Cable gland

Abstract

A cable gland for use in a hazardous environment includes a hub body having an opening extending therethrough. The gland nut is configured to engage an end of the hub body to define an internal cavity. The gland nut has a first inner annular stepped portion and a second inner annular stepped portion. And the sealing piece, the annular piece and the spring are arranged in the inner cavity. A spring is disposed in the inner cavity between the surface of the ring and the oppositely facing frustoconical surface. The first inner annular stepped portion engages the first end of the seal when the gland nut is in the first position. When the gland nut is in the second position, the second inner annular step engages the ring and the seal deflects radially inward. When the gland nut is located at the third position, the spring deflects inwards in the radial direction.

Description

Technical Field

[0001] The present application relates to cable glands. More specifically, an explosion-proof cable gland is provided for attaching armored or unarmored cables to explosion-proof housings or enclosures for use in harsh and hazardous locations. Background Art

[0002] Cable glands are commonly used on enclosures to allow cables, wires or tubes to enter the enclosure. Cable glands provide strain relief and seals to prevent contaminants such as dirt, dust and water from entering the enclosure. When cable glands are used on explosion-proof enclosures in harsh and hazardous locations, the design of the cable glands must allow the high temperature and high pressure fumes generated by an explosion within the enclosure to be safely released to the surrounding environment.

[0003] Due to the multiple functions of the cable gland, the traditional cable gland is a three-piece assembly that must be partially assembled by the user. These multiple parts increase installation time, and each part must be cataloged and tracked by the user.

[0004] The present invention provides a cable gland with fewer parts, which meets the requirements of being used in harsh and dangerous environments. Summary of the invention

[0005] A cable gland for use in hazardous environments is provided. The cable gland includes a hub having a first end, a second end, and an opening extending between the first end and the second end. A gland nut is configured to engage the second end of the hub to define an inner cavity between the hub and the gland nut. The gland nut has a first inner annular step and a second inner annular step spaced from the first inner annular step. A seal is disposed in the inner cavity and has a first end positioned adjacent to the first inner annular step and a second end facing in an opposite direction. An annular member is disposed in the inner cavity and adjacent to the second end of the seal. The annular member has a first surface facing the seal and a second surface facing in an opposite direction from the first surface. A spring is disposed in the inner cavity and between the second surface of the annular member and an oppositely facing frustoconical surface fixed in the inner cavity. When the gland nut is in a first position at a first distance from the first end of the hub, the first inner annular step engages the first end of the seal and the second inner annular step is spaced from the first surface of the annular member. When the gland nut is in a second position at a second distance from the first end, the second distance is less than the first distance, the second inner annular step engages the first surface of the annular member, and the seal is compressed by the first inner annular step and the first surface of the annular member and deflected radially inward. When the gland nut is in a third position at a third distance from the first end, the third distance is less than the second distance, and the spring is deflected radially inward by the second surface of the annular member and the opposite frustoconical surface.

[0006] In the aforementioned cable gland, oppositely facing frustoconical surfaces are formed on a first end portion of a chamber portion configured to be at least partially received in an opening of the hub body.

[0007] In the aforementioned cable gland, a labyrinth joint is defined between the chamber portion and the hub body.

[0008] In the aforementioned cable gland, the labyrinth joint has a first end communicating with the opening of the hub body and a second end leading to a space defined by the gland nut, the chamber portion and the hub body.

[0009] In the aforementioned cable gland, the labyrinth joint is at least partially defined between an annular tongue formed on the chamber portion and an annular groove formed in the hub body, the annular groove being sized to receive the annular tongue.

[0010] In the aforementioned cable gland, the spring is a spiral wire formed into a loop.

[0011] In the aforementioned cable gland, the annular member has a rectangular cross section.

[0012] In the aforementioned cable gland, the first end of the hub body is configured to engage a mating hole in the housing, and the second end of the hub body has external threads formed thereon.

[0013] In the aforementioned cable glands, the gland nut includes internal threads configured to engage external threads on the hub body.

