SK157098A3 - Weldable clamp for a pipe made of a thermally weldable material - Google Patents

Abstract

The clip of thermaly weldable material for repairing the pipe (10) of tube made of weldable material, consisting of at least two pipe (10) surrounding segments (11, 12) of which at least one has a pipe outlet (13), with on the segments (11, 12) to each other turned reducing edges (16, 17) for mutual fixation under pressure, with reducing edges (16, 17) extending with the sphenic curved feeders on one segment (11, 12), which are placed on the clamp between the inner part of the neighbouring segment (11, 12) and the pipe (10) of the tube, and with heating mats (20) of the wound electrically heated conductors (61)m which are fixed on the inner surfaces (14) of the segments (11, 12). On each of the both reducing edges (16, 17) of the relating segment (11, 12) there are the feeders and clamps arranged mutually alternately and additionally to the relating neighbouring segment (11, 12) and creating gearing of the narrow mouldings (30) or wide mouldings (36) locally extending reducing edges (16, 17) and also of among them lying bags (40, 46) which are made under the reducing edges (16, 17) for placing the mouldings (30, 36), whilst the heating mats (20) have with the gearing conforming graded side profile from to the front extending clappers (24, 26) in the area of mouldings (30, 36) and between tham placed gaps (25, 29) in the area of bags (40, 46).

Description

Disclosed is a repair bracket comprising at least two tubes (10) surrounding segments (11, 12), at least one of which has a tube outlet (13) with facing edge edges (16, 17) on the segments (11, 12), which are pressurized to each other for attachment with limiting edges (16, 17) overlapping the wedge-shaped extensions on one segment which lie on the clamp between the inner surface of the adjacent segment and the pipe (10) and with heating mats (20) of wound electrically heated conductors (61) that are mounted on the inner surfaces (14) of the segments (11, 12). On each of the two limiting edges (16, 17) of each segment (11, 12), the extension and clamp are arranged alternately and complementary to the respective adjacent segment (11, 12) and form a toothing from the limiting edge (16, 17) of the locally overlapping narrow rails (30) or wide rails (36) on the one hand, and between them the casings (40, 46) on the other, which are below the limiting edges (16, 17) and serve to accommodate narrow rails (30) or wide strips (36).

1 '-fy-qy

CALIPER FROM THERMAL WELDING MATERIAL

Technical field

The invention relates to a caliper made of thermally weldable material for a pipe of the same weldable material as a repair caliper, of at least two tubes, if necessary surrounding segments, at least one of which has a tube outlet and, if necessary, boundary edges on the segments which are pressurized to each other for attachment with limiting edges projecting wedge-shaped extensions on one segment, which, if necessary, are in the clamp between the inner surface of the adjacent segment and the pipe and with heating mats of wound electrically heated conductors fixed on the inner surfaces of the segments.

BACKGROUND OF THE INVENTION

It is known that such calipers are used, for example, for already laid, pressurized pipelines, where branching is required. For this purpose, yokes are used which have at least one outlet on at least one of the cylindrical segments arranged around the pipe. This outlet serves first to drill the pipe, but then also to guide the environment into the branch connected to the pipe. In other cases, where there is a breakage on the pipeline, a yoke from segments without piping outlet is placed around the pipeline for repair.

In the known caliper described in the patent specification (DE 295 12 309 U1), two segments are arranged around the duct, one segment being formed with two arms. The two arms extend over the entire axial length of the yoke at the boundary edges without interruption, and there are two wedge-shaped opposites which serve to attach the boundary edges of this segment and overlap in the direction of another segment. In use, these passing extensions are housed in a clamp between the inner surface of the adjacent segment and the duct. In order to seal the environment at the weld site,

101 / B, two positions of the heating mats are used, namely the first heating mat on the inner surface of the extensions and the second heating mat in a clamp on the inner surface of the adjacent segment. This requires high construction costs and higher heating energy as a result of the two-position welds.

