Wooden flanged beam

The invention relates to a wooden belt carrier in which an upper belt is connected to a lower belt by a lattice or solid wall web, the belt ends are protected by a cap and edges on the end face of the belts are beveled to form inclined surfaces.

In a wooden belt carrier of this type made known by the utility model DE 72 40 306 U, a cap is attached to the face of a belt, which is fastened in grooves milled in the face of the belt and is pushed transversely to the longitudinal direction of the belt onto the belt end and into these recesses, which are partially undercut in order to hold the glued-in cap permanently in place. The cap has an end face and bevels on the edges of the belt surface facing away from the web and the surface facing the web. The recesses in which the cap is held, however, weaken the belt wood and, moreover, promote tearing of the belt wood due to the weather.

DE 17 84 779 A relates to the attachment of the strut serving as a connection between the upper chord and the lower chord of a girder. The strap ends of this known carrier are not protected and do not have a cap for the strap end.

DE 29 00 065 A also shows only a fastening of the struts of a lattice girder in the upper chord or lower chord of the girder. Protection for the belt ends is not disclosed in this publication. The connecting struts between the upper and lower chords of a girder are exposed to completely different loads than the ends of the chord. When fastening these struts in the upper and lower chords, standards must be observed that are not applicable to the ends of the chords. An average person skilled in the art, who is supposed to protect the belt ends from splitting the wood, does not receive any suggestions from these two publications as to how the belt ends can be protected.

The invention is based on the object of improving the protection of the belt ends in the case of the wearers of the aforementioned type.

This object is achieved according to the invention in that the cap has cap legs which cover the inclined surfaces and then at least a portion of the side surfaces of the end of the belt and that the cap legs are connected to one another in this section by a fastening extending transversely through the belt wood.

An advantage of the invention is that the legs of the cap cover the side surfaces of the straps beyond their inclined surfaces. The inclined surfaces reduce the stress on the end of the belt in the event of an impact or when the carrier is pulled on a surface. In addition, this slope is protected by the cap, which can be made of metal or a suitable plastic. Only at a relatively large distance from the face of the belt is the transverse fastening engaged in the belt wood, i.e. at a place where such an engagement no longer promotes the tendency of the belt wood to tear open to the face of the belt when subjected to a corresponding load. The legs of the cap extending up to the fastening cover a relatively large portion of the side surfaces of the belt which, in most applications of such belt carriers, are exposed and exposed to the weather.

It is known with belt carriers to bevel the face opposite the side faces of the belt over a relatively large area and also to provide the edge between the face of the belt and the surface of the belt facing away from the web with a relatively small bevel. A transverse bolt is used to reinforce these belt ends and penetrates the belt wood at a distance from the belt end. However, these belt carriers do not have a cap. Rather, there was the prejudice among the experts that the known caps insufficiently protect the end of the belt because they do not take part in the swelling and shrinking of the wood and therefore largely lose their protective function. In contrast, the fastening according to the invention acts on the limbs of the protective cap, so that a pretensioning exerted on this fastening can be absorbed by the cap limbs and transferred to a relatively large area of ​​the belt wood and thus, apart from the protective function of the cap limb, the end of the belt can be torn open and mechanically Damage to the belt wood is permanently prevented. Such a pretension cannot be given directly to the fastening elements acting on the wooden surface, the head of the fastening elements would dig into the wood surface at least after some time, and the pretension would be reduced.

AT 409 01 3 Β

In one embodiment of the invention, the edges between the end face and the belt surface facing away from the web are also beveled. These inclined surfaces and the adjacent belt surfaces are exposed, so that if there should ever be a gap between the cap, its legs and the belt wood due to the shrinkage of the wood, it will be ventilated.

The fastening running transversely through the belt wood can be done in various ways, for example by means of bolts formed from a screw sleeve and screw shaft and inserted into a bore. In one embodiment of the invention, however, this fastening consists of a rivet which engages over the cap part at its ends and presses against the wood of the belt. In one embodiment of the invention, the cap legs extend a little way beyond the attachment away from the end of the carrier.

The invention can be implemented with all wooden belt girders, for example also with wooden belt girders, in which the web consists of a solid wall panel and extends to the end of the belts, the end face of the solid wall web therefore runs in a plane with the end face of the belts. In this embodiment of the invention, the material thickness of the cap extends beyond the end face. The cap can be made of plastic, but also of preferably hot-dip galvanized sheet steel, the material thickness being 0.5 to 1 mm. The end face of the belt therefore does not need to be ground in embodiments of the invention, only in the following embodiment slots are milled into the end face of the belt and the cap is pushed on and fastened by the aforementioned bolt or rivet.

