FI68306C - KOMBINERAT FORMNINGS- OCH TAETNINGSELEMENT - Google Patents

Description

68306

COMBINED SHAPING AND SEALING BODY - COMBINATION FORMNINGS-OCH TÄTNINGSELEMENT

The present invention relates to a combined forming and sealing member for the end of a thermoplastic pipe sleeve comprising an annular member which is a resiliently compliant material and a rigid inelastic stiffening ring which is circular in cross-section, approximately circular or arcuate, positioned above is provided with two opposite side portions and an outer surface having an outer, radially outwardly directed surface portion located between the two side portions, and an inner surface having at least one radially inwardly directed sealing portion forming the sealing surface interposed between the two side portions.

More specifically, the invention relates to a reinforced, combined forming and sealing member which acts as a seal between the end of the pipe sleeve and the end to be fitted inside the pipe in a pipe extension in which a high or low pressure or vacuum can be provided inside the pipe.

The combined forming and sealing member has been further developed from the inventions disclosed in Norwegian patent publications 133818, 134963, 134964 and 134695. The combined forming and sealing member thus has two different purposes, firstly to act as a forming member and secondly as a sealing member. As a result, the terms "shaped member" and "sealing member" will be used in the following description to clarify the specific operating effects to be achieved in each case, however, it is to be understood that both terms mean the same thing, so that the sealing member is used to seal a sleeve joint with a radially expanded sleeve end The shaped body, in turn, is used as part of the forming apparatus for providing the end of the sleeve with internal grooves for the sealing piece, the shaped body being left in the groove to form a sealing member on the end of the sleeve thus obtained. a material, such as rubber, to which a stiffening ring is attached to the resilient material.

When the insertable end and the sleeve end are pushed together, the sealing ring is pressed together radially at a pressure almost exactly equal to the pressure at which the member is pressed against the surface of the mandrel as the finished sleeve end is pulled away from the mandrel. The appearance of the mandrel is such that it substantially corresponds to the shape of the socket end being manufactured in the interior. Thus, the end of the sleeve is substantially cylindrical in shape above the portion into which the end of the tube is inserted, with the sealing member pointing somewhat radially outward from the surface of the cylinder so as to provide the desired seal when the end of the tube is inserted into the end of the sleeve. When inserting the pipe end into the sleeve head, it is important in all cases that the sealing ring is not pushed out of its groove in the sleeve head, even in cases where the insertable end is not sufficiently beveled or otherwise shaped at its outer edge.

It is known that as the end of the sleeve expands from the area of the groove of the sealing ring, this area becomes relatively thin-walled, thus forming a vulnerable point. During storage and transport, the sleeve ends of the pipes rest completely on these most expanded point. In pipelines dug into the ground, the load on the ground, rocks, traffic, etc. causes stresses precisely at these protruding, partially weakened points in the pipe sleeve. Extra support for these parts is therefore important to prevent harmful deformations or fractures that may result from knocks as well as during transport to the support. Due to thermal stresses that may occur in the pipeline during storage during warm summer weather, during operation near a heat source (e.g. a steam pipe in the same trench) or otherwise, it is important to be able to support the annular groove at the sleeve end.

It is an object of the invention to provide a combined shaped and sealing member with which the harmful movement of the sealing member can be avoided when installing the pipe end inside the pipe sleeve end as well as during the operation of the pipe.

Another object of the invention is to reduce the elongation of the sleeve head during the manufacture of the sleeve head and when using the pipe and to stiffen the pipe sleeve head and thus to reduce the risk of harmful deformation of the pipe sleeve head.

In addition, it is intended to provide a seal between the sleeve end of the pipe and the end of the pipe to be inserted into it by means of a combined forming and sealing member, the sealing of which must withstand any overpressure or underpressure which may exist in the pipeline.

In addition, attention has been paid to the fact that a sealing ring with a minimum cross-section and consequently a minimum volume and a minimum material consumption can be manufactured in order to keep the manufacturing costs as low as possible.

Another object of the invention is to be able to manufacture the member with the smallest possible tolerances and thus, in connection with the formation of the sleeve, to ensure a relatively constant compression in the pipe 68306 4 and thus to ensure a reduction in the manufacturing cost of the mold element itself.

In addition, attention has been paid to the fact that the stiffening member can be placed in the body at sufficiently fixed points in a relatively easy manner so as to avoid deformations in the member, in particular changes in diameter which would result in tolerances in the stiffening ring itself.

It is also desirable to provide the member with an appearance that is suitable for the shape characteristics of the hot, thermoplastic tube end.

