EP0645508A2 - Scaffold platform made of square lumber - Google Patents

Abstract

In the case of a scaffolding-platform plank (1) made of rectangular lumber with preferably covered ends (3) which are supported on rests of the scaffolding, the invention provides that, essentially over their length between the ends (3) and out of the plane of their flat underside (6), there projects at least one strip or a plurality of strips (4, 5; 14 to 16; 22 to 25), the strips being in parallel arrangement in the latter case, and the strip(s), when the plank ends (3) are supported in the scaffolding, is/are provided as reinforcement against bending when the plants are subjected to loading, and is/are arranged such that it/they serves/serve for support in a stack of a plurality of horizontal planks (1) of the same design located vertically one above the other.

Description

The invention relates to a scaffold plank made of rectangular sawn timber according to the preamble of claim 1.

Scaffolding planks made of rectangularly cut solid wood are popular with users of stand scaffolding, because on the one hand they are relatively cheaper than scaffolding planks made of other materials, e.g. B. are made of steel or aluminum and because on the other hand wood forms a comparatively safe standing and stacking area. Such scaffolding planks span the distances between vertical scaffold ladders or vertical frames of, for example, tubular steel scaffolding. Selected rung or frame trusses serve as supports for the scaffold plank ends. If these ends are steamed up, a positive fit is generally sought in the covering plane, which, for. B. can be ensured by pairs of hooks that overlap the crossbeams, or by pins on the frame crossbeams used as supports, in the latter case holes being provided in the fittings in which the pins engage.

The requirements placed on the safety of such a screed covering have already led to the standardization of the screed dimensions. This is based on load groups, which include different loads depending on the intended use. For this reason, lower loads are provided for the painting craft than for masons. The maximum load depends on the distance between the supports in the scaffolding and on the permissible deflection that occurs when the screed covering is loaded. The deflection must be kept at a relatively low value because larger deflections at the screed ends lead to stumbling edges and the resulting hazards for occupational safety cannot be accepted. In order to keep the permissible deflection within the prescribed limits, the thickness of the screed, ie the distance between the flat surfaces of its top and bottom, is specified in the rectangular screed cross-section. In practice, this leads to considerable cross sections and thus to heavy and correspondingly unwieldy planks if you want to achieve a specific load on the plank surface. This can be of the order of approx. 200 kg / m ² if the span is approx. 3 m.

In contrast, the invention takes a different path, the basic idea of which is given in claim 1. Further features of the invention emerge from the subclaims.

According to the invention, to increase the resilience of the scaffold covering screed, its cross-sectional shape is converted from the rectangular cross-section into a cross-sectional design that takes static requirements into account, which is also possible in sawn timber or in composite planks by arranging or designing the strips, e.g. B. by other material, preferably metal. However, this cross-sectional design of the new scaffold covering screed according to the invention presupposes that the tensile forces occurring on the underside of the screed when the top of the screed is loaded are transmitted to and removed from the strips provided for reinforcement. This can be achieved by fastening the strips made of wood with the fasteners known from woodworking, but can also be made from the timber of the screed. In addition to the improvements in statics, the invention takes into account the practical handling of the scaffold plank on the one hand by leaving the screed ends unchanged, so that the screed according to the invention can be used in place of the known scaffold planks in existing scaffolding and furthermore ensures the stackability of the planks which results on the one hand from the fact that preferably several strips are used and on the other hand these strips and not, as is known, the flat underside of the planks are used for support in the stack.

The invention has the advantage that either the load-bearing capacity of the scaffold decking is substantially maintained while maintaining the usual screed thickness. H. depending on the training, can increase by about 50%, or is able to reduce the screed thickness, until the usual and prescribed load-bearing capacity of the screed is reached.

The invention is preferably realized with the features of claim 2, in particular providing wooden profiled strips. A different, basic embodiment of the invention provides for the strips to be worked out of the sawn timber so that they form a structural unit with the rectangular plank cross section.

While existing wooden strips, provided that they do not form a structural unit with the sawn timber, are advantageously glued to the underside of the planks, in other embodiments of the invention the strips are connected to the plank body. This is done according to the features of claim 4, with screwing or nailing being particularly recommended.

