AU2009200426A1

AU2009200426A1 - Heat-shrinkable cable joint for protecting at least one connection point between cables

Info

Publication number: AU2009200426A1
Application number: AU2009200426A
Authority: AU
Inventors: Andreas Kupczyk; Simon Thibault
Original assignee: CCS Technology Inc
Current assignee: Corning Research and Development Corp
Priority date: 2008-02-07
Filing date: 2009-02-05
Publication date: 2009-08-27
Anticipated expiration: 2029-02-05
Also published as: EP2088658A2; EP2088658A3; AU2009200426B2; DE202008001748U1

Description

S&F Ref: 894088 AUSTRALIA PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name and Address CCS Technology, Inc., of 103 Foulk Road, Wilmington, of Applicant: Delaware, 19803, United States of America Actual Inventor(s): Simon Thibault Andreas Kupczyk Address for Service: Spruson & Ferguson St Martins Tower Level 35 31 Market Street Sydney NSW 2000 (CCN 3710000177) Invention Title: Heat-shrinkable cable joint for protecting at least one connection point between cables The following statement is a full description of this invention, including the best method of performing it known to me/us: 5845c(1 957369_1) Heat-shrinkable cable joint for protecting at least one connection point between cables 5 The invention relates to a heat-shrinkable cable joint for protecting at least one connection point between cables in accordance with the preamble of claims 1 and 9. 10 Heat-shrinkable cable joints have a heat-shrinkable sheath, such heat-shrinkable sheaths being known, for example, from the prior art in accordance with EP 0 776 753 Bi and EP 0 443 696 B2. The heat-shrinkable sheaths 15 known from the prior art have a heat-activated, shrinkable surface layer, which is also referred to as a collar, and a likewise heat-activated adhesive layer, which is positioned on the inside of the surface layer. In order to apply such a heat-shrinkable sheath to a 20 connection point between cables, the heat-shrinkable sheath is heated with the aid of a gas burner, as a result of the effect of the heat from the gas burner the heat-activated surface layer shrinking and conforming around the connection point between the 25 cables. The heat-activated adhesive layer on the inside of the surface layer is liquefied, starting from a solid state of aggregation, as a result of the effect of heat and then transfers to the solid state of aggregation again after cessation of the effect of heat 30 in order thus to ensure the seal between the cables with respect to one another and the shrunk surface layer. The adhesive layer of the heat-shrinkable sheath accordingly acts as a sealing layer, which is unstable in terms of its state of aggregation. 35 - 2 In particular when a plurality of connection points between in each case two cables are intended to be protected using a heat-shrinkable cable joint, i.e. when in each case a plurality of cables are intended to 5 be inserted into the cable joint or passed out of the cable joint on both sides or at both ends thereof, in each case at least one sealing element is used in the region of each end or each side of the heat-shrinkable cable joint in order to seal off the cables with 10 respect to one another and with respect to the heat-shrinkable sheath. In accordance with the prior art, such a sealing element comprises a metallic basic body, which is coated with a heat-activated adhesive, a so-called hot-melt adhesive. As a result of the effect 15 of heat, firstly the heat-activated surface layer of the heat-shrinkable sheath and secondly the heat-activated adhesive of the or each sealing element is accordingly transferred to a liquid state of aggregation in the case of such a cable joint, with 20 them transferring into a solid state of aggregation again after the cessation of the effect of heat. In accordance with the prior art, accordingly both the heat-activated adhesive layer of the heat-shrinkable sheath and the adhesive of the or each sealing element 25 are unstable in terms of their state of aggregation. Against this background, the present invention is based on the problem of providing a novel heat-shrinkable cable joint for protecting a connection point between 30 cables. This problem is solved in accordance with a first aspect of the invention by virtue of the fact that the heat-shrinkable cable joint mentioned at the outset is developed by the features of the characterizing clause of claim 1. In accordance with 35 said claim, the or each sealing element is in the form of a sealing element which is stable in terms of its state of aggregation, with the result that the or each sealing element maintains its state of aggregation during shrinking of the sheath, the heat-shrinkable -3 sheath deforming the or each sealing element during the shrinking process so as to seal off the or each cable and, after the shrinking process, keeping it in a deformed state. 