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EP-4261434-B1 - CABLE WITH JOINTS FOR THE CONNECTION OF CABLE ARMOUR NON-METALLIC ELEMENTS

EP4261434B1EP 4261434 B1EP4261434 B1EP 4261434B1EP-4261434-B1

Inventors

  • CONSONNI, Enrico Maria
  • CORDO', FEDERICO

Dates

Publication Date
20260506
Application Date
20230222

Claims (11)

  1. A cable (100) comprising a cable core (101, 102, 103) and an armour (107), the armour (107) being formed by a plurality of consecutive sections of non-metallic tensile elements (109) wound around the cable core, each section including a first non-metallic tensile element (109') connected to a second non-metallic tensile element (109") of the consecutive sections by a joint (1) comprising: - a first socket (2') and a second socket (2"), each of said sockets (2', 2") comprising a flat body (4) extending longitudinally along a longitudinal axis (S) between a proximal end (5) and a distal end (6) and comprising an inner through bore (9) between a proximal aperture (7) at the proximal end (5) and a distal aperture (8) at the distal end (6), the first (109') and second (109") non-metallic tensile elements having an end portion (112) being housed in the inner through bore (9) of respectively the first (2') and second (2") socket by the proximal aperture (7) and secured therein by a bonding material, and each inner through bore (9) being shaped to translationally and rotationally lock the bonding material and having a rectangular or polygonal or elliptical shape in cross section; - an interconnecting device (3) translationally and rotationally locked in the distal apertures (8) of the first and the second sockets (2', 2") and allowing the sockets (2', 2") to relatively rotate exclusively around at least one rotation axis (R) perpendicular to a plane where the socket body longitudinal axes (S) of the first (2') and the second (2") sockets lie.
  2. The cable (100) of claim 1, wherein the non-metallic tensile elements (109) connected by the joint (1) have a round or flat cross-section.
  3. The cable (100) of claim 1, wherein the inner through bore (9) is shaped such that if a traction force along the socket body longitudinal axis (S) in a direction from the distal end (6) towards the proximal end (5) is applied to the non-metallic tensile element (109), the bonding material securing the non-metallic tensile element (109) end portion (112) is compressed inside the inner through bore (9).
  4. The cable (100) of claim 1, wherein at least one portion (21) of the inner through bore (9) is tapered towards the proximal end (5).
  5. The cable (100) of claim 4, wherein the inner through bore (9) has a rectangular cross section transversal to the socket body longitudinal axis (S), wherein in the inner through bore (9) the length of the longer sides (23) of the inner through bore (9) cross section is fixed and the length of the shorter sides (22) of the inner through bore (9) cross section decreases along the socket body longitudinal axis (S) towards the proximal end (5).
  6. The cable (100) of claim 1, wherein the bonding material securing the end portion (112) of the non-metallic tensile element (109) is a thermoset material or a two-part resin.
  7. The cable (100) of claim 1, wherein the interconnecting device (3) comprises a first block (10') and a second block (10"), extending along the longitudinal axis (S), and a pivot (19) joining them and allowing relative rotational movements of the first block (10') and the second block (10") around a rotation axis (R) perpendicular to a plane where the longitudinal axes (S) lie, wherein the blocks (10', 10") are locked at a first portion (11) in the respective socket body (4', 4") distal apertures (8), and are pivotally interconnected at a second portion (12) opposite to the first portion (11).
  8. The cable (100) of claim 7, wherein the first and second blocks (10', 10") cross section transversal to their longitudinal axes (S) at their first portions (11) and the respective socket body distal aperture (8) have matching shapes.
  9. The cable (100) of claim 7, wherein at their first portions (11) the first and second blocks (10', 10") comprise a through hole (18) extending perpendicular to their longitudinal axes (S), and the respective socket body (4) comprises two opposite ridges (14) protruding along the longitudinal axis (S) from the distal end (6), each having a through hole (15) extending perpendicular to the socket body longitudinal axis (S) and aligned to the block through hole (18), wherein the interconnecting device (3) further comprises a pin or bolt (16) inserted into the aligned block and socket through holes (13, 15).
  10. The cable (100) of claim 7, wherein at their second portions (12) the first and second blocks (10', 10") comprise one or more ridges (17) protruding along their longitudinal axes (S) and parallel thereto, each having a through hole (18) perpendicular to the block longitudinal axis (S), wherein a pin or bolt (19) is inserted.
  11. The cable (100) of claim 7, wherein at their first portions (11) the first and second blocks (10', 10") comprise a plug portion (20) for closing and sealing the distal aperture (8) of the respective socket body (4).

