DE2954743C2 - Clips for sealing branches from distributor boxes - Google Patents

Abstract

Branch lines as from cable junctions, etc. consisting of at least two substrates such as a distributor box and conductors or pipes, are sealed relatively to each other and to the outside by means of a sleeve of heat shrinkable material having elastic memory, so that when heated it shrinks to its original dimensions. A pronged clip having >=2 long legs is pushed to its end over the outer surface of the sleeve of heat-shrinkable material, so as to form >=2 channels at the end of the sleeve.The substrates are inserted into the channels, and heat is applied so as to bring about the shrinkage and form the desired seal. The heat shrinkable sleeve is a tubular sleeve in one piece. The clip clamps the two thicknesses of the sleeve against each other and for pref. the channel may be formed by clamping one thickness of the sleeve against the substrate, which may itself be a shrinkable hood

Description

The invention relates to a Process for the formation of a branching tight connection between a heat shrinking Sleeve and at least two substrates.

Heat recoverable items, in particular heat shrinking items, are on many Areas widely used where Insulation requires sealing and encapsulation are. Such items usually get when heated back to their original shape which they were previously deformed. The in the description used term "heat resettable" or however, "heat resettable" includes an object a different kind of heating Takes shape even if it deforms beforehand has been.

In their most common form, such items have a heat shrinkable sleeve made of a polymer Material that has an elastic or plastic memory or has storage behavior, for example in of US 2,027,962 is described. The originally dimensional heat stable form can be a transitional form be in a continuous process where for example an extruded piece of pipe in warm Condition to a dimensionally heat unstable Shape is stretched. For other applications becomes a preformed dimensionally heat stable Subject to a dimensionally heat unstable Shape deformed in a separate step.  

Heat shrinkable sleeves or sleeves are versatile usable, especially in the production of Connections and connections of wires, cables and pipes. For other applications however, it is desirable to have a connection Insulation or a heat-resisting protective layer Element for elongated objects, such as. B. Cables and pipes, the ends of which are not accessible are, or if their ends are accessible that these are not separated from one another or somehow shifted should be. For such use cases so-called "envelope sleeves or sleeves" developed.

These mainly include heat recovery Flat structures that form around the substrate essentially tubular in shape can be and where in general fasteners are provided, the fabrics in their encased form during the reset establish. Such fastening devices are usually used mechanically designed and have, for example rigid clamps, pins or channel-shaped elements on that with appropriately shaped or extruded Protrusions work together in the Close to the overlapping edges of the heat-recoverable Surface material. Different types of fasteners are for example in US 3,379,218. With others However, the surface material can be used while wrapped in the default Shape can be held by means of an adhesive, which in applied directly on the spot in some cases can be.

Heat-recoverable sleeves or sleeves and cover sleeves were successfully with the different areas used. It can however, difficulties arise when two or more Substrates such as B. supply lines, in particular Cables or pipes, be tight at one point have to. This difficulty, which is referred to as "diversion" is, for example, at the outlet of a heat-recoverable part occur. Amongst other things this difficulty occurs particularly at the outlet points of splice cases based on that in the GB 1 431 167 are described.

For tubular sleeves, molded, heat shrinkable parts used with preformed Outlets for the individual supply lines are provided. These molded and cast However, parts are generally only for specific ones Application forms provided. Your versatility was further improved by the fact that End caps used, which sealed the outlets closed, but which are not always needed, such as B. in the embodiments according to DE 27 48 383 A1. Despite everything, they are expensive and their use is economically unjustifiable in many cases.  

Another cheaper, commonly used method provides for a mastic band that covers the gap between the Closes supply lines so tight that at the reset at the end of the heat recoverable A corresponding encapsulation is partially formed becomes. The use of such a tape is based however on experience with the installation work, and this procedure is not for large sized parts suitable. In addition, the mastic can look the whole and affect the functioning of the products, the one with an inner layer or an inner coating made of a hot-melt adhesive are.

