DK148666B - THE ANCHORING SITE PRINCIPLES FOR ANCHORING IN CONCRETE PARTS - Google Patents

Description

148666

The present invention relates to an anchoring set preferably for anchoring in concrete building parts and consisting of a spreading devil and a fastening screw, the spreading devil being of plastic and for turning and tightening the fastening screw having a longitudinal smooth bore or gap.

The anchoring of plastic spreading devils is generally done by turning in wood screws which, as is well known, are provided with a sharp profile thread. Upon recess, the sharp edge of the threaded profile penetrates deep into the dowel material, causing a weakening of the dowel cross section. This weakening is usually of minor importance because the thickness of the dowel is substantially greater than the thread depth. Moreover, the spreading effect is generally based on the fact that the bore of the devil is smaller than the core diameter of the screw, so that the spreading effect is primarily due to a flushing due to the insertion of the core of the screw into the slit slit or bore. An example of such a spread of dowels is described in French Patent Specification No. 2,310,490.

Threads other than the sharp wood screw thread are known. From British Patent Specification No. 733,587 are known screws with round thread arranged for fastening in wood devils. These screws are inserted into bore holes already provided with an internal thread, and the purpose of the method is to prevent the wood in the dowels from being shattered, cutting the longitudinal fibers of the wood, which would result in a reduction in retaining value.

The object of the present invention is to provide an anchoring set suitable for piercing mounting, i.e., that the die is only slightly larger than the largest diameter of the screw, in such a way that good holding values are obtained in both hard and less hard materials. .

Thus, the aim of the anchoring set is to be that, for hard materials that can withstand a large spread pressure, a strong pressure is obtained against the borehole wall, while in softer materials a larger spread is obtained, but a smaller pressure against the borehole wall.

According to the invention, this is achieved by having the fastening screw, the core diameter of which is approximately the same as the inside diameter of the longitudinal bore of the spreading drill, has a round thread and a screwed point with a tapered thread outlet, the spreader of the spreading cutter being formed as ends along the ends. a list is placed whose length corresponds to the incisions.

The tapered thread outlet at the screw tip causes the screw to be inserted immediately and playback of the dowel can be started, the moldings preventing the rotation of the dowel. Due to the thread shape, a very large pressure is required to deform the fabric of the devil around the edge of the thread. Only hard materials in the borehole wall will be capable of this, and in these cases the dowel material will be compressed in the recesses of the thread under a very high pressure. Less hard materials will not be able to withstand such pressure, and therefore, during a minor deformation over the edge of the thread, the die will be played out accordingly, thus ensuring a good wedge wedge in the material. Thus, the anchoring set provides an almost automatic adaptation to the material in which the borehole is made, and therefore provides great resistance to extraction under all conditions.

Furthermore, according to a supplement according to the invention, the outside diameter of the spreading devil can approximately correspond to the outside diameter of the thread. The same outside diameter of the dowel and the mounting screw allow the use of a through-diameter borehole in the article to be fastened and in the masonry, which bore can be completed in a single operation. The fastening screw hereby abuts immediately against the wall of the object to be attached, and by a deeper inserted dowel also against the wall of the borehole orifice in the masonry, so as to exclude bending effects as far as possible. In addition, this design results in a very strong tensioning and wedging of the dowel material in the threaded threads, so that even exceptionally high holding forces can be obtained.

The drawing shows an exemplary embodiment of the anchoring set according to the invention.

The anchoring of the dowel 1 according to the invention requires that a borehole 4 having a diameter corresponding to the outside diameter of the dowel 1 throughout its length is arranged in the wall 2 and the object 3 to be attached. The fastening screw 5 has on its opposite head 6 an end of a round thread 7 which, in order to reduce the turning resistance, extends at the tip of the screw 8 in a taper.

After inserting the die 1 into the borehole 4, the fixing screw 5 is tightened to anchor the object 3 in the die. Since the core diameter of the fastening screw 5 corresponds to the inside diameter of the longitudinal bore 9 in the dowel 1, the threaded profile engraves itself by screwing in the fastening screw while simultaneously densifying and wedging the dowel material between the threaded flanks and the borehole wall into the dowel mold. In soft masonry, due to axially extending and towards the ends of the devil, limited incisions 10, there is a spread which produces a holding force, which supplements the holding force of bends 11 next to the threaded peaks.

As soft turning rotation and for filling the slits 10 in hard materials, along the slits there is a longitudinal groove 12 extending along the slits, which partly serves for stiffening in the direction of rotation, and by anchoring in hard materials for better bending into the The slots are provided with a triangle profile.

For anchoring of door frames or window frames, the dowel may be provided with an elongated neck 13. engaging in the object 3 to be fixed in the case of diameters corresponding to the illustrated embodiment between the fastening screw and the dowel, the threadless shaft 14 of the fastening screw 5 is reduced. relative to the outer diameter of the thread 7 with the wall thickness of the elongated neck portion.