A favorable stackability results if one proceeds according to the features of claim 6. As is known, the central symmetry means that the strip arrangement is mirrored on the longitudinal center plane of the screed, so that the screed halves are the same. Since, in this embodiment, the downward-oriented profile surfaces of the strips are also designed to be flat there is a sufficiently large support area on each profile strip, resulting in safe stacking.

The invention also allows the screed body, i. H. using the rectangular cross-section of the scaffold planking, essentially without considering the strip arrangement described, to further improve the load-bearing capacity. This possibility is offered by claim 7. Since the sawn timber glued together forms the plank body, this can be provided on the underside with the strips according to the basic idea of the invention, the gluing of the sawn timber giving a relatively greater resistance to bending than is the case with one solid body made of uniform wood is the case.

A further improvement in the load-bearing capacity is provided by the features of claim 8. The arrangement of a flexible traction device in addition to the described arrangement of the strips increases the resistance to deflection, so that a further traction reinforcement results from the traction device. According to the features of claim 9, this traction device is expediently attached in the center of the screed in order to ensure the required symmetry when the screed bends. Then the arrangement of the traction means on a bar, as u. a. is reproduced in claim 10. As a result, the distance of the traction means from the neutral fiber of the screed is increased, and the traction means is better utilized. In particular, a band-shaped traction means is suitable for this purpose, which should be arranged according to the features of claim 11 and attached to the screed.

Another embodiment of the invention, which realizes the basic idea given above, but ensures a stable arrangement of the traction means, which is retained even when the screed is heavily loaded is the subject of claim 17. The envelope profile can basically consist of the material wood. However, metallic materials are expedient, for which light metals are also suitable. The envelope profile itself has great bending stiffness and tensile strength due to its high section modulus, which results from the formation of a profile chamber and the material distributed around it. Its more or less complete filling of the profile chamber with the cross-section of the last in connection with the fastening means that connect the envelope profile with the cross-section of the last leads to a stabilization of the overall cross-section and to a composite effect which considerably improves the statics of the scaffold plank. If the envelope profile consists of a material that is harder than the last material, in particular metallic material, the risk of damage when stacking the scaffolding planks is considerably reduced by the contact surface formed by the envelope profile.

This basic embodiment according to claim 17 can be further developed. It has proven to be advantageous to design the envelope profile according to claim 18. In this case, there is a comparatively simple, i.e. H. either commercially available or from a sheet metal cut-out U-profile, which covers the strips on several longitudinal surfaces. It depends on strength considerations whether only one bar of the scaffold plank according to the invention or, in the case of several bars, some or all of the bars are reinforced with such an envelope profile. With the features of claim 19, however, it is advisable to provide the cross sections assigned to the screed center with such envelope profiles, since experience has shown that the main load in the center of the screed can be assumed.

The cross section of the strips can be adapted to the materials used and selected according to the structural requirements. A preferred embodiment describes claim 20, according to which the strip cross-section is square. Such strips can be easily made of wood and metal.

The inventive concept relating to the envelope profile is preferably applied to such strip cross sections according to the features of claim 21. The U-profile described above is suitable for rectangular to square strips.

Depending on the structural requirements, it may be the case that the wrapping of even one bar is too complex. For these cases, the embodiments according to claim 22 are provided. This makes it possible to use envelope profiles with cross-sectional dimensions that are smaller than the strip cross-sections. Then, however, taking into account symmetrical screed loads, the arrangement of such envelope profiles as specified in claim 22 must be made.

If the scaffold plank in the middle of the screed is subjected to the greatest stress, as is usually the case, the screed can tend to deform transversely to its longitudinal extent. This then leads to the fact that strips arranged on the outside dodge and can no longer be fully loaded statically. Such disadvantages are avoided by claim 23, with the features of which the transverse stability of the screed can be increased considerably.

