Fastening element for hard substrates

p0001The invention relates to a fastener for hard surfaces, comprising a base body, which extends along a longitudinal axis and having a lateral surface, an at least partially arranged on the base body, self-tapping thread, the height of which extends from the lateral surface of the basic body radially outward and at least has a groove on the base body, the depth of which extends from the outer surface of the main body radially inward.

p0002There are different types of fasteners for hard surfaces such as concrete, masonry and the like are known, which are set in a previously made hole in the ground. Such fasteners are set in rotation and / or striking depending on the configuration.

p0003From the <patcit id="pcit0001" dnum="EP0623759B1"><text>EP 623 759 B1 0</text></patcit> is a self-tapping screw to be screwed into hard surfaces is known comprising a shank as a main body and a screw head as engagement means for a setting tool at one end of the shaft. Along the stem extends range, a self-tapping thread, the height of which extends from the outer surface of the shank radially outwards. In order to facilitate the screwing of the screw circumferential grooves for receiving the broken ground material on the base are provided on both sides of the thread, the depth of which extend from the outer surface of the base body radially inwardly.

p0004From the <patcit id="pcit0002" dnum="EP1536149A2"><text>EP 1536149 A2</text></patcit> discloses an internally threaded sleeve with a self-tapping thread. The internally threaded sleeve has a base body with a casing surface. At the base is a self-tapping thread is provided in some areas, the amount of which extends from the outer surface of the base body radially outwards. Further, the internally threaded sleeve on an inner engagement means and provided with an internal thread as load application means, from one end of the body accessible for receiving a threaded rod or bolt.

p0005From the <patcit id="pcit0003" dnum="US4350464A"><text>US 4,350,464 A</text></patcit> is a striking settable anchor rod known to a shaft as a main body, a self-tapping thread, the height of which extends from the outer surface of the shaft radially outwards, and it is then a machine thread for fixing an object, eg. as by a nut, to having the ground.

p0006About the bond length of the self-tapping thread in the underground, the force applied to the respective fastener load is introduced into the ground. A load increase can be achieved in that the annular gap between the outer surface of the base body and the borehole wall is minimized, thereby resulting in setting the fastener dust is compressed between the outer surface of the base body and the borehole wall.

p0007A disadvantage of the known solutions is that due to the characteristics of the substrate and the type and condition of the tool to create the borehole, the size of the annular gap between the outer surface of the base body and the borehole wall of can attachment point vary attachment point strongly. In addition, high pressures on the undercuts produced by the thread can act in the underground, which to a partial or - lead to a complete failure of the attachment point started - in the most extreme case. To avoid this and to achieve a high load capacity, have such fasteners on a relatively large bond length of the thread in the underground, but what caused a lot of effort to set the appropriate fastener.

p0008From the <patcit id="pcit0004" dnum="DE19820671A1"><text>DE 198 20 671 A1</text></patcit> is a screw with a self-tapping thread is known which is set to reduce the required bond length of the thread in largely complete utilization of the bearing capacity, in a previously a filled with a curable material wellbore. The thread of this fastener is anchored after curing the curable material in the ground and in the ground.

p0009Suitable curable compositions such. As two-component mortar based on epoxy, which are known to the expert, for example as a universal mortar, advantageously have a high filler content, which ensures a high viscosity and low shrinkage at a sufficient internal strength of the cured material. These curable compositions are relatively expensive, so that there is a need for economic reasons, the required amount of curable mass per attachment point to be kept to a minimum.

p0010A disadvantage of the solution according to the <patcit id="pcit0005" dnum="DE19820671A1"><text>DE 198 20 671 A1</text></patcit> is that the annular gap between the outer surface of the base body and the borehole wall must have sufficient size so that in addition to low-viscosity materials and curable compositions are used with fillers. For complete filling of this annular gap thus a large amount of curable material is required. In addition, a screw according to the<patcit id="pcit0006" dnum="DE19820671A1"><text>DE 198 20 671 A1</text></patcit> set in a borehole without curable material, the achievable utilization of the bearing capacity is only a fraction of a conventional concrete screw.

p0011If a conventional generic type fastener set in a previously a filled with a curable material wellbore, the annular gap between the outer surface of the base body and the borehole wall for most types of curable compounds is too small. Thus, low-viscosity, curable compositions can only be used, which are relatively expensive and with fillers have a lower strength compared to curable compositions. In addition, the hole must be completely cleaned before the introduction of the hardenable mass from the resulting debris in order to prevent clogging of the annular gap through the drilling dust.

p0012The object of the invention is to provide a rotation in a wellbore and / or percussion settable fastener that has an advantageous structural behavior and is suitable for use with a universal mortar.

p0013The object is achieved by the features of the independent claim. Advantageous developments are set forth in the dependent claims.

p0014According to the invention the spaced apart at least one groove on the base body axially disposed on the thread.

