WO2003012950A1

WO2003012950A1 - Sealing method and device

Info

Publication number: WO2003012950A1
Application number: PCT/GB2002/003125
Authority: WO
Inventors: Christiaan Radelet; Luc Crabbe
Original assignee: Tyco Electronics Raychem Nv; Tyco Electronics Uk Ltd
Priority date: 2001-07-27
Filing date: 2002-07-08
Publication date: 2003-02-13
Also published as: GB0118328D0

Abstract

A method of sealingly enclosing an elongate object (20) comprises the step of applying a flexible sleeve (1) around the object (20), and the further step of rotating one end (2, 3) of the sleeve (1) relative to the other end so as to bring the middle part of the sleeve towards the object. A device (10) for applying the method comprises support members (5, 6) engaging the ends (2, 3) of the sleeve and preferably a tubular body, at least one support member being rotatable relative to the body.

Description

SEALING METHOD AND DEVICE

The present invention relates to a method and a device for sealingly enclosing an object. More in particular, the present invention relates to a method of sealingly enclosing an elongate object, the method comprising the step of applying a flexible sleeve around the object, the sleeve having two ends, and to a device for applying said method.

It is well known to enclose an object, in particular an elongate object such as a cable splice, by applying a flexible sheet and firmly wrapping the sheet around the object. International Patent Application PCT/GBO 1/01021 (Tyco Electronics Raychem) for example describes a flexible sheet which can be wrapped around a cable splice so as to form a closure. The flexible sheet of said International Patent Application comprises a gel layer, a support layer and an optical vapour barrier layer. Tape, such as an elastic plastics tape or a rubber tape, may be wound around the applied sheet. International Patent application WO 92/11675 (Raychem) discloses a sheet of mastic for wrapping around a cable splice which is to be used in conjunction with a heat-shrinkable sleeve. In both the above-mentioned documents a sheet is applied around the object, thus effectively forming a sleeve, and then the diameter of the sleeve is decreased so as to closely envelop the object. Decreasing the diameter is achieved by winding tape or heat-shrinking an additional sleeve. Although both methods work well, they are relatively labour-intensive.

It is therefore an object of the present invention to eliminate the disadvantages of the Prior Art and to provide a method of sealingly enclosing an elongate object which is more economical.

It is a further object of the present invention to provide a method of sealing and enclosing an elongate object which is quick and requires few tools.

It is another object of the present invention to provide a device for carrying out the inventive method.

Accordingly, a method as defined in the preamble is in accordance with the present invention characterised by the step of rotating one end of the sleeve relative to the other end so as to bring the sleeve towards the object. By rotating the ends of the sleeve relative to each other the sleeve is twisted and decreases in diameter. This causes the sleeve to be pressed against the outer surface of the object and thus to sealingly enclose the object. The amount of pressure exerted by the sleeve is determined by the amount of relative rotation and the outer diameter of the object. Even when no object is present, a good sealing action can be obtained, thus removing the need for plugs in some applications. The pressure exerted by the sleeve onto the object additionally provides axial pull resistance.

In order to maintain a sealing pressure on the object, the sleeve is preferably resilient. In an advantageous embodiment, the sleeve comprises a gel, a rubber or a combination thereof. Especially the combination of a gel and a (natural or synthetic) rubber is advantageous in that the rubber, when twisted, puts the gel under pressure, thus providing excellent sealing properties.

In a further advantageous embodiment the step of applying a flexible sleeve is preceded by the step of applying a cover around the object, the cover preferably comprising a flexible sheet. Such a cover may be a hard or soft lining but preferably is a flexible sheet of the type described in International Patent Application PCT/GBO 1/01021. In case such a flexible sheet, or simply a gel sheet, is used, it is not necessary for the sleeve to contain gel to still obtain excellent sealing properties.

The sleeve may itself be constituted by a flexible sheet which is wrapped around the object, thus allowing side-entry of the object.

Preferably, each end of the sleeve is provided with a substantially annular support member. The support members, which are attached to the respective ends of the sleeve, facilitate the handling and in particular the twisting of the sleeve. They may also assist in maintaining the twisted position. The invention further provides a flexible sleeve for applying around the object, the sleeve having two ends and a middle section with a certain inner diameter, characterised by support members engaging the respective ends, the support members being rotatable relative to each other so as to decrease the inner diameter of the sleeve.

