DE3208347C1

DE3208347C1 - Expanding dowel

Info

Publication number: DE3208347C1
Application number: DE19823208347
Authority: DE
Inventors: Albert 7835 Teningen Frischmann; Herbert 7800 Freiburg Kistner
Original assignee: Upat Max Langensiepen KG
Current assignee: Upat Max Langensiepen KG
Priority date: 1982-03-09
Filing date: 1982-03-09
Publication date: 1983-09-29

Abstract

An expanding dowel (1) has two expanding limbs (3, 4) on which in each case two rows of teeth are arranged having teeth (16) which engage in associated tooth gaps (17) of the respective other expanding limb (4, 3). Adjacent teeth (16) are connected to one another by longitudinal webs (25) so that displacement of the teeth (16) in the tooth gaps (17) when a bending load is applied to the expanding dowel (1) is effectively suppressed, and the expanding dowel (1) is in consequence provided with a significantly greater bending strength. <IMAGE>

Description

Der Dübelkern 5 dient in bekannter Weise zur Aufnahme eines in der Zeichnung nicht dargestellten Befestigungselementes, mit dessen Hilfe eine Spreizung des ersten Spreizschenkels 3 und des zweiten Spreizschenkels 4 bewirkt wird. An dem zum zylindrischen Halsteil 2 weisenden Ende des konischen Abschnittes 8 sind an dem Dübelkörper zwei radialsymmetrisch angeordnete Sperrlaschen 9 vorgesehen, denen jeweils eine taschenförmige Vertiefung 10 zugeordnet ist Entsprechende Sperrlaschen 11 mit taschenförmigen Vertiefungen 12 befinden sich in der Nähe des Einsteckendes des Spreizdübels 1 und dienen ebenfalls dazu, eine Verdrehung des Spreizdübels 1 beim Einschrauben eines Befestigungselementes in den Dübelkern 5 zu verhindern. The dowel core 5 is used in a known manner to receive one in the Drawing not shown fastening element, with the help of which a spreading the first expansion leg 3 and the second expansion leg 4 is effected. At the end of the conical section 8 facing the cylindrical neck part 2 two radially symmetrically arranged locking tabs 9 are provided on the dowel body, which respectively a pocket-shaped recess 10 is assigned corresponding Locking tabs 11 with pocket-shaped recesses 12 are located near the Insertion of the expansion anchor 1 and also serve to prevent rotation of the Expansion anchor 1 when screwing a fastening element into the anchor core 5 to prevent.

Wie man in den F i g. 1 und 3 erkennt, verläuft zwischen dem ersten Spreizschenkel 3 und dem zweiten Spreizschenkel 4 ein Schlitz 13, der in der Nähe des Dübelhalses 2 als Längsschlitz 14 und am einsteckseitigen Ende als kurzer Längsschlitz 15 ausgebildet ist Zwischen dem Längsschlitz 14 und dem kurzen Längsschlitz 15 hat der Schlitz 13 eine mäanderförmige Gestalt, die sich durch das Zusammenwirken von Zähnen 16 und Zahnlücken 17 ergibt. As shown in Figs. 1 and 3 recognizes runs between the first Spreading leg 3 and the second spreading leg 4 a slot 13, which is in the vicinity of the dowel neck 2 as a longitudinal slot 14 and at the end on the insertion side as a short longitudinal slot 15 is formed between the longitudinal slot 14 and the short longitudinal slot 15 the slot 13 has a meandering shape, which is due to the interaction of Teeth 16 and tooth gaps 17 results.