In one embodiment of the invention, portions of the cap surface covering the end face of the belt are bent approximately at right angles about an axis running parallel to the longitudinal axis of the fastening. These engage in grooves cut out at right angles to the end face. As a result, the end cap is held in place in addition to the aforementioned fastening so that it remains immovable on the end of the belt even when the belt wood shrinks.

In embodiments of the invention, the height of the end cap surface plus the height of the sections bent at right angles corresponds to the width of the legs which cover the side surfaces of the belt end. This has the advantage that the cap can be produced in the simplest possible way from a sheet metal strip which is as wide as the height of the straps and as long as the legs plus the cap surface covering the end face. A recess in each of the two legs for attachment and a small corner in the area of ​​the end cap surface need only be punched out of this material strip and the legs and sections then bent around the respective axes, which can be done in a single operation on modern machines.

Further features of the invention emerge from the following description of an embodiment of the invention in conjunction with the claims and the drawing. The individual features can be implemented individually or in groups in embodiments of the invention.

In the drawing, an embodiment of the invention is shown.

Fig. 1 shows a side view of the belt end, partially in section along the line II of Fig. 2;

FIG. 2 shows a plan view of the belt end, partly in section along the line II-II in FIG. 1.

Fig. 3 shows a plan view of an embodiment of the cap on a smaller scale;

Fig. 4 shows a plan view of a strip of material for producing the cap.

In the embodiment of the invention shown in the drawing, a full-wall web 2 is glued into a belt 1 on its underside. The belt 1 is provided at its end with an inclined surface 3 which leads from an end face 4 of the belt 1 to the upper surface 5 of the belt 1 facing away from the web 2. On the lower side of the belt 1, a surface section 6 running in the plane of the end face 4 connects the end face 4 with the surface 7 of the belt 1 facing the web 2. Further inclined surfaces 8 connect the end surface 4 of the belt 1 with its side surfaces 9 on both of its sides.

The end of the belt is protected by a cap made of plastic or metal, e.g. sheet steel, which has a flat cap surface 10 that covers the end face 4 and is followed by two legs 11, which initially form an inclined surface 12 corresponding to the inclined surface 8 of the belt 1

AT 409 01 3 B which cover the inclined surface 8. The legs 11 then run along the surface 12 on the side surfaces 9 of the end of the belt 1. This is somewhat offset on its side surfaces with respect to the belt section 13, which extends essentially over its entire length; the shoulder between the belt section 13 and the belt end 1 has an inclined surface 14. The legs 11 extend over the entire height of the side surface of the end of the belt 1, the leg ends 15 engage in grooves 16 of the belt section 13, which are recessed as an extension of the side surfaces 9 of the end of the belt 1.

Short cap sections 17, which are bent at right angles and which engage in grooves 18 recessed in the end face 4, adjoin the cap surface 10 of the cap on two opposite sides.

At a distance from the end face 4 of the belt 1, a hollow rivet 19 penetrates the legs 11 and the belt 1 of the leg end. The hollow rivet 19 creates a prestress on the legs 11 and the underlying wood of the belt 1, which mostly corresponds to quality class 1 and heartwood or is cut from the trunk adjacent to the core.

In the embodiment of the invention shown, the belt cross-section in the region of the belt section 13 is approximately 80 to 40 mm, the legs 11 on the side surfaces of the end of the belt 1 are approximately 72 mm long up to the cap surface 10, and the distance between the tubular rivet 19 and the end face 4 of the end of the belt 1 is about 55 mm. The fact that the leg ends 15 engage in a groove 16 of the belt portion 13, these are protected against unintentional bending zt.

In the embodiment shown, the web 2 extends to the front end of the belts 1, so that the front end face 4 of the web 2 runs in a plane with the end face 4 of the belt 1. The cap surface 10 projects over this end face 4 of the carrier approximately by its material thickness.

3 and 4 show the manufacture of the cap. Fig. 4 shows the strip of material from which the cap shown in Fig. 3 is bent. Only the corners 20 and the holes 21 for the groove 19 have to be punched out in this material strip. The sections 17 are then bent at right angles around an axis 22 and the material section is bent around the axes 23 and around the axes 24 by an angle corresponding to the inclined surfaces 8 at the end of the belt 1, for example about the axes 23 at an angle of 60 °. The cap can then be placed on one end of the belt 1 from the front in the form shown in FIG. 3, the sections 17, which can be 7 mm long, engaging in the groove 18. The cap is then fastened with the aid of the hollow rivet 19.

In embodiments of the invention, instead of inclined surfaces 8, roundings can also be provided.

In the embodiment shown, the solid wall web 2 extends to the front end of the straps 1. In other embodiments of the invention, the web 2 ends at a certain distance from the front end of the straps 1, especially if the web 2 is not made of a solid wall panel , but consists of bars. The web 2 can then end, for example, in the area of ​​the bending axes 24.