5 In accordance with the first aspect of the present invention, the or each sealing element is designed to be stable in terms of its state of aggregation, the heat-shrinkable sheath deforming the or each sealing 10 element during the shrinking process and, after the shrinking process, keeping it in the deformed state. The or each sealing element is accordingly compressed and deformed as a result of shrinking forces being released during the shrinking of the sheath in order 15 thus to seal off the cable with respect to the heat-shrinkable sheath. For this purpose, it is not necessary for any heat to act on the or each sealing element, but it is merely necessary for the heat-shrinkable sheath to be subjected to the action of 20 heat. Overall, the heat-shrinkable cable joint accordingly requires a considerably lower amount of heat than cable joints known from the prior art, for which reason both the assembly and the dismantling of the cable joint according to the invention can take 25 place in a manner which is more gentle on the cables and possibly on the splicing components disposed in the cable joint. In accordance with a second aspect of the invention, 30 the problem is solved by a heat-shrinkable cable joint as claimed in claim 9. According to said claim, the heat-shrinkable sheath has, in addition to the heat-activated surface layer, a sealing layer, which is positioned on the inside of the surface layer and is 35 stable in terms of its state of aggregation, with the result that the sealing layer maintains its state of aggregation during shrinking of the sheath, the surface layer deforming the sealing layer during the shrinking -4 process and, after the shrinking process, keeping it in a deformed state. In accordance with the second aspect of the present 5 invention, a sealing layer, which is stable in terms of its state of aggregation and which maintains its state of aggregation during shrinking of the sheath, is applied to the inside of the surface layer, the surface layer of the heat-shrinkable sheath deforming the 10 sealing layer during shrinking of the heat-activated surface layer and, after the shrinking process, keeping it in a deformed state. In this case, it is possible to completely dispense 15 with a heat-activated adhesive layer on the inside of the surface layer under certain circumstances. The cable joint in accordance with the second aspect of the present invention also requires a markedly lower quantity of heat during shrinking and therefore when 20 providing the sealing function for protecting the or each connection point between cables. The assembly and dismantling of the cable joint can therefore take place in a manner which is more gentle on the cables and the splicing components to be protected in the cable joint. 25 The two aspects according to the invention can be used alone or in combination with one another. Preferred developments of the invention result from the 30 dependent claims and the description below. Exemplary embodiments of the invention, without the invention being restricted thereto, are explained in more detail with reference to the drawing, in which: 35 figure 1 shows a very schematic, perspective illustration of a heat-shrinkable cable joint according to the invention which comprises a heat-shrinkable sheath and at least one sealing element; -5 figure 2 shows a detail of the sealing element of the cable joint according to the invention; figure 3 shows an alternative sealing element to 5 the one in figure 2; figure 4 shows a further alternative sealing element to the one in figure 2; figure 5 shows a further alternative sealing element to the one in figure 2; 10 figure 6 shows a further alternative sealing element to the one in figure 2; figure 7 shows a further alternative sealing element to the one in figure 2; figure 8 shows a detail of the heat-shrinkable 15 sheath of the cable joint according to the invention; figure 9 shows an alternative heat-shrinkable sheath to the one in figure 8; and figure 10 shows a further alternative 20 heat-shrinkable sheath to the one in figure 8. Figure 1 shows a schematic illustration of a heat-shrinkable cable joint 20 according to the 25 invention which, in the exemplary embodiment shown, is used to seal off four connection points between in each case two cables. In figure 1, the four incoming cables are identified by the reference numeral 21 and the four outgoing cables are identified by the reference numeral 30 22, the connection points between the cables 21, 22 being formed in the region 23, which comprises splicing components. The cable joint 20 comprises a heat-shrinkable sheath 35 24. In accordance with one aspect of the present invention, the heat-shrinkable sheath 24 is designed in the sense of figures 8 to 10, in this case the heat-shrinkable sheath 24 comprising a heat-activated - 6 surface layer 25, which is also referred to as a collar or shrink collar. As shown in figures 8 to 10, a sealing layer 26, which 5 is stable in terms of its state of aggregation, is associated with an inside of the heat-activated surface layer 25. As shown in figures 8, 9, the sealing layer 26, which is stable in terms of its state of aggregation, is