Assemblies and methods for electrical splice connections of cables

Abstract

An assembly for electrical splice connection of cables may include: a first connector, including a first spigot and first crimping portion, configured to be crimped onto a first cable conductor; a second connector, including a second spigot and second crimping portion, configured to be crimped onto a second cable conductor; a first open shell configured to accommodate the first and second spigots; and/or a second open shell configured to be fastened to the first open shell to wrap and hold the first and second spigots. A method for electrical splice connection of the cables may include: crimping the first crimping portion onto the first cable conductor; crimping the second crimping portion onto the second cable conductor; accommodating the first and second spigots on the first open shell; and/or fastening the second open shell to the first open shell to wrap and hold the first and second spigots.

Claims

1. An assembly for electrical splice connection of cables, the assembly comprising: a first connector, comprising a first spigot and a first crimping portion, configured to be crimped onto a first cable conductor; a second connector, comprising a second spigot and a second crimping portion, configured to be crimped onto a second cable conductor; a first open shell configured to accommodate the first and second spigots; and a second open shell configured to be fastened to the first open shell so as to wrap and hold in position the first and second spigots; wherein each of the first spigot and the second spigot comprises, at a respective free end portion thereof, an enlarged head, and wherein each of the first open shell and the second open shell comprises, at an axially central portion of a radially inner surface thereof, a recessed portion for accommodating the enlarged heads of the first spigot and the second spigot.

2. The assembly of claim 1, further comprising an outer sleeve configured to at least partly surround the first open shell and the second open shell.

3. The assembly of claim 2, wherein the outer sleeve comprises at least two first through holes, each of the at least two first through holes configured to align with a respective through hole of at least two second through holes formed in at least one of the first open shell and the second open shell, and wherein the assembly further comprises at least one locking screw.

4. The assembly of claim 1, wherein the first open shell and the second open shell are substantially identical to each other.

5. The assembly of claim 1, wherein each of the first and second cable conductors has a respective cross-sectional size, and wherein each of the first crimping portion and the second crimping portion has a cross-sectional size selected according to the cross-sectional size of a respective cable conductor of the first and second cable conductors.

6. The assembly of claim 1, wherein the first spigot and the second spigot are substantially identical.

7. The assembly of claim 1, wherein at least one of the first and second open shells comprises, at a radially inner surface thereof, a serration.

8. The assembly of claim 1, wherein each of the first and second cable conductors has cross-sectional size, and wherein each of the first spigot and the second spigot has a cross-sectional size which is equal to, or greater than, the cross-sectional size of a respective cable conductor of the first and second cable conductors.

9. The assembly of claim 1, wherein the first and second cable conductors are made of a respective material, and wherein each of the first crimping portion and the second crimping portion is made of the same material as that of a respective cable conductors of the first and second cable conductors.

10. The assembly of claim 3, wherein the at least one locking screw is a shear bolt.

11. A method for electrical splice connection of cables, the method comprising: providing a first connector, comprising a first spigot and a first crimping portion; providing a second connector, comprising a second spigot and a second crimping portion; crimping the first crimping portion onto a first cable conductor; crimping the second crimping portion onto a second cable conductor; accommodating the first and second spigots on a first open shell; and fastening a second open shell to the first open shell so as to wrap and hold in position the first and second spigots.

12. The method of claim 11, wherein the fastening of the second open shell to the first open shell comprises: positioning an outer sleeve in a radially outer position with respect to the first open shell and the second open shell, the outer sleeve comprising at least two first through holes; aligning each of the at least two first through holes to a respective through hole of at least two second through holes formed in at least one of the first open shell and the second open shell; and inserting a locking screw into each of the at least two first through holes and the at least two second through holes.

13. The method of claim 11, wherein the accommodating of the first and second spigots on the first open shell comprises accommodating an enlarged head provided at a free end portion of each of the first and second spigots onto a recessed portion provided at a central portion of the first open shell.

14. An assembly for electrical splice connection of cables, the assembly comprising: a first connector, comprising a first spigot and a first crimping portion, configured to be crimped onto a first cable conductor; a second connector, comprising a second spigot and a second crimping portion, configured to be crimped onto a second cable conductor; first and second open shells configured to accommodate the first and second spigots; and an outer sleeve configured to at least partly surround the first open shell and the second open shell; wherein the first and second open shells are configured to be fastened together to hold the first and second spigots, and wherein the outer sleeve comprises at least two through holes.