In an advantageous embodiment at least one support member is substantially annular so as to allow the object to pass therethrough. This allows the device to be used for in-line cable splices. It is also possible that at least one support member is substantially disc-shaped so as to close off the respective end of the sleeve. For butt cable splices, a device having one annular and one disc-shaped support member is appropriate.

In a further advantageous embodiment the device can be opened along its longitudinal axis so as to allow side-entry of the object. This embodiment is particularly suitable for long objects, such as poles and in-line cables splices.

In a preferred embodiment the device further comprises a substantially tubular body for accommodating the flexible sleeve. The body is preferably substantially rigid to provide support and mechanical protection. At least one support member may be rotatably mounted on the body. It is possible for one support member to be integral with the body, thus reducing the number of parts. In that case one sleeve end is directly attached to the body, preferably near one of its ends. The body may be transparent to allow visual inspection of the twisted sleeve.

Preferably, locking means are provided for locking a support member in a rotational position relative to the body. This ensures that the set twisting of the sleeve is maintained. To obtain a re-enterable device, the locking means may be releasable. In a preferred embodiment, the locking means comprise a serrated surface on the body and/or the at least one support member. By providing at least one of the body and the support member with a first serrated surface and the other one with a pin or a second serrated surface which can engage the first serrated surface, simple yet effective releasable locking means are obtained. It can also be envisaged that the locking means have a different structure, and/or that the sleeve is structured so as to remain in its twisted state.

The present invention will further be described below with reference to the accompanying drawings, in which:

Figures la and lb schematically show, in perspective, a device according to the present invention applied on a first object;

Figures 2a and 2b schematically show, in perspective, a device according to the present invention applied on a second, thinner object; Figures 3a-d schematically show, in side view and partial cross-sectional view, a cable splice closure according to the present invention; and

Figures 4a-d schematically show, in side view and partial cross-sectional view, a cable seal according to the present invention.

The device 10 shown merely by way of non-limiting example in Figs, la and lb comprises a flexible sleeve 1 having a first end 2 and a second end 3. Each end is provided with a support member 5, 6 which may be integral stiffer parts of the sleeve 1 or separate parts which have been attached to the sleeve ends. If the sleeve 1 is made of rubber, the support members 5, 6 may be constituted by thickened and/or reinforced rims of the sleeve 1. The support members 5, 6 may also be made of plastic and/or metal and may be provided with suitable clamps or other means for fastening onto the sleeve 1. The sleeve proper is preferably made of a combination of rubber and gel, and may comprise additional layers, such as a vapour barrier layer (e.g. made of metal) and a reinforcement layer (e.g. made of polypropylene).

According to the present invention, the support members 5, 6 and hence the ends 2, 3 are rotated relative to each other, preferably by rotating one support member in one direction and the other support member in the opposite direction, as shown in Fig. lb. It is, of course, possible to keep one support member stationary while rotating only the other one. The relative rotation of the sleeve ends 2, 3 and the corresponding twisting of the sleeve causes the diameter of the sleeve 1 to decrease, at least in its middle section 4. Rotating the sleeve ends further will result in the sleeve diameter decreasing further, until the inner diameter of the sleeve equals the outer diameter of the object (if the object is flexible, its outer diameter may decrease due to the pressure exerted by the sleeve). Rotating further will increase the pressure on the object. In this way, a suitable sealing pressure can be achieved. As shown in Figs 2a and 2b, the same device 10 can be used for enclosing an object 20' having a much smaller diameter. Sufficient rotation will result in the sleeve sealing around the object. If no object is present in the device 10, the inner diameter of the sleeve will ultimately equal zero, the sleeve sealing upon itself. Thus a longitudinal seal can be achieved without the need for a plug.

The object which is sealingly enclosed in accordance with the present invention may be elongate, such as a cable or a cable splice. In that case the object may protrude from at least one end of the device 10. In the case of a butt cable splice, the object (cable) will protrude from one end of the device only, the other end being suitably closed off for example by a disc-shaped support member which also acts as an end cap (alternatively, a separate end cap could be provided). It is also possible for the device 10 to completely enclose a relatively short object.

The present invention is particularly suitable for providing cable splices, as will be discussed now with reference to Figs 3a-d.

