EP0051270B1 - Connection of wooden girders in end to end relationship - Google Patents

Abstract

A supporting beam includes a first and second parallel spaced apart flange. A lattice web holds the two flanges apart. At one end of the flanges, there is a solid web of wood. The butt end of the solid web has a recess which is profiled for receiving an adapter section. The recess may be triangular or semi-circular or flat walled. The adapter section is symmetric with one half in and the other half projecting out of a recess. When two butt ends of two solid webs are overlain, the respective recesses overlie and an adapter section is disposed in the overlaying recesses. The adapter section and the recesses both extend transversely of the direction between the flanges and fully across the solid web. The abutting solid webs of two beams define a single beam assembly. Respective brackets behind each of the solid webs are clamped together for pushing the solid webs together. In an array of a plurality of the beam assemblies, the brackets may extend across the parallel solid webs of a number of the beam assemblies. Various other clamping arrangements for clamping together the solid webs of two beams of a beam assembly are disclosed, including a screw connection arrangement.

Description

The invention relates to a connection of wooden beams in a raised form on the end face.

Such wooden girders are used in particular in the form of lattice girders, to a large extent as formwork girders and here again in particular in connection with formwork elements which consist of large-area formwork panels which are supported on the back by several parallel steel belts on which a plurality of wooden lattice girders parallel to one another is anchored, which give the formwork panel the required rigidity. These large-area formwork elements are very popular due to their light weight, nailability and the possibility of easy cleaning. Problems arise because of the need to have panels of different sizes available. This requirement also applies in particular to wall formwork, since the modern design often provides for different storey heights, which necessitates a change in the height of the formwork elements. In order to meet this requirement for formwork elements of different heights, the wooden lattice girders that can be used for such formwork elements are supplied in various lengths, for example from 2.50 m to 6 m in ten different lengths. This means that a large assortment of carriers must be kept ready in order to have the required lengths available.

In order to reduce the number of different beam lengths, it is also known to design formwork beams that are adjustable in length. An example of this is shown in DE-PS 1 147 018. In the length-adjustable formwork girder described here, two wooden lattice girders are slidably guided against each other by bandages which can be braced against the girders by means of wedges. These have proven to be excellent, but have the disadvantage of the protrusion of the bandaged formwork beams at the overlap point by their own beam width of approx. 10 cm and an unevenness on the formwork covering surface due to the width of the bandage sheets.

It is also known to extend beams of different lengths with one another and in particular to excessively long beams from 10 m to 15 m by finger jointing. These extra-long beams should be separated by the customer later at the joint if shorter beam lengths were required. In practice, however, this separation did not take place and they mostly remained in their full length on the storage bin, thus increasing the problem of storage.

In a beam connection according to the type specified in the preamble of claim 1, as described in DE-A-2 556 301, Fig. 9, the tendons are designed as double wedges which can be driven into dovetail grooves in the end plates of the beams. These wedges have the disadvantage that they loosen and fall out as a result of vibrations or vibrations. Such stresses can occur during the shaking movements carried out after the concrete is filled in, or also during the transport of the carriers. Furthermore, the wedge engagement surfaces are very small and due to the formation of the double wedges there is a risk that the inclined surfaces forming the abutments will be pressed apart due to the wedge effect, which leads to a loosening of the end connection. Furthermore, inevitable wear results in inaccuracies in fit, which lead to tolerances and preclude a secure connection.

The invention is therefore based on the object of providing a carrier connection which enables any increase and is insensitive to vibrations and vibrations and can transmit large forces without the risk of buckling.

The problem is solved by the features specified in the characterizing part of claim 1.

The invention makes it possible to produce spiked girders of different lengths, the flexural strength of which at the abutment points is large enough to be able to place and pick up formwork panels carried by them with the crane without fear of breakage or deformation. The final reinforcement, which is formed by the solid wall web, results in a high strength in the support area, and it also enables secure anchoring of the tie rods offset to the fitting recesses, which prevents buckling with high lateral force transmission with certainty.

Further refinements of the invention result from the subclaims. Thereafter, the profile adapters can each be guided over a beam width in such a way that slight lateral displacements of the beams, which can occur during formwork operation, can be accommodated.

It is also possible to design the adapters as continuous rods or tubes if the joints of the beams run at the same height. The tendons can engage on cross members that are supported on the back of the full-strength webs. Instead, the tendons can also be anchored in recesses in the full-wall webs using suitable abutments.