[0014] In the aforementioned cable gland, the annular groove is formed on the outer cylindrical surface of the sealing member.

[0015] A method for assembling a cable to a housing via a cable gland is also provided. The cable gland includes a hub body having a first end, a second end, and an opening extending between the first end and the second end. A gland nut is configured to engage the second end of the hub body to define an inner cavity between the hub body and the gland nut. The gland nut has a first inner annular step portion and a second inner annular step portion spaced apart from the first inner annular step portion. A seal is disposed in the inner cavity and has a first end positioned adjacent to the first inner annular step portion and a second end facing oppositely. An annular member is disposed in the inner cavity and adjacent to the second end of the seal. The annular member has a first surface facing the seal and a second surface facing oppositely to the first surface. A spring is disposed in the inner cavity and is located between the second surface of the annular member and a truncated conical surface facing oppositely fixed in the inner cavity. The method includes the following steps: inserting a cable through a gland nut and a hub body; positioning the gland nut at a first position at a first distance from a first end of the hub body, wherein a first inner annular step engages a first end of the seal and a second inner annular step is spaced apart from a first surface of the annular member; moving the gland nut to a second position at a second distance from the first end, the second distance being less than the first distance, wherein the second inner annular step engages the first surface of the annular member, and the seal is compressed by the first inner annular step and the first surface of the annular member and deflected radially inwardly toward an outer surface of the cable; and moving the gland nut to a third position at a third distance from the first end, the third distance being less than the second distance, wherein the spring is deflected radially inwardly toward the outer surface of the cable through the second surface of the annular member and the opposite truncated conical surface.

[0016] In the foregoing method, the step of moving the gland nut to the second position secures the cable in the inner cavity.

[0017] In the foregoing method, the step of moving the gland nut to the third position causes the spring to at least partially penetrate the outer surface of the cable.

[0018] In the aforementioned method, the second end of the hub body includes external threads formed thereon, and the gland nut includes internal threads configured to engage the external threads, and the method of moving the gland nut to the first position or the second position includes twisting the gland nut relative to the hub body.

[0019] A cable gland for use in hazardous environments is also provided. The cable gland includes a hub having a first end, a second end, and an opening extending between the first end and the second end. The first end is configured to engage a mating hole in a housing, and the second end has an external thread formed thereon. A gland nut is configured to engage the external thread on the hub to define an inner cavity between the hub and the gland nut. The gland nut has a first inner annular step and a second inner annular step spaced from the first inner annular step. A seal is disposed in the inner cavity and has a first end positioned adjacent to the first inner annular step, a second end facing oppositely, and an annular groove formed on an outer cylindrical surface of the seal. An annular member is disposed in the inner cavity and adjacent to the second end of the seal. The annular member has a first surface facing the seal and a second surface facing oppositely from the first surface. A spring is disposed in the inner cavity and is located between the second surface of the annular member and an oppositely facing truncated conical surface fixed in the inner cavity. When the gland nut is in a first position at a first distance from the first end of the hub body, the first inner annular step engages the first end of the seal and the second inner annular step is spaced apart from the first surface of the annular member. When the gland nut is in a second position at a second distance from the first end, the second distance being less than the first distance, the second inner annular step engages the first surface of the annular member, and the seal is compressed by the first inner annular step and the first surface of the annular member and deflected radially inward. When the gland nut is in a third position at a third distance from the first end, the third distance being less than the second distance, the spring is deflected radially inward by the second surface of the annular member and the oppositely directed frustoconical surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a side perspective view of a cable gland according to the present invention;

[0021] Figure 2 yes Figure 1 Exploded view of the cable gland;

[0022] Figure 3 is along Figure 1 The line 3-3 in Figure 1 A side cross-sectional view of a cable gland;

[0023] Figure 4A yes Figure 1 A side cross-sectional view of a cable gland of , showing a cable proximate to the cable gland, wherein a gland nut of the cable gland is in a first position;

[0024] Figure 4B yes Figure 1 A side cross-sectional view of a cable gland of , showing a cable proximate to the cable gland, wherein a gland nut of the cable gland is in a second position;

[0025] Figure 4Cyes Figure 1 A side cross-sectional view of a cable gland of , showing a cable proximate to the cable gland, wherein a gland nut of the cable gland is in a third position; and

[0026] Figure 5 yes Figure 4A An enlarged side view of the cable gland. DETAILED DESCRIPTION

[0027] The following presents a description of the present disclosure; however, various aspects may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. In addition, the following examples may be provided alone or in combination with one or any combination of the examples discussed herein.