Die auf den Spreizschenkeln 3 und 4 angeordneten Zähne 16 sind an Außenzähne 18 angeformt und erstrecken sich in radialer Richtung, wie in F i g. 2 dargestellt ist, bis zum konischen Abschnitt 8 des Dübelkernes 5. Dabei weisen die Zähne 16 mit ihren ebenen Flächen 19 auf zugeordnete ebene Flächen 20 der Zahnlücken 17. The teeth 16 arranged on the expansion legs 3 and 4 are on Outer teeth 18 are integrally formed and extend in the radial direction, as in FIG. 2 is shown up to the conical section 8 of the dowel core 5 the teeth 16 with their flat surfaces 19 on associated flat surfaces 20 of the tooth gaps 17th

Die Spreizschenkel 3 und 4 verfügen jeweils über zwei Zahnreihen mit Zähnen 16. In F i g. 1 sind jeweils die ersten Zahnreihen zu erkennen, während in F i g. 3 die zweiten Zahnreihen dargestellt sind, die in der Darstellung nach F i g. 1 im wesentlichen verdeckt sind und lediglich an den Stellen sichtbar sind, an denen die Mäanderform des Schlitzes 13 in Längsrichtung des Spreizdübels 1 verläuft. Dort, wo die Mäanderform des Schlitzes 13 sich quer zur Längsachse erstreckt, fluchten die mäanderförmigen Bereiche des Schlitzes 13 miteinander. The expansion legs 3 and 4 each have two rows of teeth with teeth 16. In FIG. 1 the first rows of teeth can be seen while in Fig. 3 the second rows of teeth are shown, which in the illustration according to F i g. 1 are essentially covered and are only visible in the places where the meander shape of the slot 13 runs in the longitudinal direction of the expansion anchor 1. There, where the meander shape of the slot 13 extends transversely to the longitudinal axis, are in alignment the meandering areas of the slot 13 with one another.

Wie man in den Fig 1, 2 und 3 erkennt, wird der Schlitz 13 an mehreren Stellen durch angeformte Stege überbrückt. As can be seen in FIGS. 1, 2 and 3, the slot 13 is at several Areas bridged by molded webs.

Am Einsteckende befindet sich ein Mittelsteg 21, der die einsteckseitigen Enden der Spreizschenkel 3 und 4 im nichtgespreizten Zustand miteinander verbindet Im Längsschlitz 14 sind, wie in den F i g. 1 und 3 ebenfalls zu erkennen ist, zwei radial gegenüberliegend angeordnete Querstege 22 zwischen den Spreizschenkeln 3 und 4 in der Nähe des Halsteiles 2 vorgesehen. Die Querstege 22 sind radial nach innen bis an den Dübelkern 5 versetzt angeordnet und haben eine wesentlich geringere Materialstärke als der Dübelkörper des Spreizdübels 1, so daß die beiden Querstege 22 beim Aufspreizen der Spreizschenkel 3 und 4 einreißen können. At the plug-in end there is a central web 21, which connects the plug-in side Ends of the expansion legs 3 and 4 connects to one another in the non-expanded state In the longitudinal slot 14, as in FIGS. 1 and 3 can also be seen, two transverse webs 22 arranged radially opposite one another between the expansion legs 3 and 4 are provided in the vicinity of the neck part 2. The transverse webs 22 are radially arranged offset inside up to the dowel core 5 and have a much lower Material thickness than the anchor body of the expansion anchor 1, so that the two transverse webs 22 can tear when spreading the expansion legs 3 and 4.

Um beim Verbiegen des Spreizteils des Spreizdübels 1 ein Verschieben der Zähne 16 in den Zahnlücken 17 zu verhindern und dadurch eine höhere Festigkeit zu erreichen, sind die Zähne 16 jeweils mit einem ihrer Nachbarn über einen Längssteg 25 verbunden. Bei dem in der Zeichnung dargestellten Ausführungsbeispiel sind die Längsstege 25 so angeordnet, daß sie sich jeweils paarweise gegenüberstehen, wie am besten in F i g. 2 zu erkennen ist Die Längsstege 25 werden bei einer Biegebelastung des Spreizdübels 1, wie sie beispielsweise beim Einbringen in eine Dübelbohrung auftreten können, je nach Richtung der Biegebelastung auf Zug oder auf Druck in ihrer Längsrichtung beansprucht. To move when bending the expansion part of the expansion anchor 1 of the teeth 16 in the tooth gaps 17 and thereby a higher strength To reach, the teeth 16 are each with one of their neighbors via a longitudinal web 25 connected. In the embodiment shown in the drawing are Longitudinal webs 25 arranged so that they face each other in pairs, such as best in Fig. 2 can be seen The longitudinal webs 25 are under a bending load of the expansion anchor 1, as it is, for example, when it is inserted into a dowel hole can occur, depending on the direction of the bending load on tension or compression in their longitudinal direction claimed.

