Pipe coupling

The invention relates to a pipe coupling for Joining pipes with non-profiled end portions, with an elastomer sealing sleeve for dense recording surrounding the tube end, with a sealing sleeve Clamp with a clamp band, on its Ends of which are formed clamping jaws which by clamping means are contractible, and that at its end faces having inwardly projecting flanges, with between arranged sealing sleeve and the flanges, at Inside of the clamp band supporting clamping rings in C-form, which means during the tensioning of the clamp band Projections on its radially inner surface in the Tubing intervene.

In a known pipe coupling of this type (EP 0205896 A2) consists of each clamping ring of a thin frustoconical spring ring and a retaining ring. The spring ring is with its inner circumference on a formed on the outer circumferential surface of the holding ring to shoulder, while its outer periphery in the formed by the bending of the flanges bend throat bears. The spring ring and the retaining ring consist each metal. The retaining ring is further on its radially inner surface with raspelartigen teeth provided, the pushed out of the material of the retaining ring are. The preparation of the clamping ring is complicated.

The invention is based on the object, a pipe coupling specify the type mentioned initially, in which the production of clamping rings will be easier without their compromising strength.

According to the invention, a first solution is that the clamping rings at least partially made of plastic and of a first ring part and a on the radially inner Circumference of the first ring part fixed second ring member approximately triangular consist and in cross-section are, so that they, the spaces between the sealing sleeve and the flanges largely filled.

A second solution is according to the invention is that clamping rings consist essentially of the plastics and in cross section are approximately triangular, so that they the spaces between the sealing sleeve and the flanges largely filled in, and that the projections over the inner circumference of the clamping ring extending, radially inwardly tapering ribs.

In both solutions, the clamping rings can easily Compounds are produced and inexpensive. She at conventional pipe couplings for the most part in cross-section triangular annular spaces between the sealing sleeve and the adjacent flange without additional support members in fill substantially completely, they have a correspondingly large cross-section with a correspondingly high Strength to the one the pipes axially against high internal pressures support and other high radial forces withstand the tensioning of the clamp. In the second solution holding the ribs beyond high Stand axial forces, even if they - as well as the second ring member in the first solution - essentially made of plastic.

The projections may in the first solution through a predetermined, uniform roughness of the radially inner Surface of the clamping rings can be formed. Here, the rough inner surface of the clamping rings largely extensively on the periphery of the end portions of the tubes abut, the tiny projections of the rough surface at best very fine scratches in tubing form when the tubes and the collars relative to each other move due to high internal pressures of the tubes. Accordingly is the risk of reduction in strength of the tubes, in particular those made of plastic, very low.

Further, in the first solution, it is possible that the second ring part a roughness having Direction friction lining is. This may be pre-assembled, for example positively or cohesively. need when mounting the clutch then only the collars to be mounted.

It is favorable when the second ring member in a groove mounted in the radially inner circumference of the first ring member and the depth of the groove is smaller than the radial thickness the second ring part is. The groove then transmits simultaneously for axially in the second ring part, wherein the attachment in a simple manner by glueing can take place.

The roughness can however also in a simple manner by Emery be effected.

If the emery directly into the inner surfaces the clamping rings is embedded, also just the clamping rings to be mounted.

Alternatively, the projections next incisions can in Linings of metal from the outside in the manner of scales be forced out.

Then it can be provided in the first solution that the first ring part is substantially made from plastic and the second ring part is made of metal and that the projections over the inner circumference of the second ring portion extending radially inwardly tapering Ribs. The fins are also made of this Metal and therefore have a correspondingly high strength, so that the pipe joint correspondingly higher Axial loads withstands than plastic ribs.

Further, in this case, the first ring portion in a groove in fixed radially outer periphery of the second ring portion and the depth of the groove is smaller than the radial thickness of his first ring part. Here, since the walls of the groove as well as the radially inner second ring member made of metal exist, the risk of breakage of these walls is less than for formation of the second ring portion from the essentially plastic.

The plastic can made of a reinforced with glass fibers Polyamide. He then has a very high Strength.

Preferably, the polyamide is PA 66th

The metal may consist essentially of brass. This material is easy to mold, yet has a relatively high strength.

An even higher strength of the metal results, if it additionally comprises manganese.

