DE2406207A1 - Anchor bolt for blind hole in low density building material - has radially movable blades to form anchorage - Google Patents

Abstract

An anchor plug such as used in aerated concrete or similar low density building material has a number of closed anchor blades. When installing the plug in a blind hole, a circular plate which carries the blades is pulled outwards by the action of the central tension bolt. A tapered distance bush forces the free blade ends outwards into the wall of the hole thus forming an anchorage which has a large contact area between plug and material. Similar results are obtained by having a number of eccentric plates carried by a shaft. With the plates in line, the shaft is inserted into the hole. The plates are then turned until they are equally spaced around the shaft and firmly anchored in the wall of the hole.

Description

Dowels for porous materials such as aerated concrete or the like.

The invention relates to a dowel for producing highly resilient Fastening arrangements in bores of components made of porous soft materials, such as aerated concrete, pumice building materials and the like.

Heavy-duty fastening arrangements in components made of so-called Up to now, lightweight construction materials such as aerated concrete and the like can only be produced by that the component is pierced and in the area of the bore through each to the outside Placed plates is clamped, one of the plates and the hole in the component penetrating through screw for bracing the plates and for introduction is used for the stress in the component. For non-through holes are off Plastic-made so-called aerated concrete dowels known, which basically the the usual dowels suitable for hard materials such as concrete, in addition but with one Row of helically protruding from the dowel Fins are provided. When this dowel is hammered into a hole in aerated concrete the fins penetrating the material enlarge the holding surface. The real one The anchor is fixed in the usual way by spreading the inner one Dowel end by screwing in a screw. The load capacity of these dowels is - especially in the longitudinal direction of the bore - comparatively low because the forces are over relatively small areas have to be transferred to the component.

The same goes for the so-called perforated sleeves that tried is, the adhesion between the sleeve and the component through a hardening adhesive to increase, on the one hand in a large number of holes in the sleeve and on the other hand penetrates into the porous material. However, since the penetration depth of the adhesive is small is, the stresses introduced into the sieve sleeve are applied to a small volume of material transfer. Therefore, this sleeve can be used in the soft building materials in question can only be used for low loads.

In contrast, the object of the invention is to provide a dowel for building materials such as aerated concrete or the like. to create with which it is possible to withstand high loads to be introduced into bores that are only accessible from one side, without the risk of tearing out the anchor or damage to the component.

Based on the knowledge that it is necessary to do this, the Stresses over the largest possible area distributed over the largest possible volume of material To transfer the component, this object is achieved according to the invention by a elongated tension anchor insertable into the bore, on which in the area of his inner end one in the outer dimensions -reducible to less than the bore diameter and after being inserted into the bore with penetration into the hole surrounding material enlargeable planar anchor element is arranged; An institution to enlarge the anchor element in the state inserted into the bore; and through an outer clamping plate which can be placed on the outside of the component and which, while generating a compressive bias in that enclosed between the anchor element and the tensioning plate Volume of material can be braced against the anchor element by means of the tension anchor. Due to the large volume of material captured between the clamping plate and the anchor element of the component, the dowel constructed in this way is much more heavily loaded than before was possible.

In the case of longer bores, there is also a series arrangement and coupling several anchor elements of the type described can be used with advantage.

In a preferred embodiment, the anchor element has a dimensioned central part that can be introduced into the bore and is arranged on the tensioning anchor, on the elongated armature wing from an approximately parallel to a radial and arranged so that it can be spread about at right angles to the tensioning anchor are. The anchor element thus has approximately before being inserted into the associated bore the shape of a slotted sleeve, while the anchor wings are star-shaped when the dowels are in place protrude from the middle part.

To make it easier for the anchor wing to penetrate the component, we recommend it is to form the anchor wings pointed at their outer ends and / or to be provided with a cutting edge, in the end so in the direction of the Bore walls are bent over so that they enter the bore walls when the tensioning anchor is tensioned penetration.

