DOWEL

Description

[0001] The present invention relates to a dowel according to the preamble of claim 1 and an anchoring system according to the preamble of claim 15.

[0002] Dowels are used to attach a fixing object, for example a picture, a ceiling lamp or a hanging cabinet, to an anchoring base, in particular a wall or ceiling of a building.

[0003] Anchors are used in buildings for a wide variety of applications. This includes the use of anchors in wet areas, such as bathrooms and showers. In wet areas, water and moisture can penetrate the hole in the wall base, causing damage. To prevent this damage, extensive additional sealing is usually necessary. However, to avoid the need for this additional sealing, waterproof anchors are commonly used.

[0004] DE 198 45 696 A1 discloses a dowel for receiving a fastening element, e.g., a screw, a hook, or the like, on a surface, which essentially consists of a dowel head and a dowel shaft adjoining it, wherein the dowel has at least one sealing element on the dowel head or in the vicinity of the dowel head.

[0005] DE 20 2020 106 135 U1 discloses a dowel with an anchoring body for anchoring the dowel in a borehole in a substrate and with a sleeve body arranged behind the anchoring body in the insertion direction, wherein the sleeve body has a screw channel into which a fastening element can be inserted, and wherein the sleeve body has a sealing section that circumferentially encloses the screw channel as a closed circumferential wall, wherein a connecting section is arranged on the anchoring body, which projects into the sleeve body, is enclosed by it, and which can be radially expanded by inserting the fastening element into the screw channel, such that when the connecting section is expanded, at least a part of the sealing section is radially movable outwards. The dowel is formed in multiple parts using a multi-component injection molding process with a first and second plastic.

[0006] DE 33 35 841 A1 discloses an expansion dowel with an expansion sleeve that can be expanded by an expansion element, which has an expansion area longitudinally slotted from the insertion-side end and a neck area adjoining it opposite the insertion direction with at least one annular bead projecting into the central bore, wherein the expansion sleeve has a circumferential sealing lip on the outside, opposite the annular bead.

[0007] DE 42 35 864 A1 discloses a dowel for anchoring screws in bores of hollow walls made of elastic plastic in one piece, which can be manufactured by injection molding, wherein during assembly the middle part of the dowel (webs) takes over the function of wings which cause the anchoring of the dowel to the hollow wall.

[0008] DE 20 2006 019 559 U1 discloses an expansion and buckling anchor made of plastic with a resistant anchor foot with an axial through hole for self-tapping a thread, with a closed expansion-pressure-free anchor neck and an intermediate expandable anchor body, wherein the anchor body consists of an anchor jacket which is provided with longitudinal slots which divide the anchor jacket into preferably left-hand spiral expansion legs.

[0009] The object of the present invention is therefore to provide a dowel and an anchoring system for anchoring a fixing object by means of a screw in a bore in an anchoring base, in which a complete sealing of the bore with the dowel and a screw as the anchoring system is ensured with a reliable and secure fastening of the fixing object in different anchoring bases with and without cavities and the dowel is inexpensive to manufacture.

[0010] Furthermore, the dowel should not be blocked when inserting it into the hole.

[0011] This task is solved by a dowel for anchoring a fixing object by means of a screw in a bore in an anchoring base and for sealing the bore, comprising a dowel sleeve with an inner and an outer surface, which includes a front anchoring area for anchoring in the anchoring base and a rear sealing area with sealant for sealing the bore with the dowel and the screw, circumferential sealing rings are formed on the outer surface of the dowel at the rear sealing area as a sealing element, a longitudinally extending guide channel, which is bounded by the inner surface of the dowel sleeve, for receiving the screw, and expansion elements which are formed on the outer surface of the front anchoring area.wherein the anchor is formed in one piece and the inner diameter of the guide channel at the anchoring area is smaller than the inner diameter of the guide channel at the sealing area, wherein the guide channel between the sealing area and the anchoring area is bounded by a transition area that tapers conically from the rear end to the front end of the anchor, and annular grooves are formed longitudinally between the sealing rings, and the volume of each annular groove corresponds to the volume of the sealing ring in front of that annular groove with a deviation of less than 30%. The anchor is formed in one piece and / or in one piece.The anchor is manufactured in a single injection molding process using a single plastic injection mold. This advantageously makes the anchor inexpensive to produce and enables a particularly reliable and effective seal for boreholes in an anchoring base. Preferably, the anchor is manufactured in one piece.

[0012] In an additional variant, the length in the longitudinal direction of the rear sealing area is at least 10% or 15% of the total length of the anchor. Preferably, the length in the longitudinal direction of the rear sealing area is less than 90%, 70%, 50%, 30%, or 20% of the total length of the anchor.

[0013] In another embodiment, the number of sealing rings is greater than 2 or 3.