[0028] like Figure 1 As shown, the cable gland 100 has a first opening 102 and a second open end 104 through which a cable, wire or tube may extend. Figure 2 The cable gland 100 generally includes a hub body 110 , a chamber portion 120 , a stopper 140 , a spring 150 , a ring 160 , a bushing or a seal 170 and a gland nut 180 .

[0029] The hub body 110 includes a first end 110a and a second end 110b. The first end 110a includes a Figure 3 ) as described in detail below. The second end 110b includes external threads configured to engage internal threads on the gland nut 180. The profile of the central portion of the outer surface of the hub body 110 has flat faces 112, which are positioned in a hexagonal arrangement for allowing a user to apply torque to the hub body 110 using a wrench or equivalent tool when attaching the hub body 110 to the housing.

[0030] An opening 114 extends through the hub body 110. Figure 3 , a portion of the opening 114 on the second end 110b of the hub body 110 includes a tapered surface 116 that terminates in a groove 118. The tapered surface 116 and the groove 118 are configured to receive a mating surface of a cavity portion 120, as described in detail below.

[0031] Return to reference Figure 2, the chamber portion 120 is configured to be received in the opening 114 of the hub body 110. The chamber portion 120 includes a first end 120a and a second end 120b. A peripheral flange 122 is formed at the first end 120a and is adjacent to an outer tapered surface 124. The outer tapered surface 124 terminates in a tongue 126 at the second end 120b. The configuration and size of the peripheral flange 122, the tapered surface 124, and the tongue 126 are designed to engage mating surfaces defining the opening 114 of the hub body 110, namely the second end 110b, the tapered surface 116 ( Figure 3 ) and groove 118 ( Figure 3 ) to define a labyrinth joint between the hub body 110 and the chamber portion 120, as described in detail below.

[0032] The opening 128 extends through the chamber portion 120 between a first end 120a and an opposite second end 120b of the chamber portion 120. Figure 3 , the inner surface defining the opening 128 includes a first frustoconical surface 132 and a second frustoconical surface 136 that open to a cylindrical surface 134 at the first end 120a. The remaining inner surface is shown as cylindrical, and it is contemplated that the surface may have other shapes.

[0033] The stopper 140 is sized to be received in the opening 128 of the chamber portion 120. Figure 2 , the stopper 140 is shown as a flat annular element having a plurality of tabs 142 on its periphery. Figure 3 As shown in , the stop 140 is sized to engage and rest against the second frustoconical surface 136 of the chamber portion 120 when the stop 140 is positioned into the opening 128 .

[0034] refer to Figure 2 The spring 150 is sized to engage the first end 120a of the chamber portion 120. The spring 150 is a spiral wire formed into a loop. Figure 3 As shown in FIG. 4 , the spring 150 is positioned to engage the first frustoconical surface 132 of the chamber portion 120, as described in detail below. The spring 150 is made of a metal material and has a cross-sectional shape such that it can partially penetrate the cable 200 ( FIG. 4A to FIG. 4B )'s outer jacket 210 to provide grounding and hold the cable, as described below.

[0035] The ring 160 is sized to be positioned adjacent to the spring 150 and opposite the first end 120a of the chamber portion 120. The ring 160 has a first surface 162 and a second surface 164 opposite the first surface 162. The ring 160 is shown as a flat annular element and has a rectangular cross-section. It should be understood that the ring 160 can have other shaped cross-sections.