The solution according to the invention is characterized in that the stiffening ring is arranged in an area bounded by two opposite side parts and at a certain distance from them, and which is radially outside the radial, inwardly directed sealing part or inwardly directed sealing parts.

By placing the stiffening ring in said position in the member, several significant manufacturing and operational advantages are achieved.

In an embodiment in which the outer side surface of the combined forming member and the sealing member is provided with an oblique guide surface-forming portion, it is preferred that the stiffening ring be disposed in the member near the boundary between the oblique guide surface and the radial outer portion of the member. It is particularly preferred that the stiffening ring is located in the area between the radial plane passing through the sealing part of the element and the radial plane passing through the oblique guide surface.

In an embodiment in which the combined deformation and sealing member is provided with a support surface at a certain distance from the oblique guide surface, it is preferred that the stiffening ring is located in the region of the boundary point between the support surface and the oblique guide surface. In this connection, it is further preferred that the radial plane passing through the stiffening ring passes substantially through the sealing part of the member.

The stiffening ring may be wholly or partially guided within the member and may be formed with a variable cross-section to provide the advantages desired in each individual case. In an embodiment in which particular emphasis is placed on a cheap stiffening ring which is strong in relation to the amount of material used, a solution with a circular or nearly circular cross-section is most preferred. In such a case, the stiffening ring may possibly also form part of the outer surface of the member. In another embodiment, where it is preferred to allow the stiffening ring to form a large portion of the outer surface of the member or to stiffen a large portion of the axial length of the member, it is preferred to form the stiffening ring with a curved cross section. Another preferred embodiment of the stiffening ring consists of a few rings which may have a circular cross-section and which may be connected to each other by intermediate parts.

In the following, the invention will be explained in detail with reference to the accompanying drawings, in which

Fig. 1 shows a cross-section of a combined forming and sealing member according to the invention.

Figures 2-6 show cross-sections of various embodiments of the member shown in Figure 1.

Fig. 7 shows a cross-section of the member according to Fig. 2, 6 68306 placed on the mandrel of the shaping device.

Fig. 8 shows the same as Fig. 7, but the end of the pipe sleeve is formed on it.

Fig. 9 shows a section of the sleeve end of the pipe according to Fig. 8 after being pulled out of the mandrel.

Fig. 10 shows the same as Fig. 9 after connecting the end of the pipe to another pipe in a pipe extension which is subjected to internal pressure.

Fig. 11 shows a cross-section of a mold for manufacturing a member according to the invention.

Figure 1 shows a combined forming member and sealing member (sealing ring) 20 made of an annular portion 21 of an elastic resilient material such as rubber and a rigid inelastic stiffening ring 22. The annular portion 21 is approximately teardrop-shaped in cross-section and a radially inwardly extending sealing portion 23 and a straight, conically shaped surface portion 24 as an extension of the sealing portion 23 and an outer surface having an oblique (e.g. conical) outer surface portion 25 which together with the inner surface portion 24 defines a guiding edge portion 26 and forms an outer radius on the upper surface to the parallel surface portion 27, which in turn forms an extension to the rounded cam portion 28 located at the opposite end of the cross section. As shown in the figures, the stiffening ring 22 is circular in cross-section and is fitted to the rubber mass 21 close to the cam part 28, i.e. in the area where the cam part 28 and the radially oriented surface part 27 join. The outer surface of the stiffening ring is located close to the boundary point between the cam portion 28 and the radial surface portion 27 of the 68306 7.

As shown in Fig. 1, a radial plane A (centerline plane) passing through the rounded sealing portion 23 is located between the radial plane passing through the stiffening ring 22 and the guide side surface portion, which side surface portion is bounded between the conical inner surface portion 24 and the conical outer surface portion 25. The radial plane is arranged as a plane forming an angle of 90 ° with the axis direction of the tube.

Figure 2 shows the corresponding parts with the same reference numerals as in Figure 1. The member 30 is provided with a planar or slightly conical inner surface portion 41 spaced from the sealing portion 23. The inner portion 41 extends radially outwardly toward the conical portion 25 to form a guide edge 26. A concave groove 42 is formed between the sealing portion 23 and the inner surface portion 41. As shown in Fig. 2, the radial plane B of the stiffening ring 22 is located between the radial plane A passing through the center of the sealing portion 23 and the radial plane G passing through the guide surface portion 25. The stiffening ring 22 is positioned at a certain level radially outward from the guide edge 26 of the member, thereby ensuring that the guide edge 26 is compressed downward when the hot end of the tube is mounted on the member 40.

