DESC:FIELD OF THE INVENTION

[001] The present invention relates to electrical cable glands and more particularly to armored cable glands.

BACKGROUND OF THE INVENTION

[002] Cable glands are commonly used to attach and secure the end of an electrical cable to an electrical equipment by passing through the wall of the electrical equipment enclosure. Cable gland also seals cable entries to junction boxes for increased safety, particularly in hazardous environments, and provide a leak proof path to prevent the ingress of moisture and dirt into the interior of the electrical equipment from outside.

[003] Cable glands are mechanical cable entry devices used throughout a number of industries in conjunction with cable and wiring in electrical instrumentation and automation systems. Cable glands may be used on all types of electrical power, control, instrumentation, data and telecommunications cables. They are used as a sealing and termination device to ensure that the characteristics of the enclosure which the cable enters can be maintained adequately. Cable glands are made of various materials including plastics, steel, brass or aluminum.

[004] An armored cable is an assembly of multiple stranded conductors in an extruded core of moisture resistant, flame resistant non-metallic material, covered with an overlapping metal armor and jacketed with an extruded non-metallic material that is resistant to destructive environmental conditions. The armor is usually made of interlocking or continuous aluminum or stainless steel, or a metal tape. It should also be noted that the wire shield consists of suitably wrapped grounding conductors. Such cable, because of the double jacketing and the grounding conductors situated between the two jackets, provides more mechanical protection to the conductors which are located at the cable core, in addition to providing a low impedance electrical path for ground fault currents.

[005] The use of armored cables with an elastomer sheath covering is nowadays common in the electrical industry where there is a need to withstand harsh environmental conditions. These cable needs special connectors to provide the connection between the cable and the equipment enclosure.

[006] The cable glands for the armored cable referred herein as armored cable glands help to assemble the armored cable and fit to ensure electrical continuity for grounding between the sheathing the electrical equipment at which the cable terminates.

[007] Currently available cable glands includes a main body with a cone and a cone ring which is used to grab the armor. The cone is housed inside the main body along with a sealing member, holding the entire assembly of cable gland. In total, around seven individual components of a cable gland come together to do the anchoring and sealing for ingress protection.

[008] More number of components increase the cost and complexity in installation of the cable gland. So it is better to have few components which can be installed and manufactured easily. Additionally, a significant portion of the total cost of the gland is that of the material and hence reducing the number of components may lead to cost reduction of the gland. The cables are made to different sizes with different numbers of conductor cores, and cable glands have to be made to a range of different sizes.

[009] In view of the limitations inherent in the available armored cable glands, there exists a need for an improved armored cable gland, which overcomes the disadvantages of the prior art and which can be used in a simple, cost effective, reliable, secure and environmental friendly manner.

[0010] The present invention fulfils this need and provides further advantages as described in the following summary.

SUMMARY OF THE INVENTION

[0011] In view of the foregoing disadvantages inherent in the prior arts, the general purpose of the present invention is to provide an improved combination of convenience and utility, to include the advantages of the prior art, and to overcome the drawbacks inherent therein.

[0012] A primary objective of the present invention is to provide a marine anti-fouling device for removing marine growth from offshore platform structures which is simple, easy to install and cost effective.

[0013] In one aspect, the present invention provides a cable gland assembly for mounting a cable having a core, an armor and an outer cover on an enclosure wall having an hole. The cable gland assembly includes a collet having a double walled structure and a plurality of longitudinal slots with a conical side and a cylindrical side, the collet is adapted to hold the armor of the cable, a collet holder to contain the collet inside it, the collet holder comprises a hollow cylindrical structure with threads on its outer surface and a hexagonal collar wherein the hexagonal collar divides the cylindrical structure into a first portion and a second portion, a lock nut having internal threads adapted to engage with the outer threads of the first portion of the collet holder and mount the collet holder in the hole of the enclosure wall, an end nut having a cylindrical structure with internal threads adapted to engage with the external threads of the second portion of the collet holder and contain the collet inside the collet holder and the end nut, a seal disposed adjacent to the cylindrical side of the collet for preventing any leakage of liquid and gas across the enclosure wall through the cable gland assembly and a seal compressor disposed inside the end nut to abut against the seal and compress the seal when the end nut is tightened to engage with the collet holder.