A method is already known from DE 24 13 623 A1 to seal at least two in a sleeve housing against a parallel cable described the sleeve housing. With this procedure are at the end areas of the shrinkable sleeve X-shaped spacers between adjacent cables arranged, in such a way that the cables and the spacers form undulating surfaces. In the troughs formed by the spacers after shrinking on the end area of the Sleeve clamp-like clamps arranged to one later opening of the shrunk plastic hose with higher mechanical loads to prevent the sleeve. Such a seal is structurally complex, since not only spacers are required but these spacers depending on Substrate are shaped differently. Besides, that is Production of such a seal is complex, since after inserting the cables into the shrink sleeve the spacers must first be inserted and then to achieve a proper seal after shrinking the ends of the shrink sleeve a tool is used on cables and spacers with jaws that can move against each other is provided, which is so attached and braced be that the plastic hose the wavy Surfaces of the cables and those arranged between them Spacers so tight that the shrunk plastic tubing becomes a fitting. After cooling, this tool is removed and a U-shaped one in the area of the troughs Clamping piece clamped on.

DE 25 43 338 A1 describes a method for forming a tight connection between a heat-shrunk sleeve and at least two entering the sleeve from the same end Substrates known, in which the sleeve end preformed inlet and outlet channels for the substrates. Before the shrink heat is at least one clamp attached to the socket end in such a way that two opposite points of the socket between the substrates are held together, followed by the sleeve end with the clip attached is heated.

The object of the invention is to develop a method of the type mentioned in such a way that to form a tight connection, d. H. a seal between a heat shrinkable Sleeve and at least two elongated substrates in the entry area the substrates into the sleeve, a simple, easy-to-use method is provided.  

The invention is based on the surprising finding that an effective branch at the end of a heat-recoverable part can be obtained by Received outlets exclusively by means of suitably trained brackets, which consist of a relative rigid material.

This object is achieved by the Features of claim 1 solved.

Attaching the bracket to the end of the socket and that Placing the substrates in the sleeve can be in any Order or can be made simultaneously. For example, in many applications after the clamp is pushed into its end position the sleeve has been placed around the substrates.

According to one embodiment, the at least two channel-shaped connecting strands formed, in which the clip with elongated legs pushed onto the open socket end is so that both outer legs on the outer surface of the heat shrinking Sleeve come to rest and opposite sleeve areas meet. According to a further embodiment, the channel-shaped connecting strands are formed by one leg of the clip lies on the outer surface of the heat shrinkable sleeve while the other leg interacts with an element inserted into the sleeve end.

It is surprising that such a bracket does not release or jump off during the reset (this effect during heat recovery is called "milk-off"). Of course the bracket must then be sufficient be long if the substrates are large. The Appropriate length can be determined by simple experiments quickly determine. The resistance to notching can be improved if necessary be that the outer surfaces on the legs of the Bracket are sawtooth or sinusoidal. In general, however, this is not necessary.

Another way of jumping off can be avoided, it can be seen in that on the bracket and the heat-recoverable material nearby Applies heat before the final reset becomes. This local warming causes the local Increased strength of the heat-recoverable material and increases the gripping effect of the clip. If additionally in preferred embodiments the sleeve or the envelope sleeve with an inner layer  is provided with an adhesive, the adhesive becomes flowable and thus provides a satisfactory adhesive bond near the bracket before the reset to make the substrates safe. Such local warming can expediently in all embodiments performed the clip according to the invention will.

The clip provided according to the invention exists advantageously made of a heat-conducting material and / or is designed such that the application of the Heat on the heat-recoverable material in the The vicinity of the bracket is facilitated (cf. DE 27 56 021 A1. On the other hand, however heat-recoverable sleeve with internal or independent Heaters may be provided, then the clip made of a non-heat conductive material can exist.

