Cable gland

Abstract

The invention relates to a cable gland (A) for mounting cables on a housing. The cable gland (A) comprises a lower body (2) made of electrically conductive material which can be fixed to the housing, an insert (3) made of electrically conductive material, which can be connected to the lower body (2), an upper body (4) made of electrically insulating material which protects the insert (3) against corrosion, a first part (5) can be connected to the distal end of the upper body (4), which provides protection against ingress of dust and liquids. Furthermore, the cable gland (A) comprises at least one locking edge (10) is provided in the insert (3), which has at least one first element (11) at its end, at least one second element (12) is provided in the upper body (4) to which at least one first element (11) is connected, thereby locking the insert (3) and the upper body (4), and preventing the insert (3) from moving independently of the upper body (4).

Description

[0001] CABLE GLAND

[0002] Technical Field

[0003] The invention relates to cable glands for mounting cables on a housing.

[0004] In particular, the invention relates to cable glands that resist corrosion and provide the mounting of armored cables on a housing.

[0005] Background of the Invention

[0006] Cable glands are widely used at termination and junction points in electrical systems where armored cables are used. Cable glands provide sealing and mechanical and / or electrical connection between the cable and the housing. Cable gland design has to meet national and international standards which constrain the choice of a number of parameters. Thus, it is necessary for cable glands to meet torque and sealing performance standards, as well as to provide the necessary earthing performance. Metal cable glands are preferred to ensure the desired performances.

[0007] GB666004A, GB825020A, and GB872376A disclose cable glands made of metal for armored cables. On the other hand, metal cable glands are not suitable for use in corrosive environments. Corrosive liquids and gases in the environment cause corrosion of metal surfaces and reduce electrical conductivity.

[0008] Plastic cable glands can be used in some cases for economy, to reduce component weight, and to avoid corrosion. However, their mechanical properties are relatively poor and they cannot be used to make electrical connections in armored cables. For this reason, some solutions are provided in the state of the art to protect metal cable glands from the effects of corrosion.

[0009] GB849235A discloses a flexible shroud made of plastic material that surrounds the cable gland. This protects the metal cable gland and cable armor from corrosion. The service life of shrouds is limited and relatively short compared to the lifetime of the system in which the cable gland is installed. In order to maintain effective corrosion protection, the shrouds must be periodically replaced. Since the cable gland must be disassembled and reassembled during the replacement process, the electrical connection of the system must also be disconnected. Therefore, the shroud replacement process includes material, labor, and system downtime costs. Also, such shrouds can easily be cut, dislodged, vandalized, or otherwise tampered with.

[0010] GB1228743A discloses a cable gland made from materials that are both electrically insulating and electrically conductive. There are some advantages of the cable gland which consists of insulating and conductive parts. The cable gland is more cost- effective than the equivalent metal cable gland. The cable gland has better corrosion resistance as the parts in contact with the external environment are made of plastic.

[0011] The metal-plastic hybrid parts of the cable gland are connected to each other using methods such as threaded fitting, over-molding, or adhesive bonding. When metal and plastic parts are connected with threaded fitting, the sealing performance of the cable gland is reduced. The manufacturing tolerances of metal and plastic parts and their reactions to changes in the surrounding conditions are different for these reasons dust and liquid can ingress the cable gland through the threads. The over-molding is both a difficult and expensive process. The adhesive bonding increases the assembly time and the results vary depending on the skill of the operator.

[0012] As a result, it has become necessary to make an improvement in the relevant technical field due to the above-mentioned negativities and the inadequacy of the existing solutions in solving the problem.

[0013] Purpose of the Invention

[0014] The invention has been inspired by the present situations and purposes to solve the aforementioned disadvantages.

[0015] The main purpose of the invention is to provide a cable gland which is resistant to corrosion and can be used for armored cables. The parts of the cable gland in contact with the external environment are made of plastic. The parts of the cable gland in contact with the cable armor are made of metal to ensure that the cable armor is earthed.

[0016] Another purpose of the invention is to provide a simplified and more easily manufactured cable gland. It aims to provide solutions to the problems encountered with other methods by connecting plastic and metal parts with snap-fit. Another purpose of the invention is to provide an easy to assemble cable gland. The insert has at least one locking edge. At least one first element at the end of the locking edge is connected to at least one second element in the upper body. Thus, the insert is locked to the upper body, and the insert does not move independently of the upper body. The upper body and the insert work together as a single piece. Once the insert and upper body are locked, they cannot be separated from each other.