Fig. 7 shows a shaping device 31 by which a pipe sleeve of the end of a thermoplastic tube (not shown in the figures) is formed for a combined shaping member and sealing member 40 comprising a mandrel 32 having a groove 33 and a support ring 34. The groove 33 of the mandrel 32 is adapted to receive a ring 40 shaped part 21, and the support ring 34 is shaped so that the cam part 28 fits therein and the support ring can force the cam part upwards, thus counteracting the turning of the mold member and the tendency of the opposite ends of the cross-section to grip the hot end during pipe installation (Fig. 8). . The embodiment for shaping the hot tube end on the member 40 in the shaping device 31 is similar to that in Norwegian patent 133818 and therefore does not need to be explained further in this context. As shown in Figure 8, the tube 35, after being pressed radially outwardly onto the member 40, has a groove 36 in which the member is located. As shown in Fig. 9, the inner diameter d of the member 40 is smaller than the inner diameter D of the sleeve end of the tube 35. It is also shown in Fig. 9 that the tube 35 and the member 40 are tightly together from the cam portion 28 to the guide edge 26.

As shown in Figure 10, the tube 35 (after being removed from the mandrel of the shaping device) is connected to the second tube 37, the member 40 forming a sealing member between the tubes 35 and 37. It can be seen from Figure 10 that the outer diameter of the inner tube 37 is larger than the inner diameter of the member 40. As a result, the part 21 is compressed and elastically deformed. In contrast, the ring 22 does not deform, but retains its original shape. This causes the member to remain in place despite the pressure exerted on the member 40 within the gap between the tubes 35 and 37.

As illustrated in Figure 10, the sealing ring is compressed inwardly into the annular gap between the sleeve end of the tube 35 and the tip end of the tube 37 due to internal pressure in the pipeline, but the member 40 is secured by a stiffening ring 22 embedded in the rubber part 21.

Fig. 7 further shows how the stiffening ring 22 together with the support ring 34 holds the forming member securely in place when pressing the rubber mass against the mandrel 32. The dashed lines show the cam portion 28 in the unloaded state. The stiffening ring 22 allows the rubber mass to be compressed downwards onto the surface of the mandrel without the outer part of the mold member becoming compressed or displaced because the support ring 34 prevents the mold member 40 from turning. As a result, the hot pipe end can be pushed onto the mandrel 32 and the mold member 40, thereby maintaining its desired appearance in the groove inside the sleeve head, after the pipe has been compressed and cooled in a manner similar to that disclosed in U.S. Patent No. 3,776,682. In Fig. 8, the broken lines show the position of the cam portion when the support ring 34 is retracted.

The mandrel 32 of Fig. 7 has longitudinal grooves 38 which ensure that air is sucked out of both end portions of the cross-section of the member through bores (not shown). In order to avoid turning the guide edge of the member and to ensure the correct position of the shaping member with the mandrel 32, small grooves 33 are arranged in the member 40 slightly above the longitudinal slots 38. The area C, shown by a cross-line, shows, as an arrow diagram, the pressing of the mold member 40 against the mandrel 32.

It can be seen from Figure 2 that by fitting the stiffening ring 22 over the sealing member or in the direction of the missile edge, rotation of the member can be avoided by moving the shaping member axially over the mandrel, and consequently rotation of the guide edge can be avoided during subsequent hot pipe installation. Since the stiffening ring in Fig. ‘2 is. in contrast, located to the left and up of the guide rim relative to the sealing member, turning can be avoided by using the support ring 34 shown in Fig. 7, which is intended to lift the cam portion 28 upwards and thus force the guide edge 26 downwards against the mandrel.

In Figure 3, the cross-section of the member differs from said droplet shape. As can be seen, the side of the member 50 which is connected to the arcuate portion 25 is provided with a guide portion 51 crossed by a rotary 68306 10. The guide portion 51 and the sealing portion 23 combine to form a concave groove. The cross-section of the blime 50 is specifically calculated for the shaping device disclosed in U.S. Patent 3,793,427.

Fig. 4 shows a stiffening ring 61 # arranged in the shape element 60, the cross section of which is curved. The shape rigidity of the strip-like annular portion of the stiffening ring 61 is specifically designed to withstand both internal and external radial loads. A stiffening ring 61 is placed between the cam portion 28 and the outer surface portion 27 of the main member 21. The stiffening ring then forms an internal support for the sleeve end of the pipe. The stiffening ring 61 provides an effective support for the sealing ring and prevents the member 60 from squeezing inwardly into the annular space between the tip portion and the sleeve end when there is an internal overpressure in the pipe.