[0014] In another aspect of the present invention, the cable core passes through the collet and the collet electrically connects the armor to a ground potential when the cable is installed.

[0015] In one aspect of the present invention, the plurality of longitudinal slots including a first set of slots and a second set of slots adjacent located on the collet.

[0016] In another aspect of the present invention, the first set of slots extend from an edge of the cylindrical side to an edge of the conical side of the collet, such that each of the slots of the first set is open at the cylindrical side and closed at the conical side.

[0017] In yet another aspect of the present invention, the second set of slots extend from an edge of the conical side to an edge of the cylindrical side of the collet, such that each of the slots of the second set is open at the conical side and closed at the cylindrical side.

[0018] In a further aspect of the present invention, the core passes through the collet holder such that when the cable gland is installed, the first portion and the second portion are located inside and outside of the enclosure wall respectively.

[0019] In another aspect of the present invention, the collet holder further includes a taper inside it, the taper is adapted to squeeze the conical side of the collet to move the collet axially inside the collet holder. The inside taper is adapted to allow the conical side of the collet to move inside and then stop after some predefined distance of insertion is achieved.

[0020] In yet another aspect of the present invention, the seal consists of a hollow cylindrical structure with two walls at its ends radially extending above the diameter of the cylindrical structure, such that when the seal is compressed along the axial direction the two walls come closer to seal the cable gland assembly.

[0021] In a further aspect of the present invention, the seal compressor consists of a cylindrical structure with a protruded ring at one end and the end nut further includes an inner flange to abut against the protruded ring to push the seal compressor inside when the end nut is rotated.

[0022] In another aspect of the present invention, wherein the seal is compressed between the collet and the seal compressor when the end nut is rotated.

[0023] These together with other aspects of the invention, along with the various features of novelty that characterize the invention, are pointed out with particularity in the description annexed hereto and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be made to the accompanying drawings and descriptive matter in which there are illustrated exemplary embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The advantages and features of the present invention will become better understood with reference to the following more detailed description taken in conjunction with the accompanying drawings in which:

[0025] FIG. 1 illustrates an exploded view of the armored cable gland showing different components, according to one embodiment of the present invention;

[0026] FIG. 2A illustrates a schematic view of the collet from conical side, according to one embodiment of the present invention;

[0027] FIG. 2B illustrates a schematic view of the collet from cylindrical side, according to one embodiment of the present invention;

[0028] FIG. 3 illustrates a cross sectional view of the assembled armored cable gland, according to one embodiment of the present invention; and

[0029] FIG. 4 illustrates a cross sectional view of the assembled armored cable gland with cable, according to one embodiment of the present invention.

[0030] Like reference numerals refer to like parts throughout the several views of the drawings.

DETAILED DESCRIPTION OF THE DRAWINGS

[0031] In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without these specific details.

[0032] As used herein, the term ‘plurality’ refers to the presence of more than one of the referenced item and the terms ‘a’, ‘an’, and ‘at least’ do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.

[0033] Reference herein to “one embodiment” or “another embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Further, the diagrams representing one or more embodiments of the invention do not inherently indicate any particular order nor imply any limitations in the invention.

[0034] The terms “enclosure” or “electrical enclosure” or “electrical equipment enclosure” or “equipment enclosure” are interchangeably used in the present description and both mean enclosure of any electrical equipment such as distribution box. The term ‘cable gland’ or ‘armored cable gland’ or ‘cable gland assembly’ have been interchangeably used in the present description and refers to the same component.

[0035] Referring to FIG. 1 that illustrates an exploded view of the armored cable gland assembly 10 showing different components, according to one embodiment of the present invention. The cable gland assembly 10 is for mounting a cable 12 (shown in FIG.4) having a core 14, an armor 16 and an outer cover 18 on an enclosure wall (not shown) having a hole. The cable gland assembly 10 comprises a collet 20 adapted to hold the armor 16 of the cable, a collet holder 30 to contain the collet 20 inside it, the collet holder 30 comprises a hollow cylindrical structure with threads on its outer surface and a hexagonal collar 32 wherein the hexagonal collar divides the cylindrical structure into a first portion 34 and a second portion 36, a lock nut 40 having internal threads adapted to engage with the outer threads of the first portion 34 of the collet holder and mount the collet holder 30 in the hole of the enclosure wall, an end nut 42 having a cylindrical structure with internal threads adapted to engage with the external threads of the second portion 36 of the collet holder and contain the collet 20 inside the collet holder 30 and the end nut 42, a seal 44 disposed adjacent to the collet 20 for preventing any leakage of liquid and gas across the enclosure wall through the cable gland assembly 10 and a seal compressor 46 disposed inside the end nut 42 to abut against the seal 44 and compress the seal 44 when the end nut 42 is tightened to engage with the collet holder 30.