[0017] In order to fulfill the purposes described above, the invention is a cable gland for use in the mounting of cables on a housing, comprising; a lower body made of electrically conductive material which can be fixed to the housing, an insert made of electrically conductive material, which can be connected to the lower body, an upper body made of electrically insulating material which protects the insert against corrosion, a first part can be connected to the distal end of the upper body, which provides protection against ingress of dust and liquids, further comprising; at least one locking edge is provided in the insert, which has at least one first element at its end, at least one second element is provided in the upper body to which at least one first element is connected, thereby locking the insert and the upper body, and preventing the insert from moving independently of the upper body.

[0018] The structural and characteristic features of the invention and all its advantages will be understood more clearly thanks to the figures provided below and the detailed explanations given by reference to these figures and detailed explanations into account.

[0019] Brief Description of Figures

[0020] Figure 1 : is exploded view of the cable gland.

[0021] Figure 2: is a half cross sectional view of the cable gland.

[0022] Description of Part References

[0023] A. Cable gland

[0024] 1. Cable feedthrough axis

[0025] 2. Lower body

[0026] 3. Insert 4. Upper body

[0027] 5. First part

[0028] 6. Second part

[0029] 7. Grounding cone

[0030] 8. Clamping ring

[0031] 9. Sealing element

[0032] 10. Locking edge

[0033] 11. First element

[0034] 12. Second ridge

[0035] 13. Shoulder

[0036] 14. End face

[0037] 15. Guiding protrusion

[0038] 16. First groove

[0039] 17. Second groove

[0040] 18. First rib

[0041] 19. Second rib

[0042] Detailed Description of the Invention

[0043] In this detailed description, preferred embodiments of the cable gland (A) subject to the invention are explained only for a better understanding of the subject.

[0044] Referring to Figure 1 , the cable gland (A) according to the invention generally comprises a lower body (2) fixing to a housing, an insert (3) connecting to the lower body (2), an upper body (4) protecting the insert (3) against corrosion, a first part (5) connected to the distal end of the upper body (4) and assisting in sealing protection, and a second part (6) connected to the proximal end of the upper body (4) and protecting the lower body (2) against corrosion. The cable gland (A) also comprises at least one grounding cone (7) and at least one clamping ring (8) to compress the armor of the cable.

[0045] The lower body (2) is made of electrically conductive material. In preferred embodiments of the invention, the lower body (2) is made of metal or alloy. At least one sealing element (9) is placed in the lower body (2) to provide sealing protection.

[0046] The insert (3) is made of electrically conductive material. In preferred embodiments of the invention, the insert (3) is made of metal or alloy. The insert (3) is connected to the lower body (2). In preferred embodiments of the invention, the insert (3) is connected to the lower body (2) by threaded engagement. The grounding cone (7) and the clamping ring (8) are placed in the insert (3). The grounding cone (7) and clamping ring (8) are also made of metal or alloy. Thus, while mechanically compressing the cable armor, they also provide an electrical connection. The current on the cable armor passes through the grounding cone (7) and the clamping ring (8) to the insert (3) and then to the lower body (2) respectively. If the lower body (2) is fixed to a metal housing and the housing is earthed, the current is conducted to earth via this path. If the lower body (2) is fixed to an insulating housing, the lower body (2) is earthed by means of an earthing element, and the current is conducted to earth.

[0047] Referring to Figure 2, the insert (3) is locked to the upper body (4) and works as a single piece. The insert (3) has at least one locking edge (10). The locking edge (10) ensures that the insert (3) is locked to the upper body (4). At least one first element (11) is provided at the end of the locking edge (10). The first element (11) is connected to at least one second element (12) in the upper body (4). Thus, the insert (3) is locked to the upper body (4), and the insert (3) does not move independently of the upper body (4). The upper body (4) has at least one guide protrusion (15). The guide protrusion (15) prevents the insert (3) from rotating around the cable feedthrough axis (1) independently of the upper body (4). At least one shoulder (13) on the insert (3) abuts at least one end face (14) of the upper body (4). Therefore, the movement of the upper body (4) is transferred to the insert (3). The upper body (4) is torqued with a tool to fix the cable, and simultaneously the insert (3) moves with the upper body (4). Therefore, the insert (3) is fixed to the lower body (2). Additionally, this allows the clamping ring (8) to move forward in the direction of the cable feedthrough axis (1) and to clamp the cable armor. Upper body (4) is made of plastic material. Thus, the upper body (4) protects the insert (3), the grounding cone (7) and the clamping ring (8) against corrosion. The upper body (4) also provides electrical insulation.

