DE29620985U1 - Expansion dowels, especially for connecting panels such as Chipboard - Google Patents

Description

E 10162 Gbm 03. December 1996

G+G Fittings GmbH, Maybachstrasse 3, 72202 Nagold

Expansion dowels, especially for connecting panels such as chipboard

* Description:

The invention relates to a expansion dowel, in particular for connecting panels such as chipboards with the features of the preamble of claim 1.

Well-known expansion dowels, especially for connecting panels such as chipboard, are often used in the furniture industry, and in particular in the area of portable furniture. It is important to achieve the highest level of strength while being easy to handle.

Known expansion dowels have the disadvantage that, due to their structural design, they have a relatively large diameter, resulting from the requirement for high strength, so that it is necessary to provide the holes that accommodate the expansion dowels with a correspondingly large diameter, so that holes of different sizes are required in the individual furniture panels, i.e. on the one hand to fix the dowels and on the other hand to position shelves, for example.

The invention is therefore based on the object of creating an expansion anchor which is characterized on the one hand by a cheaper and simpler manufacturing option and on the other hand by easy handling

with a firm fit and a small outer diameter, i.e. the possibility of using standard bores.

This object is achieved in an expansion anchor of the type mentioned at the outset with the features of the characterizing part of claim 1. Further advantageous embodiments of the invention are the subject of the subclaims.

Because the expansion pin and expansion cone are designed as one piece and because the expansion pin and expansion cone are made of steel, a maximum level of tensile strength and overall load-bearing capacity is achieved, so that the expansion dowel equipped in this way guarantees the required durability, i.e. a firm fit and the correspondingly high tensile force, even with a small diameter.

If the expansion cone is a tumbled expansion cone, i.e. the expansion cone is produced by a tumbling process, this enables a one-piece design of the expansion cone in the simplest way, whereby the expansion pin can first be inserted into the expansion dowel body and can be provided with the corresponding expansion cone in the inserted state, i.e. the expansion cone is produced by a corresponding tumbling process without this having to be done separately, i.e. the expansion cone can be an expansion cone that is tumbled after the expansion pin has been inserted into the expansion dowel body, so that the expansion dowel can be manufactured easily and this contributes to a considerable reduction in costs.

If the expansion anchor body is made of zinc die-cast, this provides an expansion anchor body that is characterized by low production costs and

others the possibility of creating a firm fit in the holes provided.

If the expansion area of the expansion dowel body has at least two expandable legs, and the expansion area of the expansion dowel body has four expandable legs, this also contributes to an optimal fit of the expansion dowel according to the invention.

10' If at least one projection serving for a first positioning and fixing is provided above the expandable legs, arranged on the outer circumferential surfaces of the lower section of the expansion dowel body, a first positioning and fixing of the expansion dowel is achieved as this projection comes into operative engagement with the inner wall of the bore receiving the lower section of the expansion dowel body, so that the expansion dowel is also lost during transport of the plate having the bore without a direct connection to the plate to be arranged above or on it, and in addition, this also ensures that the expansion dowel spreads if the plate to be fixed by means of the expansion dowel is not arranged correctly, i.e. is in direct contact with the lower collar of the expansion dowel.

If the projection consists of two thread halves arranged diametrically opposite each other on the same vertical plane and the thread halves have identical thread pitches, this further increases the contact between the expansion anchor and the bore, i.e. the inner wall of the bore that receives the lower section of the expansion anchor, so that this contributes to an even more favorable fit, i.e. a pre-positioning, in the bore that receives the lower section of the expansion anchor body, so that expansion is possible even with extremely inaccurate

Positioning of the second plate to be attached to a first plate is ensured.

If the thread halves have identical thread pitches as the anchoring thread arranged on the expansion legs, this enables the expansion anchor body to be released without problems by turning it out of the chipboard hole.

10- If the thread halves have identical thread pitches, this ensures that the expansion anchor according to the invention can be positioned optimally in the bore.

If the thread halves are designed as saw threads or trapezoidal threads, an optimal fit, i.e. optimal anchoring of the expansion anchor in the bore hole that accommodates it, is achieved.

If the lower section of the expansion anchor body is provided with an external thread, at least in the area of the expandable legs, at least partially, and if the lower section of the expansion anchor body is provided with an external thread over the entire height of the expandable legs, and if this external thread is a sawtooth thread, this will ensure that, with appropriate expansion, a very good anchoring of the anchor in the hole is achieved, i.e. the sawtooth thread comes into contact with the inner wall of the hole in an optimal manner.

