WO2021211067A1

WO2021211067A1 - A cable gland

Info

Publication number: WO2021211067A1
Application number: PCT/TR2020/050315
Authority: WO
Inventors: Oktay BÜYÜKIKIZ; Fatih Burak TAN
Original assignee: Bi̇med Tekni̇k Aletler Sanayi̇ Ve Ti̇caret Anoni̇m Şi̇rketi̇
Priority date: 2020-04-14
Filing date: 2020-04-14
Publication date: 2021-10-21
Also published as: EP4136724A4; EP4136724A1

Abstract

The invention is a ventilation cable gland (A) to be used in cable connections, comprising a body (1) mounted to an opening on a wall and allowing cable passage, a cap nut (2) mounted on the body (1) and clamping the cable, at least one ventilation hole (4) located on the body (1) providing air flow, at least one insert (6) with at least one air-permeable waterproof membrane (5) which is located inside the body (1).

Description

A CABLE GLAND

Technical Field

The invention relates to a ventilation cable gland with an air-permeable waterproof membrane to balance the internal and external pressure of the system and/or equipment.

Background of The Invention

Generally, cable glands are used in power distribution systems, electrical and electronic equipment. One of its main functions is to prevent the entry of water or dust into the system or equipment by sealing the cable connection points. Thus, safe and reliable operation of the system or equipment is ensured. The heat generated during the operation of the system or equipment increases the temperature of the sealed indoor environment. The indoor air expands with the effect of temperature and increases the internal pressure. Increasing internal pressure and temperature affects the lifetime and safety of the system or equipment. In humid environments, with the effect of temperature change, moisture condensate in the system or equipment, causing disadvantages such as short circuit, leakage current and damage of sensitive parts.

To prevent this, pressure balance elements are used in addition to cable glands in systems and/or equipment. The pressure balance elements have air-permeable waterproof membranes. Thus, it ensures that the pressure inside the system or equipment is balanced with the external pressure. In addition, moisture condensation in the system or equipment is prevented. However, there may not always be enough space on the system or equipment for mounting pressure balance elements. In addition, mounting a second element on the system or equipment causes additional time and cost.

CN108075433 discloses a water-proof air permeable cable gland. Said cable gland includes a cylindrical body, at least one vent hole formed on the side wall of the body and a waterproof ventilation ring. The waterproof ventilation ring allows air inlet and outlet into the cable gland from the vent hole, preventing water ingress. Thus, the sealing protection is assured while the pressure between the external and internal are balanced. On the other hand, when the cable with the largest diameter is used, there is not enough space inside the ventilation ring for the air to flow. There are sealing elements at the bottom and top of the ventilation ring placed inside the body. When the cap nut is screwed, the sealing elements apply pressure on the ventilation ring, causing concave or convex (barreling) shape. In this case, air flow decreases due to blocked pores of the ventilation ring. In some applications, ventilation rings are produced by punching a filter plate. If the punching process is not carried out properly, the pores are damaged and air flow decreases. In addition, sharp tools can damage the ventilation ring by passing through the ventilation hole. Thus, the waterproof feature of the ventilation ring is damaged.

CN202696103 describes a waterproof cable gland that includes the body, seal, cap nut and nut. There are ventilation holes on the side surface of the body. Each vent hole has an air-permeable, waterproof membrane. Said vent hole is placed on the body hexagon. The dimensions of the body hexagon are limited by certain standards and market expectations. For this reason, since the size of the membranes placed on the body hexagon are relatively small, the air flow rate is also low.

In the prior art, ventilation cable glands are not efficient in terms of IP (ingress protection) class IP69K. IP69K provides sealing protection against water jet at high pressure (80 bar) and high temperature (dOΌ).

As a result, due to above described disadvantages and inadequacy of existing solutions, it has been necessary to make development in the related art.

Purpose of The Invention

The invention has been developed with inspiration from existing situation and purposes to eliminate the above-mentioned disadvantages.

The main purpose of the invention is to develop a ventilation cable gland with pressure compensation. This eliminates the need to use two different products for both pressure balancing and cable assembly on the system or equipment.

