outside edge 14 of flange 18 keeps covering tight and shortly before wedging it in the groove gives it a span. This ensures even and stretched attachment of covering 20 to the surface 16 of the building slab and a waterproof connection with it.
Building slabs provided with a waterproof coating are particularly advantageous for use as root linings, or the Waterproof coating may be used to protect building slabs which are sensitive to water, such as slabs made of gypsum or magnesite.
FIG. 4 shows the abutting point of two building slabs 1 and 2 which are used as roof coverings and laid on an inclined roof beam construction 27. To increase their bending resistance, the marginal portions 23 of slabs 1 and 2 are of thicker section than the center portions. The grooves and ribs are nearer the top than the ribs 5, 6 in the embodiment of FIGS. 1 to 3, by which arrangement the flanges 25 and 26 of armouring strips 3 and 4 form a direct continuation of the ribs 28. This causes the ribs 28 to be a greater distance from the line of bending neutrality of armouring strips 3 and 4 and thus increases the bend ing resistance of armouring strips 3 and 4. The building slabs may, due to this increase in bending resistance, for instance, be laid self-supporting from one roof beam to another. So that the abutting point will be weatherproof when the slabs are used as roof coverings the flange 26, which bears over building slab 2, is provided with an inelined pa-rt allowing the rain water to run down flange 25, on to flange 26 and off over covering 20. As the upper surfaces of building slabs 1 and 2 are in alignment with each. other the rain water can be disposed of without hindrance.
To reduce the heat conductivity of the metallic abutting point of the two armouring strips, the two building slabs of FIG. 5 are provided with a recess 22 which is shown by dotted lines. This causes an excavation at the abutting point, into which a high quality heat insulation strip 21 may be inserted in such a manner that its surface is in alignment with the surfaces 15, 1 6 of the building slabs. At the same time, the lower sides of the slabs may be elevated up to the dotted line 24, which makes it possible to reduce the thickness of the center portion of the building slab without prejudicing its bending resistance.
Apart from the savings in building materials enabled by this construction, the construction according to the invention offers an advantage in that the building slabs may, due to their marginal portions 23, easily be piled up upon one another, as may be seen from FIG. 6. In the pile of slabs, the respective lower flange 17 of a building slab rests on flange 18 of the building slab underneath, whereas the upper and lower sides of the building slabs are spaced from one another and therefore stay in full contact with the surrounding air.
For additional savings of time and labour on the building site, the outside surfaces 15 and 16 may in the process of manufacture of the Slabs be provided with a cement layer offering protection against damage to the slabs by being trodden on, and also ensuring a smooth upper surface, which is of advantage for application of tar paper etc.
The building slabs according to the invention are of such a high degree of bending resistance that they are practically self-supporting over their whole length. They may therefore be laid directly from one roof beam to another without requiring the intermediate supporting construction which has been needed so far. Other advantages of the building slabs are their relatively light weight, their capability of being dried while piled up and the protection against damage offered by the armouring of their edges, which is particularly important on transport.
What I claim is:
1. A building slab of mineralized wood wool having a U-shaped sheet metal strip extending longitudinally along the edges of said slab and forming an armouring edge t-herealong, said U-shaped sheet metal strip having a center portion extending laterally on said edges from one side of said slab to the other side of said slab, a first flange portion joined integrally to said center portion and extending longitudinally along one side of said slab adjacent the edge thereof, said first flange portion having at its end an inwardly bent portion projecting and seated in a groove extending longitudinally along said one side of said slab, a second flange portion joined integrally to said center portion and extending longitudinally along the opposite side of said slab adjacent the edge thereof, said second flange portion having at its end an inwardly bent portion for projecting into and seating in a groove extending longitudinally along said opposite side of said slab, and means on said center portion and at the second flange end of said center portion for bending and fixing said second flange into engagement with said opposite side of said slab and for moving said inwardly bent portion at the end of said second flange into and seating said inwardly bent portion in fixed position in said groove extending longitudinally along said opposite side of said slab.
2. A building slab is recited in claim 1 in which said bending means is an S-shaped portion of said center porton extending longitudinally along said center portion adjacent to said second flange.
3. A building slab as recited in claim 2 in which said opposite side of said slab is covered with a waterproof layer.
4. A building slab as recited in claim 3 in which said waterproof layer is held in engagement on said opposite side by said inwardly bent portion at the end of said second flange.
5. A building slab as recited in claim 4 in which said first and second flange portion are formed by folding said sheet metal over itself at said flanges.
References Cited UNITED STATES PATENTS 6 2,180,317 11/1939 Davis 52588 2,950,786 8/1960 Markle 52588 2,771,165 11/1956 Bell 52627 FOREIGN PATENTS 715,770 1954 Great Britain.
FRANK L. ABBOTT, Primary Examiner.
ROBERT A. STENZEL, SAM D. BURKE, Assistant Examiners.