For these and other reasons, the bracket is there expediently including a metal for example steel, copper, brass, beryllium copper and especially aluminum. An aluminum bracket can be molded, for example, by injection molding and this can be used for deburring Connect the removal of the sharp edges. A Steel clip can be made by stamping and if necessary, deburring can then take place be made. In many applications it is desirable to close the bracket from corrosion protect. An aluminum bracket, for example subjected to a black anodizing treatment or provided with a chromate layer, which is also in front mechanical damage, for example by a Epoxy resin coating can be protected. Such one Coating also allows electrical insulation, if, for example, two lead-sheathed cables be used.

The role of the bracket in heat transfer to and before the heat-recoverable material and the glue in the area is not yet recognized been. According to BE-PS 833 016 a For example, clip made of a metal are, however, are other, not heat conductive Materials such as B. plastics specified, however not suitable for the present invention are. The preferred material is polyamide with glass filler specified. The material is in DE 24 13 623 A1 the brackets not specified.

For certain uses, the metal of the Bracket a memory alloy or an alloy be with storage behavior, e.g. B. one of the nickel-titanium alloys according to US 3 174 851, 3 351 463, 3 753 700 and 3 759 552 or a β-brass alloy, as described in US 3,783,037 and 4,019,925. Here is the bracket even heat recovery, so that the legs of the Bracket can move towards each other when the Assembly is heated to shrink the sleeve (alternatively, the bracket can be in front of or after the final warming before resetting be reset by heat. Pretreated Memory alloys, in particular β-brass alloys, are in the bracket according to the invention preferably used. Such alloys as well Methods for their pretreatment are in the US 4,036,669, 4,067,752 and 4,095,999.

In other embodiments, the bracket can made of a resilient material, such as. B. from Spring steel or beryllium copper are made so that they has a resilience that forms a dense Degree supported. The resilient deformed outer legs can for example kept outside with the help of a hot-melt adhesive be so that when they are warming up to each other to move.

Although the simplest embodiment of the bracket formed essentially U-shaped according to the invention However, it should be noted that the shape and training the bracket from the application area depends. For example, in some applications it may be necessary to have more than two outlets at the end of the heat recoverable component to build. This can be done with the help of two or more U-shaped brackets are achieved between the outlets be, or it can be convenient use only parenthesis. Such Clip has three or more legs, so that each two adjacent legs or arms in shape a U-shaped bracket.  

The strength of those provided according to the invention Braces are reinforced by being made of flat Base material are produced, which means that the width of the heat recovery above and below the Sleeve extending leg larger than its strength that comes into contact with the sleeve. Conveniently the width is 1.5 to 3 times that Strength.

Although generally not considered will, the parentheses in conjunction with others Using elements may be necessary in some use cases be useful, a cooperating with the bracket Insert element and / or the application the method according to the invention in connection with other approaches including the to be provided with a mastic tape. It can also from Be advantageous to use the bracket to be a heat-recoverable Surface material with another Connect component. For example, several Parentheses to form multiple branches around one Distribution box or to form several branches used by a single splice housing be another heat-recoverable component, such as B. a cap is used, the is inserted into the heat shrinkable sleeve. Such Embodiments are described in more detail below.

The heat-recoverable sleeve can be an envelope sleeve be and / or have a closed end, d. H. it can form an end cap. The sleeve can also be part of a larger item, such as e.g. B. a larger heat-recoverable object his. The invention is by no means limited to dimensions or the shape of the heat recoverable Component limited. The heat-recoverable sleeve can for example consist of two (or more) fabrics made of heat-recoverable material will. The only requirement of the invention is the one that the heat shrinkable component high connection section, placed in the substrates will.