The middle part and the anchor wings can be made in one piece from metallic Material made and connected by webs, the width of which compared to the Width of the wing surfaces is reduced. The narrow webs set the point when clamping of the anchor element occurring tension forces compared to the anchor wings reduced resistance, whereby they act as a flexure joint.

Alternatively, the disc-shaped central part and the anchor wing manufactured separately and releasable with the formation of flexible or tilting joints or be inextricably linked.

In such a configuration, the central part is preferred at equal angular intervals with one corresponding to the number of anchor wings Number of slots provided in the protruding from the inner anchor wing ends complementary webs can be used.

To prevent the anchor wing from spreading through Application of a clamping force that is accidentally too high or temporary Overload of the fastening arrangement formed with the bracket bent backwards and the dowel can then be pulled out of the hole, it recommends to support the anchor wings in the spread position on their back. The support can be realized in that the middle part or an in Direction of the inner end of the bore arranged under it support part with the number the armature wing and its radial arrangement corresponding radially protruding flat support webs is provided, which are dimensioned and arranged so that they when Insert the dowel into the hole and cut into the component material with their rear edges pointing towards the mouth of the bore, the anchor wings are spread open Support state. The support bars cut at Introduce the anchor slot-like grooves running in the longitudinal direction of the bore into the bore surrounding material, however, is the loss of between the anchor element and the The volume of material enclosed in the clamping plate is low, as the support webs are very thin and can also be made considerably shorter than the associated anchor wing.

In an advantageous development of the invention it is provided that between the anchor element and the clamping plate an insertable into the bore Sleeve is slidably arranged, which is a conical in the region of its inner end Has taper with which it on the inner surfaces of the bent end regions the anchor wing rests, the length of the sleeve up to the conical taper about the same or slightly shorter than that in the fastening position between the anchor element and the clamping plate is provided distance. This sleeve not only ensures an inevitable guidance of the anchor wings at the beginning of the expansion process of the anchor element, but it also centers the tensioning anchor in the middle of the hole and thereby sets it the even wearing of all anchor wings safely It is advisable to put the sleeve under Recess of windows for the passage of the anchor wing over the conical thickening extend towards the inside of the bore. In the extended area Support webs of the type described above can then also be arranged on the sleeve will.

In a modified embodiment of the anchor according to the invention the anchor element has several at right angles in the area of the inner end of the tensioning anchor to its longitudinal center axis arranged elongated flat anchor wings on, from at least one part of which, each in a perpendicular to the clamping axis : running plane is rotatably mounted, the length of the Anchor ball about the same or slightly shorter than the diameter of the associated Dimension the bore and its axis of rotation to the longitudinal center axis of the tensioning anchor is eccentric in Direction is offset on the bore wall. The tension anchor preferably has an elongated shaft on which the anchor wings are mounted. With this one The anchor wings are first on top of each other before being inserted into a drill hole aligned and pushed into the borehole in this position. The tension anchor shaft lies eccentrically in the hole. Then the wings are relative to each other twisted so that they are at equal angular intervals around the then centric in the shaft of the clamping anchor lying on the bore are arranged.

This twisting of the wings and the centr cal alignment of the tensioning anchor can be done with a simple tool, with one at the front end over the Shank of the tensioning anchor slidable sleeve a driving; ft is provided which is attached to the wing side edges or in both holes in the wing surfaces can be. A lever at the outer end of this tool then makes this possible Rotating the tool and assessing the size of the compared to the starting position rotation of the respective wing.

The above-mentioned embodiment can still be used according to the invention be further developed in that the angle of rotation of the wing limiting stops are provided on the tension anchor, the stops being arranged in such a way that that the wings when rotated from the aligned superimposed position in the end position are at equal angular distances from one another.

The anchor wings can also be different, preferably two opposite axes offset from the center longitudinal axis of the tensioning anchor in opposite radial directions be rotatably mounted. Such a dowel is for example like this built up, that the tensioning anchor has a sleeve which can be inserted into the bore to fit the anchor wings are mounted, and that the sleeve in the area of the anchor wings with Slits are provided, through which the anchor wing from one inside the sleeve lying position rotatable in a position protruding radially from the sleeve are.

