SK286187B6 - Plug for fixing to hollow and to solid building materials - Google Patents

Abstract

Plug (10) for fixing to hollow and to solid building materials, having longitudinally expansible limbs (18) that are expansible by screwing an expansion screw (44) into the plug (10), the expansible limbs (18) being joined to one another at the rear end by sleeve-form plug end (14), through which the expansion screw (44) is insert able, and at the leading end by a sleeve-form plug tip (16), into which the expansion screw(44) can be screwed. The expansible limbs (18) are joined to one another circumferentially by a stretchable material (22) that is pierced by several helically arranged slots (24).

Description

Technical field

BACKGROUND OF THE INVENTION The invention relates to an anchor for fastening in hollow and solid building materials with longitudinally extending arms which are expandable by screwing an expansion screw into the anchor, the expansion arms at the rear end being connected to each other by a sleeve end of the anchor at the front end, they are connected by a sleeve-shaped anchor tip into which an expanding screw can be screwed. Hollow building materials are, for example, hollow bricks or slabs behind which a cavity is located. Full building materials are, for example, concrete and the like.

BACKGROUND OF THE INVENTION

Such anchors are known. They are generally made of plastic and have a longitudinally extending expansion sleeve (s) or arms in the central region, which are (are) separated by notches, see DE-A-19 600 931 , DE-A-19 855 139 and US-A-4 861 206. At the rear end, the expansion arms are connected to each other by the sleeve end of the armature and at the front end by the sleeve end of the armature. The expansion screw can be pushed through the sleeve end of the anchor and screwed into the tip of the anchor. To fix the anchor in solid building material, the anchor is inserted into the bore in solid building material and an expansion screw is screwed into the anchor. The expansion screw pushes the expansion arms apart, i. j. the expansion screw expands the expansion arms and thereby anchors the anchor in the borehole in solid building material.

In the hollow building material or in the plate, the anchor is pushed through the bore, so that the sleeve-like end of the anchor is located in the hollow building material. Subsequently, the expansion screw is pushed through the end of the armature, guided between the expansion arms and screwed into the tip of the armature. By screwing the expansion screw into the anchor tip, it moves to the end of the anchor, while the expansion arms expand. Two expansion possibilities are known. The first is that by expanding the anchor tip to the end of the anchor, the expanding arms deflect outwardly and thereby engage in positive contact with the hollow building material. A second possibility is that the anchor tip rotates against the end of the anchor when the expansion screw is screwed in, whereby the expansion arms twist around each other and form a knotted formation which engages in the hollow building material.

Known anchors have the disadvantage of poor screw guidance, the expansion screw can laterally protrude through the notches between the expansion arms when screwing. A further disadvantage of the known anchor is its slight torsional stiffness, which, when the expansion screw is screwed in, leads to an elastic push-through of the anchor tip against the end of the anchor. When the expansion screw is screwed by hand, the elastic turning of the anchor tip relative to the end of the anchor causes the anchor tip to turn back together with the expansion screw screwed into it when the screwdriver is released for "next engagement". As a result, the expansion screw can hardly be screwed into the armature by hand.

SUMMARY OF THE INVENTION

The object of the invention is to avoid these disadvantages.

This object is achieved according to the invention in an anchor of the kind mentioned at the outset in that the expansion arms are connected to one another in a circumferential direction by a stretchable material which is interrupted by a plurality of screw-like notches.

A preferred embodiment of the invention is that the anchor end has a larger diameter than the anchor in the region of the expansion arms and the anchor tip.

Another advantageous embodiment of the invention consists in that at least two opposing and extending longitudinally extending ribs are arranged on the outer circumference of the anchor, which are formed in a sawtooth manner over a part of their length.

Another preferred embodiment of the invention is that the anchor tip has angularly angled notches, wherein one notch leg has a pitch in the direction of the thread of the expansion screw and the other leg has a pitch in the opposite direction.

A further advantageous embodiment of the invention consists in that the anchor screw channel for the expansion screw has a cross-section deviating from the circular shape inside the anchor tip.

A further preferred embodiment of the invention is that the screw channel has a flat cross section at least inside the anchor tip. A further advantageous embodiment of the invention consists in that the screw channel is in the form of a notch. A further preferred embodiment in such a case according to the invention is that the screw channel has the shape of two intersecting notches.