[0014] Advantageously, the sealing rings have different shapes and / or volumes. In particular, the sealing rings have different shapes in a longitudinal section; preferably, a radial outer end region of the sealing rings is convexly curved and / or flat, and preferably the radial outer end region comprises at least 10%, 20%, or 30% of the radial extent of the sealing ring. Preferably, the sealing rings have a concave curve at a radial inner end region in a longitudinal section, and preferably the radial inner end region comprises at least 10%, 20%, or 30% of the radial extent of the sealing ring. Preferably, the volumes of the sealing rings differ by at least 30%, 50%, 70%, 100%, 150%, 200%, or 300%.

[0015] In In a supplementary embodiment, annular grooves are formed longitudinally between the sealing rings, and the volume of each annular groove corresponds essentially, and in particular with a deviation of less than 20% or 10%, to the volume of the sealing ring upstream of that annular groove. The sealing ring upstream of each annular groove is the immediate sealing ring with a greater distance to the rear end of the dowel than the annular groove. Preferably, the volumes of the annular grooves differ by at least 30%, 50%, 70%, 100%, 150%, 200%, or 300%.

[0016] In In a supplementary embodiment, at least one longitudinal slot, preferably two diametrically opposed longitudinal slots, is formed on the dowel to facilitate the formation of at least one knot and / or at least one interlocking connection. Preferably, the length of the longitudinal slot is at least 10%, 20%, 30%, 40%, or 50% of the length of the dowel.

[0017] In In a further embodiment, a widening is formed at each end, particularly at both ends, of the at least one longitudinal slot, and preferably the widening is bounded by a concavely curved surface of the dowel material to facilitate the formation of at least one knot and / or at least one interlock. Preferably, the extent of the widening in the tangential direction is 10% or 20% greater than the extent and / or width of the remaining longitudinal slot in the tangential direction. Preferably, the longitudinal slot has a substantially constant radial extent and / or width in the tangential direction, particularly with a deviation of less than 10%, 20%, or 30%.The longitudinal slots, preferably in combination with the expansions, increased the deformability of the dowel and thus reduced the stiffness of the dowel, so that knots and / or undercuts occur even with small forces and moments acting on the dowel.

[0018] In In another variant, the outer surface area or the sum of the outer surfaces of the at least one longitudinal slot is between 1% and 40%, in particular between 3% and 30%, of the total outer surface area of ​​the dowel. The total outer surface area of ​​the dowel includes the outer surface area of ​​the at least one longitudinal slot. The outer surface area of ​​the at least one longitudinal slot is the area of ​​the at least one longitudinal slot on the outer surface of the dowel. The total outer surface area of ​​the dowel is the entire outer surface of the dowel.

[0019] Preferably, the maximum radial extension of the dowel at the rear sealing area from the radial end of the sealing rings to a central longitudinal axis of the dowel is greater, in particular by at least 5%, 10%, 20% or 30%, than the maximum radial extension at the front anchoring area from the radial end of the expansion elements to the central longitudinal axis of the dowel.

[0020] In In a further embodiment, an additional section is formed as a head at a front end of the anchor. This additional section functions particularly as a nut to form a knot in the case of cavities in the anchoring base.

[0021] In In another embodiment, no radial projections, in particular no spreading elements, are formed on the outside of the additional area.

[0022] In In another variant, the inner diameter of the guide channel at the anchoring area is less than 50%, 60%, 70%, 80%, 90% or 95% of the inner diameter of the guide channel at the sealing area.

[0023] In In an additional embodiment, the inner diameter of the guide channel at the additional area is smaller than the inner diameter of the guide channel at the anchoring area; in particular, the inner diameter of the guide channel at the additional area is smaller than 50%, 60%, 70%, 80%, 90% or 95% of the inner diameter of the guide channel at the anchoring area.

[0024] An anchoring system according to the invention for anchoring a fixing object by means of a screw in a bore in an anchoring base and for sealing the bore, comprising a dowel for insertion into a bore in the anchoring base and in the fixing object, a screw for insertion into a guide channel of the dowel, wherein the dowel is designed as a dowel as described in this patent application.

[0025] In a further embodiment, the dowel is essentially, and in particular entirely, made of an identical material, especially plastic. "Essentially made of the same material" preferably means that the dowel is made of at least 90%, 95%, or 98% of the same material, where these percentages are expressed as volume percent or mass percent. The material properties, for example, the hardness, of the dowel are thus identical throughout the essentially entire dowel.

[0026] In a complementary variant, the expanding elements are essentially sawtooth-shaped, with a rear end extending substantially in the radial direction and a front end tapering, preferably conically, from the rear end to the front end of the dowel. "Extending substantially in the radial direction" preferably means that the rear end is oriented with a deviation of less than 30°, 20°, or 10° from the radial direction.