In order to connect the shrink sleeve between the two tubular sleeves of the tubular connection, a band heating mat is placed in the gap between the sleeve and the sleeves movable thereon, as described in DE 37 20 577 A1, where the contact ends are at the end of the heating mat strip they are staggered to one another and, if necessary, interfere with one another. The heating mat is a separate component which is arranged as a loose strip in the form of a circle around the jacket tube and forms a two-layer welded joint, mainly with the peripheral surface of the jacket tube and further with the inner surface of the impacted sleeve. There are no problems with sealing any one of the at least two cylindrical segments of the assembled caliper.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a caliper of the above-mentioned type which achieves high sealing of welded joints at very low production costs and low heating energy consumption.

SUMMARY OF THE INVENTION

SUMMARY OF THE INVENTION The invention solves the problem by providing a stirrup of thermally weldable material for the same weldable pipe tube as the repair clamp, of at least two pipes surrounding the segments if necessary, of which at least one has a pipe outlet and, if necessary, segments which are pressurized to each other for fastening with limiting edges projecting from the wedge-shaped curved extensions on one segment, which, if necessary, lie on the clamp between the inner surface of the adjacent segment and the pipe and with heating mats of wound electrically heated conductors fixed to the inner segment surfaces, the essence of which is on each of the two limiting edges of each segment, the extension and clamp are arranged alternately and complementary to the respective adjacent segment and form

101 / B toothing from the restraint edge, locally overlapping narrow strips or wide strips on one side and pockets lying between them, which are below the restraint edges and serve, if necessary, to accommodate narrow strips or wide strips, the heating mats having toothing a conformal stepped contour profile of forwardly projecting flaps, in the region of narrow strips or wide strips and of interstices lying therebetween, in the pocket region.

According to a preferred embodiment of the present invention, the toothing of the segment limiting edges divides the heating mat into three different axial sections, namely two end sections which, if necessary, have a circular closed heating collar around the pipe tube where the wound conductors extend in the form of a ring from the pocket bottom. from the end of the bar on one edge to the end of the bar or the bottom of the pocket on the opposite edge and one or more offset intermediate sections which form a heating strip in the region of one edge of the segment and extend at least partially into the extended wide bars although the conductors run between the two end sections, they leave the adjacent remaining inner surfaces of the segment together without conductors.

According to a further preferred embodiment of the present invention, the cross-sectional thickness of the wedge-shaped narrow strip or the wide strip in the limiting edge of the leg rest segment is greater than the thickness of the softening zone that occurs when the electric wire is heated in the narrow strip or wide strip.

According to a further preferred embodiment of the present invention, the electric conductor is arranged at an unheated axial distance to the side surfaces of the narrow strip or the wide strip, which is greater than the thickness of the softening zone of the material during heating.

According to a further preferred embodiment of the present invention, the segment heating mat is made with its segmented contour profile from the thread of a single running electrical conductor.

101 / B

According to a further preferred embodiment of the present invention, the wires of the mats of all segments are electrically connected to each other in series and connected to the welding machine for uniform heating.

According to a further preferred embodiment of the present invention, the threads of the conductor consist of parallel arms with the arches therebetween, the arms extending in the region of the two ring of the closed heating sleeve forming the end sections of the heating mat in the circumferential direction of the cylinder. It extends in the direction of the axis of the cylinder of the segment, while the arches lie on the line of the step contour profile of the flaps or the gaps of the heating mat.

According to a further preferred embodiment of the present invention, the electric conductor consists of one meander wire in the form of a wavy line of the running wire and the meander wire is embedded in the threads forming a heating mat.

According to a further preferred embodiment of the present invention, the meandering wire on its both of the heating strand of the projecting ends comprises further running end pieces of the wire which are connected to the electrical contacts of the segment.

According to a further preferred embodiment of the present invention, the steps in the outline profile of the heating mat are rectangular.

According to a further preferred embodiment of the present invention, the segments h and at least one of their two axes of parallel limiting edges comprise a radial edge flange and fastening means extend between the edge flanges of adjacent segments so that the radial pressure pipe tube forms a surrounding yoke.