Another advantageous embodiment according to the invention consists in that the anchor tip has two opposing notches running in the longitudinal direction of the anchor, the bottom of which is spaced from the screw channel.

In other words, in the armature according to the invention, the expansion arms in the circumferential direction are connected to each other by a stretchable material which is interrupted by a plurality of helically arranged notches. For elongation, the material can be made thin and / or undulated in the circumferential direction of the anchor. In the manufacture of the plastic anchor, the stretchable material is preferably one piece with expansion arms and thus consists of the same plastic as the rest of the anchor. In this case, the stretchable material is preferably made as thin as a plastic film. By connecting the expansion arms in the circumferential direction, the anchor of the invention takes the form of a sleeve which is also closed in the circumferential direction in the region of the expansion arms. This achieves good guidance of the expander bolt and prevents the expander bolt from laterally protruding from the anchor between the expander arms, even if the expander bolt is laterally stressed. Another advantage of joining the expansion arms in the circumferential direction is the increased torsional rigidity of the armature. In particular, the increased torsional stiffness has the advantage that the anchor tip is less co-rotating when the expansion screw is screwed in, whereby the expansion screw can be better screwed into the anchor tip. Furthermore, the increased stiffness has the cruel advantage that the anchor tip is less reversed when the tightening torque is released, i.e. when the screwdriver is further engaged. This makes it easier to screw the expansion screw into the anchor, especially when screwing the hands. In addition, the anchor according to the invention has the advantage that the torque of the expansion screw decreases less strongly after the start of the expansion in the hollow building material. With known expansible anchors, the torque decreases sharply if the expander arms start to swerve or twist around each other when fixing the anchor to the hollow building material. The increased stiffness of the anchor according to the invention due to the connection of their expanding arms in the circumferential direction makes this effect at least less. The effect of a strong decrease in the rotational torque when screwing in the expander bolt is disadvantageous, since it gives the impression that the expander bolt or anchor is torn apart by excessive overload and therefore do not have a firm seat in the hollow building material.

The torsional stiffness of the elongated material is only insignificantly reduced by the screw-like notches in the elongate material, but the formation of a bulge on the back of the hollow building material or board is promoted so that both arms almost completely and large-scale abut the bore on the back of the hollow building material. In particular, the indentations prevent uncontrolled tearing of the elongate material in the final beading phase, which in an unfavorable case may lead to a complete breaking of the connection between the two expansion arms and, depending on the circumstances, tearing of the anchor tip.

In an embodiment of the invention, the sleeve end of the anchor has a larger diameter than the other part of the anchor. The purpose of this embodiment is to provide good anchorage in the hollow or plate-like building material, in which the anchor is retained in the bore substantially only by the sleeve end of the anchor, and the remainder of the anchor is in the cavity.

In an embodiment of the invention, the anchor on the outer periphery has at least two opposing and longitudinally extending ribs for securing against twisting, which are formed saw-like over a part of their length. The anti-torsion ribs retain the torque generated when the expansion screw is screwed in and thus prevent the anchor from rotating. The saw-like design of the ribs for securing against rotation over a part of their length, in particular in the region of the expanding arms, results in interruptions which, on the one hand, allow easy anchoring of the anchor into the bore by forming scraping edges.

In an embodiment of the invention, the sleeve-shaped anchor tip is provided with angled notches, for example in the form of a "V", wherein the projection or tip of the notches preferably points to the front or rear end of the anchor. By their angular deflection, the slits have one leg with a pitch in the direction of the thread of the expansion screw and a second leg with a reverse pitch. The pitch of the slots at the anchor tip may deviate from the pitch of the expansion screw thread, only its direction being directed in the same or vice versa. The arms of the angular slots, the pitch of which extends in the direction of the pitch of the expansion screw thread, serve to engage the speed of the expansion screw thread, causing good adaptation to different screw diameters. The angled slots cause reliable engagement of the small-diameter expansion screw without pulling the expansion screw from the anchor tip when tightening the expansion screw. At the same time, the angled slots prevent a high torque rise when the expansion screw with a large screw diameter is screwed on.