As shown in Fig. 3a, a cable 20 may be provided with a cable splice 21. A flexible sheet 15 is applied around the splice 21, as shown in Fig. 3b. This is preferably a sheet as described in the above-mentioned International Patent Application PCT/GB01/01021, although other flexible sheets, such as sheets entirely consisting of gel or rubber, can also be used. The sheet 15 is preferably tightly wrapped around the cable splice and may be held in position with tape.

Then, a device 10 of the present invention is applied around the flexible sheet. The device 10 shown in Fig. 3c comprises, in addition to a flexible sheet 1 and support members 5 and 6, a body 7. In the embodiment shown, the body 7 comprises a substantially rigid tube in which the object 20 is accommodated. The body 7 serves to define the distance between the support member 5, 6 and to assist in maintaining the support members in their respective twisted positions (shown in Fig. 3d). The parts of the support members 5,6 abutting the body 7 are in preferred embodiments provided with serrated surfaces, as is the body 7, to effectively lock the support members in their positions.

The seal shown by way of example in Figs. 4a-d may be used in a domed cable closure (butt closure). The seal effectively consists of a device 10 as discussed above which is accommodated in a suitable cable port 17. This substantially tubular port 17 extends through a surface (e.g. bottom end surface) 18 of a cable splice closure.

Initially, as shown in Fig. 4a, the port 17 is closed off. After removing a plate 19, a device (seal) 10 is inserted in the port 17, as shown in Fig. 4b. Then the device 10 is attached to the surface 18 by a suitable attachment member which fixedly engages the second support member 6, as shown in Fig. 4c. After insertion of a cable 20, the first support member 5 is rotated so as to reduce the diameter of the sleeve 1 and thereby seal the cable port 17.

It will therefore be understood by those skilled in the art that the present invention is not limited to the embodiments shown and that many additions and modifications are possible without departing from the scope of the present invention as defined in the appending claims.

Claims

1. Method of sealingly enclosing an elongate object (20), the method comprising the step of applying a flexible sleeve (1) around the object (20), the sleeve having two ends (2, 3), characterised by the step of rotating one end (2, 3) of the sleeve (1) relative to the other end so as to bring the sleeve towards the object.

2. Method according to claim 1, wherein the sleeve (1) is resilient.

3. Method according to claim 1 or 2, wherein the sleeve (1) comprises a gel, a rubber or a combination thereof.

4. Method according to claim 1, 2 or 3, wherein the step of applying a flexible sleeve (1) is preceded by the step of applying a cover (15) around the object, the cover preferably comprising a flexible sheet.

5. Method according to any of the preceding claims, wherein each end (2, 3) of the sleeve (1) is provided with a substantially annular support member (5, 6).

6. Device (10) for sealingly enclosing an elongate object (20), the device comprising a flexible sleeve (1) for applying around the object (20), the sleeve having two ends (2, 3) and a middle section (4) with a certain inner diameter (d), characterised by support members (5, 6) engaging the respective ends (2, 3), the support members (5, 6) being rotatable relative to each other so as to decrease the inner diameter of the sleeve (1).

7. Device according to claim 6, wherein at least one support member (5, 6) is substantially annular so as to allow the object (20) to pass therethrough.

8. Device according to claim 6, wherein at least one support member (5, 6) is substantially disc-shaped so as to close off the respective end of the sleeve (1).

9. Device according to any of the claims 6-8 which can be opened along its longitudinal axis so as to allow side-entry of the object (20).

10. Device according to any of claims 6-9, further comprising a substantially tubular body (7) for accommodating the flexible sleeve (1).

11. Device according to claim 10, wherein at least one support member (4, 5) is rotatable relative to the body (7).

12. Device according to claim 11, wherein locking means are provided for locking a support member (5, 6) in a rotational position relative to the body (7).

13. Device according to claim 12, wherein the locking means are releasable.

14. Device according to claim 13, wherein the locking means comprise a serrated surface on the body (7) and/or the at least one support member (5, 6).

15. Device according to any of claims 6-14, wherein the sleeve (1) is resilient.

16. Device according to any of claims 6-15, wherein the sleeve (1) comprises a gel, a rubber or a combination thereof.

17. Device according to any of claims 6-16, wherein the support members (5, 6) are made of plastic.

18. Cable closure, comprising a device (10) according to any of claims 6-17.

19. Kit-of-parts for forming a device (10) according to any of claims 6-17.