According to a further preferred embodiment of the present invention, the edge flange of the segment on its inner surface has a longitudinal rib in which a heating strip parallel to the axis of the heating mat is fixedly fitted and a longitudinal groove is formed on the inner surface of the flange from the opposite edge flange of the segment and / or the adjacent segment. additional width and depth to the shape of the longitudinal rib, which, if necessary, serves to accommodate the longitudinal rib.

101 / B

According to a further preferred embodiment of the present invention, the cross-sectional thickness of the narrow strip or wide strip is so small that the softened material gets out.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is illustrated in the drawings, wherein:

Fig. 1 shows, in cross-section and cut-out, both segments of the repair caliper according to the invention before being fixed to the pipe; FIG. 2 shows the segments of FIG. 1 after their attachment to the pipe; FIG. 3 is a perspective view of the lower segment of FIG. 1 for a concave inner surface, FIG. 4 shows the lower segment shown in FIG. 3, also in a perspective view, but viewed from the opposite side, FIG. 5 is a perspective view analogous to FIG. 3 shows the upper segment of the caliper shown in FIG. 1 or FIG. 2, FIG. 6 shows the planar deployment of the heating mat segment on the concave inner surface of the segments shown in FIG. 3 or 5, which show both their particular contour profile and the winding sequence for their serving electric conductor; FIG. 7 is a view analogous to FIG. 6 is a plane deployment of the heating mats of the segments of FIG. 3 and 5 after having been fixed together with their limiting edges, FIG. 8 and 9 show schematically, but FIG. 7, two alternative shapes of the heating mat outline, FIG. 10 is a view analogous to FIG. 2 shows a cross-section of an alternative embodiment of a caliper according to the invention,

101 / B fig. Fig. 11 shows a front view of parts of a used electric conductor in the form of a meander with double-sided for the purpose of connecting the arranged elongated pieces of wire; 12 is an enlarged front elevation view of a heating cord in which the electrical conductor of FIG. 11 and which can also be used in other pipe-to-pipe welding of fixed fittings, e.g. welded sleeves; FIG. 13 is a cross-sectional view of the heating strand of FIG. 12 taken along section line XIII-XIII therein, and FIG. 14 shows an enlarged view but FIG. 12 and 13 are a reduced, longitudinal sectional view of the wall of the mold used for the injection molding of the segment of FIG. 3 to 5.

DETAILED DESCRIPTION OF THE INVENTION

The repair caliper shown in FIG. 1 and 2 consists of two cylindrical segments 11, 12 which, if necessary, are intended to be fixed at a desired location to the pipe 10 by welding. The cylindrical segments H, 12 will be referred to hereinafter as "segments". The pipe 10 and also the two segments 11, 12 are made of a material suitable for thermal welding. Both segments 11, 12 are, as shown in the comparison of FIGS. 3 and 5 of the same shape, but they differ in that only the upper segment 12 is provided with a tubular outlet 13. The tubular outlet 13 has a forward through-hole 15, seen in FIG. 1 and 5 and a partially cylindrical concave inner surface 14. Since both segments H, 12 are of the same construction, it is sufficient to describe only one, namely the lower segment 11.

The segment H has limiting edges 16, 17 to which radial edge flanges 18, 19 are attached for fixing. The fastening means in this case consist of pins 58, shown in FIG. 2, which are shown in FIG. 3 by visible bores 57 of the edge flanges 18, 19 and screwed together by nuts 59. In each case the concave inner surfaces 14 of the two segments 11, 12 are inserted a heating mat 20 having a special shape, best seen in FIG. 6th

101 / B

The heating mat 20 is also in this case also profiled in both segments 11, 12, so that in FIG. 6 follow the planar deployment of the heating mat 20 of the upper segment 12 of FIG. Third