[0036] The core 14 of the cable passes through the collet holder 30 such that when the cable gland assembly is installed on the wall of the enclosure, the first portion 34 engages with the lock nut 40 with threads and is located inside the enclosure while the second portion 36 connects with the end nut 42 with threads and is located outside the enclosure wall. This connection of the lock nut 40 and the collet holder 30 mounts the whole cable gland assembly 10 on the enclosure wall and all other components connect over this connection. The inner and outer diameters of the collet holder 30 are designed as per the diameter of the cable and the hole for cable gland in the enclosure wall respectively.

[0037] The lock nut 40 is hexagonal nut with inner threads such that the inner threads engage with the outer threads of the first portion 34 of the collet holder to form a joint. The lock nut 40 and the collet holder 30 are placed on inner and outer sides respectively of the enclosure wall and the lock nut 40 is rotated to mount the collet holder 30 on the enclosure wall.

[0038] Referring to FIGs. 2A and 2B that illustrate schematic views of the collet 20 from conical side and cylindrical side respectively, according to one embodiment of the present invention. The collet 20 consist of a double walled structure and a plurality of longitudinal slots 22. The collet includes a conical side 24 and a cylindrical side 26. The double walled structure of the collet 20 includes an inner wall and an outer wall. In one embodiment the double walls of the collet 20 are radially separated by a predefined gap. The two walls are connected and converge at the end of the conical side 24 of the collet. In one embodiment of the present invention, the cable core 14 passes through the collet 20 and the collet electrically connects the armor 16 to a ground potential when the cable 12 is installed.

[0039] The plurality of longitudinal slots 22 extend along the axis of the collet 20 which are through both the walls of the collet. In one embodiment the plurality of slots 22 are divided into including a first set 22F of slots and a second set 22S of slots adjacently located on the collet 20. The first set 22F of slots extend from an edge of the cylindrical side 26 to an edge of the conical side 24 of the collet, such that each of the slots of the first set 22F is open at the cylindrical side 26 and closed at the conical side 24. Similarly the second set 22S of slots extend from an edge of the conical side 24 to an edge of the cylindrical side 26 of the collet, such that each of the slots of the second set 22S is open at the conical side 24 and closed at the cylindrical side 26 of the collet.

[0040] The gap between the inner and the outer wall of the collet 20 and the plurality of slots 22 forms a slotted cavity. When the cable 12 is to be installed, the outer cover 18 is peeled and the armor 16 which is in the form of multiple strips of metal is inserted in the slotted cavity and the soft core 14 of the cable passes through the inner wall of the collet 20 as shown in FIG. 4. The plurality of slots 22 and the double wall construction provides the collet 20 enough flexibility which allows radial movement of collet 20 to change its internal diameter and provide strong clamping force on the cable core 14 when the end nut 42 is tightened to squeeze the collet.

[0041] During installation of an armored cable 12, the cable is prepared by peeling off different insulations like outer cover 18 such that the conductor cores can be connected to the terminals of the electrical equipment and the armor 16 is connected to the wall of the enclosure for grounding. The armor 16 consists of a number metallic strips which are to be electrically connected to the ground. During installation of the cable gland assembly on the enclosure wall with the cable, the conical side 24 of the collet is inside the collet holder 30 and the cylindrical side 26 of the collet is inside the end nut 42.

[0042] In one embodiment of the present invention, the collet holder 30 further includes a taper (not shown) inside it, the taper is adapted to squeeze the conical side 24 of the collet to move the collet 20 axially inside the collet holder 30 when pushed from behind by the rotation of end nut 42. The collet holder 30 and the end nut 42 form a telescopic arrangement with threaded joint to squeeze the collet 20 inside them.