p0015The inventive fastening element of the annular gap between the outer surface of the advantageously cylindrical base body and the borehole for exploiting the load capacity increase by the compressed drilling dust can be kept small and the anchoring of the fastening element to be improved so simultaneously by means of a filling of the hole with a curable material that the bond length of the thread in the ground can be kept small. Under the lateral surface of the base body surrounding the base body surface is understood. In a cylindrical body, the cylindrical lateral surface is the outer surface of the base body. The self-tapping threaded ends or begins in this area, so that the bottom of the thread is substantially on the outer surface of the base body.

p0016The at least one groove forms a rising groove for the curable material and provides sufficient space for curable compositions which have two-component mortar fillers of a specific particle size such. B.. This can be used to fill the annular gap between the outer surface of the base body and the borehole or the borehole according to requirements at the fastening point a suitable hardenable mass. As a result of the axially spaced arrangement of the at least one groove for thread, only a small proportion of the scraps left over from furrows the borehole dust or drillings in the at least one groove, which is an upgrade of the displaced portion of the curable material in the at least one groove is only slightly impaired. On the basic body, more than one groove may be provided. The viable cross-section of the body is only in some areas reduced by at least one groove, so that in spite of these partial weakening of the cross section of the base body a high load capacity of the set fastener is added.

p0017The hole created in the underground is filled as a curable material, for example with a mortar and then the fastener rotation and / or percussion driven into the borehole, the displaced portion of the curable material slightly in the at least one groove ascends. In this case, the space between the attachment member and the borehole is filled and the fixing element anchored in addition to the penetrated into the underground portions of the thread in the substrate form fit. From the well in the area of ​​the borehole mouth issuing shares of the curable composition to show the user the complete filling of the at least one groove. The fastening element is already partly loaded prior to full curing of the curable material.

p0018The novel fastener can be placed easily and with relatively little effort. In addition, the fastening element can be anchored in the curable material without previously created borehole, the small annular gap between the outer surface of the base body and the borehole wall ensures a good anchoring of the fastening element in the substrate.

p0019The at least one groove, for example, during a rolling process or in a separate machining process, for example by machining formed on the base, which enables low-cost manufacture of the fastener.

p0020Preferably, the at least one groove is arranged at least regionally parallel to the thread. The groove extends substantially helically in the same pitch of the self-tapping thread, which in makes it easy to upgrade the curable composition comprises at least one groove in the direction of the borehole mouth.

p0021Preferably, the at least one groove is arranged at least regionally parallel to the longitudinal axis of the body, whereby the displaced or introduced curable compound in which at least can easily get a groove in the direction of the borehole mouth.

p0022In an advantageous embodiment, the at least one groove extends in the region of the self-tapping thread helically and in the thread-free areas parallel to the longitudinal axis of the body, whereby the displaced portion of the curable material easy to at least to ascend a groove.

p0023Preferably, the at least one groove in cross section in a polygonal configuration. For example, the cross section of the at least one groove is formed trapezoidal or rectangular. Alternatively, the at least one groove having in cross section a circular segment-shaped configuration.

p0024Preferably, the depth of the at least one groove corresponding to the 0.02- to 0.5-times the diameter of the base body, whereby a plurality of curable compositions can be used, which also comprise larger particles of fillers. Advantageously, the minimum depth of at least one groove, at least the amount of 2-fold Füllstoffpartikelgrösse comprising mainly coming to the fastener applying curable material.

p0025Preferably, the measured between the thread flanks at the thread root width of the at least one groove corresponding to the 0.05- to 0.5-times the diameter of the base body, whereby a plurality of curable compositions can be used, which also comprise larger particles of fillers. The groove bottom of the at least one groove advantageously has a dimension parallel to the thread base or the lateral surface of the base body on.

p0026The depth and width of the groove is advantageously formed as a function of coming mainly apply curable material, wherein the viable cross-section of the body is only in some areas reduced.

p0027In an advantageous embodiment of the invention, the basic body is a shaft at whose lateral surface the self-tapping thread is at least locally provided. Subsequently, to the self-tapping screw may be provided for creating an anchor rod a further thread z. B. in the form of a machine screw thread for the arrangement of a nut. The self-tapping thread is for example a coarse thread, so that this fastener is hitting settable.

p0028Preferably, an engagement means for a setting tool for. Example is provided in the form of a screw head at one end of the shaft, which allows a beating and / or rotary setting of the fastener in the form of a self-tapping screw.

p0029In a further advantageous embodiment of the invention the base body has inwardly located engagement means for a setting tool and z. B. to a surface provided with an internal thread as load application means, from one end of the body accessible recording. This fastening element forms a self-tapping internally threaded sleeve. The self-tapping thread is for example a coarse thread, so that this fastener is hitting settable.