Trotz ihres verhältnismäßig kleinen und in F i g. 2 erkennbaren Querschnittes, bewirken die Längsstege 25 eine erhebliche Vergrößerung der Biegesteifigkeit, Knickfestigkeit und Torsionsfestigkeit des Spreizdübels 1.Despite their relatively small size and shown in FIG. 2 recognizable cross-section, the longitudinal webs 25 cause a considerable increase in the flexural strength and buckling strength and torsional strength of the expansion anchor 1.

Während auf die Längsstege 25 bei einer Biegebeanspruchung des Spreizdübels 1 Zug- oder Druckkräfte wirken, wirken beim Spreizvorgang selbst Kräfte in Querrichtung auf die Längsstege 25 ein, so daß diese auf Scherung und Biegung beansprucht werden. Bei einer solchen Belastung verformen sich die Längsstege 25 jedoch wesentlich leichter als bei einer Belastung in Längsrichtung, so daß beim Eindrehen einer Befestigungsschraube in den Dübelkern 5 nur eine geringe Erhöhung des Eindrehwiderstandes bewirkt wird. Die Querstege 22 reißen bei einer Spreizung der Spreizschenkel 3 und 4 leicht ein oder ab. While on the longitudinal webs 25 in the event of a bending stress on the expansion anchor 1 Tensile or compressive forces act, forces themselves act in the transverse direction during the spreading process on the longitudinal webs 25, so that they are subjected to shear and bending. With such a load, however, the longitudinal webs 25 deform much more easily than with a load in the longitudinal direction, so that when screwing in a fastening screw in the dowel core 5 only a slight increase in the screwing resistance is caused. The transverse webs 22 tear easily when the expansion legs 3 and 4 are spread apart or at.

Beim Zusammendrücken der Spreizschenkel 3 und 4 werden die Längsstege 25 ebenfalls in Querrichtung beansprucht und setzen daher dem Zusammendrücken des Spreizdübels beim Einsetzen in ein enges Dübelloch keinen großen Widerstand entgegen. Aus diesem Grunde kann der mit den Längsstegen 25 versteifte Spreizdübel 1 ohne weiteres in seinem Außendurchmesser leicht verringert und in ein enges Dübelloch eingedrückt werden Die Erhöhung der Biegefestigkeit wird somit nicht mit einer höheren Steifigkeit in radialer Richtung erkauft. Die Querstege 22 unterstützen die Wirkung der Längsstege 25, indem sie bei einer Biegebelastung des Spreizdübels 1 ein Annähern der Spreizschenkel 3 und 4 im Bereich des Längsschlitzes 14 verhindern. When the expansion legs 3 and 4 are pressed together, the longitudinal webs are 25 also stressed in the transverse direction and therefore continue the compression of the The expansion anchor does not offer any great resistance when it is inserted into a narrow anchor hole. For this reason, the expansion dowel 1 stiffened with the longitudinal webs 25 can without further slightly reduced in its outer diameter and into a narrow dowel hole The increase in flexural strength is therefore not accompanied by a higher Stiffness in the radial direction bought. The transverse webs 22 support the effect of the longitudinal webs 25 by approaching when the expansion anchor 1 is subjected to a bending load prevent the expansion legs 3 and 4 in the area of the longitudinal slot 14.

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Claims

Claims: 1. Expansion anchor with one in the direction of the anchor axis extending dowel hole for a fastener, with at least one over The expansion leg forming the slot running the expansion area of the dowel body, with on the expansion legs on both sides of the dowel hole in the longitudinal direction staggered rows of teeth, the teeth of which are in the direction of the opposite To extend splay legs and engage in the gaps between the teeth, and with between the teeth of the opposing expansion legs in the longitudinal direction of the dowel extending longitudinal webs, d a -characterized in that the longitudinal webs (25) each with their end faces pointing in the longitudinal direction of the dowel, the interlocking teeth (16) axially connect the opposing rows of teeth with one another.

