Patent ID: 12237657

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.

FIGS.1A to1Cillustrate an example of a cable gland1according to an embodiment of the invention.FIG.1Aillustrates the cable gland1in assembled form, without a cable, in sectional side view, andFIG.1Billustrates the cable gland1in exploded view.FIG.1Cillustrates the cable gland1, in assembled form, with a cable3passing through it. The cable3typically includes a number of conducting cores110(shown inFIG.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.

The cable gland1includes a body5formed by an annular wall7. The wall7defines a passage9extending through the body5in an axial direction A. The passage9extends from a first end11of the body5to a second end13. Adjacent the first end11, an external flange15is formed on the body for mounting the cable gland1to a wall, bulkhead or housing (not shown) through which the cable3is passing. In use, the first end11of the cable gland1is provided through an opening in the bulkhead, and the second end13is in an external environment.

Within the passage9, near the first end11, a sleeve-like sealing member17is formed in a compound pot19. Also within the passage9is a clamp21for gripping on to the external insulation cover of the cable3. The clamp21is provided between the compound pot19, and the second end13. At the second end13, an ingress prevention seal23is provided over the opening of the passage9. Further explosion protection seals (not shown) may also be received in the passage9, and an external rubber seal is provided on the outside of the body5. The compound pot19, clamp21and ingress prevention seal23will be discussed in further detail below.

The body5is formed of a first part25and a second part27. Each of the parts25,27forms an axial portion of the body5, such that each of the parts25,27extends around the circumference of the passage9, and along a portion of the length.

The first body part25, also referred to as the entry, incorporates the first end11and the external flange15, and receives the compound pot19. Between the first end11and the external flange15, the first body part25includes a cylindrical portion29. This may include a screw thread or the like31for receiving a nut to secure the gland to the bulkhead through which the cable passes.

The first body part25tapers outward, away from the first end11, after the flange15. A further cylindrical section33is provided opposite the first end11of the body5. In the assembled gland1, the further cylindrical section33is received within the second body part27.FIG.2illustrates the region where the first body part25extends into the second27.

A first region35of the further cylindrical section33, adjacent the taper, includes a first screw thread37. The width of the first region35is such that the first screw thread37engages with a corresponding screw thread41on the inner surface39of the second portion27, to join the body parts25,27together. Tightening the screw thread applies compression between the first end11and the second end13.

A second region43of the further cylindrical section33, at the end of the first body part25opposite the first end11, is of narrower diameter than the first region35. The second region43includes an external screw thread45to secure a spigot retaining nut47to the end of the first body part25. The spigot retaining nut47extends axially, to continue the second region43of the further cylindrical section33.

On a first axial face49of the spigot retaining nut47, at which the spigot retaining nut47joins the first body portion25, a radially extending ledge51is formed, extending into the passage9. The ledge51forms a seat for an armour clamp53arranged to grip the earth shielding of the cable, and electrically couple the earth shielding to the body5of the gland1.

A spigot (or annular retaining member)55is located between a ledge57formed in the inner surface59of the first body part25, and the end of the armour clamp53. The spigot55includes grooves61formed on the tapered surface extending inside the armour clamp53, and an annular rim63which engages the ledge57in the first body part25, and extends radially inward to form a seat for the compound pot19. The spigot55is retained in place by the ledge57on one face, and the armour clamp53and retaining nut47on the other face.

The second axial face65of the spigot retaining nut47forms a seat for the clamp21, as will be discussed in more detail below. The cable3is passed through the spigot retaining nut47, armour clamp53and spigot55. The earthing shield (not shown) is gripped by the armour clamp, in co-operation with the grooves61on the surface of the spigot55.

The second body part27forms a back nut of the cable gland1. The clamp21is received within the part of the passage9formed by the back nut27. The second body part27includes an annular ledge67extending across the second end13. An annular ring69is provided within the passage9, resting on the ledge67, and provides a second seat for the clamp21, such that the clamp21is received between the ring69and the spigot retaining nut47.

FIG.3Aillustrates the region of the compound pot19, in more detail, withFIG.3Bshowing the compound pot19by itself.

The compound pot19is formed of a transparent polymer cylindrical wall79, extending from a first end87to a second end89. The first end87of the wall79is received at the first end of the gland11, and the second end89of the wall is within the passage9.

The wall79has an outer surface71, that engages with an inner surface59of the first body portion25, and an inner surface75that forms a through passage77, through which the cable3extends, in the assembled gland1.

The outer surface71includes a ledge81formed in a rim83at the second end89, which engages with a step85formed in the inner surface75of the first body member25, to retain against the pot19being pulled out in a direction towards the first end11.

A spacing is formed between the ledge81and the step85, along the axial direction A, and, optionally also in a radial direction. The outer surface71is tapered inwards from the rim83to the first end87, to form a tapered region95. The inner surface75of the first body portion25includes a matching tapered portion97.

The inner surface75of the cylindrical wall79includes a cylindrical portion91adjacent the first end87, with a tapered portion93tapering inwards form the second end89to the cylindrical portion91.

The compound pot also has an end wall100, which caps the first end87of the wall79. The end wall seals the first end apart from orifices101for the cores110. The end wall100is removable and clips onto the wall79, to allow for a plurality of different end walls (e.g. alternative end wall102which has only two orifices101, rather than the three orifices101of the end wall100) to be placed onto the wall79. Thus, this allows an installer to create an appropriate compound pot19dependent on the number and/or size of the cores110.

In an alternative embodiment, the end wall can be formed from a settable material, which is pressed and/or moulded around each core110.

In use, the pot19is provided in the first body part25, and the cable is passed through component parts of the gland1, without screwing the body portions25,27together. The first part can be removed or slid out of the way for the time being.

A settable sealing material (not shown) is injected into the pot19as shown inFIG.4and allowed to set to form a plug. This is done using two hollow needles, each of which are used to puncture the wall79to as to access the void106within the compound put. First needle103is connected to a syringe105full of the settable sealing material. Pumping the syringe105causes the settable sealing material to flow through the first needle103into the void106(and around the cores) formed within the pot19. The second needle104allows air that was otherwise in the void106to escape through exhaust port107. Thus, the sealable setting material can flow around the cores to fill the void and seal against spigot55.

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 wall100will 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 void106, leaving no voids remaining, so the pot is properly filled and the plug is properly formed around the cable5. The pot19is then slid back into the first body part25.

When the first and second body part25,27are screwed together, the pot19and plug are compressed. Even under compression, at the ledge81in the compound pot19is spaced from the step85in the inner surface75of the first body member25, to ensure that the tapered regions95,97engage, rather than the ledge81and step85. Therefore, a seal is formed between the pot19, and the inner surface59of the first body member25, along the length of the tapered region95,97.

The invention has application including but not limited toGland assemblies for armoured electric cable or fibre optic cable or pipes or conduits;Gland assemblies for non-armoured electric cable or fibre optic cable or pipes or conduits;Barrier gland assemblies for electric cable or fibre optic cable or pipes or conduits; andNon-barrier gland assemblies for electric or fibre optic cable or pipes or conduits.

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.

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.

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