Cable gland

Abstract

The invention relates to the cable gland (A) used for mounting the cables in a housing. The cable gland (A) comprises a hollow tubular gland body (10), which can be connected to a housing, a cap nut (12) with an opening for cable passage, which can be connected to the gland body (10). At least two clamping elements (14) can be arranged between the gland body (10) and the cap nut (12). At least one first sealing element (20) positioned between the clamping elements (14) comprises at least one groove (22).

Description

[0001] CABLE GLAND

[0002] Technical Field

[0003] The invention relates to cable glands that enable cables to be mounted in a housing.

[0004] The invention particularly relates to cable glands that provide high strain relief with low tightening torque.

[0005] Background of the Invention

[0006] Cable glands are used to mount cables in a housing. Cable glands provide sealing and mechanical and / or electrical connection between cable and housing. Cable glands provide their sealing protection by means of sealing elements. Sealing elements also help to provide mechanical properties such as strain relief for cable glands. Cables with diameters suitable for the hole diameter are passed through the holes on the sealing element. While the gland nut is mounted, it compresses the sealing element. Thus, the sealing element grips the cables tightly and provides sealing and strain relief.

[0007] DE1750095A1 and GB1543678A disclose cable glands that provide sealing and strain relief by compressing the sealing element.

[0008] Depending on the hardness of the sealing element, a portion of the force applied to the sealing element is used to compress the sealing element. The remaining part of the force is applied to the sealing element as it grips the cable surface. Therefore, a force is transferred to the cable through the sealing element. This situation causes the phenomenon known as coldflow. Cold flow is the tendency of a material to move and deform over time under mechanical stress. This phenomenon causes permanent deformation in the cable insulation over time and the cable gland loses its function.

[0009] It is desirable that the assembly of the cable gland should be carried out with low tightening torques. Low tightening torques can be achieved by the use of low hardness sealing element and clamping fingers. However, in this case the sealing element may gradually loosen over time, losing its sealing and strain relief properties. Tightening the sealing element and clamping fingers to a high torque with a low hardness value will cause cold flow. Also, high tightening torques are required for high hardness sealing elements and clamping fingers.

[0010] In order to prevent permanent deformation of the cable insulation and to provide high strain relief by applying low tightening torque, the present invention ensures that the tightening torque is evenly distributed over a relatively large surface in the cable insulation.

[0011] 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.

[0012] Purpose of the Invention

[0013] The invention has been inspired by the present situations and purposes to solve the aforementioned disadvantages.

[0014] The purpose of the invention is to prevent permanent deformation in cable insulation. The tightening torque applied in the cable gland of the invention is distributed evenly over a relatively large surface in the cable insulation.

[0015] Another purpose of the invention is to provide high strain relief of the cable gland with low tightening torque. The structures designed in the sealing element allow the cable gland to provide high strain relief.

[0016] In order to fulfill the purposes described above, the invention is a cable gland used for mounting cables to a housing, comprising; a hollow tubular gland body which can be connected to the housing, a cap nut with an opening for cable passage, which can be connected to the gland body, at least two clamping elements can be arranged between the gland body and the cap nut. Furthermore, the cable gland comprises at least one first sealing element can be arranged between the clamping elements and the first sealing element has at least one groove.

[0017] 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. Brief Description of Figures

[0018] Figure 1 : is exploded view of the cable gland.

[0019] Figure 2: is a cross sectional view of the cable gland.

[0020] Description of Part References

[0021] A. Cable gland

[0022] 10. Gland body

[0023] 12. Cap nut

[0024] 14. Clamping element

[0025] 16. Clamping finger

[0026] 18. Clamping recess

[0027] 20. First sealing element

[0028] 22. Groove

[0029] 24. Second sealing element

[0030] 26. O-ring

[0031] Detailed Description of the Invention

[0032] 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.

[0033] Referring to Figure 1, the cable gland (A) of the invention comprises a gland body (10) fixed to a housing, a cap nut (12) connected to the gland body (10), at least two clamping elements (14) arranged between the gland body (10) and the cap nut (12), and at least one first sealing element (20) arranged between the clamping elements (14). In preferred embodiments of the invention, the gland body (10) can be fixed to an opening on the housing by threaded connection, snap-fit or other connection methods known in the art. The gland body (10) can be made of metal, plastic or metal-plastic hybrid material. The gland body (10) is in the form of a hollow tube. This allows the clamping element (14) and the first sealing element (20) to be located within the gland body (10).

