Cable termination and method of manufacture

Abstract

A cable termination includes a cable end of a cable having a protective outer jacket and an overmolded sealant. The cable termination is manufactured using a method having the steps of providing a cable end of a cable having a protective outer jacket, preparing the protective outer jacket of the cable end such as to promote adhesion with a sealant, and overmolding the cable end with a sealant.

Claims

1. A method of manufacturing a cable termination, the method comprising: providing a cable end of a cable having an insulation jacket; preparing the insulation jacket of the cable end to promote adhesion with a sealant; and overmolding the cable end with a sealant, wherein the sealant is a polyurethane (PUR) material provided as a protective outer jacket of the cable termination to form a watertight and sealed outer enclosure of the cable.

2. The method according to claim 1, wherein the insulation jacket is a non-polyvinyl chloride material comprising at least one of polyolefins, copolymers of polyolefins, crosslinked polyolefins, and their copolymers.

3. The method according to claim 1, wherein the step of preparing the insulation jacket comprises: applying a tape onto the insulation jacket of the cable end.

4. The method according to claim 3, wherein the tape is an adhesive tape.

5. The method according to claim 3, wherein the tape is a polyvinyl chloride tape.

6. The method according to claim 3, wherein the tape is a polyethylene terephthalate tape.

7. The method according to claim 6, wherein the tape is a polyethylene terephthalate cloth tape.

8. The method according to claim 1, wherein the step of preparing the insulation jacket comprises: applying a cold melt onto the insulation jacket of the cable end.

9. The method according to claim 1, further comprising the steps of: positioning an annular elastic sealing ring around the cable end; positioning a sleeve made of heat shrinkable material over the sealing ring; heat shrinking the sleeve to exert a compressive force onto the sealing ring; and overmolding the sleeve, the sealing ring, and an adjacent region of the cable end with the sealant.

10. The method according to claim 9, wherein the cable end is positioned in a conductive housing and wherein the sleeve is positioned to partly surround the housing.

11. The method according to claim 9, wherein an adhesive is applied to an inner surface of the sleeve.

12. The method according to claim 1, wherein the step of preparing the insulation jacket comprises: applying a rubber or silicone material onto the insulation jacket of the cable end.

13. The method according to claim 12, wherein the material is selected from a list consisting of a polyvinyl chloride material, a rubber, a polytetrafluoroethylene material, or a silicone material.

14. The method according to claim 1, wherein the step of preparing the insulation jacket comprises: plasma treating or corona treating the insulation jacket of the cable end.

15. The method according to claim 1, wherein the step of preparing the insulation jacket comprises: chemically treating the insulation jacket of the cable end with a solvent.

16. The method according to claim 1, wherein the step of preparing the insulation jacket comprises: mechanically treating the insulation jacket of the cable end, the mechanical treatment selected from a list consisting of: roughening the insulation jacket using an abrasive material; sand blasting the insulation jacket; soda blasting the insulation jacket; or brushing the insulation jacket.

17. A cable termination comprising a cable end of a cable having an insulation jacket, and an overmolded sealant, manufactured using a method comprising: providing a cable end of a cable having an insulation jacket; preparing the insulation jacket of the cable end to promote adhesion with a sealant; and overmolding the cable end with a sealant, wherein the sealant is a polyurethane (PUR) material provided as a protective outer jacket of the cable termination to form a watertight and sealed outer enclosure of the cable.

18. The cable termination according to claim 17, wherein the insulation jacket of the cable end is made of a non-polyvinyl chloride material.

19. The cable termination according to claim 18, wherein the non-polyvinyl chloride material comprises at least one of a polyolefin, copolymers of polyolefins, crosslinked polyolefins, and their copolymers.

20. The cable termination according to claim 17, comprising a plug, a socket, a Y-splice, H-splice, or T-splice.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will now be described, by way of example with reference to the accompanying drawings, in which:

(2) FIG. 1 illustrates an embodiment of a cable termination;

(3) FIG. 2 illustrates a further embodiment of a cable termination;

(4) FIG. 3 illustrates a further embodiment of a cable termination;

(5) FIG. 4 illustrates a plasma treatment of a cable end;

(6) FIG. 5 illustrates a cross-section through a cable end according to a further embodiment;

(7) FIG. 6 illustrates a partially cut-off section of a cable termination; and

(8) FIG. 7 illustrates a cable termination in the form of a Y-splice.

DETAILED DESCRIPTION

(9) FIG. 1 depicts an exemplary termination of a cable end 10 in the form of a Y-splice, the cable termination including three electrical conductors 12 surrounded by an insulating jacket 14 made of a non-PVC material, e.g., a polyolefin, polyethylene, or silicone material. The cable termination includes a splice, e.g., a copper splice 26 connecting the three electrical conductors 12. In the region of the copper splice 26 the cable end 10 is provided with an overmolding of sealant 24, e.g., of a polyurethane foam material. To improve the adhesion between the outer jackets 14 and the sealant 24 an adhesive PVC tape 30, e.g., of class T3 or T4, is wrapped around the outer protective jackets 14 next to the copper splice 26. The overmold of sealant 24 is applied with an excellent adhesion between the sealant 24 and the outer jackets 14 of the cables.