The invention and its developments are below reference to the drawings of preferred embodiments described in detail. Herein show:<dl tsize="8"><dt>Fig. 1</dt><dd>an axial view of a first embodiment a pipe coupling according to the invention,</dd><dt>FIG. 2</dt><dd>a radial view of the pipe coupling according to FIG. 1, partly in section,</dd><dt>Fig. 3</dt><dd>an axial section of the tube coupling according to FIG. 1 with the inserted therein pipe ends,</dd><dt>Fig. 4</dt><dd>the lying in circled area Neck of FIG. 3 in an enlarged scale,</dd><dt>Fig. 5</dt><dd>an axial view of a clamp ring of the pipe coupling according to FIG. 1,</dd><dt>Fig. 6</dt><dd>an axial section of the clamping ring after Fig. 5</dd><dt>Fig. 7</dt><dd>an axial view of a second embodiment a pipe coupling according to the invention, </dd><dt>Fig. 8</dt><dd>a radial view of the pipe coupling according to Fig. 7, partly in section,</dd><dt>Fig. 9</dt><dd>an axial section of the pipe coupling according to Fig. 7 with the inserted therein pipe ends,</dd><dt>Fig. 10</dt><dd>the lying in the circled area Neck of FIG. 9 on an enlarged scale,</dd><dt>Fig. 11</dt><dd>an axial view of the clamping ring of the second Embodiment,</dd><dt>Fig. 12</dt><dd>an axial section of the clamping ring after FIG. 11</dd><dt>Fig. 13</dt><dd>the lying in the circled area Neck of FIG. 12 in an enlarged scale,</dd><dt>Fig. 14</dt><dd>an axial view of a modified clamp ring the pipe coupling of Figs. 7 to 10,</dd><dt>Fig. 15</dt><dd>an axial section of the clamping ring after Figs. 14 and</dd><dt>Fig. 16</dt><dd>the lying in the circled area Neck of FIG. 15 in an enlarged scale.</dd></dl>

The pipe coupling according to FIGS. 1 to 5 is used to connect pipes 1 with substantially smooth, non-profiled End sections 2, in particular pipes, mainly Sewer pipes, made of plastic. The pipe coupling contains an elastomeric sealing sleeve 3 for dense Receiving the tube end 2 and a sealing sleeve 3 surrounding clamp 4 with a clamp band 5, at the ends of the clamping jaws 6 in the form of bent End portions of the clamp band 5 and this axially passing through bolt 7 are formed. The jaws are by clamping means 8 in the form of clamping screws, the radial through-holes of a bolt 7 and radial threaded bores of the other bolt 7 prevail, contractable circumferentially. The Clamp band 5 also has on its end faces by inwardly projecting flanges. 9

The sealing sleeve 3 is on its inside near their axial ends directed to the pipe ends, Sealing lips 10, 11 and between the sealing lips 10, 11 with a C-shaped metal band 12 for the radial support the sealing sleeve in the region of the joint between the mutually facing end faces of the end sections 2 the tubes 1 provided.

Between the sealing sleeve 3 and the flanges 9 on each side of the sealing sleeve 3 a located on the inside the clamp band 4 and the flanges abstützender Clamping ring 13 in a C-shape, see in particular Figs. 5 and 6, arranged substantially made of plastic. The Clamping rings 13 are made of a radially outer annular part 13a and a radially inner ring portion 13b and engage during tightening of the clamp band 4 using tiny, in the drawings not shown projections on its radially inner surface 14 in the pipe material on. The projections are predetermined by, uniform roughness of the radially inner surface 14 the ferrules 13 is formed, preferably by Emery.

In the illustrated embodiment, the tiny Projections by the roughness of the most radially inner periphery of the ring portion 13a fixed ring member 13b forming the friction lining formed.

The friction lining embodied as ring members 13b are each in a groove 16 in the radially inner circumference of the Ring members 13a attached. The depth of the grooves 16 is smaller than the thickness of the annular portions 13b.

The clamp rings 13 are cross-sectionally approximately triangular in shape, so as the dreiecktörmigen also about the cross section Annular spaces between the sealing sleeve 3 and the Flanges 9 largely filled. An axial ridge 17 each clamping ring 13 engages into a gap between each one of the flanges 9 and the pipe circumference.

According to FIG. 5, the ends have each clamping ring 13 a Angular distance α of about 20 to 45 °, in particular 30 to 40 °, preferably 35 °.

According to FIG. 6, the angle β, which the sealing of the sleeve 3 adjacent surface 18 of each clamping ring 13 with its axis includes about 35 to 60 °, preferably about 45 °.

The gap between the ends of the clamp band 5 is of FIG. 1 is bridged by a bridge 19.

The rough surface 14 of each clamping ring 13 or its as Friction lining formed ring portion 13b is largely extensively on the respective pipe end 2 and prevented since it comprises only tiny projections, the formation of deeper grooves in the surface of the respective tube 1, when the tubes 1 due to very high internal pressures should be moved apart axially. This is particularly in plastic pipes from Advantage, but also in ceramic, glass or metal tubes, to prevent a reduction in their strength. Further, formed by deep grooves may, sharp burrs formed not to damage the sealing faces, that the sealing lips 10, 11 of the elastomeric Sealing sleeve 3, perform when the pipes 1 uncoupled and thereafter again axially in the same pipe coupling be introduced.