[0034] The cap nut (12) has an opening for cable passage. In one embodiment of the invention, the cap nut (12) is connected to the external threads on the gland body (10) via its internal threads. The cap nut (12) can be made of metal, plastic or metal-plastic hybrid material.

[0035] Referring to Figure 2, the clamping element (14) is placed between the gland body (10) and the cap nut (12). The clamping element (14) is preferably made of plastic material. In alternative embodiments of the invention, the clamping element (14) may be made of metal or metal-plastic hybrid material. There are at least two clamping elements (14) in the cable gland (A) of the invention. There is at least one clamping finger (16) and at least one clamping recess (18) in the clamping element (14). When the clamping elements (14) are placed in the cable gland (A), a clamping finger (16) on one clamping element (14) comes across a clamping recess (18) on the other clamping element (14). The surface of the clamping fingers (16) in contact with the first sealing element (20) has an inclined structure.

[0036] The first sealing element (20) provides sealing protection for the cable gland (A). The first sealing element (20), which is compressed by the clamping element (14), also provides strain relief to the cable gland (A). The outer surface of the first sealing element (20) has an inclined structure. The sealing element (20) comprises at least one groove (22). The groove (22) ensures that most of the force applied on the sealing element (20) is used to grip the cable. Thus, high strain relief can be achieved with low tightening torque. Table 1 shows the comparative test results of the cable gland (A) with a sealing element (20) without a groove (22) and the cable gland (A) with a sealing element (20) with at least one groove (22). The cables of the appropriate diameter are mounted to the cable glands (A) of the dimensions selected for the test, with the appropriate tightening torque. The marking is made on the part of the cable that is mounted on the cable gland (A) outside of the cable gland cover (12). The test is carried out using the tensile test mechanism defined in the I EC 62444:2010 standard. In the test, increasing tensile force is applied to the cable and the test is stopped when the marking moves. When the test is stopped, the value read in the test apparatus corresponds to the tensile strength of the cable gland.

[0037] Table 1: Strain relief comparison

[0038] In the preferred applications of the invention, the groove (22) of the first sealing element (20) can exist solely on the inner surface, solely on the outer surface, or on both the inner and outer surfaces.

[0039] In preferred embodiments of the invention, at least one second sealing element (24) is placed inside the first sealing element (20). The second sealing element (24) enables the cable gland (A) to tighten cables with relatively small diameters.

[0040] In preferred embodiments of the invention, at least one o-ring (26) is placed on the gland body (10). O-ring (26) provides sealing protection between the gland body (10) and the housing. When the tightening torque is applied to the cap nut (12), the clamping fingers (16) move forward into the opposite clamping recess (18). This movement compresses the first sealing element (20) and ensures that it grips the cable. Thus, the cable gland (A) provides sealing protection and strain relief.

Claims

CLAIMS1. A cable gland (A) for a cable assembly, comprising; a hollow tubular gland body (10), which can be connected to a housing, a cap nut (12) with an opening for cable passage, which can be connected to the gland body (10), at least two clamping elements (14) can be arranged between the gland body (10) and the cap nut (12), at least one first sealing element (20) can be arranged between the clamping elements (14) characterized in that the sealing element (14) comprises at least one groove (22).

2. A cable gland (A) according to claim 1, characterized in that the outer surface of th first sealing element (20) has an inclined structure.

3. A cable gland (A) according to claim 1 , characterized in that it comprises at least one second sealing element (24) is placed inside the first sealing element (20).

4. A cable gland (A) according to claim 1 , characterized in that the clamping element (14) has at least one clamping finger (16).

5. A cable gland (A) according to claim 1 or claim 4, characterized in that the surface of the clamping fingers (16) in contact with the first sealing element (20) has an inclined structure.

6. A cable gland (A) according to claim 1 characterized in that the clamping element (14) has at least one clamping recess (18).

7. A cable gland (A) according to claim 1 characterized in that it comprises at least one O-ring (26) can be placed on the gland body (10) and providing sealing protection between the gland body (10) and the housing.

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