The heat recoverable material can be made of any polymeric material made for use in the manufacture of heat recovery Objects is suitable. In general it has Surface material a homogeneous and constant Total composition, however, can also Layer materials made from two different polymers are used that are adhesive to each other or through Melt are connected. As suitable Polymers come for example polyolefins, in particular Polyethylene, copolymers of ethylene and vinyl acetate, Copolymers of ethylene and ethyl acrylate, chlorinated and fluorinated polymers, especially polyvinyl chloride, Polyvinylidene fluoride and polymers that Units of vinylidene fluoride, hexafluoroethylene and Contain chlortrifluoroethylene, and rubbers, such as e.g. B. ethylene / propylene rubber, chlorinated rubbers, such as B. neoprene, and silicone rubbers in Consider that in the form of a mixture with a crystalline or glassy polymer, such as. B. an olefin polymer, can be used. All of these above described substances can, for example, by Radiation and / or chemical substances or chemical Treatment must be cross-linked.

As mentioned earlier, the inner surface of the heat-recoverable Component with a Coating from an adhesive or a sealant, such as e.g. B. a hot-melt adhesive or a mastic Mistake. As preferred suitable hot-melt Glue comes e.g. Polyamides, ethylene / vinyl acetate copolymers and terpolymers (with or without incorporated Waxes) and polyester. Such Materials are, for example, in GB 1 440 810  and DE 27 09 717 A1. Are also curable Suitable links that melt when heated and become fluid, but not afterwards are more hot meltable. In this context epoxy resins and customary mastices should be mentioned in particular, for example on butyl and isobutylene rubber based, with corresponding, known per se Fabrics can be modified. The use and the choice of materials depends of course of the special requirements in the respective application from.

For most uses, this is due to the Force within brackets within a range from 49.05 N to 147.15 N (5 to 15 kp), which of the Diameter of the substrate, the wall thickness and the Share of the unused provision of the sleeve depends is. In connection with the last described Dependency it should be noted that the heat recoverable sleeve compared to that Process with the mastic tape shrink less must, and thus a smaller expansion ratio because the clamp compresses the sleeve so that this adapts to the cables in the central area. At the procedure with the mastic tape comes Sleeve not in contact with the cables in this Area.

The invention provides a simple method of education a satisfactory turn. Thus no installation experience needed and the Costs can be reduced. The elongated legs of the Brackets ensure that there is a seal from the Edge of heat-recoverable material to the ends the leg forms so that the substrates in this Effectively separated from each other.

The invention is described below with reference to the drawing explained in more detail using examples. In it shows

Fig. 1a and 1b show a clip which is intended for the invention,

Fig. 2 shows the application of the clamp according to Fig. 1 in the present invention,

Fig. 3, the application of such two brackets in the invention,

Fig. 4 shows another use of the clip,

Fig. 5 shows a second embodiment of a clip

Fig. 6 shows the application of the clamp according to Fig. 5, according to the invention

Fig. 7a to 7e, the application of a further embodiment of the clamp in combination with a heat-recoverable sleeve and a junction box for forming a connection with a plurality of outlets.

An aluminum bracket 1 for use in the invention is shown in Figs. 1a and 1b. The width of the legs 2 and 3 is greater than their thickness. In addition, the reason for the gap formed between legs 2 and 3 at 4 is excluded in order to achieve additional strength. Such a clip expediently has the following dimensions: length 64 mm, width 24 mm, length of the legs 52 mm, width of the arms 10 mm, thickness of the arms 5 mm, gap between the arms 4 mm.

In Fig. 2 the way it is shown how the clip 1 for forming a turn-off for two telecommunication cables 5 and 6 can be used to go to a Spleißungsgehäuse 7, which is formed as described in GB 1,431,167. The arrangement is shown after its reset.

In the sectional view of FIG. 3, the application of such two brackets is shown to form a Dreiwegabzweigung at similar objects. The clamps 1 serve to keep the cables 8, 9 and 10 at a distance from one another and at the same time to ensure that the cables are separated by a hot-melt adhesive. This fact is particularly important if the cables are to be kept separate during the subsequent bending. When using a mastic tape, this is difficult because the mastic is pressed out, so that secondary closure paths are formed between the cable surfaces.