[0027] In an additional variant, the length in the longitudinal direction of the rear sealing area is less than 30% of the total length of the dowel.

[0028] In an additional embodiment, the length in the longitudinal direction of the stop element is less than 3%, 5% or 10% of the total length of the dowel.

[0029] In a supplementary embodiment, the guide channel between the anchoring area and the additional area is limited by a transition area that tapers from the rear end to the front end of the dowel, preferably conically.

[0030] In In a further embodiment, an internal sealing ring is formed on the inside of the dowel sleeve at the guide channel. Preferably, the internal sealing ring is formed at the sealing area of ​​the dowel. Preferably, the inner diameter of the internal sealing ring is smaller than the inner diameter outside the internal sealing ring, in particular smaller than the inner diameter of the sealing area. Preferably, the inner diameter of the internal sealing ring is smaller than 98%, 95%, 90%, or 85% of the inner diameter of the rear sealing area and / or a rear end area of ​​the dowel with a length of 5%, 10%, 15%, or 20% of the length of the dowel.

[0031] In In an additional variant, the length of the second, unthreaded section of the screw is greater, specifically by 5%, 10%, 15%, 20%, 25%, 30%, or 40%, than the length of the anchor's rear sealing area. As the screw is screwed into the anchor's guide channel, the entire rear sealing area is thus stretched radially outwards by the second section of the screw, because the diameter of the second section is larger than the inner diameter of the anchor sleeve at the sealing area. Furthermore, as the screw is tightened until the screw head rests on the anchor's stop element, a portion of the second section is also screwed into the anchoring area, resulting in additional radial compression of the outer surface of the anchoring area against the substrate in a specific section of the anchoring area.

[0032] In In another embodiment, the diameter of the second section of the screw is larger, in particular by 2%, 3%, 5%, 10%, 15% or 20%, than the inner diameter of the dowel sleeve at the sealing area.

[0033] In In a further embodiment, the length of the screw is greater, in particular by 5%, 10%, 15%, 20%, 30%, 40% or 50%, than the length of the anchor. When the screw is fully screwed into the guide channel of the anchor, the tip of the screw protrudes from the opening at the front end of the anchor, and a rear end of the screw also protrudes from the opening at the rear end of the anchor; in particular, the screw head rests on the stop element of the anchor.

[0034] In In a supplementary design, the length of the anchoring area is between 10% and 90%, in particular between 30% and 80%, of the length of the dowel.

[0035] In In another variant, the length of the sealing area is between 5% and 70%, in particular between 10% and 50%, of the length of the dowel.

[0036] In In another variant, the length of the additional area is between 5% and 70%, in particular between 10% and 50%, of the length of the dowel.

[0037] In In a further embodiment, the dowel sleeve is cylindrically shaped at the additional area, in particular with a substantially constant thickness and / or without taking into account a tip of the dowel sleeve.

[0038] In In another embodiment, the dowel has a substantially constant radial extent at the front anchoring area from the radial end of the expansion elements to the central longitudinal axis of the dowel and at the additional area from the radial end of the additional area to the central longitudinal axis of the dowel, in particular with a deviation of less than 30%, 20% or 10%.

[0039] In In another variant, the circumferential sealing rings formed on the outside of the dowel in the rear sealing area in the circumferential direction are formed as a sealing agent completely and / or partially circumferentially.

[0040] In In a supplementary variant, the dowel is made of, preferably thermoplastic, plastic, in particular polyethylene.

[0041] In In another variant, the density of the dowel material is between 0.9 g / cm³ and 1.0 g / cm³, in particular between 0.94 g / cm³ and 0.97 g / cm³.

[0042] In In a further embodiment, the Shore hardness (D) of the dowel material is greater than 30, 40, 50 or 55 and / or less than 90, 80 or 70. Circumferential annular grooves are advantageously formed between the sealing rings, particularly completely.

[0043] In another variant, the elastic modulus of the dowel material at 23°C is between 800 and 1400 N / mm².

[0044] In a further embodiment, the screw is made entirely of metal, in particular steel, brass or stainless steel.

[0045] In a supplementary variant, the inside and / or outside of the dowel sleeve is a radial inside and / or radial outside of the dowel sleeve.

[0046] Preferably, at least one stop element is formed on the outside of the dowel sleeve at a rear end area to limit the insertion of the dowel into the bore of the anchoring base.

[0047] In a further embodiment, at least one stop element is designed as a radially projecting collar and / or stop rib.

[0048] In a supplementary variant, the at least one longitudinal slot is essentially straight or curved in the longitudinal direction, preferably helical or spiral-shaped.

[0049] In an additional embodiment, the at least one longitudinal slot is formed completely through the dowel sleeve in the radial direction and / or the at least one longitudinal slot is formed as a longitudinal groove on the inside and / or outside of the dowel sleeve with a residual wall and preferably the radial extent of the residual wall is smaller than the radial extent of the dowel sleeve outside the at least one longitudinal slot.

