DE7713578U1 - Heat-restoring sleeve - Google Patents

Description

DF? .- INQ. GERALD KLOPSCH SOOO COLOGNE 1 PATENT ADVERTISER MARSPLATZ 11

April 28, 1977 Kl / En

N.V. ^ .aychem S.A.,

Diestsesteenweg 692, 3200 Kessel-Lo (Belgium )

The invention relates to a heat-recoverable object, in particular a sheathing of a splice in an electrical cable.

The use of heat-recoverable objects for wrapping or coating of connections or splices in electrical cables is known. Usually this exists Object made from a heat-shrinkable sleeve which is either tubular or plate-shaped, so that the sleeve after the Splice can be wrapped around the cable. The socket points

HO usually a layer of caulk or adhesive, e.g. a heat or hot melt adhesive that is based on their inner surface is applied. Such sleeves are described in US Pat. No. 3,297,891; suitable facilities for Joining opposing edges of wrap-around sleeves is described in U.S. Patent 3,455,336.

Such objects can be made heat-recoverable, by heating them to or above a certain temperature, expanding them and cooling them in the expanded state. A Process for this is described in US Pat. No. 3,086,242.

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• I *

• a. O mm

The disclosure of the above three patents is hereby made the subject of the present application by reference.

Numerous electrical cables are now under internal pressure, about the possibility of moisture penetrating the cable jacket, especially at splices, and destruction of materials or the creation of short circuits. The overpressure inside the cable can are effected and maintained by pumps connected to the gates through a valve. It would be convenient that To arrange the valve in the wall of a heat-resilient sleeve, for example via an opening in the jacket of the sleeve installed so that the joint location can be used to pressurize the cable. Further one can such valve sleeve can be used as a place where the internal pressure of the cable is tested. It did, however found that despite the use of numerous different valve holders, the insufficient seal between causes leaks in the valve and the socket. This problem is therefore posed by the use of valve sleeves in pressure cable splices prevented.

It is also possible to install a valve in a sleeve over a splice; as an example of a splice in electrical lines, in which an application of an internal pressure is desired, is that in GB-PS 1.431.167 to name described. The disclosure of this patent specification is hereby incorporated by reference into the subject matter of the present application did.

The invention relates to a heat-recoverable, preferably a heat shrinkable sleeve having a lug, preferably one mounted in a portion of the sleeve Valve that is dimensionally stable against the effects of heat, or a significantly smaller change in dimension than

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permanent areas of the sleeve subject to resetting.

The sleeve may have one or two open ends and is preferably tubular. If the socket has a closed end, the valve is not in the end wall, but in the peripheral wall, i.e. in the case of a tubular one, on one End closed sleeve mounted in the pipe wall.

Although the description relates particularly to the installation of a valve, the invention is applicable to all sleeves, which have devices attached to their peripheral wall or openings in the wall which enable for example, to bring an elongated structure into position in this way. Examples are an applicator for injecting a foamable material into the space enclosed by the sleeve, a pressure indicator or -sensor or an electrical conductor, for example to a piezoelectric device for indicating the pressure or other Changes or to devices for temperature measurement at points within the space enclosed by the sleeve, e.g. the interface between the inner wall of the sleeve and a substrate enveloped by the sleeve, to be mentioned.

The area of the socket can be kl & jLn, e.g. a washer ~: n the sleeve, it may extend the full length of the sleeve as an elongated band or, although it may be less is desirable "to represent a circumferential band, the shape and size of the area of the intended use of the sleeve and the processes used in its manufacture.

The area can consist of an expansion of the entire sleeve and a controlled re-shrinkage in the desired area but advantageously results from expansion of the remainder of the sleeve alone and prevention or Control the expansion of the area in question during

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the production.

For example, when a pipe is expanded by adding a heater medium is passed through while the inside of the pipe is exposed to overpressure, the heat is dissipated through an insulating or blocking device prevented from reaching a region of the circumference of the pipe wall, resulting in an elongated A tape of non-shrinkable or less-shrinkable material that extends the length of the pipe, this band appears as an area of greater wall thickness.

The pipe can then be cut into sleeves of suitable length, whereupon an opening is made in the tape and a valve is mounted in this opening. Another possible method is to use a suitably shaped component, e.g. a disc or a rectangle made of suitable material, e.g. aluminum, at intervals on a to be expanded To arrange pipe, whereby the heat is prevented from the pipe in the areas under the component in question to achieve, and whereby the expansion is limited, for example because the component acts as a heat trap.

Furthermore, the sleeve according to the invention can be produced, by subjecting the tube to uniform heating, which results from selective cooling of an area or a Place to prevent or reduce expansion is superimposed.

As shown above, it is evident that the invention can also be applied where other approaches, e.g., devices other than valves in heat recoverable articles be incorporated, and is useful in all cases where the proper puncture method to a certain extent Extent depends on the proper attachment of the device to the object.

Two aspects of the article according to the invention will become

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described below in greater detail by way of example with reference to the drawings, in which

Figure 1 is a perspective view of a heat shrinkable Represents a valve sleeve, which is a longitudinally extending band of non-shrinkable material has and

Figure 2 is a cross section through a heat-shrinkable valve sleeve with a valve located in a non-shrinkable zone.

In Figure 1, 1 represents a generally heat shrinkable one Muffρ with a longitudinal band 2, which is less shrinkable or is dimensionally stable to the action of heat. A valve 3 is arranged in the band. When resetting the sleeve remains the wall thickness of the band 2 is essentially constant, while the rest of the sleeve increases radially with an increase in wall thickness contracted.

Figure 2 illustrates a cross section through the sleeve 1 with a disc 4 made of non-expanded material. The valve 3 is arranged centrally in the disc.

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Claims (7)

Uli ■! t »P I /" "" "vj claims 1) Heat-resilient sleeve, characterized by a shoulder , which is arranged in a region of the peripheral wall of the sleeve is that when resetting against the effects of heat > is dimensionally stable or a significantly smaller change in dimension than other areas of the peripheral wall is subject. 2) sleeve according to claim 1, characterized in that : the area in which the attachment is arranged, as a longitudinal band extends over the sleeve. 3) Muff "; according to claim 1, characterized in that the area is circular. 4) sleeve according to claims 1 to 3, characterized in that the approach consists of a valve. 5) sleeve according to claims 1 to 4, characterized in that that it is tubular. 6) sleeve according to claims 1 to 5, characterized in that it is open at both ends. 7) sleeve according to claims 1 to 6, characterized in that it is heat-shrinkable. 7713578 08/04/77