The ring parts 13b can in each case a groove 16 of the Ring parts 13a to be glued. but you can also just be held positively in the grooves 16th in this connection can by a radially outwardly acting Eigenelastitzität additionally be detained. But it is also possible for the friction surfaces 14 immediately in the inner forming peripheral surface of the clamping rings 13, for example, by embedding Emery in these peripheral surfaces, when the clamping rings 13 in the rest of plastic consist. Also, the surface 14 of the friction linings designed as Ring parts 13b may be formed by Emery be, with the friction linings otherwise made of plastic may exist.

Alternatively, the designed as friction linings Ring parts 13b also made of metal and its fine Projections next radially through incisions in pushed out like scales the linings from the outside inwards be.

The second embodiment of Figs. 7 to 13 differs from the first embodiment only in the formation of the clamping rings 13. These consist from a radially outer annular portion 13a and a radially inner ring member 13b. The annular portion 13a is essentially made of plastic and the annular portion 13b made of metal. Over the inner circumference of the ring portion 13b extending several parallel ribs 20, in the illustrated Embodiment three ribs 20. The ribs 20 taper radially inwardly, whereby its cross section approximately the shape of a right triangle , said forming a cathetus side of each Rib 20 of the axial center of the pipe coupling faces and forming the hypotenuse side of the axial center is remote. Each ring portion 13b has radially on its outer side a circumferential groove 21 in which the radially outer ring member 13a is fixed, preferably by Gluing. The axially outer wall 22 of each ring portion 13b is located in a gap between each one of the flanges 9 and the pipe circumference. The axially inner wall 23 (Fig. 10) engages in an undercut of the outer Ring portion 13a, and its axially inner surface with the voltage applied to the sealing sleeve 3 surface 18 flush and at the angle β (Fig. 12) inclined. The angle α and β (Fig. 11 and 12) are the same as in the first embodiment.

The radially outer ring member 13a is substantially of plastic, preferably of glass fiber reinforced Polyamide, in particular PA 66, in which so-called Short glass fibers are embedded, which sprayed the completed Ring portion 13a a length of 0.1 to 0.8 mm have. The proportion of the glass fibers is about 25 to 30 Percent by volume of the ring portion 13a.

The radially inner ring portion 13b of each clamping ring 13 is essentially made of brass with a low Additional manganese. Preferably, the ring portion includes 30a about 57 to 59% Cu; 1.5 to 3.0% Mn, wherein said alloy may contain further additives, preferably 1.3 to 2.3% Al, 0.2 to 0.8% Pb and 0.3 to 1.3% Si.

The balance consisting of zinc (Zn). It is also possible Impurities of not more than 0.4% Sn, 1.0% Fe, 1.0% Ni and other impurities not exceeding 0.3% be included. The percentages are percent by weight.

This alloy is relatively hard and let himself yet easily shaped by the extrusion and in the Ring shape bend. Moreover, it has a certain Elasticity. Furthermore, the ribs 20 can be easily the still straight strand roll.

The clamping ring 13 shown in FIGS. 14 to 16 is integrally substantially made of plastics. He has also several, over its inner circumference extending, radially inwardly tapering ribs 23. The cross-section of the fins 23 has as well as the Cross-section of the ribs 20 is substantially the shape of a right triangle whose hypotenuse of faces away from the axial center of the pipe coupling. While the Hypotenusenabschitt like the ribs 20 with the Axial direction at an angle γ of less than 45 °, here about 41 °, with, the radially inner edge the ribs 23 against the hypotenuse a Angle δ of about 20 to 25 ° flattened. by virtue of This flattening of the ribs 23 axially higher loads.

The angles α and β (Fig. 14 and 15) are again the same as in the first embodiment.

The material of these retaining rings 13 is also a glass fiber reinforced polyamide, preferably PA 66, with a long-glass-fiber content of about 50 to 80 volume percent, preferably about 60 percent by volume. The Long glass fibers have a length of about unprocessed 5 to 10 mm and in the embedded state in the polyamide only a length of about 1 to 8 mm, because they when spraying the plastic clamping rings at least most of break. In the modification of the clamping rings 13 according to FIGS. 14 to 16 have the clamping rings 13 due to the higher glass fiber content even higher Strength than the ring parts 13a in the previous Embodiments wherein it is due its one-piece training over the two-part more easily be produced training.

Both one-piece construction of each clamping ring 13 as well as training of each clamping ring 13 with a attached thereto inner friction lining or ring part 13a eliminates the separate mounting of two separate parts the clamping ring in the clamp.