The size of the facing, with the material of the component be in contact surfaces of the anchor element and the outer clamping plate preferably dimensioned approximately the same size.

The flat disc, perforated for the passage of the tensioning anchor trained clamping plate can along its edge with a to the surface of the Component bent, circumferential edge flange be provided. The edge flange penetrates when clamping the dowel into the surface of the component, whereby it the clamping plate on the one hand laterally fixed and on the other hand the transfer of the to the clamping plate the stress acting on the component in the edge area is improved.

The invention is in the following description of several exemplary embodiments explained in more detail in connection with the drawing, and FIG. 1 shows a sectional view by a preferred embodiment of an inserted into the bore of a component, not yet fixed anchor according to the invention; Fig. 2 shows an anchor wing of the in the embodiment of Figure 1 provided anchor element; 3 shows the middle part of the anchor element according to FIG. 1; Fig. 4 is a partial sectional view through a with respect to the anchor element modified embodiment of the anchor; Fig. 5 is a sectional view along the line 5-5 in FIG. 4, the only in its interior Area shown wing but shown in the spread mounting position are; FIG. 6 shows a view corresponding to FIG. 4 of a further modified one with Support webs for the anchor wing provided embodiment of the invention; Fig. 7 a sectional view along the line 7-7 in Fig. 6, with the anchor wings, however are shown in dot-dash lines in the spread mounting position; Fig. 8 shows a plan view of the part introduced into a bore of a further embodiment of the anchor according to the invention before fixing the anchor element in the bore; Figure 9 is a sectional view taken along line 9-9 in Figure 6; Fig. 10 one of the Fig. 8 corresponding top view, in which the anchor wing is shown in the fastened position are; 11 shows a view corresponding to FIG. 8 of a dowel, in which the anchor wing are arranged so as to be rotatable about two axes which are remote from one another; and FIG. 12 a Sectional view taken along line 12-12 in FIG. 11.

The dowel designated in its entirety in Fig. 1 with 10 is in a bore 12 of a component 14 made of aerated concrete is shown inserted. The dowel 10 has a tensioning anchor shown as a screw in the exemplary embodiment shown 16, at the inner end of which is pushed into the bore 12, an anchor element 18 is arranged, which, as will be explained below, to determine the Stressing anchor inside the Bore is used. This anchor element 18 consists of a disk-shaped one supported on the inner head of the tensioning anchor 16 Middle part 20, the diameter of which is slightly smaller than the bore diameter. It is recommended that the central part 20 with the inner end of the shaft 22 of the tensioning anchor 16 - to be rigidly connected, for example by welding.

The middle part 20 is at equal angular intervals with slots 24 (Fig. 3) provided for receiving web projections 26 at the inner end of Serve anchor wings 28, which in plan view have a lanceolate, pointed shape have (Fig. 2). The slots 24 in the middle part 20 and the web projections 26 to the Anchor wings are arranged so that they are slightly S-shaped in cross-section Anchor wing 28 together with the tension anchor 16 and the central part 20 in the bore 12 can be introduced. The S-shaped curvature of the anchor wings 28 are their pointed free end regions 30 are bent in the direction of the bore wall and can penetrate into the material surrounding the bore when they come out of their Insertion position running essentially parallel to the shaft 22 of the anchor element 18 be spread radially.

This spreading takes place by exerting a tensile force on the outer End of the tensioning anchor 18. This threaded tensioning anchor end penetrates the central bore 34 is a disk-shaped one placed on the outside of the component 14 Clamping plate 32. By a nut screwed onto the end of the clamping anchor 16 36 the desired tensile force is generated.

Between the bent end areas of the anchor wings 28 and the clamping plate 32 a sleeve 38 of suitable length is arranged, the inner end 40 of which is conical rejuvenates.

