DE8811706U1 - Protective ring for pipes - Google Patents

Description

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Bergrohr GmbH Siegen

Protective ring for pipes

The invention relates to a protective ring for the front edges of pipes, consisting of a clamping sleeve with a molded radial edge that can be inserted into a pipe end.

Pipes for the construction of, for example, sewage, oil or gas pipelines usually have precisely machined ends to ensure flawless connections, e.g. weld seams. When handling and transporting the pipes, there is a risk of damage to the pipe ends in particular, which makes it more difficult to subsequently create the connections. To avoid such damage caused by, for example, mechanical impacts and/or corrosion, protective caps made of steel strip are available in various designs, which are pushed axially into or onto the respective pipe ends and fixed in place using spring clamps.

A known protective cap has a longitudinally slotted expansion sleeve with a molded radial edge, the outside diameter of which is slightly larger than the inside diameter of the pipe before being inserted into a pipe end. To insert the sleeve, it is compressed radially and places

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It then expands and adheres more or less firmly to the inner wall of the pipe due to its own elasticity or separate spring elements. This protective cap is structurally simple and inexpensive, but has the disadvantage of insufficient dimensional rigidity and, particularly in the case of large pipes, relatively difficult to install with special tools. In the case of significant diameters&mdash; {

A sufficiently tight fit is not guaranteed with the backpacks, so that the caps can come loose and fall off.

Another known protective cap has ring disks attached to an inner hollow cylinder, which can be adjusted with their outer edge, possibly with elastic deformation, to the

The protective caps have a radial end flange which covers the front face of the pipe end and can be provided with a bent-back edge. In addition to the higher outlay and the correspondingly higher costs, the main disadvantage of this protective cap is that it cannot be adapted to different pipe diameters P within the specified tolerance range .

The object of the invention is to create a protective ring for the front edges of pipes, which can be firmly and securely fixed in the pipe ends without taking diameter tolerances into account while having a simple structure.

This object is achieved according to the invention in that the diameter of the sleeve inserted into the pipe end is increased by permanent plastic compression deformation of at least one expansion element, whereby a firm pressing of the sleeve against the inner wall of the pipe is achieved, even in the case of pipes whose inner diameter is at the upper limit of the respective tolerance range.

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To achieve this permanent expansion, the sleeve has one or more longitudinal beads or folds which, after the protective ring has been inserted into the tube, are flattened by hammer blows, for _example , whereby the diameter of the ring is increased and a firmly clamped fit in the tube is achieved.

The closed shape of the protective ring makes it much easier to insert it precisely into the pipe end because the ring is dimensionally stable even with relatively large dimensions and no additional equipment or parts are required for clamping. The risk of injury to personnel when inserting and fixing the ring is largely eliminated. By using a suitable design and number of beads or folds, all diameter tolerances of both the respective pipe and the ring itself can be fully compensated. Finally, the lack of special clamping elements, such as wedges, ensures that the protective ring sits very firmly when the pipes are transported.

Further features and special features of the invention can be found in the following description of embodiments shown in the drawing. They show:

Fig. 1 shows a protective ring inserted and fixed into a pipe end in axial section,

Fig. 2 a protective ring in front view,

Fig. 3a, cross-section of a clamping sleeve before installation 3b with undeformed longitudinal bead (Fig. 3a) and in the installed state with deformed longitudinal bead (Fig. 3b),
Fig. 4 another embodiment in partial section.

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The large pipe 1 shown in Fig. ₁ made of bent welded rolled strip has a machined end piece 2 with a conical outer surface. A protective ring 3 made of steel strip shown in Fig. 2 is inserted into this pipe end, which consists of a continuous or closed sleeve 4 and a radial flange 5 formed thereon.

As can be seen from Fig. 2, the sleeve 4 and possibly also the radial flange 5 have an inner bead 6. After the sleeve 4 has been fully pushed in until its radial flange 5 stops at the front edge of the pipe end, the inner bead 6 is flattened or pressed, e.g. with a hammer or another suitable device, which leads to an expansion or increase in diameter of the sleeve 4 corresponding to the radial height of the bead. This expansion causes the sleeve 4 to fit tightly under pressure in the pipe 1.

The number and shape of the bead 6 depends on the respective circumstances, for example on the pipe diameters. The beads do not have to have a uniform shape over the entire sleeve and can also be made only on part of the sleeve length. Finally, bends in the sleeve other than bead or fold-shaped bends are also possible, which ensure a permanent expansion of the part inside the pipe after they have been reshaped.

The protective ring shown in Fig. 1, 2 is conveniently formed in an integrated flanging and bending device from an endless sheet metal strip in the desired size. The end edges of the still open ring are bent at 7

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welded together and then the beadings or folds 6 are worked into the sleeve 4 and if necessary* also into the radial flange 5, whereby the sleeve diameter is slightly reduced. This protective ring is inserted into a pipe end until its radial edge 7 rests against the pipe face* Since the outside diameter of the sleeve 4 is a few millimeters smaller than the inside diameter of the pipe 1, no major thrust forces are necessary for the insertion process.

After the sleeve 4 has been inserted, the bead 6 is deformed radially outwards in order to achieve the desired expansion and widening of the clamping sleeve. This deformation can be carried out either by e.g. hammer blows until the bead is completely stretched and leveled, as shown in Fig. 1. By using a pressing or pressure tool, the bead 6 shown in Fig. 3a can also be formed into a fold of low radial height while simultaneously spreading its fixed sections. This has the advantage that this fold 6a forms stop surfaces 10 which make it easier to knock the protective ring off the pipe by hammer blows or to pull it off using a suitable gripping device.

In the embodiment shown in Fig. 4, the protective ring has a gap or slot 8 which is bridged by an elongated inwardly curved tab 9 or by several inwardly curved crosspieces. The tab 9 or the crosspieces are welded with their side edges ^to the two inner edges of the sleeve 4.

Claims (4)

BEETZ & PARTNER j : * : : '-: Pgtterjtpnvyälte Steinsdorfstr. 10 · D-8000 Munich 22 * * European" Patent Attorneys Telephone (089) 227201 - 227244 - 295910 _D , ,., _R ^^ ^ Telex 522048 - Telegram Allpat" Munich DHna R BEETZ iun 143-41 .41 5G-Mt ^Dl>ln 9- ^w - TIMPE Dipl.-Ing. J. SIEGFRIED Prof. Qr. rer.nat W SCHMITT-FUMIAN DipL-Phys. Dr.rer.nat C-M. MAYR Dipl.-Ing. K. UMPRECHTt 1981 15 September 1988 Expectations 1. Protective ring for the front edges of pipes, consisting of a clamping sleeve with a molded radial edge that can be inserted into a pipe end, characterized in that the clamping sleeve (4) has at least one plastically permanently deformable expansion element (6). 2. Protective ring according to claim 1,
characterized, that the clamping sleeve (4) and the formed radial edge (5) are closed and the expansion element is designed as a bead (6). 3. Protective ring according to claim 1,
characterized, that the clamping sleeve (4) has a longitudinal slot (8) which is bridged by the inwardly curved expansion element (9). 4. Protective ring according to one of claims 1-3, characterized in that contact surfaces (10) are provided on the clamping sleeve (4) or on the radial edge (5) for the tool engagement when releasing the Vöffl Söhr protective ring.