DE102020102294A1 - Mounting system - Google Patents

Abstract

The invention relates to an assembly system consisting of an expansion dowel and a fastening screw, the fastening screw having an external thread and a cross-section different from the circular and the screw receiving opening of the expansion dowel having a complementary, non-circular cross-section. According to the invention, the external thread is designed on two opposite sides of the fastening screw and otherwise interrupted, the fastening screw having a first and at least one second segment each with partial thread over its length and the segments being rotatable to a limited extent relative to one another by a predetermined angle and otherwise connected.

Description

The invention relates to an assembly system consisting of an expansion dowel and a fastening screw, the fastening screw having an external thread and a cross-section that differs from the circular one and the screw receiving opening of the expansion dowel having a complementary, non-circular cross-section, according to the preamble of claim 1.

From the DE 195 11 446 A1 an expansion dowel with an expansion screw is previously known, with as little rotation of the dowel screw as possible ensuring the greatest possible expansion effect while at the same time tightening a fastening part connected to the expansion screw.

The expansion screw is first used in a free position in the central recess in the dowel part. The head of the expansion screw is then rotated with an appropriate tool and the expansion cams, which are arranged in the expansion and threaded part of the expansion screw, move into the central recess of the dowel part. The dowel part is spread outwards.

the DE 20 2004 005 964 U1 relates to a device for holding an object on an object.

In this regard, a screw-type fastening rod and a fastening element are required. The fastening element designed as a dowel has an axial cavity at the distal end for inserting the fastening rod, the cavity having two short and two long sides. By rotating the fastening rod by 90 °, the dowel is expanded, the fastening rod having a cross-section which is matched to the cavity of the dowel and its shape.

For the fastening set made of plastic expansion dowel and fastening screw EP 0 171 745 B1 the screw has two different threads, the dowel also having a section in the form of an upper thread which, on the one hand, acts as an impact protection for the fastening screw and, on the other hand, serves as a feed and guide thread for the fastening screw.

For the expansion dowel with expansion screw DE 100 55 866 A1 the expansion screw has a second screw thread.

For the generic fastening set consisting of elliptical screw and dowel DE 40 39 575 A1 The elliptical screw reduces the amount of effort required to turn it, as a single turn of 90 ° is necessary after it has been inserted into an associated expansion plug. This should make it possible to screw in places that are difficult to access. Loosen according to the fastening kit DE 40 39 575 A1 happens by turning back or further by 90 °.

In addition, the cavity of the dowel there has a small recess that stabilizes the elliptical screw in the fastened position.

The prior art described has in common that either no axial screw connection is possible or a screw cannot be inserted into a fastening dowel up to a predetermined point in order to simplify the fastening process, in particular to accelerate it.

In the case of the solution with the mounting kit DE 40 39 575 A1 there is also the risk that the connecting screw and dowel and thus the hold of the object to be fastened will loosen due to over-tightening. In particular, when a certain load is already acting on the known fastening system, this is a not inconsiderable disadvantage.

From the foregoing it is therefore the object of the invention to provide a further developed assembly system consisting of expansion dowel and fastening screw, the fastening screw only having a partial thread on the one hand and the screw not having a conventional circular cross-section on the other hand. Starting from this screw configuration, it should be possible to insert the screw quickly and without force using an expansion anchor with, for example, a rectangular channel cross-section, and then to carry out the desired screw connection in a known manner with known means. It is thus an essential aspect of the invention to drastically shorten the assembly time and thus the assembly effort by eliminating the otherwise required complex screwing / turning movement and replacing it by pressing or pushing it into the associated dowel.

The object of the invention is achieved by a mounting system according to the combination of features according to claim 1, the subclaims representing at least useful configurations and developments.

A mounting system consisting of an expansion dowel and a fastening screw is therefore assumed.

The fastening screw has an external thread and a cross-section that differs from the circular one, for example a substantially rectangular cross-section with narrow sides and broad sides.

The screw receiving opening of the expansion anchor and the adjoining channel have a complementary, non-circular cross section.