Another purpose of the invention is to connect the air-permeable waterproof membrane to a rigid insert and place it in the body. Thus, when the cable gland is assembled, the membrane does not deform and the air flow is not reduced. Another purpose of the invention is to place the air-permeable waterproof membrane on the insert parallel to the cable axis. Thus, the surface area of the membrane is independent of the cable clamping range and/or cable diameter. If the membrane is placed perpendicular to the cable axis, the center of the membrane must be empty for cable assembly. In this case, as the cable clamping range increases, membrane surface area and air flow rate decrease. The end users prefer both large cable clamping range and high air flow rate.

Another purpose of the invention is to increase the air flow rate without changing the size of the ventilation cable gland. Therefore, the membrane is located on a separate insert instead of the body.

Another purpose of the invention is to provide a homogeneous air flow through entire membrane surface by creating a space between the body and the insert.

Another purpose of the invention is to prevent damage of air permeable, waterproof membrane by preventing the entry of sharp tools through the ventilation hole.

Another purpose of the invention is to provide IP69K rating for sealing protection.

In order to fulfill the objectives described above, the invention is a ventilation cable gland to be used in cable connections, comprising a body mounted to an opening on a wall and allowing cable passage, a cap nut mounted on the body and clamping the cable, at least one ventilation hole located on the body and providing air flow, at least one insert with at least one air-permeable waterproof membrane which is located inside the body.

The structural and characteristic features and all advantages of the invention will be clarified with the detailed description of the figures and the following description. Therefore, the evaluation should be done by taking into account these figures and detailed explanation.

Brief Description of Figures

Figure 1 : is an exploded view of the ventilation cable gland.

Figure 2: is a detailed view of the insert.

Figure 3: is a cross-sectional view of the ventilation cable gland. Figure 4: is a detailed view of the retaining mechanism.

Description of Part References

A. Ventilation cable gland

I . Body 2. Cap nut

3. Lamella

4. Ventilation hole

5. Membrane

6. Insert 7. Protection cover

8. Barrier

9. Space

10. Sealing element

I I . O-ring 12. Retaining mechanism

13. Cable axis

Detailed Description of The Invention

In this detailed description, the preferred embodiments of a ventilation cable gland (A) disclosed under the invention have been disclosed solely for the purpose of better understanding of the subject.

Referring to Figure 1 , the ventilation cable gland (A) according to the invention generally comprises a body (1), a cap nut (2), a membrane (5) and an insert (6). The ventilation cable gland (A) ensures both cable assembly and compensating of system or equipment internal and external pressure. The body (1) is mounted to an opening on a wall. In preferred embodiments of the invention, the body (1) is mounted to the opening by a lock nut, snap-fit system or threaded structure. The body (1) can be plastic, metal or plastic-metal hybrid construction. The body (1) has a hollow structure allowing cable passage. There is at least one ventilation hole (4) on the body (1) for air flow. The ventilation hole (4) provides air flow between the internal and external environment, as a result pressure and temperature differences are eliminated. Condensation of moisture in the system or equipment is also prevented.

The cap nut (2) is mounted on the body (1) and clamps the cable or cables. In preferred embodiments of the invention, the ventilation cable gland (A) has more than one lamella (3). In other preferred embodiments of the invention, at least one sealing element (10) is located between the cap nut (2) and the lamellas (3). When the cap nut (2) is screwed, the lamellas (3) apply a force on the cable and/or on the sealing element (10). Thus, sealing and strain relief are provided. In preferred embodiments of the invention, the lamellas (3) can be separate or integrated with the body (1). In other preferred embodiments of the invention, the lamellas (3) can be separate or integrated with the insert (6).

The ventilation cable gland (A) comprises at least one membrane (5). The membrane

(5) is air-permeable and waterproof. In this way, it prevents the ingress of water or dust and compensates pressure and temperature. The membrane (5) is preferably made of PTFE (polytetrafluoroethylene) or acrylic copolymer material. The membrane (5) is located on the insert (6). The membrane (5) is located on the insert (6) parallel to the cable axis (13). Thus, the surface of the membrane (5) is independent of the cable clamping range. If the membrane (5) is positioned perpendicularly to the cable axis (13), the center of the membrane (5) must be pierced for the cable passage. This causes reduction of total membrane (5) surface area. On the other hand, the locating of the membrane (5) on the insert (6) parallel to the cable axis (13) increases the total membrane (5) surface area without changing the ventilation cable gland (A) dimensions. In alternative embodiments of the invention, the membrane (5) is connected to the insert (6) by bonding, welding or other methods known in the art.