[0048] The first part (5) is connected to the distal end of the upper body (4). The distal end of the upper body (4) defines the part of the upper body (4) that is far from the housing when the cable gland (A) is mounted on the housing. The first part (5) has at least one first rib (18). The first rib (18) engages in at least one first groove (16) which is located at the distal end of the upper body (4) to the housing. Therefore, the first part (5) is connected to the upper body (4). The first part (5) protects the cable gland (A) and the housing against dust and liquid ingress. The first part (5) is preferably made of elastomer material. Therefore, cables of different diameters can be mounted in the cable gland (A). In alternative embodiments of the invention, the first part (5) may be made of plastic and may be in the form of a gland nut.

[0049] The second part (6) is connected to the proximal end of the upper body (4). The proximal end of the upper body (4) defines the part of the upper body (4) that is near the housing when the cable gland (A) is mounted on the housing. The second part (6) protects the lower body (2) from the effects of corrosion. On the other hand, the second part (6) assists in ensuring sealing protection. The second part (6) has at least one second rib (19). The second rib (19) engages in at least one second groove (17) which is located at the proximal end of the upper body (4). The second part (6) is preferably made of elastomer or plastic material. In preferred embodiments of the invention, the second part (6) has a bellows structure. Therefore, the second part (6) can expand or fold depending on the cable diameter while the cable gland (A) is mounted.

Claims

CLAIMS1. A cable gland (A) for use in the mounting of cables on a housing, comprising;- a lower body (2) made of electrically conductive material which can be fixed to the housing,- an insert (3) made of electrically conductive material, which can be connected to the lower body (2),- an upper body (4) made of electrically insulating material which protects the insert (3) against corrosion,- a first part (5) can be connected to the distal end of the upper body (4), which provides protection against ingress of dust and liquids, characterized in that- at least one locking edge (10) is provided in the insert (3), which has at least one first element (11) at its end,- at least one second element (12) is provided in the upper body (4) to which at least one first element (11) is connected, thereby locking the insert (3) and the upper body (4), and preventing the insert (3) from moving independently of the upper body (4).

2. A cable gland (A) according to claim 1 , characterized in that it comprises a second part (6) which can be connected to the proximal end of the upper body (4) and protects the lower body (2) against corrosion.

3. A cable gland (A) according to claim 1 , characterized in that it comprises at least one guiding protrusion (15) which is provided in the upper body (4) and prevents the insert (3) from rotating about the cable feedthrough axis (1) independently of the upper body (4).

4. A cable gland (A) according to claim 1 , characterized in that it comprises at least one first rib (18) which is provided on the first part (5), and engages in at least one first groove (16) located at a distal end of the upper body (4), thereby enabling the first part (5) to be connected to the upper body (4).

5. A cable gland (A) according to claim 1 or claim 2, characterized in that it comprises at least one second rib (19) which is provided on the second part (6), and engages in at least one second groove (17) located at the proximal end of the upper body (4), thereby enabling the second part (6) to be connected to the upper body (4).

6. A cable gland (A) according to claim 1 , characterized in that it comprises a grounding cone (7) and a clamping ring (8) which are placed in the insert (3) and provide compression of the armor of the cable.

7. A cable gland (A) according to claim 1, characterized in that it comprises at least one shoulder (13) which is provided on the insert (3) and allows the movement of the upper body (4) to be transferred to the insert (3) by abutting at least one end face (14) of the upper body (4), thereby enabling the insert (3) to be connected to the lower body (2).

8. A cable gland (A) according to claim 1 , characterized in that it comprises at least one sealing element (9) which can be inserted into the lower body (2) and provides sealing protection.

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