[0050] In a supplementary embodiment, several longitudinal slots are formed successively in the longitudinal direction on the dowel, and preferably, with regard to the length of these longitudinal slots formed successively in the longitudinal direction, this length is assumed to be the sum of the lengths of these longitudinal slots, i.e., considered as only one longitudinal slot.

[0051] In a further embodiment, the at least one longitudinal slot has a substantially constant width, in particular with a deviation of less than 30%, 20% or 10%, and / or the at least one longitudinal slot has a variable width. The width of the at least one longitudinal slot is its circumferential extent, in particular on the outside of the dowel.

[0052] Preferably, the stop element is designed essentially in the tangential direction. The at least one stop element has a radial extension, an axial extension, and a tangential extension, and the tangential extension, i.e., the extension in the circumferential direction, is 2, 4, 6, or 8 times greater than the radial and / or axial extension.

[0053] In a supplementary variant, the guide channel of the dowel is conically tapered in one direction from a rear end of the dowel to the front end of the dowel at at least one tapering section, in particular at a transition area from the sealing area to the anchoring area and / or from the anchoring area to the additional area.

[0054] In a further embodiment, the guide channel of the dowel is formed in a direction from a rear end of the dowel to the front end of the dowel on at least one diameter section with a substantially constant diameter, in particular with a deviation of less than 30%, 20% or 10%, especially on the sealing area and / or on the anchoring area and / or on the additional area.

[0055] In a further embodiment, the geometry and / or shape of the spreading elements, in particular all spreading elements, is identical.

[0056] In a further embodiment, the expansion elements are integrally connected to the dowel, in particular the dowel sleeve.

[0057] Advantageously, the anchor sleeve of the anchor can be expanded by the screw due to the elastic and / or plastic properties of the anchor sleeve. In a further embodiment, an elongation c = ΔI / l 0 greater than 200% can be achieved with the anchor material.

[0058] An embodiment of the invention will be described in more detail below with reference to the accompanying drawings.

[0059] It shows: Fig. 1 a side view of a dowel, Fig. 2 a longitudinal section of the dowel according to Fig. 1 , Fig. 3 a side view of an anchoring system with the dowel according to Fig. 1 and a screw, Fig. 4 a longitudinal section of the anchoring system according to Fig. 3 , Fig. 5 an enlarged longitudinal section of the dowel according to Fig. 2 at a rear sealing area, Fig. 6 a perspective view of the anchoring system according to Fig. 3 , Fig. 7 a perspective view of the screw according to Fig. 3 , Fig. 8 a perspective view of the dowel according to Fig. 1 and Fig. 9 another perspective view of the dowel according to Fig. 1 .

[0060] A dowel 1, also known as a universal dowel 2, serves to fix an object (not shown), for example, a picture, a ceiling light, or a wall cabinet, in a substrate (not shown), for example, a wall or reinforced concrete ceiling of a building. The dowel 1, together with a screw 4, forms an anchoring system 3 ( Fig. 4 and 6) for anchoring a fixing object to the anchoring base. The screw 4, made of metal, preferably steel, in particular stainless steel, with a syringe 5, has a partial external thread. On a first section 7 of the screw 4, the screw 4 has the external thread and a small diameter, and on a second cylindrical section 8, the screw 4 has no external thread and a larger diameter than on the first section 7. Between the first section 7 and the second section 8, a conically tapered intermediate section without an external thread is formed ( Fig. 4 and 7At one rear end of the screw 4, a screw head 6 with a positive locking geometry is formed for applying torque to the screw 4. The anchor 1, as a universal anchor 2 or an all-purpose anchor 2, enables fixing in the anchoring base by knotting (formation of a knot) and / or forming an interlock and / or expansion. Expansion is used particularly in solid building materials as anchoring bases without a cavity, while knotting and / or forming an interlock is used in anchoring bases with a cavity, for example, a hollow brick.