[0043] In one embodiment of the present invention, the seal 44 consists of a hollow cylindrical structure with two walls at its ends radially extending above the diameter of the cylindrical structure, such that when the seal 44 is compressed along the axial direction the two walls come closer to seal the cable gland assembly 10. The seal 44 is disposed adjacent to the cylindrical side 26 of the collet between the collet 20 and the seal compressor 46 and the seal 44 is compressed between the collet 20 and the seal compressor 46 when the end nut 42 is rotated.

[0044] In one preferred embodiment of present invention, the seal 44 is a gasket type of compression seal / displacement type seal. In one preferred embodiment of present invention, the seal 44 may be made of elastomer or similar material with a compression set 10% +/- 5% and hardness of 65 +/- 10 shore oA.

[0045] In one embodiment of the present invention, the seal compressor 46 consists of a hollow cylindrical structure with a protruded ring at one end. The function of the seal compressor 46 is to hold the seal 44 and apply axial compression force on the seal 44 when the end nut 42 is rotated.

[0046] The end nut 42 is a cylindrical structure with inner threads which are adapted to engage with the outer threads of the collet holder 30. The end nut 42 further includes a hexagonal collar 50 to provide a grip to rotate the end nut. In one embodiment of the present invention, the end nut 42 further includes an inner flange (not shown) to abut against the protruded ring of the seal compressor 46 to push the seal compressor 46 inside when the end nut 42 is rotated.

[0047] Now referring to FIGs.3 and 4 that illustrate cross sectional views of the assembled armored cable gland assembly 10 and assembled armored cable gland assembly 10 with cable 12 respectively, according to one embodiment of the present invention. For installation of the cable gland assembly 10, first the collet holder 30 is inserted in the hole of the enclosure wall made for the cable gland and the lock nut 40 is tightened over the collet holder 30 from inside of the enclosure wall to fix the collet holder in position on the enclosure. The lock nut 40 is the only component of the cable gland assembly 10 which is located inside the enclosure after the installation.

[0048] The cable 12 as seen in FIG. 4 has a core 14, an armor 16 and an outer cover 18. The core conductors (not shown) in the soft core 14 are connected to the terminals of the electrical equipment. The cable 12 is prepared for installation by cutting and peeling off outer cover 18 at different lengths as per the state of the art.

[0049] The end nut 42 is slipped over the outer cover 18 of the cable and then the seal compressor 46 is also slipped behind the end nut, such that the protruded ring of the seal compressor 46 lies adjacent to the inner flange of the end nut 42. The seal 44 is then slipped over the outer cover 18 to lie adjacent to the seal compressor 46. Next the collet 20 is also slipped over and the multiple strips of the armor 16 are inserted in the slotted cavity of the collet and the soft core 14 is passed through the inner wall of collet 20. Now the collet 20 along with the armor 16 on it is disposed in the collet holder 30 and the soft core 14 of the cable is passed through the collet holder 30 to the inside of the enclosure.

[0050] To complete the installation, the end nut 42 is rotated to engage its inner threads with the outer threads of the collet holder 30. As the end nut 42 is tightened, it pushes the seal compressor 46 axially inside. The axial movement of the seal compressor applies axial force on the seal 44 and eventually to the collet 20, thereby making the collet move axially inside the collet holder 30. As the collet 20 moves inside the collet holder 30, it gets squeezed, due to which it grips the soft core 14 of the cable. The collet is adapted to move till it occupies all the axial space of the inner taper in the collet holder or when the grip over soft core is tight enough to prevent further axial movement of the collet inside the collet holder. The seal 44 gets compressed between the collet 20 and the seal compressor 46 and fills in any nearby space to make the joint water and dust proof.

[0051] The collet 20 can accommodate a range of diameters of the soft core 14 of the cable due to its flexible structure. In case a cable of bigger size is to be installed, then the collet 20 may not move till the end of the inner taper of the collet holder 30 and stops in between.

[0052] The armor 16 is electrically connected to the collet 20 which is made of electrically conducting material. The collet 20 is electrically connected to the collet holder 30, which is further connected to the wall of the enclosure. This arrangement provides the needed ground connection to the armor 16 of the cable.

