CABLE GLANDS

Abstract

A sleeve (19) arranged to be slidably received within a passage (9) defined in a body of a cable gland (1), the sleeve (19) arranged to receive a settable sealing material for forming a seal to a cable passing through the sleeve, wherein the sleeve (19) comprises: an annular side wall (79) extending along an axial length and having a first end and a second end; and an end wall (100) capping the first end of the annular side wall (79), in which the annular side wall (79) and the end wall (100) define a void (106) within them into which settable sealing material can be received.

Claims

1. A sleeve arranged to be slidably received within a passage defined in a body of a cable gland, the sleeve arranged to receive a settable sealing material for forming a seal to a cable passing through the sleeve, wherein the sleeve comprises: an annular side wall extending along an axial length and having a first end and a second end; and an end wall capping the first end of the annular side wall, in which the annular side wall and the end wall define a void within them into which settable sealing material can be received.

2. The sleeve of claim 1, in which the end wall has at least one orifice through which a core of the cable can pass.

3. The sleeve of claim 1, in which the end wall is non-unitary with the annular side wall.

4. The sleeve of claim 3, in which the end wall can be removed or replaced on the side wall without breaking any material from which the annular side wall or end wall is formed.

5. The sleeve of claim 1, in which each orifice may be provided as a press-out portion of the end wall, whereby a circumference of each orifice is formed in the end wall such that a portion of the end wall within each circumference can be pushed out by a user to form the orifice.

6. The sleeve of claim 1, in which the end wall is formed from a settable material.

7. The sleeve of claim 1, being transparent.

8. A cable gland comprising: a body having a wall defining a passage extending in an axial direction from a first end to a second end, the passage of the cable gland arranged to receive a cable; adjacent the first end of the cable gland body, a cable sleeve in accordance with claim 1, received within the passage of the cable gland.

9. A sealing apparatus for a cable gland, comprising: the sleeve of claim 1; and a hollow member for delivering settable material into the void.

10. The sealing apparatus of claim 9, in which the hollow member is arranged to puncture the material of the sleeve in order to pass through the sleeve to deliver the settable sealing material into the void, for example by having a sharpened tip.

11. The sealing apparatus of claim 9, comprising a further hollow member for exhausting air from the void.

12. The sealing apparatus of claim 11, in which the further hollow member is also be arranged to puncture the material of the sleeve in order to pass through the sleeve to allow air within the void to be exhausted, for example by having a sharpened tip.

13. The sealing apparatus 9, comprising a plurality of end walls for the sleeve, each differing the number or size of orifices defined therein.

14. A method of installing a cable having at least one core in cable gland comprising: a body having a wall defining a passage extending in an axial direction from a first end to a second end, the passage of the cable gland arranged to receive a cable; adjacent the first end of the cable gland body, a cable sleeve arranged to be slidably received within the passage, the sleeve arranged to receive a settable sealing material for forming a seal to the cable, wherein the sleeve comprises: an annular side wall extending along an axial length and having a first end and a second end; and an end wall capping the first end of the annular side wall, in which the annular side wall and the end wall define a void within them into which settable sealing material can be received, claim the method comprising: passing the cable at least partially through the cable gland; exposing at least one core of the cable at an end of the cable; placing the sleeve over each core at the end of the cable; filling the sleeve with sealable setting material; and assembling the cable gland over the sleeve so as to seal the cable gland over the cable.

15. The method of claim 14, comprising using a hollow member for delivering settable material into the void, in which the filling step comprises puncturing the sleeve with the hollow member and introducing the settable sealing material with the hollow member.

16. The method of claim 14 or claim 15, comprising using a hollow member for delivering settable material into the void, in which the step of placing the sleeve over each core comprises selecting an end wall from a plurality of end walls having a number of orifices, each orifice having a size, each end wall of the plurality of end walls differing in the number or size of orifices defined therein, and placing the end wall on an annular side wall to form the sleeve.

17. The method of any claim 14, comprising forming the end wall from a settable material, which is pressed and/or moulded around each core.

Description

[0056] There now follows, by way of example only, a description of embodiments of the invention, described with reference to the accompanying drawings, and in which:

[0057] FIG. 1A is a schematic sectional view of a cable gland, according to an embodiment of the invention;

[0058] FIG. 1B is a perspective exploded view of the cable gland of FIG. 1A;

[0059] FIG. 1C is a perspective view of the cable gland of FIG. 1A, assembled with a cable;

[0060] FIG. 2 shows the region of the cable gland of FIG. 1A where the first and second body portions join, in sectional view;

[0061] FIG. 3A shows the region of the compound pot of the cable gland of FIG. 1A, in sectional view;

[0062] FIG. 3B shows a perspective view of the compound pot of the cable gland of FIG. 1A; and

[0063] FIG. 4 shows a perspective view of the compound pot of the cable gland of FIG. 1A, being filled.