The wooden girder is designed in particular as a lattice girder, the belt struts in pairs resulting in a knot division and the half knot division corresponding to a grid which forms a unit length from which girders with lengths can be produced have integer multiples of these field lengths.

In order to be able to compensate for small changes in length, according to the invention, extension elements are further provided which can be placed and braced on a carrier end instead of extension carriers, the length of such an extension element corresponding in height to a carrier being equal to a field length.

• Fig. 1, 3 und 5 Seitenansichten des Endabschnitts von Holzgitterträgern mit unterschiedlich ausgebildeten Endverstärkungen,
• Fig. 2, 4 und 6 Stirnansichten der Träger gemäß Fig. 1, 3 bzw. 5,
• Fig. 7 eine Seitenansicht von vertikal übereinandergestellten miteinander verspannten Gitterträgern,
• Fig. 8 eine gegenüber der Fig. 7 um 90° um die Vertikalachse gedrehte Ansicht,
• Fig. 9 eine perspektivische Darstellung mehrerer nebeneinander angeordneter, stirnseitig aufgestockter Holzgitterträger mit ihren Spanngliedem,
• Fig. 10 eine perspektivische Ansicht eines zur Querkraftübertragung zwischen zwei Endverstärkungen einsetzbaren Profilpaßstückes,
• Fig. 11 eine abgewandelte Ausführungsform eines Profilpaßstückes,
• Fig. 12 eine der Fig. 7 entsprechende Ansicht zweier stirnseitig gegeneinander verspannter Träger mit plattenartigem Profilpaßstück zur Querkraftübertragung,
• Fig. 13 eine um 90" um die Vertikalachse gedrehte Ansicht der Trägerverbindung nach Fig. 12,
• Fig. 14 eine Ansicht eines Gitterträgerendes mit Aufstockelement,
• Fig. 15 eine Ansicht eines Trägerendes mit einer in eine Ausnehmung der Endverstärkung eingesetzten Druckschale, die als Widerlager für den Zugstab dient,
• Fig. 16 eine perspektivische Darstellung der Druckschale als Einzelteil,
• Fig. 17 eine Seitenansicht zweier Träger mit einem zwischen Obergurt, Untergurt und Endsteg eingefügten Profilpaßstück,
• Fig. 18 eine um 90° um die Längsachse gedrehte Ansicht des Trägers gemäß Fig. 17,
• Fig. 19 eine perspektivische Ansicht des bei dem Ausführungsbeispiel nach Fig. 17 und 18 benutzten Profilpaßstückes.

Exemplary embodiments of the invention are described below with reference to the drawing. Show in the drawing

• 1, 3 and 5 side views of the end portion of wooden lattice girders with differently shaped end reinforcements,
• 2, 4 and 6 end views of the carrier according to FIGS. 1, 3 and 5,
• 7 is a side view of vertically stacked lattice girders,
• 8 is a view rotated by 90 ° about the vertical axis compared to FIG. 7,
• 9 is a perspective view of a plurality of wooden lattice girders arranged next to one another and raised on the end face with their tensioning members,
• 10 is a perspective view of a profile fitting which can be used for the transmission of transverse force between two end reinforcements,
• 11 shows a modified embodiment of a profile fitting,
• FIG. 12 is a view corresponding to FIG. 7 of two beams braced against one another at the end face with a plate-like profile fitting piece for the transfer of transverse force, FIG.
• 13 is a view rotated 90 "about the vertical axis of the carrier connection according to FIG. 12,
• 14 is a view of a lattice girder end with extension element,
• 15 is a view of a beam end with a pressure shell inserted into a recess of the end reinforcement, which serves as an abutment for the tension rod,
• 16 is a perspective view of the pressure shell as a single part,
• 17 is a side view of two beams with a profile fitting inserted between the upper chord, lower chord and end web,
• 18 shows a view of the carrier according to FIG. 17 rotated through 90 ° about the longitudinal axis,
• Fig. 19 is a perspective view of the profile fitting used in the embodiment of Figs. 17 and 18.