It will be appreciated that the stiffening ring 22 in many other ways and may be positioned differently from that shown, in which case special support members may be fitted to the shaping device. If desired, the stiffening ring # shown in Fig. 5 may comprise two or more ring portions 62 which may be formed in one piece, for example two ring portions 62 may be joined together to form a single stiffening ring with spacers 63 between the ring portions 62.

As shown in Fig. 6, the member 70 may be provided with an internal inwardly directed portion 71 which forms a sealing tongue (shown in an unloaded condition). In this case, a groove 72 is formed between the sealing tongue and the surface portion 41. As a result, the part 71 may form a lip seal when in place instead of a pu-seal.

11 68306

As shown in Figs. 8 and 10, weight areas E are formed in the sealing portion 23 of the member 40 when the member is inserted into the mandrel as shown in Fig. 7 and then corresponding pressure areas are formed in the outer portion of the member when the hot tube end is inserted into the member 40 as shown in Fig. 8. is cooled and mounted radially outside the member 40 and the mandrel 32. During these steps, the stiffening ring 22 stiffens the member 40 to control the pressure effects on the inwardly directed and outwardly directed portions of the member 40. After the sleeve head and member 40 are removed from the mandrel as shown in Figure 9, most pressure ranges disappear, as shown in Figure 8. The pressure ranges F shown in Fig. 9 provide good adhesion between the mutual support surfaces at the sleeve head and the member and prevent dirt or the like from entering the sealing point. When the tip end is inserted into the sleeve head, the member 40 is compressed in a manner corresponding to the deformation of the pipe end shown in Fig. 8, and corresponding pressure ranges are generated at the sleeve end and the tip end. Fig. 10 shows a pressure situation when the pressure medium is passed through a pressure line in which the pipe has a pipe extension according to the invention and the pressure medium is allowed to penetrate into the gap between the member 40 and the sleeve head. In this case, the pressure ranges E may prevail in the member 40 as shown in Fig. 10. The effect of the pressure ranges provides an effective seal against leaks between the sleeve head and the tip portion in the pipe extension of the pipeline.

Referring to Figure 11, the member 40 can be made in a mold in a conventional manner. For example, the member 40 may be formed in a hollow space 80 between three separate mold parts 81, 82 and 83. The member 40 is made by bringing the finished steel ring 22 into the hollow space 80 by means of pins 84 which can be pulled axially out of the mold. Figure 11 shows one such pin 84 in broken lines.

68306 12

The pins 84 point outwards from inside the mold part 82 at suitable intervals. The pins can be used to support the rings relatively well in the mold to ensure sufficient stiffening effect on the member to be made in the mold. Before the finished member is removed from the mold, the pins 84 are removed from the member and the mold part. The elasticity of the rubber material makes it possible to remove the member from the mold and the pins even in cases where the pins are permanently attached to the mold part and do not move relative to the mold part. To release the member 40 from the mold, the mold parts are moved relative to each other in the x and y directions.

In all the embodiment examples shown, the member has a cross-section in which the stiffening ring is placed close to the outer surface of the rubber mass. However, it is clear that the stiffening ring can also be placed at a certain distance from the outer surface of the rubber mass.

It will be clear to a person skilled in the art that the invention is not limited to the above-mentioned exemplary embodiments, but can be varied within the scope of the appended claims.

Claims (3)

A combined molding and sealing joint (20, 30, kO, 60, 70) for the end of a thermoplastic pipe sleeve, comprising an annular member (21) of resiliently yielding material and a rigid inelastic stiffening ring (22). 61, 62) having a circular, approximately circular or arcuate cross-section and disposed on said member, the member being provided with two opposite side portions (26, 28) and an outer surface having an outer, radially outwardly directed surface portion (27) is located between the two side parts (26, 28) and on the inner surface with at least one radially inwardly directed sealing part (23) forming the sealing surface, which is arranged between the two side parts, characterized in that the stiffening ring (22, 61, 62) is arranged bounded by two opposite side portions (26, 28) and spaced apart and radially outwardly radially inward or inwardly directed sealing members (23, 71). A member according to claim 1, the outer surface of which at the second side part is guided by an obliquely directed guide surface, characterized in that the stiffening ring (22, 61, 62) is arranged in an area of the upper, radially outwardly directed surface part (27) and between the obliquely oriented guide surface (25). A member according to claim 2, characterized in that the radial plane (middle plane) (B) passing through the rigid ring (22) is arranged in the radial plane (A) passing through the sealing part (23), and between the radial plane (G) passing through the obliquely directed guide surface (25).