[0061] The dowel 1 is essentially formed by a dowel sleeve 9. The dowel 1 is made entirely of plastic, namely HDPE (high-density polyethylene). The dowel 1, including all geometric features, is formed in one piece and is manufactured by injection molding in a single injection mold in one operation. The cylindrical dowel sleeve 9 has an outer surface 10 and an inner surface 11. The inner surface 11 defines a guide channel 19. The central and axial guide channel 19 is essentially cylindrical with three different diameters. The guide channel 19 terminates at a front end 13 of the dowel 1 in a front opening 15, and at a rear end 14 of the dowel, the dowel sleeve 9 terminates in a rear opening 16. The front opening 15 and the rear opening 16 are essentially circular in cross-sectional shape. A conically tapered tip 12 is formed at the front end region of the dowel 1. The dowel 1 has a fictitious central longitudinal axis 32.A longitudinal direction 33 is aligned parallel to the longitudinal axis 32, a radial direction 35 or a transverse direction 35 is aligned perpendicular to the longitudinal axis 32. Furthermore, the dowel 1 has a tangential direction 34 and a circumferential direction 34 running around the outside 10 of the dowel (. Fig. 1 The dowel 1 is divided longitudinally 33 into three areas: a rear sealing area 20, a middle anchoring area 21 as an expansion area 21, and a front auxiliary area 22 as a head 22. The dowel 1, for example, has a length 36 of 7 cm, this length 36 being subdivided into a length 37 of the sealing area 20 of approximately 1.5 cm, a length 38 of the anchoring area 21 of approximately 4 cm, and a length 39 of the auxiliary area 22 of approximately 1 cm, as well as a negligible length of a stop element 17. The length 38 of the anchoring area 21 thus corresponds approximately, in particular with a deviation of less than 30%, 20%, or 10%, to the sum of the lengths 37 and 38 of the rear sealing area 20 and the auxiliary area 22.

[0062] On the outer surface 10 of the dowel sleeve 9, at the rear sealing area 20, sealing rings 26 are formed completely circumferentially 34. The sealing rings 26 have two different shapes. The sealing rings 26, 27 have the following shapes in the longitudinal section according to Fig. 5 The radial end region has only a convex surface. The sealing rings 26, 28 are shown in the longitudinal section according to Fig. 5 The radial end region is flat and convex. The longitudinal extent of the sealing rings 28 is therefore significantly larger, in particular by 10%, 20%, 30%, or 40%, than the longitudinal extent of the sealing rings 27. Thus, annular grooves 29 are formed between the sealing rings 26 in the circumferential direction 34. The volume of the sealing rings 28 is also significantly larger than the volume of the sealing rings 27. The volume of the annular grooves 29 between the sealing rings 26, 27, and 28 differs significantly. The volume of each annular groove 29 corresponds approximately, in particular with a deviation of less than 10%, 30%, or 50%, to the volume of the sealing ring 26 in front of that annular groove 29, i.e., the sealing ring 26 with the greater distance to the rear end 14 of the dowel 1. Fig. 5 Furthermore, the geometry of each annular groove 29 is approximately complementary to the geometry of the sealing ring 26 in front of this annular groove 29, i.e., the sealing ring 26 with the greater distance to the rear end 14 of the dowel 1, wherein the geometry of the annular groove 29 is shown in section in Fig. 5 This corresponds to the geometry of the sealing ring 26, which is folded inwards by 180°. When the anchor 1 is inserted into a bore in an anchoring base, any material scraped off the anchor 1, particularly material from the sealing rings 26, can thus be deposited in the annular grooves 29, so that the insertion of the anchor 1 into the bore is not blocked by the scraped material. The anchor 1 has a total of six sealing rings 26. An external taper 53 is formed at the end region of the outer surface 10 of the rear sealing area 20, in the direction of the front end 13 of the anchor 1. The outer diameter 40 of the sealing area 20 is larger than the outer diameter 40 of the anchoring area 21, so that the outer taper 53 prevents a positive locking blockage of the insertion of the dowel 1 into the bore of the anchoring base when the dowel 1 is inserted into the bore of the anchoring base.At the rear end 14 of the dowel 1, the stop element 17 is also designed as a collar 17. The ring-shaped stop element 17 serves as a stop and for blocking when the dowel 1 is inserted into the bore in the anchoring base.