15. The assembly of claim 14, wherein the first open shell and the second open shell have a same length.

16. The assembly of claim 14, wherein the first open shell and the second open shell have a same diameter.

17. The assembly of claim 14, wherein the first spigot and the second spigot have a same length.

18. The assembly of claim 14, wherein the first spigot and the second spigot have a same diameter.

Description

(1) Further features and advantages of the present invention will appear more clearly from the following detailed description of a preferred embodiment thereof, such description being provided merely by way of non-limiting example and being made with reference to the annexed drawings. In such drawings:

(2) FIG. 1 is a schematic perspective view, in an exploded configuration, of an assembly for the electrical splice connection of cables, according to a first embodiment of the present invention;

(3) FIGS. 2-4 schematically show three steps of connecting a portion of the assembly of FIG. 1 to a cable;

(4) FIGS. 5-8 schematically show four steps of connecting two cables by the assembly of FIG. 1; and

(5) FIG. 9 schematically shows an alternative embodiment of the present invention;

(6) FIGS. 10 and 11 schematically show another alternative embodiment of the present invention.

(7) In FIGS. 1-8, an embodiment of an assembly for electrical splice connection of two cables according to the present invention is indicated with numeral reference 10. The two cables (more specifically an end portion of each of the two cables) are indicated with numeral references 100a, 100b in FIGS. 5-8.

(8) In the assembled configuration thereof, assembly 10 extends coaxially to a longitudinal axis X-X.

(9) In the specific exemplary embodiment herein shown, the structure of the two cables 100a, 100b is similar. However, cables of different structures (different materials and/or different cross-sectional sizes) can be connected to each other by the assembly 10.

(10) The structure of the cables 100a, 100b will be described with specific reference to FIGS. 2-4, wherein just cable 100a (more specifically an end portion thereof) is shown. What stated with reference to cable 100a also applies to cable 100b.

(11) Cables 100a, 100b comprise, at a radially inner portion thereof, metallic conductors 101a, 101b, respectively. A protective sheath 102a, 102b of electrically insulating polymeric material is coaxially applied at a radially outer position with respect to the conductors 101a, 101b.

(12) Between conductors 101a, 101b and protective sheath 102a, 102b, moving from the conductors 101a, 101b towards the protective sheath 102a, 102b, further layers (not shown) may be provided as well as one or more conductive screens (not shown). For example one semi-conductive layer (not shown) can be radially interposed between the conductor and the insulating layer.

(13) Assembly 10 is configured to electrically connect cables 100a, 100b with each other by mechanically connecting conductors 101a, 101b with each other. To this end, the end portion of the conductors 101a, 101b is exposed by removing a predetermined length of protective sheath 102a, 102b (and of any further layer/screens optionally present) at the end portion of each cable 100a, 100b, as shown in FIG. 2.

(14) As from FIG. 1, assembly 10 comprises a first compression connector 20a configured to be coupled to cable 100a and a second compression connector 20b configured to be coupled to cable 100b.

(15) Each compression connector 20a, 20b comprises a crimping portion 22a, 22b configured to be crimped onto conductors 101a, 101b of cables 100a, 100b, respectively.

(16) Each compression connector 20a, 20b further comprises a spigot 25a, 25b having a given cross-sectional size.

(17) Each crimping portion 22a, 22b is defined at a first axial portion of the respective compression connector 20a, 20b while each spigot 25a, 25b is defined at a second axial portion of the respective compression connector 20a, 20b.

(18) When compression connectors 20a, 20b are intended to be connected with conductors 101a, 101b made of the same material and having the same cross-sectional size, compression connectors 20a, 20b are identical to each other.

(19) Should instead conductors 101a, 101b be made of different materials, each connectors 20a, 20b has its crimping portion 22a, 22b made of the same material of the respective conductors 101a, 101b which it is intended to be connected with. For example, connectors 20a, 20b having at least the crimping portion 22a, 22b made of aluminium are used with aluminium conductors 101a, 101b and connectors 20a, 20b having at least the crimping portion 22a, 22b made of copper are used with copper conductors 101a, 101b.

(20) The material of the spigots 25a, 25b can be selected irrespectively from the material of the cable conductors 101a, 101b.

(21) Should conductors 101a, 101b have different cross-sectional size, the crimping portion 22a, 22b of each connector 20a, 20b has a cross-sectional size selected according to the cross-sectional size of the conductors 101a, 101 which it is intended to be connected with. The cross-sectional size of the spigots 25a, 25b is still the same, irrespective of the cross-sectional size of the crimping portion 22a, 22b.

(22) Connectors 20a, 20b are preferably tin plated in order to resist corrosive environments, for example salty air and moisture existent in offshore wind towers, as well as to prevent galvanic corrosion caused by the natural difference in electro-potential of different materials when connecting an aluminium connector 20a, 20b with copper conductors 101a, 101b.

(23) As detailed in FIG. 2, each crimping portion 22a, 22b is substantially cylindrically-shaped and comprises an axial blind hole 23a, 23b configured to receive the end portion of the conductors 101a, 101b. Preferably, the diameter of the hole 23a, 23b is only slightly greater than that of the conductors 101a, 101b to be housed therein, so as to avoid any undesired offset between conductors 101a, 101b and centre line of the crimping portion 22a, 22b.