In FIG. 4, the use of a single clamp 1 is shown in a line seal 11, whose design is described in DE 27 48 894 A1. The line seal is designed such that multi-core cables 12 and 13 pass through a line channel (not shown). Furthermore, external flanges 14 are provided, between which sealant 15 is attached. When these flanges 14 are heated, they deform. The sealant 15 melts and flows to seal the device within the channel.

In FIG. 5, an aluminum bracket 16 is shown, which are arranged symmetrically around the longitudinal access of the clip having three legs 17, 18 is provided and 19. The legs are similar in design to the legs of bracket 1 in Figure 1, and again a portion of the bracket is recessed at the bottom of the spaces between the arms to provide additional rigidity.

Figure 6 shows how the clip 16 can be used to form a three-way tap at the end of a splice housing 20 (XAGA). One of the branching strands 21 thus formed was partially shrunk around a stiffening turn and is provided with a closure flap 23 which is designed in accordance with DE 27 48 383 A1. The end cap 23 can be removed when the bushing 22 is needed.

In Fig. 7a a distribution box 63 is shown, which is provided on its outer surfaces with hot-melt adhesive 69 . The distribution box is designed in such a way that it distributes the individual wires in pairs from a large supply cable to several outgoing smaller cables.

According to the invention, the adhesive covers 69 are cut in advance so that the strips can be removed, which is slightly wider than the thickness of the clips 70 (see FIG. 7b). The box 68 is then inserted into a heat-recoverable sleeve 71 with a large diameter, and the outgoing cables 72 are distributed around the surface of the distribution box 68 . As can be FIGS. 7c and 7d seen, the clamps are then placed 70 between the cables 72, over the outer surface of the heat-recoverable sleeve 71 and the inner surface of the junction box 68th The assembly thus formed can then be heated to reset the sleeve 71 and make the adhesive 69 flowable so that the finished junction box shown in Fig. 7e is obtained. As shown, some of the branches can be occupied by devices 73 , which are provided with caps 74 and can be occupied later.

The distribution box 68 is expediently made of a resistant, thermally conductive metal and can have recesses on its inner surface which serve to facilitate the placement of the clips. The heat-recoverable sleeve 71 can of course be designed as a wrapping sleeve and be provided on its inside with a coating that prevents the penetration of water vapor. The other end of the sleeve is shrunk around the large lead 75 .

The box 68 can be designed differently, for example circular, elliptical, star-shaped and the like. Here, differently designed brackets 70 can be used.

Claims (10)

1. Method of forming a branch tight connection between a warm shrinking sleeve and at least two substrates, in which a clamp with two elongated legs over the outer surface of a heat shrinkable sleeve on the other End is placed in such a way that at least two channel-shaped connecting strands form and shrinking by applying heat. 2. The method according to claim 1, characterized in that the at least two channel-shaped connecting strands are formed in which the two clamp legs lie on the outer surface of the heat shrinkable sleeve. 3. The method according to claim 1, characterized in that the at least two channel-shaped connecting strands are formed in that a clamp leg the outer surface of the heat-shrinkable sleeve and the other leg over an in the sleeve end engages the inserted element. 4. The method according to any one of claims 1 to 3, characterized in that before Heat shrink the sleeve near the clamp is shrunk. 5. The method according to any one of claims 1 to 4, characterized in that a bracket made of a thermally conductive material, preferably aluminum, steel or Beryllium copper is used.   6. The method according to claim 3, characterized in that as an insertion element Distribution box is used. 7. The method according to claim 6, characterized in that as an insertion element heat-recoverable component, preferably a closure cap is used. 8. The method according to any one of claims 1 to 5, characterized in that as the heat shrinking Sleeve an envelope sleeve is used. 9. The method according to any one of claims 1 to 8, characterized in that the heat shrinkable Sleeve with an inner coating of a heat-activated adhesive or sealant is provided. 10. The method according to any one of claims 1 to 9, characterized in that two or more brackets were used to form a branch with multiple outlets will.