In FIG. 6, the contours of the upper segment 12 were also bent at an angle to the plane and indicated by a dashed line. The two aforementioned limiting edges 16, 17 of the segment 12 are extended forward. A special feature of the heating mat 20 is that along its two limiting edges 16, 17, there are different contour profiles whose contour lines 26, 27 are shown in FIG. 6 marked with dashed lines. These contour lines 26, 27 are complementary to each other in the present case. There are narrow flaps 24 and wide flaps 28, with which both contour lines 26, 27 overlap both limiting edges 16, 17 and between them narrow gaps 25 and wide gaps 29, which extend below both limiting edges 16, 17. This articulated contour the profile acts on the partially cylindrical concave inner surface visible in FIG. 5 naturally such that, as shown along section line I-I in FIG. 5, the derived cross-section through the wide flap 28, the heating mat 20, the partial cylindrical shape of the concave inner surfaces 14 continues outwardly through the respective limiting edge 17. This shape is naturally reinforced by the material of the segment 12 and 11, respectively, which fills the flaps 24, 29 on the rear side 34 facing away from the inner surface 14 of the segment, thereby forming respective narrow strips 30 overlapping limiting edges 17 and wide strips 36. or narrow strips 30 are also formed integrally with the respective segment 12 and have in FIG. This curved cross-section 33 is not only a continuation of the concave cylindrical portion of the inner surface 14, but also that the rear side 34 of the wide strip 36 or the narrow strip 30 is concave, although with a flatter shape in compared to the concave inner surface 14. Thereby, the wide strip 36 or the narrow strip 30 has a tapered cross-section which is wedge-shaped to the free end 31 of the strip. In the foot region 32, the wide strip 36 or the narrow strip 30 has a larger cross-section 35 than in the region of the head 31 where the wedge top is located.

In the region of the intermediate gaps 25, the ratios are reversed. Indeed, these gaps 25 are used to provide, with suitable recesses in the concave interior surface 14 of the pocket segment 40 with the above-described peak shape 31 to 34, an additional clearance 41 and a depth 42 having a corresponding curvature of 43.

101 / B explained in FIG. 1 by means of a recess 46 having the shape of the pocket 41 to 43 described above, which is shown in FIG. 4, it only distinguishes the pocket 40 as shown in that it is formed on the wide gap 23 of the heating mat 20 indicated in FIG. 6. In FIG. 6, the dimensions and length of the recess 46 and, in the present case, the five pockets 40 are indicated by the dot hatching of the segment limiting edge 16, 17.

The contour profile of the heating mat 20 shown in FIG. 6 of one segment 11 or 12 can be divided into three sections 21 to 23 which extend along the two contour lines of the profile 26, 27 and are differently profiled. Of the two end regions 37, 38 shown in FIG. 2 of the respective segment, two sections 21, 22 are designated as " heating collars " as these sections, as seen from the case of use in FIG. 7 in plan view, it is evident that they surround the tube 10 provided with the yoke of FIG. 2. FIG. 7 the two segments 11, 12 with their limiting edges 16, 17 are in contact, it can be seen that the flaps 24 of one segment H fill the gaps 25 of the adjacent segment 12, which also applies to the flaps 24 of segment 12 and gaps 25 of the IT segment.

Between the two abutting limiting edges 16, 17, FIG. 7, the movement slots 39 of the two segments 11, 12 shown in an arrow. The two contour lines 26, 27 adjacent to each other are also shown in dotted lines. It can be seen that the lines 26, 27 have a step profile which several times crosses the contact gap 39 between the two segments H, 12. A kind of "toothing" is formed between the intervening heating collars 21 of the two segments 11, 12. the shape follows from FIG. 7, when the planar position of the two heating mats 20 shown therein is cylindrical, in a manner corresponding to the two concave inner surfaces 14 of the segments 11, 12 where the heating mats 20 are fixedly mounted. Also, both of FIG. 7, the boundary edges 17, 16 of the two segments 11, 12 shown in dotted lines at the top and dotted at the bottom are in abutment.

