The invention relates to a method as stated in the introductory part of claim 1, for joining a wall frame system for buildings, as well as an arrangement at such a wall frame system according to the introductory part of claim 2. Background

Steel stanchions have long been used for building inner and outer walls, floor structures and ceilings. Various profiles have been used, such as U- and Z-profiles, with different edges and profiles. For outer walls, greater thickness and strength has been needed. This makes the fastening of the screws joining the stanchions more demanding. Different methods of joining have been tested, but have not been suitable for on the site building, where the fastening is done with hand held and mobile tools.

This will have multiple reasons. In addition to the thickness of the material for the stanchions for outer walls, the strength of material and the need to penetrate two layers of steel sheeting will also have an impact. Object

Thus it is the main object of the invention to provide a method and an arrangement for joining the stanchions of outer walls, which will provide satisfactory results, i.e. firm fastening, in a less demanding manner than prior art building systems. The arrangement should be mounted with mobile, handheld screw drivers.

Further it is desirable that the arrangement is provided for simplified arrangement of the stanchions, to have correct position and correct direction.

Still further, it is an object to provide a stanchion increasing the attachment of the screws, i.e. to increase the screw hold, when mounting wall sheeting and similar material.

It is also an object to maintain the advantages of increased strength and reduced sound transfer achieved at known steel stanchions with longitudinal corrugations. Alternatively, it is an object to maintain the total strength with a thinner material.

The Invention

The invention is stated in claim 1 and 2.

The invention comprises a method for joining a wall framework system with stanchions for buildings, particularly for outer walls, with vertical stanchions arranged with at least the lower end in a U-rail at the lower end of the wall, screws being inserted from the side to lock the stanchions and the rails. The novelty of this method is that a self drilling screw is inserted through a slot in the side flange of the U-rails, and letting the tip of the screw be self drilling at the inserting in the adjacent stanchion.

This method will allow an easy inserting of the screw tip into the slot of the rail and into the stanchion, giving substantially the same hold, as when letting the screw drilling and making threads in both the rail and the stanchion. The screw is drilling only one layer of steel. This simplifies the mounting.

The invention allows mounting, i.e. inserting of screws for attaching of stanchions to the U- or bottom rail without overloading the tool or the operator. This may be achieved with material thicknesses which are sufficient for the purpose.

Further a screw connection superior to prior art joining can be achieved. Alternatively, one may achieve sufficient strength with thinner materials than at prior art systems.

The invention also comprises an arrangement for building system for a wall framework system for buildings, with vertical stanchions with at least two sides making a right angle, one of which at the mounting is bearing against the inner face of a U-rail arranged on a supporting structure, for inserting a mounting screw through the side flange. The main novelty is that the U-rail in one of its side flanges has a slot allowing the adjustment of the position of the screw, that the screw is self is self drilling with a diameter (d _b ), that the width (b) of the slot is less than the diameter (d _s ) of the core. The width of the slot is preferably equal to the diameter of the screw tip. The stanchion may have at least one groove provided to guide the inserting of the screw tip in the stanchion material at mounting.

The stanchion preferably has generally U-profile with two opposite side flanges, of which at least one has longitudinal corrugations with adjacent ridges and grooves. At least the bottom rail preferably has a series of mounting slots in at least one side flange. The mounting slots are facing the corrugations of the stanchion.

The series of slots are preferably arranged in a staggered chevron design, the slots preferably having an angle of 45° to the longitudinal axis. The slots are preferably arranged in the upper half of the side flange or side flanges. Further details of the invention will appear from the claims 3 - 9. More details of the invention will appear from the embodiments shown in the drawing. Example

The invention is described with reference to the drawing, wherein

Figure 1 is showing a stanchion for a building system according to the invention, Figure 2 is showing a U-rail provided for a stanchion of Figure 1, Figures 3A and 3B are showing two examples of a joint of the stanchion and the bottom rail of Figures 1 and 2 according to the invention,

Figure 4 is showing alternative main designs of the stanchions, while

Figure 5 is showing a side view of a self drilling screw for use at the invention.

Figure 1 is showing a stanchion 11 with C-profile, more specifically with right angles between the bottom part 12 and the sides 13, 14 and with an inward flange 15, 16 at the edge of each side.

Each of the sides 13, 14 has corrugations 17 over the complete width. The corrugations 17 of the example is approximating a sinusoidal design. At an alternative, not shown embodiment, the waves of the corrugations are generally trapezoidal with rounded crests. In both cases a screw entering the top of wave will have its tip guided along a side face for entering a groove, increasing the holding strength of the screw entered.

The corrugations may have a wave height (outer thickness of the corrugation) which is from 1 to 10 times the sheet thickness. Further, the waves may have a distance (pitch) from 5 to 14 times the sheet thickness. The sheet thickness may be in the range 0,7 to 3 millimeter, depending on the other measures and the field of use. A proposed measure of the corrugations for inner walls (partition walls) stanchions with 1 millimeter sheet material is a wave height of 3 - 4 millimeter and a wave distance 6 - 8 millimeter. At outer walls, the sheet thickness may be 0,7 to 3 millimeter.

In the bottom of the stanchions 11 a double rib 18, 19 is arranged adjacent each fold 20, 21, with an intermediate bottom 22.

In Figure 2, a U-rail 23 is shown, which is provided for making a bottom or top rail when mounting the stanchions 11 (Figure 1). The U-rail of this embodiment has a bottom 24 with two leveled side flanges 25, 26. The distance between the side flanges 25, 26 is accommodating the width of the stanchion 11 flush.

In one of the flanges, alternatively both flanges 25, a series of slots 27 in staggered chevron pattern, with an angle of 45° to the longitudinal, is arranged. Thus there will be an opening for inserting screws practically continuously along the U-rail. The width of the slots 27 is less than the diameter of the mounting screws 28. The inserted screws thus will engage into the bottom rail and reinforce the connection.

The slots 27 may have a length of 4 to 7 times the width.

In Figure 3A a junction of a stanchion 11 as in Figure 1, and a U-rail 23 as in Figure 2 is shown. In this case three screws 28 are mounted through three neighboring slots 27, into corresponding corrugations 17 in the adjacent flange 14. Figure 3B is showing an alternative embodiment to Figure 3A, in which the stanchion 11 has even side flanges.

Figure 4 is showing examples of stanchion profiles with U-, C-, Omega-, Z-, and Z-profile.

Figure 5 is showing a screw 28 with a core 29 and a self drilling tip 30 for mounting the elements of Figure 3. The self drilling tip 30 has a diameter d _b substantially equaling the width b of the slots 27. The core 29 has a diameter exceeding the width b of the slot with about twice the thickness of the material. With this screw-slot-geometry a particular rigid joining of the stanchions and the U-rail even with plain stanchions. Using stanchions 11 with longitudinal ribs or corrugations 17 as shown in Figure 1 increases the strength of the joint. Self drilling screws 28 with a straight or conical junction between the core 29 and the head may be used, screws with a conical junction being preferred.