In the drawing, the wooden girder is designed as a lattice girder with an upper chord 10, lower chord 12 and struts 14 which are glued into grooves in the upper and lower chord. Instead, solid wall supports could also be used, which are provided with corresponding recesses for the abutments of the tension rods. The lattice girder is designed as a grid girder, i. H. the fields formed by the inclined webs (14) have a length in the longitudinal direction of the carrier of 32 cm with a carrier height of 36 cm and a belt width of approximately 10 cm. The last field at the two ends of the girder has, as end reinforcement, a solid wall web 16 which, as can be seen in FIGS. 2, 4 and 6, has almost the same width as the upper flange 10 and lower flange 12. This solid wall flange 16 is also finger-jointed Upper and lower belt connected, it can also have the same width as the belts. It can consist of two or more pieces of solid wood or be glued to boards. According to the exemplary embodiment according to FIG. 5, an intermediate space can be left between two web sections if, for example, solid wood pieces with standard sizes with a cross section of 7. 14 cm are used (this center distance then results from the selected grid division).

A fitting recess 18 is provided on the end face in the full wall web 16, which is triangular in the embodiment according to FIG. 1, semicircular in the embodiment according to FIG. 2 and in the embodiment according to FIG. 5 by a recess of the entire full wall web. Profile fitting pieces 20 are inserted into the fitting recesses of two wooden supports which are added on the end face and which serve to transmit the transverse force. The preferred embodiment of the profile fitting 20 can be seen in FIG. 10. This training is used for carriers according to FIGS. 1 to 2, 7 to 8, 9 and 14.

This profile fitting 20 consists of a tube 22 with a square cross section, at the ends of which tabs 24 are welded, with which the fitting pieces, as can be seen in FIG. 9, can be fastened by means of nails to the full-wall web 16 of one of the supports stacked on the end face. The profile adapter 20a (FIG. 11) consists of a tubular section 26 of circular cross section, which fits into semicircular profile recesses 18 according to FIG. 3. The profile adapter 20b, which can be used in the carrier formation according to FIG. 5, can be seen from FIGS. 12, 13 and 15. Here, the profile adapter is designed as a multi-layer adapter plate, the height of which corresponds to the web height and the width of which is somewhat larger than the width of the belts (FIG. 13), so that the transfer of lateral force is reliably ensured even with slightly laterally offset beams. Instead of this profile fitting 20b, the solid wall web 16 of the final reinforcement, as indicated by dashed lines in FIG. 5, can protrude on one side of the carrier by the amount of the fitting recess at the other end of the carrier, but this has the disadvantage that the carriers can only be increased in a certain orientation.

Tensioning rods are provided for stocking up the beams, which brace the stocked beams against one another at the end. For this purpose, U-shaped bars 28 are supported as abutments on the rear side of the solid wall web 16 forming the final reinforcement. This profile is adjacent to the longitudinal axis of the beam through holes Iron 28 guided a tension rod in the form of a spindle 30, which by means of spindle nuts 32 causes a bracing of two U-profile irons 28, which are normally supported on the solid wall webs of two adjacent wooden lattice girders, the spindle 30 being located in the middle between these carriers. By means of these crossbeams 28, more than two adjacent supports can also be bridged and it is then expedient to arrange a spindle 30 with spindle nuts 32 between each of the supports. In special cases in which only a single wooden lattice girder is to be added, two spindles, one on each side of the girder, must be provided in order to ensure a central clamping of the added girders. By means of this spindle bracing, the supports are pressed against each other at the end faces and automatic centering and absorption of transverse forces takes place via the profile fittings, so that the placement of formwork panels or the like, which are supported by the lattice girders arranged parallel to one another, is possible without the panels themselves to collapse.

The profile fittings which absorb the transverse force are made from metallic pipe pieces in accordance with the exemplary embodiment according to FIGS. 10 and 11. Instead, appropriately machined wooden profile fittings could be used.

14 shows an embodiment in which an extension element 34 is clamped onto the end of a wooden lattice girder in the manner shown in FIGS. 7 to 9. Such an extension element 34, which has the length of a grid (for example 32 cm), is used when the height by which the support is to be added does not justify the use of a second lattice support. With appropriate proportioning of the individual lattice girders according to the grid dimension, any desired heights can be detected with the aid of these girders and corresponding extension elements, which serve as compensating pieces, which is particularly useful when formwork is used for buildings that have very different storey heights. The extension elements 34 are designed as solid wall girders with the corresponding length, the width of these elements corresponding to the belt width.

