DE1142224B - Expanding dowel - Google Patents

Description

The invention relates to an expansion dowel for fastening objects to enclosing cavities Components.

The known expansion anchors consisting of an expansion sleeve, optionally with an expansion cone, are Usually not suitable for this type of fastening, as the walls of such components are either too thin are or consist of a soft material, so that these expansion dowels do not have sufficient hold in the Find borehole.

There are therefore the so-called toggle or hinged dowels known for such components in which on End of a fastening bolt or the like. One or two arms are rotatably arranged. After pushing through of these known dowels through the fastening hole, the arm or arms rotate automatically either by their own weight or by additional devices from their parallel to the bolt axis directed insertion position into an operative position running transversely to the bolt axis and can now on the back of the components. These known toggle or hinged dowels are mostly Complicated and often require a special fastening bolt and additional equipment to hold and fold your arms.

There is also an expansion dowel known, which is formed in one piece and suitable for commercially available screws is. When screwing in the fastening screw, the expansion legs of this known expansion anchor by striking the screw tip on each one protruding into the movement path of the screw Approach on each leg folded in such a way that they lie against the back of the component. the The expansion legs of the dowel are provided with extensions on both sides of the screwed-in screw guided through the mounting hole and through an annular flange resting on the front of the component are connected to each other, which is also intended to hold the fastening screw.

Due to these extensions, the area of application of the anchor on components with certain Maximum or minimum thicknesses limited.

The invention is based on the object of creating an expansion dowel which is formed in one piece and is simply shaped and thus easy to manufacture, which is also used for commercially available screws and thereby for an almost unlimited range of wall thicknesses for thin-walled or hollow spaces Components is suitable.

According to the invention, this object is achieved in that the expansion dowel consists of a screw-in a fastening screw, an internal expansion plug

Applicant:

Artur Fischer,

Tumlingen (Kr. Freudenstadt),
Grünmettstetter Str. 133

Artur Fischer, Tumlingen (Kr. Freudenstadt),
has been named as the inventor

thread-having ring, which with at least two substantially in the direction of the ring axis protruding, resiliently expandable legs is provided.

The free ends of the legs are expediently shaped to taper to a point. This has the advantage that when tightening the fastening screw, the legs of the expansion anchor in the case of hard material of the component lie against the back of the component, while with soft material, the legs in the back of the component penetrate and thereby give a better hold for the ring.

The legs of the expansion anchor can be pre-expanded somewhat, which initiates the expansion process supports and to penetrate the legs in a soft material this in a more favorable starting position brings.

The expansion dowel is advantageously made of tough, non-aging plastic, whereby it is corrosion resistant.

In the drawing, the expansion anchor according to the invention is shown in one embodiment. It shows

1 shows an expansion dowel in a side view, partly in section,

2 shows the dowel in an end view,

Fig. 3 shows the built-in dowel in the locked position for a component made of hard material and

4 shows the built-in dowel in the locked position for a component made of soft material.

The dowel shown in FIG. I consists of a ring 1 with an internal thread la. At one end face of the ring 1, at least two pointed legs Ib, Ic are cast on, which protrude essentially in the direction of the ring axis. The legs Ib, Ic are resiliently expandable. In Fig. 2 are

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in addition to the legs Ib, Ic , two further legs 1d are shown in phantom.

To attach an object to a thin-walled component 2, both by the object, for. B. a plate 4, as well as through the component 2 a hole 2 a drilled with the diameter Ic of the dowel ring 1. The plugged or screwed on the tip of a fastening screw 5 is by means of the screw 5 through the two drilled holes 2 α brought to cover pushed in the plate 4 and in the component 2, the somewhat pre-spread legs 1 b and 1 c are pressed against each other except for the diameter 2 c of the bore 2 a. After the dowel emerges again from the borehole 2 a on the back 2 b of the component 2, the elastic, somewhat pre-expanded legs 1 b and 1 c go back to their starting position according to FIG. 1.

In a component 2 made of hard material (Fig. 3) is retracted into the dowel of this upon further screwing in the fastening screw 5, with the legs 1 b and 1 c of the anchor spread apart and to the back side 2b of the member 2 to create.

In the case of a component 2 made of soft material (FIG. 4), the legs 1 b and 1 c of the dowel penetrate the material of the component 2 on its rear side 2 b at an angle to the screw axis when the screw 5 is screwed in further. In this way, reliable fastening is achieved even with soft material.

In both cases, the expansion plug acts like a lock nut.

In order to prevent the dowel from turning when the fastening screw 5 is further screwed into the dowel ring 1, after the dowel has been pushed through the drill hole 2 a, the dowel is withdrawn until the ends of the legs 1 b and 1 c of the dowel are on the back Press 2b of component 2.

The expansion anchor according to the invention can also be used particularly advantageously in the case of components made of laminated composite panels with a soft core. These composite panels usually consist of two spaced apart, very thin hard panels, the space between the panels with a soft material, for. B. foamed plastic od. Like. Is filled. The two hard cover plates are usually too thin to be able to hold a dowel of the usual type, while the filling layer cannot give the dowel a reliable hold either. In the case of the dowel according to the invention inserted into the soft layer behind the first hard cover plate, the expanding force of the pre-expanded legs Ib, Ic is usually sufficient to push the soft material slightly to the side. Upon tightening of the fastening screw the legs 1 b and 1 c spread with further displacement of the soft material of the filler layer, with the legs Ib and Ic - as described above - application to the back of the first hard cover plate. Since the second cover plate is not broken through the use of the dowel according to the invention in such layer composite panels, the dowel can also be used in aircraft construction, e.g. B. be used in the composite panels for pressure cabins.

Claims (4)

PATENT CLAIMS: 1. expansion anchor for fastening objects to hollow spaces enclosing the components, characterized by a for screwing in a fixing screw (5) serving, an internal thread (la) having ring (1), the projecting with at least two of its end substantially in the direction of the ring axis, resiliently expandable legs (Ib, Ic) is provided. 2. Expansion dowel according to claim 1, characterized in that the free ends of the legs (Ib, Ic) are tapered. 3. Expansion dowel according to claim 1 or 2, characterized in that the legs (1 b, 1 c) are pre-expanded somewhat. 4. Expansion anchor according to one of claims 1 to 3, characterized in that it consists of one Plastic is formed. Documents considered: Swiss Patent No. 110 250; British Patent No. 601,678; U.S. Patents Nos. 1,224,698, 2,398,784, 2567 372. 1 sheet of drawings © 20i 757/53 1.63