[0063] A large number of expansion elements 23 are formed on the outer surface 10 of the anchoring area 21, which is called the expansion area 21. The expansion elements 23 are partially annular, i.e., they are only partially formed with interruptions in the circumferential direction 34. In a central area 33 along the longitudinal axis, the expansion elements 23 are completely continuous in the tangential direction 34, except for the interruption at two longitudinal slots 30. A stop surface, extending substantially in the radial direction 35, is present at a rear end 25 of the expansion elements 23. A tapered ramp is formed at a front end 24 of the expansion elements 23. Between the rear end 24 with the stop surface and the front end 24, which is the tapered ramp surface, a region of the expansion element 23 is formed with a constant radial distance to the longitudinal axis 32.The stop surface at the rear end 24 serves for the positive locking fixation of the dowel 1 in the anchoring base, functioning as an expansion dowel 2. Furthermore, anti-rotation features 18 are formed on the outer surface 10 of the anchoring area 21. The anti-rotation features 18 are essentially designed as webs extending in the longitudinal direction 33. The extension of the anti-rotation devices 18 in the longitudinal direction 33 is thus significantly larger than in the circumferential direction 34; in particular, the extension in the longitudinal direction 33 is 2, 4, 6, or 8 times larger than the extension in the circumferential direction 34. Furthermore, the radial extension of a radial end of the anti-rotation devices 18 decreases towards the central longitudinal axis 32 in the direction of the front end 13 of the dowel 1; that is, the radial end of the anti-rotation devices 18 is tapered, in particular conically tapered, in the direction of the front end 13 of the dowel 1.Due to the tapered, and in particular continuously tapered, design of the radial end of the anti-rotation features 18, the anti-rotation features 18 do not obstruct the insertion of the anchor 1 into the anchoring base. The anti-rotation features 18 ensure that, during the screwing of the screw 4 into the guide channel 19, the torque applied by the screw 4 to the inner surface 11 of the anchor sleeve 9 does not cause a rotational movement of the anchor 1 in the bore in the anchoring base; that is, the outer surfaces of the anti-rotation features 18 in the circumferential direction result in a positive locking fixation of the anchor 1 in the anchoring base. Furthermore, two opposing longitudinal slots 30 are formed in the anchoring area 21. The diametrically opposed longitudinal slots 30 each have a widening 31 at their ends. The widening 31 are bounded by a concavely curved surface of the anchor 1 material.The longitudinal slots 30, in combination with the expansions 31, increased the deformability of the anchor 1 and thus reduced its stiffness, so that knots and undercuts form even under lower forces and moments acting on the anchor 1. As a result, fewer cracks advantageously form in the anchor 1 when knots and undercuts are necessary. The formation of knots and undercuts is necessary for the positive locking of the universal anchor 1 in cavities of the anchoring base. Knots and undercuts are deformations of the anchor 1 due to a reduction in its length 36 and exhibit a greater radial distance from the central longitudinal axis 32 of the anchor 1 than the outer surface 10 of the anchor 1 before the deformation. The longitudinal slots 30 have a substantially constant width, i.e. preferably a constant width with a deviation of less than 30%, 20% or 10%.

[0064] At the front end of the dowel 1, the additional section 22 is designed as a head 22. The additional section 22 thus forms the front end 13 of the dowel 1. The rear sealing section 20 forms the rear end 14 of the dowel 1. In the longitudinal direction 33, the anchoring section 21 is thus formed between the additional section 22 and the rear sealing section 20. The additional section 22 is essentially cylindrical, except for the conically tapered tip 22. There are no protrusions on the outer surface 10 of the additional section 22. The additional section 22 functions as a nut.If cavities are present in the anchoring base at the borehole, the rotational movement of the screw 4 causes the additional section 22 to move as a spindle on the screw 4 towards the rear end 14 of the anchor 1, thereby compressing the remaining anchor 1, particularly at the anchoring area 21, in the longitudinal direction 34. This results in the formation of at least one node and / or at least one undercut with a large radial extent, which is inserted into the cavity at the anchoring base in the radial direction 35. The resulting at least one node and / or at least one undercut is thus positively locked into the cavity of the anchoring base, effectively acting as an anchor. This enables the anchor 1 to function effectively as a universal anchor 2 with the formation of the at least one node and / or at least one undercut.

[0065] The dowel 1 has an outer diameter of 40 and an inner diameter of 41. In the sealing area 20, the dowel 1 has an inner diameter of 42. In the anchoring area 21, the dowel 1 has an inner diameter of 43. In the additional area 22, the dowel 1 has an inner diameter of 44. The inner diameter 44 at the additional section 22 of the dowel 1 is smaller than the inner diameter 43 at the anchoring section 21, in particular smaller than 98%, 95%, 90%, or 85% of the inner diameter 43 at the anchoring section 21. The inner diameter 43 at the anchoring section 21 is smaller than the inner diameter 42 at the sealing section 20, in particular smaller than 98%, 95%, 90%, or 85% of the inner diameter 42 at the sealing section 20. Thus, a transition section 48 is formed in the guide channel 19 between the sealing section 20 and the anchoring section 21, and is a transition section 48 that tapers, in particular conically.In the guide channel 19, a transition area 49 is formed between the anchoring area 21 and the auxiliary area 22, tapering in a conical manner. The inner diameter 44 of the auxiliary area 22 is significantly smaller, particularly by at least 10%, 20%, or 30%, than the diameter of the screw 4 on the first section 7. This results in a sharp increase in the torque required to tighten the screw when it is screwed into the auxiliary area 22, which acts as a nut. To prevent this increase in torque from occurring too rapidly during tightening, the transition area 49 is designed with a conically tapered phase. An internal sealing ring 50 is formed in the guide channel 19 of the sealing area 20 in the region of the rear opening 16. Fig. 5 The inner diameter 51 of the inner sealing ring 50 is smaller than the inner diameter 42 of the remaining sealing area 20 outside the inner sealing ring 50. The inner sealing ring 50 is formed by two tapers 52 in the direction of the inner sealing ring 50 at the area with the minimum inner diameter 51. The inner sealing ring 50 serves to effectively seal between the screw 4, i.e., the second section 8 of the screw 4, and the inner surface 11 of the dowel sleeve 9. Due to the small inner diameter 51 of the inner sealing ring 50, the inner sealing ring 50 bears against the outside of the second section 8 of the screw 4 with a particularly large radial compressive force.