The external thread of the fastening screw is complete and continuous on two opposite sides and otherwise interrupted. This creates a screw with a partial thread over the longitudinal extension of the screw, the thread-free sections being opposite one another and the thread-bearing sections also being in an opposite position.

The fastening screw is divided over its length into a first and at least one second segment, each with partial threads as explained above, the segments being rotatable to a limited extent relative to one another by a predetermined angle and otherwise being connected.

As stated, the cross section of the fastening screws is essentially and advantageously rectangular, with the partial threads on the narrow side of the rectangle and the thread-free areas on the broad sides of the rectangle.

The rotatability is designed in such a way that, on the one hand, an alignment of the partial threads of the segments and, on the other hand, an angular offset of these segments is made possible.

In this way, the screw can be manually brought into a starting position in which the partial threads of the segments are aligned. The screw can then be inserted into a corresponding dowel channel very easily and quickly and with almost no force. With the application of a tool, in particular a screwdriver, the segments change their angular position relative to one another and begin to cut into the surface of the inner wall of the dowel. The resulting offset of the thread positions of the individual segments creates an almost complete thread over the surface of the screw on the force side, resulting in a secure connection that is not inferior to that of a screw with a continuous thread without interruptions. On the contrary, it has been shown that especially with expansion anchors made of a plastic material, the displaced material springs back into the thread-free section, which leads to an additional securing of the fastening screw in the expansion anchor, that is, an undesired loosening or unscrewing of the screw is prevented.

As explained, the expansion dowel has a screw receiving opening with an adjoining channel each with a rectangular cross-section in a preferred design.

The thread of the fastening screw is preferably designed as a cutting thread, so that a tapping screw is produced.

The first segment preferably merges in one piece with a screw head.

The outer circumferential surface of the fastening screw and the inner circumferential surface of the expansion anchor are matched to one another in terms of dimensions and shape so that when the segments are aligned, the fastening screw can be pushed into the expansion anchor without any significant effort, and when the fastening screw is rotated, the partial threads of the segments one after the other in a force fit and form fit with the inner wall of the expansion anchor.

The invention is to be explained in more detail below using an exemplary embodiment and with the aid of figures.

• 1a), b) und c) perspektivische Darstellungen einer erfindungsgemäßen Befestigungsschraube, einmal mit fluchtender Position der Teilsegmente (1a)) in einer ersten Ansicht sowie einer zweiten Ansicht (1b)) und eine Darstellung der Befestigungsschraube mit winkelmäßigem Versatz der Segmente (1c));
• 2a) und b) eine perspektivische Ansicht sowie eine Draufsicht auf die Oberseite eines Spreizdübels mit Dübelöffnung in nicht kreisrunder, das heißt bevorzugter Rechteckform;
• 3 eine perspektivische Darstellung der erfindungsgemäßen Befestigungsschraube mit Spreizdübel, wobei die Segmente der Befestigungsschraube fluchtend sind und sich die Befestigungsschraube in einer Position unmittelbar vor dem Einschieben in den Spreizdübel befindet;
• 4 eine perspektivische Darstellung mit teilweggebrochenem Spreizdübel, wobei sich eine Befestigungsschraube mit fluchtenden Segmenten in eingeschobener Position bezogen auf den Dübelkanal befindet; und
• 5 teilweggebrochene und perspektivische Darstellungen des Montagesystems mit Spreizdübel und Befestigungsschraube, einmal im gespreizten Zustand y sowie im unbelasteten Zustand x, wobei der angedeutete Durchmesser y > x ist.

Here show:

• 1a), b ) and c) perspective representations of a fastening screw according to the invention, once with the aligned position of the subsegments ( 1a) ) in a first view and a second view ( 1b) ) and a representation of the fastening screw with angular offset of the segments ( 1c ));
• 2a) and b) a perspective view and a top view of the top of an expansion plug with a plug opening in a non-circular, that is to say preferred rectangular shape;
• 3 a perspective view of the fastening screw according to the invention with expansion dowel, wherein the segments of the fastening screw are aligned and the fastening screw is in a position immediately before insertion into the expansion dowel;
• 4th a perspective view with partially broken away expansion dowel, with a fastening screw with aligned segments in the pushed-in position relative to the dowel channel; and
• 5 partially broken away and perspective representations of the assembly system with Expansion dowel and fastening screw, once in the expanded state y and in the unloaded state x, the indicated diameter being y> x.