When the nut 36 is turned, the shaft 22 of the tensioning anchor 16 is turned off the bore 12 pulled out. Since the conical taper 40 of the sleeve 38 abutting end regions 30 of the anchor wings 28 are outwardly guided so that the wings in the material of the component surrounding the bore 20 14 penetrate. With this spreading, there is a gradual pivoting of the Anchor wing 28, the pivot axis approximately in the area of the transition between the web projections 26 lies in the actual anchor wing. In this area are the web protrusions 26 bent during the spreading process.

This spreading process is continued until the inner face of the sleeve 38 after displacement of the tensioning anchor by the expansion distance s on the middle part 20 of the anchor element 18 comes to rest. The anchor wings then have the dimensions shown in Fig. 1 position indicated schematically in dash-dotted lines, are therefore with the most of its area penetrated into the material of the component 14. About the outwardly projecting end of the shaft 22 of the tensioning anchor 16 acting loads are therefore on the pressurized, between the wings 28 of the Anchor element 18 and the clamping plate 32 enclosed material volume of the component 14 transferred. Here is a high strength against both static and dynamic loads reached.

The penetration of the anchor wings 28 is made even easier if the outer edges of the anchor wings in addition to the tapering of the free end area 30 as a cutting edge 42 (Fig. 2> are formed.

The embodiment shown in FIGS. 4 and 5 of the invention Dowel differs from the previously described dowel only in that it is one-piece Production of the anchor element 18. Middle part 20, web 26 and wing 28 are therefore cut out together from a metal plate of suitable thickness and then in that shown in FIG Reshaped way. When setting the dowel the armature wings 28 spread radially in the same way as described above on <Fig. 5), whereby a bending of the anchor element in the area of the webs 26 he follows. In the expanded state, projecting into the bore 12 are supported Wing parts on one arranged below the anchor element 18 on the tension anchor 16 Support disks 44 from so that the webs 26 are relieved. The sleeve 38 is below here Recess of windows 39 for the passage of the anchor wings 28 to the inner end of the bore extended towards.

This extension section 41 leads to improved centering the support disk 44 - or the disk-shaped central part 20 in the embodiment according to Fig. 1 - as soon as the sleeve is retracted far enough. The windows 39 form in connection with the conical taper 40 a forced guidance for the anchor wing, which ensures optimal penetration of the anchor wing into the bore wall. It has been shown that it is advantageous if the conical taper in the The manner shown is relatively short and frustoconical, as this leads to a strong Deflection of the wing 28 leads even with short clamping distances. The conical taper 40 is here produced separately and in the intended position over the windows 39 welded into the cylindrical sleeve 38.

On the extension section 41 of the sleeve can be shown in dash-dotted lines in the drawing Support webs 46 shown are provided, their function and configuration below in connection with FIGS. 6 and 7 will be explained in more detail.

The embodiment shown in FIGS. 6 and 7 corresponds to previously described dowels largely. The arranged under the anchor element 18 Support member 45, however, has the flat, fin-like shape already mentioned above Support webs 46, the length of which is dimensioned so that they are when inserting the dowel cut into the bore 12 in the bore wall and thereby slot-like radial Cuts 4E. The rear facing towards the bore mouth, slightly sloping Edges 47 of these support webs are designed so that the wings are in the spread position lean on them. A bending of the anchor wing beyond the intended In the spread position, the support webs counteract an additional supporting force. As a result, the anchor wings themselves can be made from a relatively thin material.

It should also be noted that support webs of the described Art also in the embodiment described in connection with FIGS. 1 to 3 can be provided. For this purpose, only the central part 20 of the anchor element 18 has to be are extended in accordance with the support part 45, so that the support webs 46 are attached w can be.