• Fig. 1 bis 4 erfindungsgemäße Gerüstbelagbohlen unterschiedlicher Querschnittsformen,
• Fig. 5 in perspektiver abgebrochener Darstellung ein Bohlenende,
• Fig. 6 in der Fig. 5 entsprechender Darstellung ein beschlagenes Bohlenende,
• Fig. 7 im Querschnitt eine weitere Ausführungsform der Erfindung mit einer zusätzlichen Verstärkung des Leistenquerschnitts einer Leiste,
• Fig. 8 in der Fig. 8 entsprechenden Darstellung eine dem gegenüber abgeänderte Ausführungsform und
• Fig. 9 eine perspektivische Darstellung einer weiteren Ausführungsform, bei der die Unterseite der Gerüstbohle in abgebrochener Darstellung wiedergegeben ist.

The details, further features and other advantages of the invention result from the exemplary embodiments which are shown in the drawing and are explained in more detail below the; show it

• 1 to 4 scaffolding planks according to the invention of different cross-sectional shapes,
• 5 is a perspective broken view of a plank end,
• 6 corresponding representation of a fogged plank end,
• 7 in cross section a further embodiment of the invention with an additional reinforcement of the strip cross section of a strip,
• Fig. 8 in the Fig. 8 corresponding representation of a modified embodiment and
• Fig. 9 is a perspective view of a further embodiment, in which the underside of the scaffold plank is shown in a broken view.

1 to 4, the cross sections can be seen from the perspectively illustrated ends of scaffolding planks 1. According to the illustration in FIG. 1, a plank body 2 with a rectangular cross section 3 made of sawn timber can be distinguished from strips 4 and 5. The different embodiments of the invention essentially differ from one another in the structure of the screed body 2 and / or the arrangement and number of the strips.

These strips run essentially over the length between the plank end faces, which form the ends of the planks and show cross section 3 in the exemplary embodiment in FIG. 1. They protrude from the plane of the flat underside 6 of the screed body 2. When the screed ends are supported on a support (not shown) of the scaffold, they serve as reinforcement against deflection under the screed load, which is applied to the top 7 of the screed by deposited objects or the weight of the person entering the largest screed. The strips are arranged in all cases so that there is a mirror symmetry in the longitudinal direction of the scaffolding planks. In the embodiment of FIG. 1, the strips are located on the longitudinal edges 8 and 9 of the scaffold plank shown.

The strips also serve to support the scaffold plank in a stack of several planks of the same design lying vertically one above the other and horizontally, ie. H. of planks, which are designed according to the embodiments, which are shown for example in the drawing.

In all of the illustrated exemplary embodiments, the profile strips as well as the strips of the exemplary embodiment according to FIG. 1 drawn at 4 and 5 consist of a full profile, which in the case of FIG. 1 is essentially rectangular and arranged such that the strips 4, 5 each have a their longer profile sides 10 and 11 are attached to the underside 6 of the screed body 2. In all cases, the inspection strips of a screed are identical in shape and area. Your profile is generally designated 12.

The plank body 2 consists of sawn timber in all cases. Embodiments of the invention are shown in the exemplary embodiments, in which the strips likewise consist of wood.

In the case of Fig. 2, three strips 14 to 16 are provided, which form a structural unit with the screed body in that they are glued to cut wood strips 17, 18 in such a way that the profile surfaces 19 to 21 of the strips 14 to 16 with the top of the screed 7 are aligned.

Embodiments are not shown, the cross section of which corresponds approximately to the cross section of the exemplary embodiment according to FIG. 1, but the profiled strips 4, 5 are milled out of the underside of a sawn timber which forms the overall cross section of the scaffold covering plank.

In all of the exemplary embodiments shown in the figures, the profiled strips made of wood are glued to the plank body 2 over their entire length. Embodiments are not shown in which the profiled strips are connected to the sawn timber of the plank body 2 at a plurality of points distributed over their length by fastening means. The fastening means used for this purpose can consist of nails, screws or other means known from the building joinery.

The centrally symmetrical arrangement preferably follows with a plurality of strips, as have been explained above using the exemplary embodiments of FIGS. 1 and 2. In the embodiment of FIG. 3, their number is increased again, which results in four profile strips 22 to 25, which are arranged and fastened as shown in FIG. 1. Due to their rectangular to square cross-section, all strips have a flat profile surface 26a which is oriented at the bottom, as illustrated by the example of strip 14 in the exemplary embodiment in FIGS. 2 to 26. These profile surfaces lie in a common plane, are therefore aligned with one another and form the support surface with which the screed 1 is supported in a pile of screeds. This results in a secure support in the pile of screeds, which prevents the screed from tilting in the pile.