Referring to Figure 2, there is at least one membrane (5) on the insert (6). The insert

(6) is placed in the body (1). In preferred embodiments of the invention, there is an O- ring (11) between the body (1) and the insert (6). The O-ring (11) prevents ingress of water and dust to the system or equipment. The insert (6) prevents the membrane (5) deformation when the cap nut (2) is screwed and therefore, the air flow is not reduced. The insert (6) is a rigid material preferably plastic, metal or plastic-metal hybrid construction.

The protection cover (7) fastens the membrane (5) on the insert (6) and prevents dislocating of the membrane (5) in time. Thus, the lifetime of the ventilation cable gland (A) is extended. In preferred embodiments of the invention, there is at least one barrier (8) on the protection cover (7). The barrier (8) prevents the sharp tool passing through the ventilation hole (4) and reaching the membrane (5). The barrier (8) prevents water and dust reaching the surface of the membrane (5) directly. Thus, ventilation cable gland (A) provides IP69K rating for sealing protection. In alternative embodiments of the invention, there is also a barrier (8) in the ventilation hole (4).

Referring to Figure 3, there is a space (9) between the body (1) and the insert (6). This space (9) provides a homogeneous air flow through the entire membrane (5) surface.

Referring to Figure 4, the body (1) and/or insert (6) has a retaining mechanism (12) in the alternative embodiment of the invention. The retaining mechanism (12) ensures that the insert (6) remains stationary within the body (1). Thus, the rotation of the insert (6) during the cable assembly is prevented and the membrane (5) is aligned with the ventilation hole (4).

In alternative embodiments of the invention, high IP rating is achieved by not aligning the ventilation hole (4) and the membrane (5).

When the temperature of the system or equipment increases, the internal pressure also increases. First, the air flows through the membrane (5) from internal to external environment when the pressure increases. Then, it passes through the space (9) between the insert (6) and the body (1) and exhausts from the ventilation hole (4). Thus, the internal and external pressure and temperature are compensated.

When the system or equipment temperature decreases, the internal pressure decreases. In this case, a vacuum occurs in the system or equipment. The air flows through the ventilation hole (4) and reaches the space (9). Then, the air passes through the membrane (5) and reaches the system or equipment.

Claims

1. A ventilation cable gland (A) to be used in cable connections, comprising a body (1) mounted to an opening on a wall and allowing cable passage, a cap nut (2) mounted on the body (1) and clamping the cable, at least one ventilation hole (4) located on the body (1) and providing air flow, characterized in that the ventilation cable gland (A) comprises at least one insert (6) with at least one air-permeable waterproof membrane which is located inside the body (1).

2. A ventilation cable gland (A) according to claim 1 , characterized in that said membrane (5) is positioned on said insert (6) parallel to the cable axis (13).

3. A ventilation cable gland (A) according to claim 1 , characterized in that further comprising a space (9) between the body (1) and the insert (6) providing a homogeneous air flow through the membrane (5) surface.

4. A ventilation cable gland (A) according to claim 1 , characterized in that further comprising at least one protection cover (7) fastening the membrane (5) on the insert (6).

5. A ventilation cable gland (A) according to claim 1 , characterized in that further comprising at least one barrier (8) on the protection cover (7) protecting the membrane (5) from external impacts.

6. A ventilation cable gland (A) according to claim 1 , characterized in that further comprising at least one sealing element (10) for ingress protection.

7. A ventilation cable gland (A) according to claim 1 , characterized in that further comprising at least one O-ring (11) positioned between the body (1) and the insert (6) and providing sealing.

8. A ventilation cable gland (A) according to claim 1 , characterized in that further comprising a retaining mechanism (12) on the body (1) and/or on the insert (6), ensuring the insert (6) to remain stationary in the body (1).