p0030Preferably a Verfüllöffnung is provided in the base body, which connects the receptacle with an outer side of the base body for filling a hole in the ground. As a result, the borehole and the annular gap between the outer surface of the base body and the borehole are subsequently filled by the setting of the fastener with the curable composition, the curable material may be increased by the groove in the direction of the borehole mouth. advantageously extends the Verfüllöffnung parallel to the longitudinal axis of the plea to the front, lying in the setting direction end of the base body.

p0031The invention is illustrated below with reference to several embodiments. Show it:<dl id="dl0001"><dt>Fig.1 1</dt><dd>A side view of a first embodiment of the inventive fastening element;</dd><dt>FIG. 2</dt><dd>the fastening element shown in Figure 1 is in the set state. </dd><dt>Fig.3</dt><dd>a side view of a second embodiment of the inventive fastening element; and</dd><dt>Fig.4</dt><dd>a side view of a third embodiment of the inventive fastening element.</dd></dl>

p0032Basically, the same parts with the same reference numerals in the figures.

p0033In Figures 1 and 2 is as a fastener 11 for hard constructional 6, such as concrete, masonry and the like, a concrete screw is shown, that is placed in a previously formed borehole 7 in the ground. 6 The fastener 11 has a shaft as a base body 12 extending along a longitudinal axis 19 and a lateral surface 18 and a hexagonal head 17 as engagement means for a not shown here setting tool on. The fastener 11 is percussive and / or rotary settable. On the basic body 12 in regions, a self-tapping thread 13 is provided, the height extending from the outer surface 18 of the body 12 radially outward.

p0034Intermediate and axially spaced from the thread 13 is a parallel to the thread 13 extending groove 16 disposed on the base body 12 for a hardenable mass. 8 The groove 16 extends to a depth T1 corresponding to the 0.1-times the diameter D1 of the body 12, from the outer surface 18 of the body 12 radially inwards to the shaft and has a polygonal cross-section. Further, the groove 16 has a width B1, which corresponds to 0.3-times the diameter D1 of the basic body 12th

p0035The borehole 7 is with a certain amount of the curable composition 8, for. Example, with a two component mortar, filled, and then the fixing member 11 rotationally driven in the borehole 7. Here, the self-tapping thread 13 fear into the borehole 10 and the previously introduced hardenable mass 8 is displaced partly. The displaced portion of the hardenable mass 8 rises to the groove 16 and fills the space 9 between the fastener 11 and the borehole 10th The fastener 11 is on the one hand anchored to the self-tapping thread 13 and the other part by means of the cured composition 8 underground. 6

p0036The fastener 21 shown in FIG 3 for hard surfaces in the form of an internally threaded sleeve has a cylindrical body 22 extending along a longitudinal axis 29 and having a lateral surface 28th On the basic body 22 in regions, a self-tapping thread 23 is provided, the height extending from the outer surface 28 of the base body 22 radially outward. The base body 22 has inwardly located engagement means 31 and a subsequent thereto, from one end 35 of the base body 22 accessible receptacle 32 with an internal thread as load application means for a threaded rod or bolt, not shown here. Next a Verfüllbohrung 33 is provided which extends from the attack means 31 to a front end 34 of the base body 22nd

p0037Axially spaced from the thread 23, a groove 26 is provided on the base body 22, which is 22 22 arranged parallel to the longitudinal axis 29 of the basic body extending in the region of the thread 23 helically and parallel to the thread 23 and a thread-free region of the base body. The groove 26 extends to a depth T2 corresponding to the 0:07 times the diameter D2 of the base body 22, from the outer surface 28 of the main body 22 radially inwardly and has a slightly trapezoidal cross-section. Further, the groove 26 has a width B2 that corresponds to the 0:35 times the diameter D2 of the base body 22nd

p0038The fastener 21 is z. B. driven in rotation in a wellbore, the self-tapping thread 23 is fear in the borehole. Subsequently, the curable material is introduced through the Verfüllöffnung 33 in the main body 22 into the remaining space in the borehole, to parts of the curable compound exiting from the borehole. The groove 26 on the base body 22 allows an upgrade of the curable material in this filling process.

p0039The fastener 41 shown in FIG 4 for hard surfaces in the form of an anchor rod has a shank as a base body 42 extending along a longitudinal axis 49 and having a lateral surface 48th On the base 42, a self-tapping thread 43, the height of which extends from the outer surface 48 of the base body 42 radially outward, and another thread 44 is provided for fixing an object by means of a nut, not shown here. The self-tapping thread 43 is designed as a multi-start coarse thread and allows a striking setting of the fastener 41. At one end 51 of the base body 42 a plea 52 for a not shown here setting tool is provided. On the base body 42 43 grooves 45, 46 and 47 are provided in the region of the self-tapping thread, which extend between and axially spaced from the thread 43 helically and in the thread-free areas parallel to the longitudinal axis 49th The depths of the grooves 46 and 47 extend from the outer surface 48 of the main body 42 radially inward.