(24) Suitable fitters (not shown) configured to be housed within holes 23a, 23b can be provided for small diameter conductors 101a, 101b in order to obtain the desired alignment between conductors 101a, 101b and centre line of the crimping portion 22a, 22b, thus reducing the number of different dies to be used.

(25) As shown in FIGS. 1 and 5-8, each crimping portion 22a, 22b further comprises a plurality of crimping areas 24 arranged coaxially to the hole 23a, 23b and configured to be crimped onto conductors 101a, 101b by proper tools not shown, such as for example mechanical or hydraulic heads as well as different dies, as per cable specifications. The crimping areas 24 are not depicted in FIGS. 2-4.

(26) Thanks to the provision of the crimping portions 22a, 22b, conductors 101a, 101b can be firmly locked in position within connectors 20a, 20b.

(27) Each spigot 25a, 25b is preferably defined by a solid body portion having a substantially cylindrical shape and comprising, at the free end portion thereof, an enlarged head 26a, 26b.

(28) The cross-sectional size of spigots 25a, 25b is preferably equal to or greater than the cross-sectional size of the conductors 101a, 101b.

(29) In addition to having a given cross-sectional size, spigots 25a, 25b preferably also have the same length, so that spigots 25a, 25b are identical to each other irrespective of the conductor materials and sizes.

(30) The provision of connectors 20a, 20b designed as above allows pre-installation of connectors 20a, 20b onto cables 100a, 100b at different remote locations, thus eliminating the use of crimping tool at the installation area.

(31) Assembly 10 further comprises a first open shell 30 configured to accommodate the spigots 25a, 25b, as shown in FIG. 5, and a second open shell 40 configured to be fastened to open shell 30 to wrap and hold in position the spigots 25a, 25b, as shown in FIG. 6.

(32) In the exemplary embodiment shown in the attached figures, both open shells 30 and 40 have a substantially semi-cylindrical shape and are made of aluminium, preferably tin plated in order to prevent corrosion.

(33) Both open shells 30 and 40 comprise, at an axially central portion of a radially inner surface thereof, a recessed portion 35 for accommodating the enlarged head 26a, 26b of the spigots 25a, 25b, as shown in FIG. 1. At the opposite axial portions with respect to the abovementioned recessed portion 35, serrations 33a, 33b are provided in both shells 30 and 40.

(34) In the embodiment shown in the attached drawings, the recessed portion 35 lacks the serrations 33a, 33b.

(35) Advantageously, serrations 33a, 33b break through oxide/s formed on the surface of the spigots 25a, 25b thus reducing the resistance at the shell-spigot interface while increasing the grip between them.

(36) Thanks to the elongated shape of both open shells 30 and 40 and spigots 25a, 25b, a large contact surface at the shell-spigot interface is advantageously provided.

(37) As the spigots 25a, 25b have a given size, open shells 30 and 40 have a given size, depending on the spigot size, irrespective of the conductor sizes.

(38) In the embodiment shown in FIGS. 1-8, open shell 40 comprises a plurality of through holes 45a, 45b configured to receive respective locking screws 60a, 60b (FIGS. 1 and 6).

(39) More specifically, at least one through hole 45a is arranged at a first end portion of the open shell 40. Said at least one through hole 45a is located at a radially outer position with respect to spigot 25a (FIG. 6). Analogously, at least another through hole 45b is arranged at the opposite end portion of the open shell 40 (FIG. 6). Said at least one through hole 45b is located at a radially outer position with respect to spigot 25b.

(40) As shown in FIGS. 1-8, two through holes 45a and two through holes 45b are preferably provided, wherein through holes 45a are arranged at the first end portion of the open shell 40 and through holes 45b are arranged at the opposite end portion of the open shell 40.

(41) In an embodiment not shown, open shell 30 comprises the above through holes 45a, 45b too. In this case, open shells 30 and 40 are fully identical to each other.

(42) In the embodiment shown in the FIGS. 1-8, the mutual fastening of open shells 30 and 40 is obtained by positioning, in a radially outer position thereof, an outer sleeve 50 (shown in FIGS. 1, 7 and 8). In the present case, the outer sleeve 50 totally surrounds open shells 30 and 40.

(43) Sleeve 50 is preferably made of aluminium, more preferably tin plated in order to resist to corrosive environments.

(44) Sleeve 50 comprises a number of through holes 55a, 55b equal to the number of through holes 45a, 45b, each through hole 55a, 55b being intended to be aligned to a respective first through hole 45a, 45b so as to allow locking screws 60a, 60b inserted in through holes 55a, 55b to pass through holes 45a, 45b and to press onto the spigots 25a, 25b, thus firmly holding in position spigots 25a, 25b.