In the embodiment shown in FIGS. 15 and 16, the cross members 28 are not required. Here, the full-wall web 16 forming the end reinforcement has a central circular recess 36 and into this a bore 38 leads in the longitudinal axis of the beam, which passes through the full-wall web 16 in the middle and continues in the profile fitting 20b. Through this bore 38 and the bore 40 in the profile fitting a tension rod 42 is guided, on which a pressure shell 44 designed as a cast part is placed within the recess 36, which can be seen in FIG. 16 in detail and which with its cylindrical wall on the wall of the Central extension 36 fits snugly. At the back of the pressure shell, a wedge supports 46 from which is wrapped in a slot of the pull rod 42, _J m to ensure a tension. Instead of the wedge clamping, a wing nut could also be screwed onto the threaded pull rod 42.

As can be seen from FIG. 14, the extension element 34 is provided at the rear end with a recess 35 into which the cross-beam 28, which is designed here as a double-U profile, protrudes so that this cross-beam does not protrude beyond the end face of the formwork beam or the formwork element.

In the exemplary embodiment according to FIGS. 17 and 18, lattice girders are used, in which double webs 16a set back towards the ends are arranged, between which a gap 48 remains. The fitting 20c shown in FIG. 19 consists of a T-shaped metal plate 50 which carries fitting shells 54 welded onto the ends 52 of its transverse leg, which fit the upper or lower flange 10 or 12 and the end face of the double webs 16a and thus the Ensure shear force transmission. The vertical leg 56 of the T-plate 50, which converges towards the lower end, carries reinforcing plates 58 and thus fits into the gap 48 between the double struts 16a. After the bracing via spindle 30, spindle nuts 32 and crossbeams 28, which are supported on the rear side of the double struts 16a, there is a rigid, raised support with transverse force transmission at the connection point.

Claims (10)

1. The combination of a plurality of wooden girders in the form of frame girders or full wall girders stacked end to end, with the end faces of the girders being provided with registration recesses (18) into which sectional registration elements (20) which transmit transverse forces can be fitted, and wherein clamping members (30; 42), which act in the longitudinal direction of the girders on the web via abutments (28; 44), c)amp two stacked beams together end to end, characterised in that the clamping members are constructed as tie bars (30; 42) which act with their abutment (28; 44) on a respective support surface of the web which is formed by the edge of a recess which is adjacent to the end face of the girder and which is set back in the longitudinal direction of the girder relative to the registration recess.

2. A combination in accordance with claim 1, characterised in that securing means (24) for fixing to the web (16) are provided on the sectional registration elements (20) which are constructed as tube sections.

3. A combination in accordance with the claims 1 and 2, characterised in that the sectional registration elements (20) project so far in the transverse direction that the transmission of transverse forces is ensured even when the girders are stacked up in a displaced manner.

4. A combination in accordance with claim 1, characterised in that the abutments are formed by cross-beams (28) in the form of iron sections which are braced against the reverse side of full wall webs (16) which form the web end reinforcement; and in that the tie rods (30) extend parallel to and alongside the girders.

5. A combination in accordance with claim 4, characterised in that, with a plurality of wooden girders arranged parallel to one another, for example in a shuttering panel, the cross-beams (28) are braced on the full wall webs (16) which form the end reinforcement of a plurality of frame girders and the tie bars (30) act in the middle between two girders.

6. A combination in accordance with one of the claims 1 to 5, characterised in that a stacking element (34) is provided which is matched in depth and cross-section to the end cross-section of the girder and has a registration recess (18); and in that the length of the stacking element corresponds to one half the strut node pitch of a frame girder.

7. A combination in accordance with claim 6, characterised in that the stacking element (34) is provided at the rear end with a recess (35) for the cross-beam (28).

8. A combination in accordance with claim 1, characterised in that each tie bar (42) extends through a bore (38) which passes in the longitudinal direction of the girder through a full wall web (16) forming the web end reinforcement; and in that the end reinforcement-forming full wall web (16) has a central recess (36) into which is inserted the abutment which is constructed as a pressure shell (44) in the form of a section of a right cylinder against which the tie rod (38) can be clamped via a wedge (46).

9. A combination in accordance with claim 1, characterised in that the registration recess is formed by the top and bottom flanges (10, 12) and also by the end face of a set back wall web (16a); and in that the sectional registration element (20c) has a web plate (50) which carries at its ends (52) fitting shells (54) which contact the flanges and the wall web (16a) (Figures 17 to 19).

10. A combination in accordance with claim 9, characterised in that the wall web is constructed as a double wall web (16a); in that the sectional element has at least one lug (56, 58) which fits into the gap (48) in the double wall web; and in that the lug is formed by a limb (56) of the T-shaped web plate (50).

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