If the external thread has a section with the greatest thread depth, a section with a continuous thread depth increase and a section with a continuous thread depth decrease, this ensures that the material thickness of the expansion anchor body can be kept extremely low, particularly in the area of the expandable legs, since

Optimum material thicknesses can be achieved in the bending area and in the area of the conical design without having to forego a high thread depth in large areas of the thread.
5

If the lower section of the expansion dowel body has an outer diameter of < 5 mm, this ensures that the expansion dowel according to the invention can also be used in conventional holes, e.g. in rows of holes intended for positioning shelves, without the need for separate holes for expansion dowels, i.e. it is possible to provide the entire panel with a hole of the same size.

The drawing shows two embodiments of the expansion anchor according to the invention, in particular for connecting panels such as chipboard, schematically shown, namely

Fig.l the expansion dowel according to the invention in the unspread position, positioned in two panels to be connected without the eccentric nut pulling the expansion pin into the spread position,

Fig.2 the expansion anchor body in longitudinal section without expansion pin,

Fig.3 a detail of the course of the thread depth, Fig.4 a single part drawing of the expansion pin from Fig.l

Fig. 5 a detailed drawing "A" from Fig.2,

Fig.6 is a detail drawing of the expansion pin from Fig.l according to a second embodiment and

Fig.7 a detailed drawing "A" from Fig.2 corresponding

of a second embodiment.

As can be seen from Fig. 1, the expansion dowel 1 according to the invention serves, for example, to position and connect two chipboards 2, 3, whereby the expansion dowel body 4 is positioned with its lower section 5 in the direction of view in Fig. 1 and 2 in such a way that the lower collar 6 of the expansion dowel body 4 rests on the surface 8 of the plate 3, projecting beyond the diameter of the bore 7.

The lower section 5 of the expansion dowel body 4 has, as can be seen from Figures 1, 2 and 3, two thread halves 9 which serve for a first positioning of the expansion dowel body 4 in the bore 7 and which each begin and end in the same vertical orientation, i.e. height, i.e. have identical thread pitches, which, when the expansion dowel body 4 is positioned accordingly in the bore 7, come into operative engagement with its peripheral surface 10 in such a way that the expansion dowel body 4 experiences a first positioning in the bore 7, i.e. is to be positioned there in such a way that the expansion dowel body 4 does not fall out of the bore 7 without a corresponding rotational movement even when the plate 3 is transported and at the same time serves as a counter bearing during the corresponding expansion process of the expansion dowel body 4 and when the second plate 2 is positioned on the plate 3.

The upper section 11 of the expansion anchor body 4 is positioned in a bore 12 arranged in the upper plate 2, whereby the head 13 of the expansion pin 14 protrudes into a bore 15 receiving an eccentric nut (not shown here).

By means of this eccentric nut (not shown here), arranged in the bore 15, the expansion pin 14 is caused to move in the direction of arrow 16, so that the expansion cone 17 shown in Fig.4 also

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a movement in the direction of arrow 16 and thereby causes a spreading movement of the spreading legs 22.

The expansion pin 14 with its head 13, the expansion cone and the collar 27 is designed as a single piece, in the present embodiment made of QST 37 or QST 33 steel, cold-pressed, whereby the expansion cone 17 was designed by means of a wobble riveting process, i.e. wobble.

10- According to a second embodiment, the expansion pin 14 does not have a collar 27, but rather, as can be seen from Fig.6, a compression 27a, whereby the expansion pin 14 is designed as a single piece with its head 13, the expansion cone 17 (not shown in Fig.6) and the compression 27.

In Fig.6, the expansion pin 14 is shown before the wobble, i.e. the design of the expansion cone 17, which otherwise corresponds to the expansion cone 17 described and shown in accordance with the first embodiment.

As can be seen from Fig.6 in this context, the expansion pin 14 has a section above the compression 27a which is provided with a larger diameter than the section 31 adjoining the compression 27a.

In the present embodiment, the diameter of the upper section is preferably 3.5 mm, while the diameter of the lower section 31 has a diameter of 2.5 to 3 mm, preferably 2.5 mm.