(45) Through holes 45a, 45b and 55a, 55b are preferably aligned in a single longitudinal line, thus requiring a single direction to access the locking screws 60a, 60b during installation.

(46) Preferably, locking screws 60a, 60b are shear bolts which, more preferably, are made of brass. This provision allows avoiding or at least reducing cold welding of locking screws 60a, 60b with aluminium open shells 30 or 40 and outer sleeve 50, which would cause premature shearing of the bolts.

(47) Since the locking screws 60a, 60b press onto the spigots 25a, 25b, conductors 101a, 101b are neither damaged nor moved during installation. As the cross-sectional size of spigots 25a, 25b remains constant even for different conductor sizes, the locking screws will shear at substantially the same height all the times, thus eliminating or at least reducing risk of shearing failure or of shearing at incorrect heights, which would cause, for example, the sheared bolts to have undesired sharp edges radially projecting outside the assembly 10.

(48) Advantageously, locking screws 60a, 60b allow using at the installation area single, universally available tools, such as a spanner or a wrench.

(49) In a different embodiment shown in FIG. 9, at least one clamp 70a, 70b can be provided to fasten open shells 30 and 40 to each other. For example, as shown in FIG. 9, two clamps 70a, 70b are provided, each clamp 70a, 70b being arranged at a respective end portion of the shells 30 and 40. Clamps 70a, 70b are first located over the shells 30 and 40 at the desired position and then tightened to fasten each other, thus steadily holding in position the spigots 26a, 26b arranged between them.

(50) In a further embodiment shown in FIGS. 10 and 11, a snap coupling can be provided to fasten open shells 30 and 40 to each other. For example, a projecting grooved tongue 81 can be provided at both the longitudinal sides of one of shells 30, 40 (shell 40 in FIGS. 10 and 11) and a spline 82 can be provided at both the longitudinal sides of the other shell 30, 40 (shell 30 in FIGS. 10 and 11) to snap housing a respective one of the projecting grooved tongues 81.

(51) In the embodiments of FIGS. 9-11, one or more through holes 45 can be provided in open shell 30 and/or 40 for the insertion of locking screws, for example shear bolts, as auxiliary fastening members.

(52) In another further embodiment, both the open shells 30, 40 comprise at least two through holes 45a, 45b configured to receive respective locking screws 60a, 60b. According to this embodiment, the mutual fastening of open shells 30 and 40 is obtained by inserting locking screws 60a, 60b, preferably shear bolts, into the at least four through holes.

(53) The assembly 10 described above allows connecting different material and size cable conductors 101a, 101b with no orientation issues at the installation area, thus eliminating stress induced into the cables 100a, 100b during installation.

(54) The assembly 10 is capable of withstanding mechanical forces it is subjected to, including vibration.

(55) As from FIGS. 2-3, the electrical connection of cables 100a, 100b comprises at first preparing the cable ends to expose conductors 101a, 101b which are then inserted into the respective blind hole 23a, 23b of connectors 20a and 20b. These operations can be done at different locations, even far away from the installation area.

(56) Then, as from FIG. 4, the crimping portions 22a, 22b of connectors 20a, 20b are crimped onto conductors 101a, 101b, so as to obtain pre-connectorized cables 100a, 100b. This operation can be done at the same location of the above operation or at a different location, even far away from the installation area.

(57) Cables 100a, 100b so pre-connectorized are then connected with each other at the installation area, as detailed herein below.

(58) If the outer sleeve 50 is used, like in the embodiment of FIGS. 1, 5-8, it is slid over one of the pre-connectorized cables 100a, 100b. In the case of vertical installation, the outer sleeve 50 is preferably made slid over the upper cable end. Tapes or cable ties can be used to hold the sleeve 50 in position.

(59) Spigots 25a, 25b are aligned and then accommodated onto open shell 30, with the enlarged heads 26a, 26b arranged in the recessed portion 35 of the open shell 30, as from FIG. 5.

(60) Open shell 40 is then fastened to open shell 30 to wrap spigots 25a 25b, as from FIG. 6. Shells 30 and 40 can be held in position by tapes or cable ties.

(61) As from FIG. 7, sleeve 50 is then positioned over shells 30 and 40. Through holes 55a, 55b are aligned to through holes 45a, 45b upon having cut the above tapes or cable ties.

(62) As from FIG. 8, locking screws 60a, 60b are inserted into through holes 55a, 55b and tightened to exert at predetermined pressure onto said spigots 25a, 25b until shear occurs.

(63) Clamps 70a, 70b or snap fit members 81, 82 can be used in place of sleeve 50 to fasten open shells 30 and 40 to each other, as discussed above.

(64) Of course a man skilled in the art can make further modifications and changes to the invention described above in order to meet specific and contingent application requirements, these modifications and changes falling in any case within the scope of protection as defined by the following claims.