[0036] The seal or bushing 170 is a tubular element positioned adjacent to the annular member 160. The seal 170 has an inner opening 172 extending between a first end 170a and a second end 170b of the seal 170. The second end 170b is positioned adjacent to the annular member 160 to engage a surface of the annular member 160. The seal or bushing 170 is made of an elastic material (e.g., rubber or an elastomer). It is contemplated that the elastic material may be silicon or neoprene. An annular groove 174 is formed in the outer cylindrical surface of the seal 170. The annular groove 174 is configured to deflect the inner surface of the seal 170 (which defines the opening 172) inwardly when the first end 170a is compressed toward the second end 170b, as described in detail below.

[0037] refer to Figure 3 and FIG. 4A to FIG. 4C , the gland nut 180 is configured to engage the hub body 110 to capture the seal 170, the annular member 160, the spring 150, the stopper 140 and the chamber portion 120 in the inner cavity defined between the gland nut 180 and the hub body 110. The gland nut 180 is a cup-shaped element having an opening 182 in its bottom wall 180a. The outer side surface of the gland nut 180 includes a plurality of flat faces 184, which are positioned in a hexagonal arrangement for allowing a user to torque the gland nut 180 using a wrench or an equivalent tool.

[0038] The inner surface of the gland nut 180 includes a first inner annular step 186 and a second inner annular step 188. The first inner annular step 186 is sized to engage the first end 170a of the seal 170, and the second inner annular step 188 is sized to engage the ring 160, as described in detail below. The inner surface includes an internal threaded portion 192 that is sized to engage threads on the second end 110b of the hub body 110.

[0039] refer to Figure 3 and FIG. 4A to FIG. 4C , the cable gland 100 is preassembled by placing the cavity portion 120 into the opening 114 of the hub body 110. When positioned in the hub body 110, the tapered surface 124 on the outer surface of the cavity portion 120 engages the tapered surface 116 of the hub body 110, and the tongue 126 engages the groove 118.

[0040] The stopper 140 is positioned within the opening 128 of the chamber portion 120 and adjacent the second frustoconical surface 136 of the chamber portion 120. The spring 150 is positioned adjacent the first end 120a of the chamber portion 120 and proximate the first frustoconical surface 132. The annular member 160 is then positioned adjacent the spring 150, and the seal 170 is positioned adjacent the annular member 160. The gland nut 180 is positioned to engage the hub body 110 to retain all of the aforementioned components between the gland nut 180 and the hub body 110. It is contemplated that grease may be applied to the first end 170a of the seal 170 and the first inner annular step 186 of the gland nut 180 prior to securing the gland nut 180 to the hub body 110. The grease may assist in the rotation of the gland nut 180 relative to the seal 170 so that the seal 170 does not deform during the twisting of the gland nut 180. As shown in FIG. Figure 3 As shown, the opening 182 in the gland nut, the opening 172 of the seal, the opening 128 of the chamber portion, and the opening 114 of the hub body 110 are sized and positioned to align and define a continuous internal cavity from the first opening 102 to the second opening 104 of the cable gland 100.

[0041] like Figure 3 As shown, the seal 170 is held between the first inner annular step 186 and the ring 160 , and the spring is held between the other surface of the ring 160 and the first frustoconical surface 132 of the chamber portion 120 .

[0042] The following will now discuss the process of connecting the cable 200 ( FIG. 4A to FIG. 4C ) assembled to the housing 250 ( Figures 3 to 5 ) to describe the present invention. The cable gland 100 is initially screwed into the housing 250 ( Figures 3 to 5 ). In the illustrated embodiment, the housing 250 is made of metal so that the external threads engage the mating threaded opening. It is contemplated that the housing 250 may be made of plastic. In this embodiment (not shown), the opening in the housing 250 is a through hole, and a nut (not shown) is provided for threading onto the second end 110b of the hub body 110. The nut and the flange of the hub body 110 sandwich the wall of the housing 250 therebetween to secure the cable gland 100 to the housing 250.