[0066] The sealing rings 26 have a maximum radial extension 45 from the radial end of the sealing ring 26 to the central longitudinal axis 32. The expanding elements 23 have a maximum radial extension 46 from the radial end of the expanding elements 23 to the central longitudinal axis 32. Fig. 2 The outer surface 10 of the additional area 22 has a maximum radial extension 47 from its radial end to the central longitudinal axis 32. The maximum radial extension 47 of the outer surface 10 of the dowel 1 at the additional area 22 corresponds essentially, in particular with a deviation of less than 30%, 20%, 10% or 5%, to the maximum radial extension 46 of the radial end of the expansion elements 23 to the central longitudinal axis 32.

[0067] The maximum radial extension 46 of the radial end of the expansion elements 23 to the central longitudinal axis 32 is smaller than the maximum radial extension 45 of the radial end of the sealing rings 26 to the central longitudinal axis 32, in particular less than 98%, 95%, 90%, or 85% of the maximum radial extension 45 of the radial end of the sealing rings 26 to the central longitudinal axis 32. The sealing rings 26 thus have, apart from the stop element 17, the maximum radial distance to the central longitudinal axis 32, so that the sealing rings 26 bear the greatest radial compressive force on the anchoring base and thereby ensure a very effective seal of the bore in the anchoring base to the outer surface 10 of the anchor 1.The sealing rings 28 with the larger volume serve in particular to increase the radial compressive force between the inner surface 11 of the anchor 1 and the screw 4 on the second section 8, thus increasing the tightness between the screw 4 and the anchor 1. The sealing rings 27 with the smaller volume serve in particular to increase the tightness between the anchor 1 and the anchoring base in the bore.

[0068] The anchoring system 3 is formed by the dowel 1 and the screw 4 ( Fig. 4 and 6To form the anchoring system 3, a bore is first drilled into the anchoring base using a drill bit (not shown). The anchor 1 is then inserted into this bore until the stop ring 17 rests against the anchoring base and the outer end of the bore. Next, the tip 5 of the screw 4 is inserted into the opening 16 at the rear end 14 of the anchor 1, and then a torque is applied to the screw 4 by means of the positive locking elements on the screw head 6, causing the screw 4 to rotate about its central longitudinal axis 32. The screw 4 and the anchor 1 are essentially coaxial and concentric with each other.During the screwing of the screw 4 into the guide channel 19 of the anchor 1, the thread of the first section 7 of the screw 4 is pressed into the material on the inside 11 of the anchor 1, in particular at the anchoring area 20 and the additional area 22, so that a corresponding internal thread is formed on the inside 11 by the external thread of the first section 7 of the screw 4. The screw 4 is screwed in until the tip 5 of the screw 4 has passed through the opening 15 of the anchor 1 and protrudes from the guide channel 19. Fig. 4The outer diameter of the second section 8 of the screw 4 is larger, in particular by 5%, 10%, 20%, or 30%, than the inner diameter 42 of the anchor sleeve 9 at the sealing area 20. This ensures that the sealing area 20, with the sealing rings 26, is pressed against the anchoring base with a particularly high radial compressive force, thus guaranteeing a very effective seal. The diameter of the first section 7 of the screws 4 and also the diameter of the second section 8 of the screw 4 are larger than the inner diameter 43 of the anchor sleeve 9 at the anchoring base. Therefore, when the screw 4 is screwed into the anchor 1, the expansion elements 23 are pressed into the anchoring base with a high radial compressive force, creating a positive and non-positive connection between the expansion elements 23 and the anchoring base.Insofar as cavities are present in the anchoring base, further screwing in of the screw 4 causes a movement of the additional area 22 as a functional nut in the longitudinal direction 33 towards the rear end 14 of the dowel 1, so that at least one node and / or at least one undercut is formed by the remaining dowel 1 outside the additional area 22, in particular by the anchoring area 21, and the length 36 of the dowel 1 is reduced.

[0069] Overall, the dowel 1 and the anchoring system 3 according to the invention offer significant advantages. The dowel 1 is manufactured cost-effectively in a single injection molding process. Due to the material properties of the plastic used in the dowel 1 and its geometric design, for example, with the sealing rings 26 on the outer surface 10 of the dowel sleeve 9 and the inner sealing ring 50 on the inner surface 11 of the dowel sleeve 9, a particularly effective and reliable seal of the borehole in the anchoring base is ensured. Moisture and water, especially in wet rooms such as bathrooms, are thus prevented from entering the borehole of the anchoring base, thereby advantageously eliminating any resulting damage to a building.