As already seen in FIG. 6, the length of the flaps 24 and the gaps 25 in the region of the heating collars 21 is complementary to both lines of the contour profile 26, 27. The flaps 24 and the gaps 25 are in opposing pairs. A similar arrangement is also provided for the two opposite ends 38 of the segments in FIG. 2

However, in the cuff 22, the flaps 24 and the gaps 25 are interchanged compared to the above-mentioned heating cuff 21. As in FIG. 6, in the heating sleeve 22 indicated by the dashed contour profiles 26, 27, the shape of the sleeve 22 results from a double mirror image around two perpendicular symmetry axes from the corresponding profile of the aforementioned heating sleeve 2T Mathematically speaking, this means that the heating sleeve 22 has outline. As shown in FIG. 2 and FIG. 4, this symmetrical shape also applies to the spatially curved narrow strips 30 in the region of the flaps 24 and to the pockets 25 arranged at the gaps 40.

The above-mentioned third section of the heating mats 20 is shown in FIG. 6, the heating strip 23, which is substantially parallel to the axis of the heating mat 20 and arranged between the two heating collars 21, 22, is visible. This heating strip 23 forms a flap 24 on the heating collar 22 and can thus be as shown in FIG. 6, connected to said wide flap 28. According to FIG. 6, one half 44 of the heating strip 23 is disposed above the limiting edge 17 of the segment and is thus, together with the adjacent flap 24 of the second heating sleeve 22, fixedly embedded in the concave inner surface of the curved wide strip 36 described above. 3. The second half 45 of the heating strip 23 is disposed below the limiting edge 17 on the concave inner surface 14 of the segment 11, respectively 12. It is significant, as best seen in FIG. 6, the heating strip 23 lies off-center, so that the adjacent inner storage surface 47 of the segment is outside the heating mat 20. In this space, FIG. 6, the through hole 15 shown on the segment 12 of the seated outlet 13 of the pipe 10 is shown in dashed lines. As shown in FIG. 2, the outlet 13 of the pipe 10 has a diameter of the opening 48, which may be equal to the diameter 49 of the pipe 10. If necessary, they could also be shown in FIG. 6, outside the through hole 15 in the inner receptacle 47, arranged terminals 56 filled with threads of the electrical conductor, thereby contributing to the formation of the heating mat 20.

However, in order to save heating energy, relatively narrow heating strips 23 are formed, since these are, as shown in FIG. 7, with their two heating steam halves 44, 45 disposed on both sides of the separating slot 39, and thus form a very effective, airtight welded connection there. These ratios

101 / B are particularly well observable in FIG. 2, where the two segments 11, 12 are connected together into a yoke on the pipe 10. In FIG. 2, a curved wide strip 36 provided with a heating strip 23 extends into an additionally curved recess 46. In these regions 36, 46, a yoke wall is formed to which both segments 11, 12 with their weldable material contribute. Thus, the most important areas of the concave inner surface 14 of the caliper are covered with a heating mat 20, as is evident in FIG. 2, a heating strip 23 is shown. As already mentioned, at the location of the end regions 37, 38 of the segment 11 or 12 defining the heating collars 21, 22 there is an overall arrangement of the described parts of the heating mat on the inner surface 14 of the caliper.

The fastening means 57, 59 described so far are the two segments H, 12 in FIG. 2 visible flanges pressed together. A stop 35 arranged on the radial flange 19 makes it possible to determine the external dimension of the relative compression of the two segments H, 12. Thus, by means of a curved depression 46, the wide strip 36 is pressed against the skirt 54. This naturally applies in the same sense of the same shape. As a result, a good radial pressure of the assembled segments 11, 12 on the jacket surface 54 of the tube is also created on these stirrups. When the heating mat 20 is heated, the material capable of welding at the contact areas between the concave segment surface 14 and the convex casing surface 54 of the conduit will liquefy. Here, the softened material zone 50, as shown in FIG. 2 shown by dot hatching.