The arms of the angular notches, the pitch of which is set against the pitch of the expansion screw thread, cause axial elongation of the anchor tip, thereby varying the axial spacing of the angular notches located axially one behind the other at the anchor tip. This achieves adaptation to the different pitches of the expansion screw thread.

In an embodiment of the invention, the anchor has a screw channel for an expansion screw having a cross-section deviating from a circular shape inside the sleeve-shaped anchor tip. Thus, the screw channel has different transverse dimensions inside the anchor tip in different directions. This measure also serves to adapt the anchor to different diameters of the expansion screws. In another embodiment, the screw channel within the anchor tip has a flat screw channel, for example in the form of a notch. The screw channel may also have two intersecting notches inside the anchor tip.

Finally, the anchor tip may have two oppositely extending axial slits, the bottom of which is spaced from the screw channel. This embodiment achieves a further reduction in the torque for screwing in when the expansion screw is screwed into the anchor tip, since the elongation of the anchor tip is improved by the notches.

BRIEF DESCRIPTION OF THE DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be explained in more detail with reference to the drawings, in which: FIG. 1 shows a perspective view of the anchor according to the invention, FIG. 2 is a side view of the anchor of FIG. 1; FIG. 3 shows the anchor of FIG. 1 in axial section A-A; FIG. 4 and 5 are cross-sections along planes I-I and II-II; and FIG. 6 and 7 show two examples of the use of the anchor of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

The anchor 10 according to the invention shown in FIG. 1-3 is made of plastic, it has approximately the shape of a housing. The armature 10 has a screw channel 12 for an expansion screw 44, which is not shown in FIG. 1-3 which axially extends the armature 10 and tapers conically in two places.

In the rear region, the anchor 10 has an anchor end 14 of the anchor 10, in the front region a sleeve-shaped tip 16 of the anchor 10, the anchor tip 16 being connected in one piece to the end 14 of the anchor 10 by two extending arms 18 extending in the longitudinal direction. The expansion arms 18 define an expansion region 20 of the armature 10 that extends from the end 14 of the armature 10 to the tip 16 of the armature 10. In the circumferential direction, the expansion arms 18 are connected to each other by an elongate material 22 which is interrupted by a plurality of helically arranged notches 24. of the same material as the rest of the armature 10, the stretchable material 22 is a one-piece part of the armature 10. The stretchable material 22 is formed as a thin film that connects the expansion arms 18 in the circumferential direction with each other (cf. cross section II of the expansion region 20 in FIG. 4). The thin film has a corrugation in the circumferential direction. The thin film, both by its ripple and by its thin design and the elongation of the plastic of which it consists, can be elongated in the circumferential direction of the armature 10. The screw-like notches 24 support the deposition of the extension arms 18 shown in FIG. at the same time tearing thin for the pull material 22.

On the outer periphery of the armature 10, starting from the end 14 of the armature 10, two opposing anti-pivot ribs 28 extending in the longitudinal direction of the armature 10 extend over the expansive region 20 out to the tip 16 of the anchor 10. formed in a part of its length in a saw-like manner, the perpendicularly standing leading edge 30 points in the direction of the tip 16 of the anchor 10.

The sleeve tip 16 of the armature 10 is provided with angled slots 32 whose tip or apex is directed forward. The notches 32 are disposed opposite to the tip 16 of the armature 10 at two locations, and a plurality of notches 32, here three, are disposed on the tip 16 of the armature 10 at an axial distance from each other. The angled slits 32 have arms 36, 38, the arm 36 having a pitch in the direction of the thread of the expansion screw 44, not shown in FIG. 1-3, and the second arm 38 has a pitch in the opposite direction. The pitch of the arm 36 need not coincide with the pitch of the thread of the expansion screw 44, the pitch only going in the same direction.

The screw channel 12 has an approximately circular cross section in the region of the end 14 of the armature 10, tapers in the expansion region 20 (FIG. 4) and is notched at the tip 16 of the armature 10 (FIG. 5). This allows good adaptation of the screw channel 12 to the expansion screws 44 of different diameters. For the same purpose, the two oppositely extending notches 39 in the region of the tip 16 of the anchor 10, the bottom of which extends from the screw channel 12, serve the same purpose.