Claims

1. Screw anchor (1) for anchoring, by means of a screw (4) in a hole in an anchoring base, an object to be fixed, and for sealing the hole, comprising - a screw anchor sleeve (9) having an inner face (11) and an outer face (10), which screw anchor sleeve comprises a front anchoring region (21) for anchoring in the anchoring base and a rear sealing region (20) having sealing means (26) for sealing the hole by means of the screw anchor (1) and the screw (4), - peripheral sealing rings (26) are formed as the sealing means (26) on the outer face (10) of the screw anchor (1) at the rear sealing region (20) in a circumferential direction (34), - a guide channel (19) extending in a longitudinal direction (33) and delimited by the inner face (11) of the screw anchor sleeve (9), which guide channel is for receiving the screw (4), - spreading elements (23) which are formed on the outer face (10) at the front anchoring region (21), - the screw anchor (1) being formed in a single piece and the inner diameter (43) of the guide channel (19) at the anchoring region (21) being smaller than the inner diameter (42) of the guide channel (19) at the sealing region (20), characterized in that the guide channel (19) is delimited between the sealing region (20) and the anchoring region (21) by a transition region (48) which tapers conically from the rear end (14) to the front end (13) of the screw anchor (1), and ring grooves (29) are formed between the sealing rings (26) in the longitudinal direction (33) and the volume of each ring groove (29) corresponds, having a deviation of less than 30%, to the volume of the sealing ring (26) in front of this ring groove (29).

2. Screw anchor according to claim 1, characterized in that the length (37) in the longitudinal direction (33) of the rear sealing region (20) is at least 10% or 15% of the total length (36) of the screw anchor (1).

3. Screw anchor according to one or more of the preceding claims, characterized in that the number of sealing rings (26) is greater than 2 or 3.

4. Screw anchor according to one or more of the preceding claims, characterized in that the sealing rings (26) have a different shape and / or a different volume.

5. Screw anchor according to one or more of the preceding claims, characterized in that ring grooves (29) are formed in the longitudinal direction (33) between the sealing rings (26) and the volume of each ring groove (29) corresponds substantially, in particular having a deviation of less than 20% or 10%, to the volume of the sealing ring (26) in front of this ring groove 29.

6. Screw anchor according to one or more of the preceding claims, characterized in that at least one longitudinal slot (30), preferably two diametrically opposite longitudinal slots (30), is or are formed on the screw anchor (1) in order to facilitate the formation of at least one nub and / or at least one undercut.

7. Screw anchor according to claim 6, characterized in that a widening (31) is formed at each end, in particular at the two ends, of each at least one longitudinal slot (30) and the widening (31) is preferably delimited by a concavely curved surface of the material of the screw anchor (1) in order to facilitate the formation of at least one nub and / or at least one undercut.

8. Screw anchor according to claim 6 or 7, characterized in that the outer surface or the total of the outer surfaces of the at least one longitudinal slot (30) is between 1% and 40%, in particular between 3% and 30% of the total outer surface of the screw anchor (1).

9. Screw anchor according to one or more of the preceding claims, characterized in that a maximum radial extension (45) of the screw anchor (1) at the rear sealing region (20) from the radial end of the sealing rings (26) to a central longitudinal axis (32) of the screw anchor (1) is greater than the maximum radial extension (46) at the front anchoring region (21) from the radial end of the spreading elements (23) to the central longitudinal axis of the screw anchor (1).

10. Screw anchor according to one or more of the preceding claims, characterized in that an additional region (22) is formed as a head (22) at a front end region of the screw anchor (1).

11. Screw anchor according to claim 10, characterized in that no radial projections, in particular no spreading elements (23), are formed on the outer face (11) of the additional region (22).

12. Screw anchor according to one or more of the preceding claims, characterized in that the length in the longitudinal direction (33) of the rear sealing region (20) is less than 30% of the total length of the screw anchor (1).

13. Screw anchor according to one or more of claims 10 to 12, characterized in that the inner diameter (44) of the guide channel (19) at the additional region (22) is smaller than the inner diameter (43) of the guide channel (19) at the anchoring region (21).

14. Screw anchor according to one or more of the preceding claims, characterized in that an outer taper (53) is formed at the end region of the outer face (10) of the rear sealing region (20) in the direction toward the front end (13) of the screw anchor (1).

15. Anchoring system (2) for anchoring, by means of a screw (4) in a hole in an anchoring base, an object to be fixed, and for sealing the hole, comprising - a screw anchor (1) for inserting into each hole in the anchoring base, - a screw (3) for inserting into a guide channel (13) of the screw anchor (1), characterized in that the screw anchor (1) is designed according to one or more of the preceding claims.