applied to the inside of the 10 heat-activated surface layer 25 partially or over part of the area. In figure 10, on the other hand, the sealing layer 26, which is stable in terms of its state of aggregation, is applied to the inside of the heat-activated surface layer 25 over the whole area. 15 During shrinking of the heat-activated surface layer 25 as a result of the effect of heat, the sealing layer 26 maintains its state of aggregation, i.e. the sealing layer 25 does not transfer to a liquid state. Instead, 20 the surface layer 25 of the sheath 24 deforms the sealing layer 26 during the shrinking process and keeps it in the deformed state after the shrinking process and after the cessation of the effect of heat. In order to provide the sealing function via the sealing layer 25 26, accordingly no heat effect is required for the sealing layer 26, but only for the heat-activated, heat-shrinkable surface layer 25. Preferably, the sealing layer, which is stable in terms 30 of its state of aggregation, is produced from an elastically deformable plastic, in particular from an elastomer. The material for the sealing layer 26 can be a polyurethane gel or a silicone gel. In contrast to this, it is also possible for the sealing layer 26 to 35 be produced from a plastically/elastically deformable material or a plastically deformable material. In the exemplary embodiment in figures 8 and 9, in which the sealing layer 26 is applied to the inside of -7 the surface layer 25 only partially and therefore only over part of the area, the sealing layer 26 has cutouts 27. These cutouts 27 can be filled with a heat-activated adhesive, which is unstable in terms of 5 its state of aggregation during the shrinking process, in order thus to assist the sealing function, which is provided by the sealing layer 26, which is stable in terms of its state of aggregation during the shrinking process. 10 In the case of the heat-shrinkable sheaths 24 in figures 8 to 9, the sealing layers 26, which are positioned on the inside of the surface layers 25, can be connected to the surface layers 25. It is also 15 possible for the surface layers 25 and the sealing layers 26 of the heat-shrinkable sheaths 24 in figures 8 to 10 not to be connected to one another but to be in the form of separate components. 20 As has already been mentioned in connection with figure 1, in the exemplary embodiment shown the cable joint 20 is used for protecting four connection points between in each case two cables 21, 22, which are to be connected to one another, the sealing function between 25 the cables 21 and 22 and the sheath 24 being assisted via at least one sealing element 28, which seals off the cables 21 and 22 with respect to the shrinkable sheath 24 and with respect to one another. Figures 2 to 7 show different embodiment variants for such sealing 30 elements 28, which differ in terms of their outer shape and the number of cables to be sealed off. In accordance with another aspect of the present invention, the or each sealing element 28 is designed 35 to be stable in terms of its state of aggregation, with the result that it maintains its state of aggregation during shrinking of the heat-shrinkable sheath 24. The heat-shrinkable sheath 24 deforms the or each sealing element 28 during the shrinking process whilst - 8 maintaining the state of aggregation thereof and keeps it in the deformed state after the shrinking process. The provision of the sealing function of the or each 5 sealing element 28 accordingly takes place via shrinking forces, which are provided during the shrinking of the heat-resilient sheath 24, and therefore the effect of heat is only required for shrinking the sheath 24. 10 The or each sealing element 28 of the cable joint 20 according to the invention is preferably produced from an elastically deformable material, in particular from an elastomer. Thus, the or each sealing element 28 can 15 be produced from a polyurethane gel or a silicone gel. In contrast to this, it is also possible for the or each sealing element 28 to be produced from a plastically/elastically deformable material or a plastically deformable material. 20 The sealing elements 28 in figures 2 to 7 all have a basic body 29, which has at least one cutout 30 for accommodating, guiding and sealing off in each case one cable on its outer face and/or in a central section. In 25 the exemplary embodiments in figures 4, 6 and 7, in this case the basic body 29 has a cylindrical contour and has a plurality of cutouts 30 for accommodating, guiding and sealing of f in each case one cable on its outer face, in the exemplary embodiments in figures 4 30 and 6 the basic body 29 having six cutouts 30 and, in the exemplary embodiment in figure 7, four cutouts 30 along its outer face. In the exemplary embodiments in figures 2 and 3, the 35 basic body 29 of the sealing elements 30 has in each case two cutouts 30 and, in the exemplary embodiment in figure 5, has three cutouts 30 for accommodating, guiding and sealing off in each case one cable.