In the mounting system according to the exemplary embodiment, an expansion dowel is used 1 and a fastening screw 2 went out.

The fastening screw 2 has a partial external thread extending over a longitudinal axis direction 3 and a cross-section deviating from the circular, which can be seen from the illustration according to FIG 1b) in particular results.

The expansion dowel 1 has a screw receiving opening 4th which has a corresponding cross-section complementary to the cross-section of the fastening screw, preferably a non-circular cross-section, in turn preferably a cross-section in a rectangular shape according to FIG 2a) and b).

As in particular from the 1b) , 1c ) and 5 is understandable, is the external thread 3 on opposite sides of the fastening screw 2 present and otherwise carried out interrupted.

The fastening screw 2 has a first segment along its length 5 and a second segment 6th each with partial thread 3 on, with the segments 5 ; 6th are rotatable to a limited extent relative to one another by a predetermined angle and are otherwise connected. The rotatability is indicated in the illustration according to 1c ) or in the representation according to 5 in the expanded state y.

For quick, uncomplicated and force-free insertion of a fastening screw 2 into an associated dowel 1 First of all, care is taken to ensure that the segments 5 and 6th in relation to their partial threads are aligned, like this the 3 makes clear.

When this state is reached, the fastening screw can according to 4th into the dowel channel via the screw receiving opening 4th be inserted.

A corresponding predefined position is shown here by the 5 in state x, that is, in the unloaded state. So there is no noteworthy exertion of force on the dowel 1 instead of.

In the next step, the fastening screw can be over its screw head 20th be set in a rotary motion. This results in a twisting of the segments 5 and 6th . When a corresponding end position is reached, both the first and the second segments rotate 5 ; 6th . This is where the threaded sections come from 3 with the inner wall of the dowel 1 in contact with the desired form and force fit.

The solution according to the invention thus enables a combination of inserting or pushing a fastening screw into a dowel with subsequent screwing, without being restricted to a specific insertion position or a twist angle, as is the case with the prior art.

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 19511446 A1 [0002]
• DE 202004005964 U1 [0004]
• EP 0171745 B1 [0006]
• DE 10055866 A1 [0007]
• DE 4039575 A1 [0008, 0011]

Claims (7)

Mounting system, consisting of expansion dowel (1) and fastening screw (2), whereby the fastening screw (2) has an external thread (3) and a cross-section that differs from the circular one and the screw receiving opening (4) of the expansion dowel (1) has a complementary, non-circular cross-section , characterized in that the external thread (3) is designed on two opposite sides of the fastening screw (2) and otherwise interrupted, the fastening screw (2) having a first (5) and at least one second segment (6) each with a partial thread over its length has, wherein the segments (5; 6) can be rotated to a limited extent relative to one another by a predetermined angle and are otherwise connected. Mounting system according to Claim 1 , characterized in that the cross section of the fastening screw (2) is essentially rectangular, with the partial thread or partial thread sections being located on the narrow side of the rectangle. Mounting system according to Claim 1 or 2 , characterized in that the rotatability enables an alignment of the partial threads of the segments (5; 6) and a limited angular offset of these. Mounting system according to Claim 2 , characterized in that the expansion plug (1) has a screw receiving opening (4) with an adjoining channel each with a rectangular cross-section. Assembly system according to one of the preceding claims, characterized in that the threads (3) of the segments (5; 6) are designed as cutting threads. Assembly system according to one of the preceding claims, characterized in that the first segment (5) merges in one piece into a screw head (20). Mounting system according to Claim 3 , characterized in that the outer circumferential surface of the fastening screw (2) and the inner circumferential surface of the expansion anchor (1) are matched in terms of dimensions and shape so that when the segments (5; 6) are aligned, the fastening screw (2) can be pushed into the expansion anchor (1 ) is possible without significant effort and when the fastening screw (2) is rotated, the partial threads (3) of the segments (5; 6) successively come into force and form fit with the inner wall of the expansion dowel.

Images