This softened material 50 could be pushed out through the tactile gap 39 between the two segments 11, 12. In many cases, this is even required, because by this way of expelling the material outwards, an indicator of good welding completion is provided at the intended location. In other cases, however, this is not required, which can be equally easily accomplished by the invention. This is only necessary from FIG. 1 in the leg region 23, the slight cross-sectional thickness 35 of the wide strip therein 36 or a similar narrow strip 30 can be made slightly larger than that shown in FIG. 2, the thickness 51 of this softened material zone 50 is shown in the form of a wedge-shaped wide strip 36 or a narrow strip 30.

101 / B

Fig. 8 and 9 show schematically alternative ratios for the contour profiles of the heating mats 20 in both the segments 11, 12 indicated by the dashed lines in FIG. 7 in a comparable representation. The position of the two heating mats 20 ', 20 is shown by opposite hatching and shows only the complementary profile lines 26', 27 'of the contour or 26, 27 of the two longitudinal sides also by the broken lines 16', 17 'and 16, respectively. 17. FIG. 8, a trapezoidal or jagged profile 26 ', 267' is used instead of the rectangular graduated profile described above. In FIG. 9, the contour profiles 26, 27 have the shape of wines. These contour profiles can be formed by suitable threading of the strand 60 comprising the electric conductor without further measures, which will be described in more detail below.

As mentioned above and as shown in FIG. 1, the tubular spout 13 has a through hole 15 formed in the concave inner surface 14 on the front side. After heating the heating mat 20 installed in both segments H, 12 and cooling the melt, it is easy to determine by pressure test whether the welded connection is truly flawless. For this, it is only necessary to connect a pressure source and a pressure gauge to the pipe outlet 13. The pipe 10 at the location of the segments 11, 12 is not yet drilled and is below an arbitrarily high inner such. Only when the pressure test has been satisfactorily carried out, the pipe 10 is returned, which can also be carried out through this pipe outlet 13 or through the opposite segment 11 provided with a similar pipe outlet. Then, as shown in FIG. 2, inside the tubular outlet 13, a bore 77 in the tubing 10, thereby creating an environment flow in the tubular outlet 13.

Fig. 10 shows a cross-section similar to FIG. 2 shows an alternative embodiment of a segment 11 'comprising a heating strip 23' to FIG. 6 of an analogous heating mat 20 '. In FIG. 10, shown in Figures 10, one of which may also carry a tubular outlet 13 ', have a longitudinal rib 52 arranged vertically on the inner surface 68 of the edge flange 18', while a longitudinal groove is formed on the opposite inner surface 59 of the edge flange 19 ' 53, which is complementary in shape and size to the shape of the longitudinal rib 52. In the central region of the heating mat 20 therein, where the heating web 23 'lies, the contact gap between the flange 18', 19 'is also sealed by welding. The heating sleeve 21, 22 also formed in this case

101 / B in the end bands of the segments H 'and 12' are naturally described above, the interlocking narrow strips 30 and the pockets 40. These heating sleeves develop welding regions which also surround the entire surface and on all sides of the duct housing 54 .

The conductor 61 used in the heating mat 20 has a special shape and represents only one component of one, in FIG. 11 to 14 of the illustrated heating heater 60 shown. The wire of the conductor 61, consisting of an electrically conductive material, is transformed into a 63 meander shape. This meander shape 63 is used because the wire is guided by two interlocking gears whose tooth shape forms the meander arcs 63 The stretched wire sections 64 are formed simply by having the aforementioned gears apart at these points of automatic wire feed 61 so distant that they no longer engage with their inner teeth. Meander 63 is a straight-running wave line. As shown in FIG. 11, the meander 63 is provided with elongated, extending end portions of the wire 64 that serve to connect to the electrical contacts that are disposed on the segments 11, 12. These contacts serve to connect the welding machine. The connected contacts connected to one end of the heating mat 20 are connected to each other by a cable, whereby both heating mats 20 of the segments 11, 12 are heated simultaneously and thus lead to a uniform weld at all points of the finished caliper.