When arranged accordingly in the expansion anchor body, the expansion pin rests in the compressed section 27a on the upper edge 26 of the expansion anchor body 4, while the lower section 31 of the expansion pin 14 is arranged in the expansion anchor body, i.e. is positioned and arranged there,

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as in accordance with the expansion pin embodiment in Fig.4, i.e. as described below and previously.

In its rest position, the expansion cone 17 is located with its lower surface 19 (viewed in the direction of Fig.4) flush with the lower edge 20 (viewed in the direction of Fig.2) of the expansion anchor body 4.

This means that the expansion cone 17 is located largely in the area of the conical section 18 of the lower section 5 of the expansion anchor body 4.

The expansion dowel body 4 has, in its lower section 4, slots 21 distributed at the same angular distance on the peripheral surface, which begin at the lower edge 20 of the expansion dowel body 4 and end at a distance from it, thus dividing the lower area of the lower section of the expansion dowel body 4, in the present embodiment, into four segments, i.e. four legs 22.

In addition, as can be seen from Fig. 1 and 3, this lower area has an external thread 23 which, according to Fig. 3, has three sections of different thread depths.

The thread depth approaches, starting at the lower edge 20 of the expansion anchor body 4, the section 24 with the greatest thread depth over a predetermined length, i.e. in an approach section or a section 38 of continuous thread depth increase, this remains the same over a precisely defined length and then runs out in a subsequent section 25, constantly decreasing in the direction of the thread halves 9.

The external thread is designed as a saw thread 23, as can be seen from Fig. 5, or as a trapezoidal thread, as can be seen from Fig. 7.

This external thread 23 ensures that the expansion anchor 1 is firmly seated when the lower section or the legs 22 are appropriately spread, and this external thread also enables the expansion anchor 1 to be inserted into the hole 7 provided for it, even in cases where the hole 7 has only a slight oversize, i.e. by simply turning the expansion anchor body 4 or by simply rotating the expansion anchor body 4.

The expansion pin 14 has an upper collar 27 in the area of the upper edge 26 of the expansion dowel body 4, as can be seen in Fig. 1 and 4, which ensures that when a corresponding pressure load is applied to the head 13 of the expansion pin 14, the latter cannot be pressed out of the expansion dowel body 4 beyond the desired lower position.

The same applies if a compressed section 27a is provided instead of the upper collar 27.

To produce the expansion dowel 1 according to the invention, after completion of the expansion dowel body 4, the expansion pin 14 is inserted into the dowel body 4 in the opposite direction to the arrow 16 from Fig. 1 and 4, whereby after introduction of the expansion pin 14, the expansion cone 17 is produced by a wobble process, so that the expansion pin 14 is also protected against unwanted displacement in the direction of arrow 16, i.e. against slipping out of the expansion dowel body 4, after appropriate wobble, i.e. completion of the expansion cone 17.

After inserting the expansion anchor 1 into the hole 7 provided for it, i.e. by pressing the expansion anchor 1 or the expansion anchor body 4 into the corresponding hole 7 and the associated first fixing by means of the thread halves 9 in the hole 7, the upper plate is fixed by means of the hole 28 onto the upper part 29 of the

expansion anchor body 4, whereby the head 13 projects into the bore 15 containing the eccentric nut.

The plate 2 to be positioned rests with the peripheral surface of the bore 12, i.e. the bore 12 enclosing the upper part of the expansion anchor body 4, on the lower collar 6 of the expansion anchor body 4.

When the eccentric nut rotates accordingly, it comes into active engagement with the head 13 of the expansion pin 14, causing a vertical displacement of the expansion pin 14 in the direction of the arrow 16. Caused by the resulting expansion effect of the expansion cone 17, which has an oversize defined in relation to the inner diameter of the lower expansion dowel body 5, the lower area of the lower section of the expansion dowel body 4, i.e. the expansion legs 22, expands.

The four legs 22 of the lower region of the lower section 5 of the expansion anchor body 4 are pressed against the inner wall, i.e. the peripheral surface 10 of the bore 7 , whereby the saw or trapezoidal thread 23 penetrates at least partially into the peripheral surface 10 of the bore 7.

The thread halves 9 ensure that even if the upper plate 2 (in the direction of view in Fig. 1) is not positioned precisely, this plate is firmly seated on the lower plate 3, i.e. the upper plate 2 is pulled against the lower plate 3 so that it then acts as a counter bearing in conjunction with the lower collar 6. This ensures that even if the upper plate 2 is not positioned precisely, there is no unwanted displacement of the expansion anchor.