4 corresponds to the number and arrangement of the strips 26 to 28 the number and arrangement of the strips 14 to 16 in the embodiment of FIG. 2 with the exception that a plank body 2 made of sawn timber with a rectangular cross section 3 according to the embodiment of FIG. 1 is used. The middle bar 27 is recessed and accommodates a steel strip 29 with a rectangular cross section, which is therefore sunk in the underside 26a of this bar. The length of this steel strip is also connected to the strip 27, for which purpose known fastening means can be used, which are arranged and introduced at a plurality of points distributed over the strip length. When the screed bends, this steel band, like the lasts, acts as reinforcement under the screed load, but does not hinder the pile's stackability.

Instead of a steel band, ropes or rods can also be considered, which can expediently be made from steel, but also from any other materials which are suitable for reducing tensile stresses.

The traction means 29 is arranged in the center of the screed, which results from the symmetry of the screed load. Since only additional tensile reinforcement and experience has shown that the screed load is greatest in the middle, the central arrangement of the tensile reinforcement results from these considerations. In a departure from the exemplary embodiment shown, however, several tensile reinforcements can also be provided or arranged in all or individual strips 26 to 28.

In the embodiment of FIG. 4, the drawstring has a rectangular cross section and is expediently arranged with one of its broad sides 30 so that its plane is parallel to the plane of the screed body 2.

5 and 6, preferred embodiments of the scaffold plank are shown. Here, the ends are provided with fittings 31 to 32, which ensure a positive fit with the supports of the scaffold, not shown. In the embodiment of FIG. 5, which corresponds essentially to the arrangement of the strips of the embodiment according to FIG. 1, the fitting 31 is a hollow body 32 made of sheet metal, which is slipped over the end of the screed and used to produce the positive connection the support 2 has hook elements 33, 34 which are open at the bottom. In the case of the exemplary embodiment in FIG. 6, the U-shaped fitting body 35 is provided with perforations 36, 37 which also penetrate the screed body 2 and receive mandrels which protrude upward from the supports of the scaffold.

5 and 6, the strips 4, 5 end in front of the inner edges of the fittings 32, 33 and are provided with a fillet 38 there to ensure a suitable transition. The chamfer 38 can also be replaced by a simple bevel.

The embodiment according to FIG. 7 essentially corresponds to the embodiment according to FIG. 2, which serves to reproduce a screed reinforced with an envelope profile. Here, the cross-section 39 protruding downward from the screed of the bar 15 lying in the plane of symmetry is reinforced with an envelope profile 40. This envelope profile is a U-profile folded from sheet metal and accordingly has a profile web 41 and two parallel profile flanges 42, 43 in one unit. At certain intervals, screw nails 44, 45 penetrate the profile flanges 42, 43 and are in cross section 39.

The embodiment according to FIG. 8 differs from this embodiment by a likewise U-shaped envelope profile 46, which has a smaller cross section than the envelope profile 40 in the embodiment according to FIG. 7. Its flanges 42, 43 are elongated compared to the flanges in the embodiment according to FIG. 7. The cross-section 39 has one of two parallel grooves 47, 48 for receiving the flanges 42 and 43, into which the flanges 42 and 43 are inserted, as a result of which the envelope profile 46 is sunk under the underside 49 of the strip 15. In contrast to the embodiment according to FIG. 7, the screw nails 50 are driven through the profile flange 41 into the cross section 39. In the embodiment according to FIG. 9, which likewise follows the embodiment according to FIG. 2, the strips 14 to 16 are connected to one another by a plurality of crossbars, one of which is shown at 52 in FIG. 9. These crossbars consist of a band steel section 53 which is nailed to the undersides 57 to 59 of the strips 14 to 16 with the aid of screw nails 54 to 56. Under normal circumstances, the arrangement of the crossbars 52 prevents the screed from bending in the transverse direction. The design in steel strip leads to a flat underside 60 of the cross bar 52, which promotes the stackability of the scaffolding planks.