-9 The contouring of the basic body 29 of the sealing element 28 shown in figure 6 allows for simplified accommodation and sealing of cables with different diameters in the cutouts 30 of the sealing element 28. 5 When cables to be sealed off are inserted into the sealing elements 28 in figures 2 to 7, in addition a strip, which is stable in terms of its state of aggregation during the shrinking process, of a gel-like 10 material, for example, can be wound around the unit comprising the sealing element 28 and the cables to be sealed off in order to improve the sealing function. It is also possible to dispense with the sealing 15 elements 28 and to wind a strip, which is stable in terms of its state of aggregation during the shrinking process, made of a gel-like material, for example, to be wound around a plurality of cables to be sealed off. 20 The effect of heat during the shrinking of the heat-shrinkable sheath 24 can be provided in particular via a gas burner or via a hot air blower.

- 10 List of reference symbols 20 Cable joint 5 21 Cable 22 Cable 23 Region 24 Sheath 25 Surface layer 10 26 Sealing layer 27 Cutout 28 Sealing element 29 Basic body 30 Cutout 15

Claims

1. A heat-shrinkable cable joint, for protecting at 5 least one connection point between cables, with a heat-shrinkable sheath, which has at least one heat-activated surface layer, and with at least one sealing element for sealing off in each case at least one cable with respect to the heat-shrinkable sheath 10 and/or with respect to at least one other cable, wherein the or each sealing element (28) is in the form of a sealing element (28) which is stable in terms of its state of aggregation, with the result that the or each sealing element (28), during the shrinking of the 15 sheath (24), maintains its state of aggregation, the heat-shrinkable sheath (24) deforming the or each sealing element (28) during the shrinking process so as to seal off the or each cable and, after the shrinking process, keeping it in a deformed state. 20

2. The cable joint as claimed in claim 1, wherein the or each sealing element (28) is produced from an elastically deformable material or a plastically/elastically deformable material or a 25 plastically deformable material.

3. The cable joint as claimed in claim 1 or 2, wherein the or each sealing element (28) is produced from an elastomer. 30

4. The cable joint as claimed in one of claims 1 to 3, wherein the or each sealing element (28) is produced from a polyurethane gel or from a silicone gel. 35 5. The cable joint as claimed in one of claims 1 to 4, wherein the or each sealing element (28) has a basic body (29), which has at least one cutout (30) for accommodating a cable on its outer face and/or in a central section. - 12 6. The cable joint as claimed in claim 5, wherein the basic body (29) has a cylindrical contour. 5 7. The cable joint as claimed in one of claims 1 to 6, wherein the heat-shrinkable sheath has, in addition to the heat-activated surface layer, a likewise heat-activated adhesive layer, which is positioned on the inside of the surface layer. 10

8. The cable joint as claimed in one of claims 1 to 7, characterized by features as claimed in one or more of claims 9 to 15. 15 9. A heat-shrinkable cable joint, for protecting at least one connection point between cables, with a heat-shrinkable sheath, which has at least one heat-activated surface layer, wherein the heat-shrinkable sheath (24) has, in addition to the 20 heat-activated surface layer (25), a sealing layer (26), which is positioned on the inside of the surface layer and is stable in terms of its state of aggregation, with the result that the sealing layer maintains its state of aggregation during shrinking of 25 the sheath, the surface layer (25) deforming the sealing layer (26) during the shrinking process and, after the shrinking process, keeping it in a deformed state. 30 10. The cable joint as claimed in claim 9, wherein the sealing layer (26) is produced from an elastically deformable material or a plastically/elastically deformable material or a plastically deformable material. 35

11. The cable joint as claimed in claim 9 or 10, wherein the sealing layer (26) is produced from an elastomer. - 13 12. The cable joint as claimed in one of claims 9 to 11, wherein the sealing layer (26) is produced from a polyurethane gel or from a silicone gel. 5 13. The cable joint as claimed in one of claims 9 to 12, wherein the sealing layer (26) is designed to cover the whole area.

14. The cable joint as claimed in one of claims 9 to 10 12, wherein the sealing layer (26) has cutouts (27).

15. The cable joint as claimed in claim 14, wherein the cutouts (27) are filled with a heat-activated adhesive. 15

16. The cable joint as claimed in one of claims 9 to 15, characterized by features as claimed in one or more of claims 1 to 7.

17. A heat-shrinkable cable joint substantially as hereinbefore described with reference to any one of the embodiments as that embodiment is shown in the accompanying drawings. Dated 5 February, 2009 CCS Technology, Inc. Patent Attorneys for the Applicant/Nominated Person SPRUSON & FERGUSON