[0053] Although a particular exemplary embodiment of the invention has been disclosed in detail for illustrative purposes, it will be recognized to those skilled in the art that variations or modifications of the disclosed invention, including the rearrangement in the configurations of the parts, changes in steps and their sequences may be possible. Accordingly, the invention is intended to embrace all such alternatives, modifications and variations as may fall within the spirit and scope of the present invention.

[0054] The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching.

[0055] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the appended description.
,CLAIMS:WE CLAIM:

1. A cable gland assembly (10) for mounting a cable (12) having a core (14), an armor (16) and an outer cover (18) on an enclosure wall having an hole, the cable gland assembly (10) comprising:
- a collet (20) having a double walled structure and a plurality of longitudinal slots (22) with a conical side (24) and a cylindrical side (26), the collet (20) is adapted to hold the armor (16) of the cable;
- a collet holder (30) to contain the collet inside it, the collet holder comprises a hollow cylindrical structure with threads on its outer surface and a hexagonal collar (32) wherein the hexagonal collar divides the cylindrical structure into a first portion (34) and a second portion (36);
- a lock nut (40) having internal threads adapted to engage with the outer threads of the first portion (34) of the collet holder and mount the collet holder (30) in the hole of the enclosure wall;
- an end nut (42) having a cylindrical structure with internal threads adapted to engage with the external threads of the second portion (36) of the collet holder and contain the collet (20) inside the collet holder (30) and the end nut (42);
- a seal (44) disposed adjacent to the cylindrical side (26) of the collet for preventing any leakage of liquid and gas across the enclosure wall through the cable gland assembly; and
- a seal compressor (46) disposed inside the end nut (42) to abut against the seal (44) and compress the seal when the end nut (42) is tightened to engage with the collet holder (30).

2. The cable gland assembly according to claim 1, wherein the cable core (14) passes through the collet (20) and the collet electrically connects the armor (16) to a ground potential when the cable is installed.

3. The cable gland assembly according to claim 1, wherein the double walls of the collet (20) are radially separated by a predefined gap.

4. The cable gland assembly according to claim 1, wherein the plurality of longitudinal slots (22) including a first set (22F) of slots and a second set (22S) of slots adjacently located on the collet (20).

5. The cable gland assembly according to claim 4, wherein the first set (22F) of slots extend from an edge of the cylindrical side (26) to an edge of the conical side (24) of the collet, such that each of the slots of the first set is open at the cylindrical side (26) and closed at the conical side (24).

6. The cable gland assembly according to claim 4, wherein the second set (22S) of slots extend from an edge of the conical side (24) to an edge of the cylindrical side (26) of the collet, such that each of the slots of the second set is open at the conical side (24) and closed at the cylindrical side (26).

7. The cable gland assembly according to claim 1, wherein the core (14) passes through the collet holder (30) such that when the cable gland is installed, the first portion (34) and the second portion (36) are located inside and outside of the enclosure wall respectively.

8. The cable gland assembly according to claim 1, wherein the collet holder (30) further includes a taper inside it, the taper is adapted to squeeze the conical side (24) of the collet to move the collet (20) axially inside the collet holder (30).

9. The cable gland assembly according to claim 1, wherein the seal (44) consists of a hollow cylindrical structure with two walls at its ends radially extending above the diameter of the cylindrical structure, such that when the seal (44) is compressed along the axial direction the two walls come closer to seal the cable gland assembly.

10. The cable gland assembly according to claim 1, wherein the seal (44) is made of elastomer or similar material with a compression set 10% +/- 5% and hardness of 65 +/- 10 shore oA

11. The cable gland assembly according to claim 1, wherein the seal compressor (46) consists of a cylindrical structure with a protruded ring at one end.

12. The cable gland assembly according to claim 11, wherein the end nut (42) further includes an inner flange to abut against the protruded ring to push the seal compressor (46) inside when the end nut (42) is rotated.

13. The cable gland assembly according to claim 1, wherein the end nut (42) further includes a hexagonal collar (50) to provide a grip to rotate the end nut.

14. The cable gland assembly according to claim 1, wherein the seal (44) is compressed between the collet (20) and the seal compressor (46) when the end nut (42) is rotated.