A modified embodiment of the anchor according to the invention is illustrated in Figures 8-10. Also in this embodiment Anchor element 50 has a series of anchor wings 52 on the inner end of the shaft 22 of the tension anchor 16 are arranged. The flat anchor wings 25 are arranged one above the other rotatably arranged at the end of the shaft 22 of the tensioning anchor 16. The Storage not in the middle, but on one of the outer end areas of the anchor wing 52. The wings can be rotated into an aligned position on top of one another, whereupon the tension anchor can be inserted into a bore 12, the diameter of which is slightly greater than the length of the wings 52. The shaft 22 of the tension anchor 16 is offset eccentrically to the center of the hole. If now the anchor wings 52 by a suitable tool - for example that in Fig. 9 in dash-dotted lines Sleeve-shaped tool 54 indicated by lines with a shoulder 56 - on uniform Angular distances are rotated, and at the same time the shaft 22 is centered on the bore is aligned, the outer portions of the anchor wings 52 penetrate into the bore 12 surrounding material of the component 14 and thus lead to an anchoring of the Dowel inside the hole.

It can be ensured by means of attacks or other suitable measures be that the anchor wings 52 of the anchor element 50 when rotated to the end position have equal angular distances to each other. In Figs. 8 and 10 there are openings 58 shown in the wings 52, into which the extension 56 of the tool 54 is inserted can be.

In this embodiment, too, it is advisable to use at least the The area of the anchor wings penetrating into the bore wall with a cutting edge 60 (Fig. 8) to be provided.

FIGS. 11 and 12 represent a further development of the previously described Dowel is in which the anchor element 61 on two eccentrically arranged shafts 62 has anchor wings 66 within a sleeve 64 representing the tension anchor, which is screwed out of the interior of the sleeve through appropriately arranged slots 68 in the sleeve 64 can be, whereby they penetrate into the material of the component 14. In the drawing only one anchor wing 66 is shown for each shaft 62, but it is clear that further wings can be provided offset in height. The possible arrangement of four shafts 62 serving as an axis of rotation is shown in FIG. 11 by the two in addition indicated by dash-dotted shafts. The tensioning of the dowel takes place in this case by a thread 70 at the outer end of the sleeve 64 Flat nut 72 screwed on and supported on clamping plate 32. Outer Stresses are introduced into the tensioned sleeve in a suitable manner.

Within the scope of the concept of the invention, further configurations are possible, in which, for example, at the end of the tensioning anchor, radially linearly displaceable Tension wing from a retracted to a extended position can be transferred, in which the wings in the material of the component penetration. The basic idea is in any case that when inserting into the drilling of the component initially retracted or folded in anchor surfaces after insertion of the dowel cut into the surrounding material, whereupon in cooperation with the outer clamping plate clamped a relatively large volume of material through the dowel will.

Claims (18)