Claims (23)

1. scaffolding plank (1) made of rectangular sawn timber with preferably fogged ends (3), which are supported on supports of the scaffolding, characterized in that essentially over their length between the ends (3) and from the plane of their flat underside (6) at least one ledge, in the case of several ledges (4, 5; 14 to 16; 22 to 25) the ledges protrude in a parallel arrangement and the ledge (s) when the plank ends are supported (3) provided in the scaffolding as reinforcement against bending under screed loading and is (are) arranged in such a way that it serves (is) used for support in a stack of a plurality of planks (1) which are arranged vertically one above the other and horizontally. 2. scaffolding plank according to claim 1, characterized in that the profile strips (4, 5; 14 to 16; 22 to 25; 26 to 28) consist of a full profile (12). 3. scaffolding plank according to one of claims 1 or 2, characterized in that the strips (4, 5; 14 to 16; 22 to 25; 26 to 28) consist of the sawn timber and form a structural unit (14 to 18) with this. 4. scaffold planking according to one of claims 1 or 2, characterized in that the strips (4, 5; 14 to 16; 22 to 25; 26 to 28) are profile sections which at a plurality of points distributed over their length by fastening means the lumber (2) are connected. 5. scaffolding plank according to one of claims 1 to 4, characterized in that the strips (4, 5; 14 to 16; 22 to 25; 26 to 28) are glued to the sawn timber (2). 6. scaffolding plank according to claims 1 to 5, characterized in that the strips (4, 5; 14 to 16; 22 to 25; 26 to 28) are arranged centrally symmetrically to the center of the screed and with one of their flat profile surfaces (26 a) oriented downwards which are aligned with each other and serve as support surfaces in the stack. 7. scaffolding plank according to one of claims 1 to 6, characterized in that a plurality of glued sawn timber (14 to 18) form the plank body (2) which is provided on its underside with the strips (14 to 16). 8. scaffolding plank according to one of claims 1 to 7, characterized in that a further tensile reinforcement is provided and realized with at least one flexible traction means (29) which is attached to the screed (1). 9. scaffold decking according to claim 7, characterized in that the traction means (29) is attached in the center of the screed. 10. scaffolding plank according to one of claims 8 or 9, characterized in that the traction means (29) in a central bar (27) under the outside (26 a) is sunk. 11. Scaffolding plank according to one of claims 7 to 10, characterized in that the traction means consists of a metal strip (29) which is fastened to the screed with one of its broad sides (30). 12. Scaffolding plank according to one of claims 1 to 11, characterized in that the profiled strips are attached to the longitudinal edges (8, 9) of the screed body (2). 13. scaffolding plank according to one of claims 1 to 12, characterized by three strips (14 to 16) arranged distributed over the width of the plank. 14. scaffolding plank according to one of claims 1 to 12, characterized in that four profile strips (22 to 25) are attached distributed over the width of the planks. 15. scaffolding plank according to one of claims 1 to 14, characterized in that the profiled strips (4, 5) on the inner edge of the screed fittings (31, 32) end. 16. scaffolding plank according to claim 15, characterized in that the ends of the strips (4, 5) on the fittings (31, 32) have a throat (38). 17. Scaffold plank according to one or more of claims 1 to 16, characterized in that at least one of the strips (15) is connected to an envelope profile (40). 18. Scaffolding board according to claim 17, characterized in that the envelope profile (50) is designed as a U-profile (41 - 43). 19. Scaffold plank according to one of claims 17 or 18, characterized in that in the case of a symmetrical arrangement of the strips (14-16), the strip (s) (15) arranged in the plane of symmetry or directly next to this plane is provided with the envelope profile (40) (are). 20. Scaffold plank according to one or more of claims 1 to 19, characterized in that the projecting cross-section (39) of the bar (s) (14 - 16) is square. 21. scaffolding plank according to one or more of claims 1 to 20, characterized in that the envelope profile (40) covers the square cross-section on three adjacent sides. 22. Scaffolding plank according to one or more of claims 1 to 21, characterized in that the envelope profile (40) includes a partial cross section (39) of the bar (s) (15) which is arranged in the middle of the bar. 23. Scaffold plank according to one or more of claims 1 to 22, characterized in that the strips (14-16) are connected to one another by one or more cross bars (53) which are spaced apart from one another.

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