The Meander 63 will now be as shown in the enlarged view of FIG. 12, fixedly embedded in a flat sheet 62 of thermally weldable material, which now forms the second component of the aforementioned heating strand 60. This flat sheet 62 has, as shown in FIG. 13, a cross-section of a flat rectangle whose width 65 is only slightly greater than that of FIG. 11 an observable length of 67 wire. The strip thickness 66 is also only slightly greater than that shown in FIG. 13, a visible diameter of 71 wire.

Fig. 14 shows a longitudinal section through the wall of the injection molding tool 76 in which the segment H or 12 is to be produced. Around the concave interior surface 14 of the segment 11, 12, a convex interior surface 88 of the mold with grooves 70 is received. the strand 60 before the segment material is injected. Separate bridges 61 may be formed between the grooves 70, which are formed with a cross section

101 / B converge so sharply that the adjacent, already in FIG. 14, the threads 73 of the heating strand 60 may touch. The threads 73 of the heating strand 60, disposed in the inner mold surface 78, will be firmly seated in the grooves 70. By introducing the segment material into the mold, the heating strand 60 with its threads 73 is firmly seated in the segment 11, 12 to be formed.

One possible course of the threads 63 of the heating strand 60 is shown in FIG. 6. According to FIG. 6, the threads 73 consist of parallel arms 74 and arcs 75 disposed therebetween. In this case, the threads of the heating strand 60 are housed in the heating sleeves 2Ί, 22 as opposed to the threads housed in the intermediate heating strip 23. In FIG. 5 is a heating strand 60 which, for the sake of simple illustration, is drawn in a round profile and only its parallel arms 74 are shown. In FIG. 5 shows the visible ends of the parallel arms 74 in FIG. 6, the arcs 75 shown in FIG. 5 and 6, the parallel arms 74 of the heating strand 60 extend in the region of the heating collars 21, 22 in the circumferential direction, but in the region of the heating strip 23 in the axial direction of the segment roller 11. The arcs 75 are then mounted. 6, on the dashed lines 26, 27 of the profile contour.

Such mounting of the electrical conductor 61 in the heating strand 60 in the form of flat, juxtaposed threads 73 is particularly effective for the welding process. The use of such a heating wire 60 is therefore not limited to the segments U, 12 of the caliper described above. Other welded fittings could also be equipped with electric conductors in this way. For example, Welded sleeves that bluntly seal the airtight tubes. Another possibility of using such heating strands 60 is on the seat surfaces of bore fittings or valve bore fittings to be welded to the pipe tubes 10 in an analogous manner. Thus, the manufacture and use of the heating strand 60 has a separate meaning within the meaning of the invention.

101 IB

PATENT CLAIMS

Claims (13)