Expectations \ Dowels for the production of heavy-duty fastening arrangements in bores of components made of porous soft materials such as aerated concrete, pumice building material and the like by an elongated tensioning anchor (16) that can be introduced into the hole tal2), at which in the area of its inner end one in the outer dimensions to less than Bore diameter reducible and after insertion into the bore with penetration flat anchor element which can be enlarged into the material surrounding the bore (12) (18, 50) is arranged; a device for enlarging the anchor element in in the inserted state in the bore (12); and one on the outside of the component (14) outer clamping plate (32) which can be applied and which, while generating a compressive prestress in that enclosed between the anchor element (18; 50; 61) and the clamping plate (32) Material volume by means of the tensioning anchor (16) against the anchor element (18; 50; 61) is braced. 2. Dowel according to claim 1, characterized in that the anchor element one dimensioned to be insertable into the bore (12) and arranged on the tensioning anchor (16) Has central part (20), on the elongated anchor wing (28) of an approximately parallel to the central longitudinal axis of the tensioning anchor into a radial and approximately at right angles to this running position are arranged spreadable. 3. Dowel according to claim 2, characterized in that the anchor wing (28) pointed at their outer ends and / or provided with a cutting edge (42) and are bent in their end area in the direction of the bore walls, that when the tensioning anchor (16) is tensioned, it enters the walls of the bore penetrate 0 4. Dowel according to claim 2 or 3, characterized in that the central part (20) and the anchor wings (28) made in one piece from metallic material and made by Bridges (26) are connected, the width of which compared to the width of the anchor wing (28) is decreased. 5. Dowel according to claim 2 or 3, characterized in that the central part (20) and the anchor wing (28) produced separately and forming bending or tilting joints are releasably or non-releasably connected to one another. 6. Dowel according to claim 5, characterized in that the central part (20) at equal angular intervals with one of the number of anchor wings (28) corresponding Number of slots (24) is provided in the projecting from the inner anchor wing ends complementary webs (26) can be used. 7. Dowel according to one of claims 2 to 6, characterized in that that the middle part (20) or one in the direction of the inner end of the bore below it arranged support part (45) with the number of anchor wings (28) and their radial Order corresponding radially projecting flat support webs (46) is provided, which are dimensioned and arranged so that they are when inserting the dowel (10) in the Cut the bore (12) into the material of the component (14) and with your to the bore mouth facing rear edges (47) the anchor wings (28) in the spread-open state prop up. 8. Dowel according to one of claims 2 to 6, characterized in that that between the anchor element (18) and the clamping plate (32) one in the bore (i2) insertable sleeve (38) Is slidably arranged in the Area of their inner end has a conical taper with which they to the Inner surfaces of the bent end regions (30) of the anchor wings (28) bear against, wherein the length of the sleeve (38) up to the conical taper (40) is approximately the same or approximately shorter than that in the fastening position between the anchor element (18) and the clamping plate (32) provided distance. 9. Dowel according to claim 8, characterized in that the sleeve (38) with recess of windows (39) for the passage of the anchor wing (28) over the conical joint (40) is also extended in the direction of the inside of the bore is. 10. Dowel according to claim 9, characterized in that the extension section (41) of the sleeve (38) with the number of anchor wings (28) and their radial arrangement corresponding radially projecting flat support webs (46) is provided which are dimensioned and arranged so that they are when inserting the dowel (10) into the bore (12) penetrate into the material of the component (14) and with their to the bore mouth facing rear edges (47) the anchor wings (28) in the spread-open state prop up. 11. Dowel according to claim 1, characterized in that the anchor element (50) several in the area of the inner end of the tensioning anchor (16) at right angles to this arranged elongated flat anchor wings (52), of which wentptens one part in each case in a perpendicular to the longitudinal center axis of the tensioning anchor Plane is rotatably mounted, the length of the anchor wings (52) approximately the same or slightly shorter than the diameter of the associated bore (12) and its axis of rotation to the longitudinal center axis of the tensioning anchor eccentrically in the vicinity of the bore wall is offset. 12. Dowel according to claim 11, characterized in that the clamping anchor (16) has an elongated shaft (22) on which the anchor wings (52) are mounted are. 13. Dowel according to claim 12, characterized in that the angle of rotation the wing (52) limiting stops are provided, the arrangement of the stops is made so that> the wings (52) when rotated from an aligned one on top of the other Position in the end position are at equal angular distances from one another. 14. Dowel according to claim 11, characterized in that the anchor wing (62) by at least two different from the central longitudinal axis of the tensioning anchor Axes offset in radial directions are rotatably mounted. 15. Dowel according to claim 14, characterized in that the tensioning anchor has a sleeve (64) which can be inserted into the bore (12) and in which the anchor wings (62) are mounted, and that the sleeve in the area of the anchor wing with slots (68) is provided, through which the anchor wing of a lying in the sleeve interior Position can be rotated into a position protruding radially from the sleeve. 16. Dowel according to one of claims 1 to 15, characterized in that that the sizes of the facing, with the material of the component (14) in contact standing surfaces of the anchor element (13; 50) and the outer clamping plate (32) about are the same. 17. Dowel according to one of the preceding claims, characterized in that that the outer clamping plate (32) as flat, perforated for the passage of the clamping anchor Disc with a circumferential edge flange bent over to the surface of the component (14) (35) is formed. 18. Dowel according to claim 8 or 15 and 17, characterized in that that the sleeve (38) is firmly or detachably connected to the clamping plate (32). L e r s e i t e