2. Expansion dowel according to claim 1, characterized in that the web width and the web thickness of the longitudinal webs (25) smaller than the distance between the Teeth (16) is the corresponding web length.

3. Expansion anchor according to claim 1 or 2, characterized in that the longitudinal webs (25) in alignment with the edge of the teeth pointing towards the dowel hole (5) (16) are arranged.

4. Expansion anchor according to claim 3, characterized in that the longitudinal webs (25) of the first row of teeth radially opposite the longitudinal webs (25) of the second row of teeth are arranged.

The invention relates to an expansion dowel with one in the direction of Dowel axis extending dowel hole for a fastening element, with at least one extending over the expansion area of the dowel body, forming expansion legs Slot, with the dowel hole on both sides of the expansion legs in the longitudinal direction staggered rows of teeth, the teeth of which are in the direction of the opposite To extend splay legs and engage in the gaps between the teeth, and with between the teeth of the opposing expansion legs in the longitudinal direction of the dowel extending longitudinal webs.

Such expansion dowels are from DE-OS 27 29 828 and DE-OS 2840087 known. The tooth areas that are opposite each other in the transverse direction Connected webs give the known expansion anchors one compared to expansion anchors without such webs significantly higher resistance to kinking, bending and torsion, by restricting the relative freedom of movement of the two spreader legs will. In doing so, the ones extending essentially transversely to the dowel axis Longitudinal webs subjected to bending or shear stress. To achieve the highest possible flexural rigidity to achieve it is therefore necessary to each tooth several relatively in the longitudinal direction assign wide, transversely extending longitudinal webs.

When screwing a fastening screw into the dowel hole the expansion legs pressed apart and the longitudinal webs transverse to the longitudinal axis of the dowel stressed on tension, whereby they tear one after the other. are finally separated. However, the separation of these longitudinal webs forming a Söll Separation area makes it more difficult the spreading of the expansion anchor and therefore results in a large screw-in resistance for the fastening screw.

The invention is based on the object of an expansion dowel of the initially to improve said type so that it has a fastening screw a lower Opposing screw-in resistance and nevertheless when inserting into a dowel hole has a high resistance to buckling, bending and torsion.

This object is achieved according to the invention in that the longitudinal webs each with their end faces pointing in the longitudinal direction of the dowel the interlocking Axially connect the teeth of the opposing rows of teeth to one another.

By connecting the longitudinal webs to theirs in the longitudinal direction of the dowel facing sides it is achieved that the longitudinal webs to increase the strength compared Buckling; Bending and torsion no longer perpendicular to the longitudinal direction on bend or on Shear stress, but that the increase in strength is essentially results from a compressive stress on the longitudinal webs in the longitudinal direction. This allows the longitudinal webs are not only reduced in their dimensions and number, rather, they do not cause any significant effects when the expansion anchor is spread open Resistance, as they open transversely to the longitudinal direction when the expansion anchor is expanded Bending and can therefore easily yield or tear.

So that the screwing resistance remains as small as possible, it is advantageous to if the cross-section of the longitudinal webs is weak. An easy tear off the longitudinal webs during the spreading process result in particular when the longitudinal webs are arranged in alignment with the edge of the teeth facing the dowel hole.

Other useful developments are the subject of subclaims.

In the drawing is an embodiment of the subject matter of Invention shown. It shows F i g. 1 shows a side view of the expansion anchor according to FIG of the invention, FIG. 2 shows a cross section through the dowel according to FIG. 1 along the line II-II in a view from the rear end of the dowel and Fig. 3 in the longitudinal direction cut dowel according to FIG. 1 in a side view The in F i g. 1 shown Expansion dowel 1 is made in one piece in a known manner from plastic. Of the The anchor body of the expansion anchor 1 has a cylindrical neck part 2 to which a first expansion leg 3 and a second expansion leg 4 are integrally formed.

As shown in FIG. 3 recognizes, the expansion anchor 1 has a Dowel core 5 with a cylindrical section 6 and an adjoining section and the conical section 8 tapering towards the tip 7 of the expansion anchor 1.