(10) FIG. 2 depicts a further embodiment of a cable termination like the embodiment of FIG. 1 wherein the preparation of the protective outer jackets 14 is performed by applying a cold melt 32 onto the outer jackets 14 and onto the copper splice 26.

(11) FIG. 3 depicts a further embodiment of a cable termination wherein sealing rings 34 of a rubber or silicone material are applied onto the protective outer jackets adjacent to the copper splice 26 to promote adhesion of the overmold of the sealant 24 and to provide a watertight sealing.

(12) FIG. 4 depicts a cable end of a cable termination including an electrical conductor 12 surrounded by an insulating jacket 14 wherein a plasma head 40 including a plasma nozzle 42 is used for treating the protective outer jacket 14 with a plasma beam 44 resulting in a plasma treated area 46 extending over the circumference of the outer jacket 14 which is made of a non-PVC material, e.g., of a XLPE material, polyolefins, copolymers of polyolefins, crosslinked polyolefins, and their copolymers.

(13) FIG. 5 depicts a cross-section of the cable end 10 shown in FIG. 4 which has been overmolded with a sealant 24 of polyurethane foam. The preparation of the protective outer jacket 14 through application of atmospheric plasma significantly promotes the adhesion of the sealant 24 to the outer jacket 14.

(14) FIG. 6 depicts a termination of a cable end 10, the cable including one or more electrical conductors 12 surrounded by an insulating jacket 14 made of a non-PVC material, e.g., a polyolefin, polyethylene, or silicone material. The cable termination includes an annular elastic sealing ring 16 of a rubber or a silicone material or of any other material such as PTFE that has the function of compressed sealing against the cable insulation. The sealing ring 16 is optionally serrated e.g., by providing annular grooves at the outer circumference, and is positioned over the cable end 10 to surround its outer circumference. The sealing ring 16 may include at least one of ethylene propylene rubber (EPR), nitrile butadiene rubber (NBR), Standard Indonesia Rubber (SIR), fluororubber (FPM), Ethylene acrylic rubber (AEM), fluorosilicone, fluorocarbon, and polyacrylate rubber.

(15) In the disclosed embodiment the cable end 10 extends into a conductive housing 18 wherein the sealing ring 16 is located adjacent an end surface of the housing 18. Next to the sealing ring 16 the housing 18 is provided with a collar 20 forming an annular protrusion.

(16) Before the cable end 10 is inserted into the housing 18, a sleeve 15 which is made of heat shrinkable material (e.g., a polyvinyl chloride (PVC) material, polyvinylidene fluoride (PVDF), or fluorinated ethylene propylene (FEP) material and the sealing ring 16 are positioned over the cable end and a braided shield 22 of the cable is folded backwards. Thereafter, the cable end 10 is inserted into the housing 18 such that the braided shield 22 is located between the inner circumference of the housing 18 and the insulating jacket 14 of the cable end 10. Thereafter, the housing 18 is caulked at a location C around its outer circumference to connect the cable end 10 with the housing 18 and to provide an electrically conductive interconnection between the housing 18 and the braided shield 22.

(17) To compress the sealing ring 16 and to provide a tight seal against water and humidity, the sealing ring 16 is compressed by the sleeve 15 which is positioned over the sealing ring 16 and the collar 20. The sleeve 15 is thereafter heat shrunk over the sealing ring 16 and the collar 20 of the housing 18 and snuggly fits against the insulating jacket 14 of the cable end 10. Thereafter, the housing 18, the sealing ring 16, the sleeve 15 and the cable end 10 are connected to form a unit.

(18) Finally, the sleeve 15, the sealing ring 16 the adjacent region of the cable end 10 and the housing 18 are provided with an overmolding of sealant 24 (e.g., a polyurethane sealant). The sealant forms an outer enclosure of the cable end 10.

(19) To improve the adhesion between the sleeve 15, the sealing ring 16, the insulating jacket 14 and the optional housing 18 an adhesive layer 17 may be provided at the inner surface of the sleeve 15. Such adhesive can be coated onto the sealing ring or can be provided as a separate intermediate layer.

(20) It should be noted that the adhesive layer 17 and the housing 18 are merely optional and not necessarily required to provide a cable end which is sealed and isolated against humidity and water. Furthermore, the housing 18 may be designed as or to include a plug or a socket. Further embodiments of the cable termination are a Y-splice, T-splice, or an H-splice, e.g., for high voltage applications in electric vehicles.

(21) FIG. 7 depicts an example of a Y-splice including three cable ends 10 enclosed in an overmolding of sealant 24 of polyurethane material having a block shape and forming an outer enclosure of the Y-splice.