Clamp of thermally weldable material for pipe tubes (10) of the same weldable material as repair calipers, of at least two tubes (10) surrounding segments (11, 12) if necessary, of which at least one has a tube outlet (13) ) with, if necessary, confined edge edges (16, 17) on segments (11, 12) which are pressurized to each other for fastening with the edge edges (16, 17) overlapping wedge-shaped extensions on one segment, which if necessary they lie on the clamp between the inner surface of the adjacent segment and the pipe (10) and with the heating mats (20) of the wound electrically heated conductors (61), which are mounted on the inner surfaces (14) of the segments (11, 12). of each of the two limiting edges (16, 17) of each segment (11, 12) of the extension and the clamp are arranged alternately and complementary to the respective neighbor segment (11, 12) and form a toothing from a limiting edge (16, 17) of locally overlapping narrow strips (30) or wide strips (36) on one side and pockets (40, 46) lying between them which are below the limiting edges (16, 17) and serve, if necessary, to accommodate narrow strips (30) or wide strips (36), the heating mats (20) having a conformal stepped contour profile from the forwardly projecting flaps (24, 26) in the region narrow strips (30) or wide strips (36) and gaps (25, 29) therebetween in the pocket region (40, 46). Caliper according to claim 1, characterized in that the toothing at the limiting edges (16, 17) of the segment (11, 12) divides the heating mat (20) into three different axial sections (21, 22, 28), namely two end sections. sections (21, 22) which, if desired, have a circular closed heating collar around the pipe (10) where the wound conductors (61) extend in the form of a part of the ring from the bottom of the pocket or from the end of the strip at one limiting edge (16) up to the end of the strip or the bottom of the pocket at the opposing limiting edge (17) and one or more offset intermediate sections (23) forming a heating strip (23) in the region of one limiting edge (17) of the segment (11, 12); at least partially (44) extend into extended wide strips (36), where the wound conductors (61), although between the two 31 101 / B run through the sections (21, 22) but leave adjacent residual inner surfaces (47) of the segment (11, 12) to one another without conductors. The yoke according to claim 1 or 2, characterized in that the cross-sectional thickness (35) of the wedge-shaped curved narrow strip (30) or the wide strip (36) in the limiting edge (16, 17) of the upstream segment (11, 12). the foot (32) is greater than the thickness (51) of the material softening zone which occurs when the electric conductor (61) is heated in the narrow strip (30) or the wide strip (36). Caliper according to at least one of Claims 1 to 3, characterized in that the electric conductor (61) is arranged at an unheated axial distance to the side surfaces of the narrow strip (30) or the wide strip (36) which is greater than the thickness ( 51) a material softening area (50) during heating. Caliper according to at least one of Claims 1 to 4, characterized in that the heating mat (20) of the segment (11, 12) is made with its segmented contour profile (26, 27) from the thread (73) of a single running electrical conductor. (61). The yoke according to claim 5, characterized in that the conductor (61) of the heating mat (20) of all the segments (11, 12) are electrically connected to each other in series and connected to the welding machine for uniform heating. Caliper according to at least one of Claims 1 to 6, characterized in that the threads (73) of the conductor (61) consist of parallel arms (74) and bends (75) lying between them, the arms (74) running in the region of both. , the partial ring of the closed heating sleeve forming the end sections (21, 22) of the heating mat (20) in the circumferential direction of the cylinder and in the region of the intermediate heating section (28) the heating band (23) extends (11, 12), while the arches (75) lie on the line of the step contour profile (26, 27) of the flaps (24, 28) or the gaps (26, 29) of the heating mat (20). 31 101 / B The yoke according to at least one of claims 1 to 7, characterized in that the electric conductor (61) consists of one meander wire (63) in the form of a wavy line of the running wire and that the meander wire (63) is embedded in the threads (73). forming a heating mat (20). The yoke according to claim 8, characterized in that the meandering wire (63) on both of the protruding ends of the heating strand (60) comprises further extending wire end pieces (64) which are connected to the electrical contacts of the segment (11, 12). Caliper according to at least one of Claims 1 to 9, characterized in that the steps in the contour profile (26, 27) of the heating mat (20) are rectangular. Caliper according to at least one of Claims 1 to 10, characterized in that the segments (11, 12) on at least one of their two axes of parallel limiting edges (16, 17) comprise a radial edge flange (18, 19) and between fastening means (57-59) engage the peripheral flanges of adjacent segments (11, 12) so that the radial pressure pipe (10) forms a surrounding yoke. Caliper according to at least one of Claims 1 to 11, characterized in that the edge flange (18) of the segment (11) has, on its inner surface, a longitudinal rib (52) in which the heating strip (23) parallel to the axis is fixed. and that a longitudinal groove (53) with an additional width and depth to the shape of the longitudinal rib is formed on the inner surface (69) of the flange from the opposite edge flange (19) of this segment (11) and / or the adjacent segment (12). (52), which, if necessary, serves to accommodate the longitudinal rib (52). Caliper according to at least one of Claims 1 to 12, characterized in that the cross-sectional thickness of the narrow strip (30) or the wide strip (36) is so small that the softened material (50) gets out. 31 101 / B ft / Kiv-fy Fig. 2 «f Ο | 'Ρ?> 7Γ <o Fig. PI / /> -4 / ...- '1 V- ... ...- _in '. 27 76 \ Fig. 7 phi t & v-W