The expansion anchor body 4 consists, as already explained, of a die-cast zinc material.

^1A *

By means of a movement in the opposite direction of the arrow 16, the expansion pin 14 is returned to its previously described starting position, so that the expansion dowel 1 according to the invention can be removed from the bore 7 by a corresponding rotational movement, whereby the legs 22 of the expansion area of the expansion dowel body 4 are brought into their starting position, so that the expansion dowel 1 according to the invention can be used again.

Claims (22)

E 10162 Gbm 03. December 1996 G+G Beschläge GmbH, Maybachstraße 3, 72202 Nagold, expansion dowels, in particular for connecting panels such as chipboards Protection claims: 1. Expansion dowel, in particular for connecting panels such as chipboards with an expansion dowel body and an expansion pin with expansion cone, characterized in that the expansion pin (14) and expansion cone (17) are designed as a single piece and the expansion pin (14) and expansion cone (17) are made of steel 0. 2. Expansion dowel according to claim 1, characterized in that the expansion cone (17) is a tumbled expansion cone (17) is.
25 3. Expansion dowel according to claim 2, characterized in that the expansion cone (17) is an expansion cone (17) which is tumbled after the expansion pin (14) has been inserted into the expansion dowel body (4). 4. Expansion dowel according to one of claims 1 to 3, characterized in that the expansion dowel body (4) consists of die-cast zinc. 5. Expansion dowel according to one of claims 1 to 4, characterized in that the expansion region of the expansion dowel body (4) has at least two expandable legs (22). * 4 # I · 6. Expansion dowel according to claim 5, characterized in that the expansion region of the expansion dowel body (4) has four expandable legs (22). 7. Expansion dowel according to one of claims 1 to 6, characterized in that above the expandable legs (22) at least one projection (9) serving for a first positioning and fixing is arranged on the 10- outer peripheral surface of the lower section (5) of the expansion anchor body (4). 8. Expansion anchor body according to claim 7, characterized in that the projection consists of two diametrically opposed oppositely arranged thread halves (9). 9. Expansion dowel body according to claim 7 or 8, characterized in that the thread halves (9) have identical thread pitches. 10. Expansion dowel according to one of claims 7 to 9, characterized in that the thread half (9) is designed as a saw thread. 11. Expansion dowel according to one of claims 7 to 9, characterized in that the thread half (9) is designed as a trapezoidal thread. 12. Expansion dowel according to one of claims 1 to 11, characterized in that the lower section (5) of the expansion dowel body (4) is at least partially provided with an external thread (23) at least in the region of the expandable legs (22). 13. Expansion dowel according to claim 12, characterized in that the lower section (5) of the expansion dowel body (4) is provided with an external thread (23) over the entire height of the expandable legs (22). 14. Expansion dowel according to claim 12 or 13, characterized in that the external thread (23) is a saw thread. 10· 15. Expansion dowel according to claim 12 or 13, characterized in that the external thread (23) is a trapezoidal thread. 16. Expansion dowel according to one of claims 12 to 15, characterized in that the external thread (23) a section (24) of maximum thread depth, a section (28) of continuous thread depth increase and a section (25) of continuous thread depth decrease. 20 17. Expansion dowel according to one of claims 1 to 16, characterized in that the end (20) of the expansion dowel body (4) facing the expansion cone (17) has a conical section (18) on its inner peripheral surface. 18. Expansion anchor according to one of claims 1 to 17, . characterized in that the lower section (5) of the expansion anchor body (4) has an outer diameter < 5mm. 19. Expansion dowel according to one of claims 1 to 17, characterized in that the expansion pin (14) has a compressed stop (27a). 20. Expansion dowel according to one of claims 1 to 19, characterized in that the expansion pin (14) in addition to the expansion cone (17) and head (13), it has at least two sections of different diameters, wherein the section arranged in the expansion dowel body (4) has a diameter of 2 to 3.5 mm. 21. Expansion anchor according to claim 20, characterized in that the section located in the expansion anchor body (4) between the compressed section (27a) 10- and the expansion cone (17) has a diameter of 2.5 mm. 22. Expansion dowel according to one of claims 1 to 21, characterized in that the thread halves (9) have a thread pitch that is identical to the external thread (23).