The function of the armature 10 according to the invention will be explained on the basis of FIG. 6 and 7. FIG. 6 shows the fastening of the object 40 to the sheet building material 42. The anchor 10 is inserted into the bore in the sheet building material 42. Due to the larger diameter of the end 14 of the anchor 10 extends the end 14 of the anchor 10 and reinforces the building material surrounding the end 14 of the anchor 10. The anti-twist means 28 provide support surfaces that prevent the anchor 10 from co-rotating when the expansion screw 44 is screwed on.

Upon insertion of the anchor 10, the fastened object 40, provided with a bore, is held on the plate building material 42, and the expander bolt 44 is pushed through the object 40 and screwed into the anchor 10. The screw thread 46 of the expander bolt 44 is cut into the tip 16 of the anchor 10 and screw the thread 46 engages the arms 36 of the angled notches 32 having a pitch in the same direction as the screw thread 46 of the expansion screw 44. The arms 38 of the angled notches 32 having a pitch in the opposite direction allow axial extension of the anchor tip 16 so that the axial spacing of the notches 32 adapts to the pitch of the screw thread 46. In connection with the notch-shaped screw channel 12, flat at the tip 16 of the anchor 10, the angled notches 32 cause the tip 16 of the anchor 10 to align well with the diameter of the expanding bolt 44 as well as its pitch. thread 46.

Upon screwing in and tightening, the expander bolt 44 pulls the anchor tip 16 in the direction of the anchor end 14, the distance between the anchor tip 16 and the anchor end 14 decreases. In this case, the expansion arms 18 5 knot twist around each other so that the expansion arms 18 of the anchor 10 engage the sheet-like building material 42 by positive fit, thereby giving a good anchorage of the anchor 10 even to the sheet-like building material 42 of less strength, such as plasterboard.

In FIG. 7 shows anchoring of the article 40 on a solid building material 48, such as concrete. Here, the expansible anchor 10 is inserted in a manner known per se into the bore 50 in the full building material, the article 40 is sucked in and the expander bolt 44 is pushed through the object 40 and screwed into the anchor 10. The expander bolt 44 pushes the expander arms 18 apart to anchor the expander An anchor 10 in the bore 50. Thin films of elongate material 22 connecting the expanding arms 18 in the circumferential direction do not prevent the expanding arms 18 from being pushed apart, that is, they expand because they are thin and have undulations and are therefore elongated in the circumferential direction. The thin foils that connect the expansion arms 18 in the housing-like region of the stretching region 20 prevent the expansion screw 44 from being laterally protruding between the expansion arms 18 from the screw channel 12 when screwed in.

Claims (9)

PATENT CLAIMS An anchor (10) for fastening in hollow and solid building materials, with expansion arms (18) extending in the longitudinal direction, which are expandable by screwing the expansion screw (44), the expansion arms (18) at the rear end connected to each other by a sleeve the end (14), which is a push-in expansion screw (44), and at the front end are connected by a sleeve-shaped tip (16) into which it is screwed- 25 is a detachable expansion screw (44), characterized in that the expansion arms (18) are connected to one another in a circumferential direction by a stretchable material (22) which is interrupted by a plurality of screw-like notches (24). Anchor according to claim 1, characterized in that the end (14) has a larger diameter than the region of the expansion arms (18) and the tip (16). 30 Anchor according to claim 1, characterized in that at least two opposing and longitudinally extending anti-twist ribs (28) are formed on the outer periphery of the anchor, which are formed sawtooth over a portion of their length. Anchor according to claim 1, characterized in that the tip (16) has angularly angled notches (32), wherein one leg (36) of the notch (32) has a pitch in the direction of the thread of the expansion screw (44) and 35, the second arm (38) has a pitch in the opposite direction. Anchor according to claim 1, characterized in that the screw channel (12) for the expansion screw (44) has a cross-section inside the tip (16) deviating from the circular shape. Anchor according to claim 1, characterized in that the screw channel (12) has a flat cross-section at least inside the tip (16). 40 Anchor according to claim 6, characterized in that the screw channel (12) is notched. Anchor according to claim 7, characterized in that the screw channel (12) has the shape of two intersecting notches. Anchor according to claim 1, characterized in that the tip (16) has two opposing notches (39) extending in the longitudinal direction, the bottom of which is spaced from the screw channel (12).