Description

BACKGROUND Technical field The present disclosure relates to a cable with a joint for connecting non-metallic elements forming a cable armour, particularly a submarine or an umbilical cable. Description of the Related Art Submarine and umbilical cables may comprise an armour having one or more layer of wires usually made of metal (e.g. steel or composite comprising steel). New submarine power cables and umbilical cables have been developed which employ non-metallic lightweight tensile elements as armour wires which allows decreasing the total weight of the cable and thus its deployment in very deep water (typically 2,000 m or more). Armour strength elements are wound on the cable core in unilay configuration using machine with rotating cages equipped with the necessary number of bobbins. Each single armour element is unwound by an individual bobbin that, depending on the armour unit size, can generally carry few kilometres (typically every 1-3 km) of the armour element itself. Typical length of a submarine cable loaded on an installation vessel, depending on the specific design, can range between 100 and 200 km. It is therefore necessary to link the armour elements during cable manufacturing. While the jointing of armour metallic elements is made with well-known techniques, jointing non-metallic strength elements poses problems in terms of suitable mechanical continuity, dimensions, process speed and environmental resistance of the non-metallic elements. Furugen M. et al., "Completion of Submarine Cable Lines Combining Low Environmental Impact with Low Cost", Furukawa Review No. 21, 2002, p.44, relates to a 22 kV submarine cable with a double armour, and the compound armour consisted of high-density polyethylene sheathed FRP (fiberglass-reinforced-plastic ) for the first layer. For FRP, splicing technology is crucial in that, depending on the formation of the splice, the drop in tensile strength of the FRP wire may be greater than desired. The splicing method developed for use in this work involves crimping of a stainless steel sleeve. Several other solutions are known in the art, which however relate to jointing ropes and not non-metallic cable armour elements. GB 1 381 690 relates to swage sockets useful to connect lengths of wire rope to other lengths of wire rope and to fixed connectors. A wire rope has a two-piece swage socket swaged to it, and this swage socket is connected by a connecting pin to a two-piece swage socket fixedly connected to one pulley block. The rope swage socket includes an open (clevis) pin receiving section, while the pulley block swage socket includes a closed (tongue) pin receiving section. These swage sockets also include shank sections. Open and closed pin receiving sections each includes a reduced neck portion integrally connected to a clevis or tongue end piece and a part spherical ball portion integrally connected to the neck portion. Each of the part spherical balls of the pin receiving sections is mounted for rotational movement and limited pivotal movement with respect to a mating cup portion of one of the shank members. US 4,652,166 relates to a device for connecting two cables together, comprising a short linking rod having a partially spherical member at each end thereof, a first pair of sockets, each socket of said first pair receiving a respective one of said spherical members and forming a ball and socket joint therewith, and a second pair of sockets, each socket of said second pair being detachably connected to a respective one of the sockets of said first pair and having an axial passage receiving one end portion of one of the two cables to be connected, wherein each socket of the second pair has a generally cylindrical outer shape and its axial passage is also cylindrical with a diameter corresponding to that of the end portion of the cable received therein, and each socket of the second pair is secured to the end portion of the corresponding cable by constricting said socket of said second pair through a constricting die. GB 2 313 853 relates to a rope terminated in the tapered bore of a housing. The rope end is secured in the bore by a conical wedge, by a resin, or by a combination of these. DE 26 38 531 A1 describes a cable termination, wherein preformed cable wires are unlaid so that they form an unstressed envelope with a bulge and a flare. The cable end is positioned in a sleeve having a tapered bore that is coextensive with the envelope. Resin that forms an incompressible plug inside the sleeve is forced into the bore by a fitting screwed onto the sleeve at the larger end of the bore. SUMMARY OF THE DISCLOSURE The Applicant aims at providing a joint for connecting consecutive cable armour non-metallic elements in a quick process which, if necessary, can be completed offline. Such joint should have a reduced size for not substantially increasing the overall cable diameter, should ensure a suitable mechanical continuity and integrity of the non-metallic ele