[0064] In the description of the embodiments that follows, the construction and/or arrangement and/or function and/or operation is only described insofar as necessary for an understanding of each embodiment and therefore the description of features that are the same or similar in different embodiments may not be repeated as these will be understood from their description in other embodiments. Accordingly, the embodiments are not to be read and interpreted in isolation and any feature described in a particular embodiment will be understood to have application to other embodiments unless specifically excluded by the description.

[0065] FIGS. 1A to 1C illustrate an example of a cable gland 1 according to an embodiment of the invention. FIG. 1A illustrates the cable gland 1 in assembled form, without a cable, in sectional side view, and FIG. 1B illustrates the cable gland 1 in exploded view. FIG. 1C illustrates the cable gland 1, in assembled form, with a cable 3 passing through it. The cable 3 typically includes a number of conducting cores 110 (shown in FIG. 4), each having its own insulating jacket (not shown). The cores are surrounded by an inner sheath (not shown). This, in turn, is surrounded by an insulating outer sheath (not shown). An earthing shield, such a braid or armour, is provided between the inner and outer sheath.

[0066] The cable gland 1 includes a body 5 formed by an annular wall 7. The wall 7 defines a passage 9 extending through the body 5 in an axial direction A. The passage 9 extends from a first end 11 of the body 5 to a second end 13. Adjacent the first end 11, an external flange 15 is formed on the body for mounting the cable gland 1 to a wall, bulkhead or housing (not shown) through which the cable 3 is passing. In use, the first end 11 of the cable gland 1 is provided through an opening in the bulkhead, and the second end 13 is in an external environment.

[0067] Within the passage 9, near the first end 11, a sleeve-like sealing member 17 is formed in a compound pot 19. Also within the passage 9 is a clamp 21 for gripping on to the external insulation cover of the cable 3. The clamp 21 is provided between the compound pot 19, and the second end 13. At the second end 13, an ingress prevention seal 23 is provided over the opening of the passage 9. Further explosion protection seals (not shown) may also be received in the passage 9, and an external rubber seal is provided on the outside of the body 5. The compound pot 19, clamp 21 and ingress prevention seal 23 will be discussed in further detail below.

[0068] The body 5 is formed of a first part 25 and a second part 27. Each of the parts 25, 27 forms an axial portion of the body 5, such that each of the parts 25, 27 extends around the circumference of the passage 9, and along a portion of the length.

[0069] The first body part 25, also referred to as the entry, incorporates the first end 11 and the external flange 15, and receives the compound pot 19. Between the first end 11 and the external flange 15, the first body part 25 includes a cylindrical portion 29. This may include a screw thread or the like 31 for receiving a nut to secure the gland to the bulkhead through which the cable passes.

[0070] The first body part 25 tapers outward, away from the first end 11, after the flange 15. A further cylindrical section 33 is provided opposite the first end 11 of the body 5. In the assembled gland 1, the further cylindrical section 33 is received within the second body part 27. FIG. 2 illustrates the region where the first body part 25 extends into the second 27.

[0071] A first region 35 of the further cylindrical section 33, adjacent the taper, includes a first screw thread 37. The width of the first region 35 is such that the first screw thread 37 engages with a corresponding screw thread 41 on the inner surface 39 of the second portion 27, to join the body parts 25, 27 together. Tightening the screw thread applies compression between the first end 11 and the second end 13.

[0072] A second region 43 of the further cylindrical section 33, at the end of the first body part 25 opposite the first end 11, is of narrower diameter than the first region 35. The second region 43 includes an external screw thread 45 to secure a spigot retaining nut 47 to the end of the first body part 25. The spigot retaining nut 47 extends axially, to continue the second region 43 of the further cylindrical section 33.

[0073] On a first axial face 49 of the spigot retaining nut 47, at which the spigot retaining nut 47 joins the first body portion 25, a radially extending ledge 51 is formed, extending into the passage 9. The ledge 51 forms a seat for an armour clamp 53 arranged to grip the earth shielding of the cable, and electrically couple the earth shielding to the body 5 of the gland 1.

[0074] A spigot (or annular retaining member) 55 is located between a ledge 57 formed in the inner surface 59 of the first body part 25, and the end of the armour clamp 53. The spigot 55 includes grooves 61 formed on the tapered surface extending inside the armour clamp 53, and an annular rim 63 which engages the ledge 57 in the first body part 25, and extends radially inward to form a seat for the compound pot 19. The spigot 55 is retained in place by the ledge 57 on one face, and the armour clamp 53 and retaining nut 47 on the other face.

[0075] The second axial face 65 of the spigot retaining nut 47 forms a seat for the clamp 21, as will be discussed in more detail below. The cable 3 is passed through the spigot retaining nut 47, armour clamp 53 and spigot 55. The earthing shield (not shown) is gripped by the armour clamp, in co-operation with the grooves 61 on the surface of the spigot 55.

[0076] The second body part 27 forms a back nut of the cable gland 1. The clamp 21 is received within the part of the passage 9 formed by the back nut 27. The second body part 27 includes an annular ledge 67 extending across the second end 13. An annular ring 69 is provided within the passage 9, resting on the ledge 67, and provides a second seat for the clamp 21, such that the clamp 21 is received between the ring 69 and the spigot retaining nut 47.

[0077] FIG. 3A illustrates the region of the compound pot 19, in more detail, with FIG. 3B showing the compound pot 19 by itself.

[0078] The compound pot 19 is formed of a transparent polymer cylindrical wall 79, extending from a first end 87 to a second end 89. The first end 87 of the wall 79 is received at the first end of the gland 11, and the second end 89 of the wall is within the passage 9.

[0079] The wall 79 has an outer surface 71, that engages with an inner surface 59 of the first body portion 25, and an inner surface 75 that forms a through passage 77, through which the cable 3 extends, in the assembled gland 1.

[0080] The outer surface 71 includes a ledge 81 formed in a rim 83 at the second end 89, which engages with a step 85 formed in the inner surface 75 of the first body member 25, to retain against the pot 19 being pulled out in a direction towards the first end 11.

[0081] A spacing is formed between the ledge 81 and the step 85, along the axial direction A, and, optionally also in a radial direction. The outer surface 71 is tapered inwards from the rim 83 to the first end 87, to form a tapered region 95. The inner surface 75 of the first body portion 25 includes a matching tapered portion 97.

[0082] The inner surface 75 of the cylindrical wall 79 includes a cylindrical portion 91 adjacent the first end 87, with a tapered portion 93 tapering inwards form the second end 89 to the cylindrical portion 91.

[0083] The compound pot also has an end wall 100, which caps the first end 87 of the wall 79. The end wall seals the first end apart from orifices 101 for the cores 110. The end wall 100 is removable and clips onto the wall 79, to allow for a plurality of different end walls (e.g. alternative end wall 102 which has only two orifices 101, rather than the three orifices 101 of the end wall 100) to be placed onto the wall 79. Thus, this allows an installer to create an appropriate compound pot 19 dependent on the number and/or size of the cores 110.

[0084] In an alternative embodiment, the end wall can be formed from a settable material, which is pressed and/or moulded around each core 110.

[0085] In use, the pot 19 is provided in the first body part 25, and the cable is passed through component parts of the gland 1, without screwing the body portions 25, 27 together. The first part can be removed or slid out of the way for the time being.

[0086] A settable sealing material (not shown) is injected into the pot 19 as shown in FIG. 4, and allowed to set to form a plug. This is done using two hollow needles, each of which are used to puncture the wall 79 to as to access the void 106 within the compound put. First needle 103 is connected to a syringe 105 full of the settable sealing material. Pumping the syringe 105 causes the settable sealing material to flow through the first needle 103 into the void 106 (and around the cores) formed within the pot 19. The second needle allows air that was otherwise in the void 106 to escape through exhaust port 107. Thus, the sealable setting material can flow around the cores to fill the void and seal against spigot 55.

[0087] As such, unlike the compound pot described in our earlier PCT patent application PCT/GB2019/051382, the filling can occur with the compound pot in any orientation; the end wall 100 will prevent the settable sealing material from leaking out. The transparent material of the compound pot allows visual inspection to ensure that the sealable setting material fills the void 106, leaving no voids remaining, so the pot is properly filled and the plug is properly formed around the cable 5. The pot 19 is then slid back into the first body part 25.

[0088] When the first and second body part 25, 27 are screwed together, the pot 19 and plug are compressed. Even under compression, at the ledge 81 in the compound pot 19 is spaced from the step 85 in the inner surface 75 of the first body member 25, to ensure that the tapered regions 95, 97 engage, rather than the ledge 81 and step 85. Therefore, a seal is formed between the pot 19, and the inner surface 59 of the first body member 25, along the length of the tapered region 95, 97.

[0089] The invention has application including but not limited to [0090] Gland assemblies for armoured electric cable or fibre optic cable or pipes or conduits; [0091] Gland assemblies for non-armoured electric cable or fibre optic cable or pipes or conduits; [0092] Barrier gland assemblies for electric cable or fibre optic cable or pipes or conduits; and [0093] Non-barrier gland assemblies for electric or fibre optic cable or pipes or conduits.

[0094] While the invention has been described with reference to exemplary embodiments, it will be understood that we do not intend the invention to be limited thereto and that various modifications and changes may be made without departing from the principles and concepts of the invention.

[0095] Other modifications and changes that can be made without departing from the principles and concepts described herein will be apparent to those skilled in the art and are covered herein.

[0096] It will also be understood that the invention extends to and includes any novel feature or combination of novel features described herein.