[0043] refer to Figure 4A, the cable 200 can be prepared in advance by exposing the inner wires 220 from the outer jacket 210 of the cable 200. When the cable 200 is inserted into the cable gland 100 in the direction marked "A", the wires 220 pass through the inner opening of the stopper 140, but because the inner diameter of the stopper 140 is smaller than the outer jacket 210, the outer jacket 210 is prevented from passing through the stopper 140. The cable 200 continues into the inner cavity 252 of the housing 250 to terminate at a desired location (not shown). It is also contemplated that before inserting the cable 200 into the cable gland 100, the user can insert a barrier compound (e.g., epoxy) into the cable gland 100, which cures around the cable 200 to fill any gaps between the outer surface of the cable 200 and the inner surface of the cable gland 100.

[0044] After the cable 200 is positioned in the cable gland 100, the outer surface of the outer jacket 210 is positioned adjacent to the spring 150 and the seal 170. In this first position of the gland nut 180, the gland nut 180 is a first distance D1 (see Figure 4A ). Then, the user twists the gland nut 180, and the threads on the gland nut 180 and the hub body 110 are configured so that the gland nut 180 is twisted along the Figure 4A The direction marked "B" in the figure is from the first position ( Figure 4A ) moves to the second position ( Figure 4B ). In the second position, the gland nut 180 is a second distance D2 from the end of the hub body 110. The second distance is less than the first distance. When the gland nut 180 moves, the seal 170 is compressed between the first inner annular step 186 and the ring 160. Similarly, the spring 150 is compressed between the ring 160 and the first truncated conical surface 132 of the chamber portion 120. Because the seal 170 is made of an elastic material with a lower rigidity than the spring 150, the continuous torque of the gland nut 180 compresses the seal 170 between the gland nut 180 and the ring 160, so that the seal 170 moves along the inner annular step 186. Figure 4A and Figure 4B The direction marked "C" deflects inwards, see Figure 4B The inward deflection of the seal 170 causes the seal 170 to engage and seal against the outer surface of the outer jacket 210 .

[0045] The seal 170 continues to be compressed until the second inner annular step 188 engages the ring 160. Thereafter, continued twisting of the gland nut 180 causes the ring 160 to apply pressure to the spring 150. As the spring 150 moves toward the chamber portion 120, the first frustoconical surface 132 of the chamber portion 120 causes the spring 150 to move in a direction that is substantially perpendicular to the chamber portion 120. Figure 4AThe spring 150 is deflected inwardly in the direction marked "D" in the figure toward the outer surface of the outer jacket 210. The spring 150 thus engages and optionally partially penetrates the outer jacket 210 to provide grounding for the cable 200 and help retain the cable 200 in the cable gland 100, as shown in FIG. Figure 4C As shown. When a predetermined torque value is reached based on the size of the cable gland 100, the twisting of the gland nut 180 stops. The torque value is generally defined by the manufacturer of the cable gland 100 after several experiments. For example, depending on the size of the cable gland 100, it is contemplated that the cable gland 100 can be twisted at a torque of 300 inch-pounds to 1600 inch-pounds to achieve the desired result. When the twisting is completed, the gland nut 180 is in a third position, wherein the gland nut 180 is a third distance D3 from the end of the hub body 110. The third distance is less than the second distance.

[0046] refer to Figure 5 In addition to grounding and retaining the cable 200 in the cable gland 100, the cable gland 100 also defines a labyrinth joint that is configured to dissipate volatile gases released from the interior cavity 252 of the housing 250 during an explosion in the interior cavity 252 of the housing. The labyrinth joint begins at a joint formed between the hub body 110 and the chamber portion 120. As described above, the chamber portion 120 includes a tongue 126 that engages the groove 118 of the hub body 110. Adjacent to this engagement structure is an opening that defines an entrance to the labyrinth joint (see arrow "E"). The labyrinth joint continues between the tapered surfaces 124 of the chamber portion 120 and the tapered surfaces 116 of the hub body 110, respectively. Gas passing along the labyrinth sealing structure is injected into the area 260 within the gland nut 180. Due to the seal 170 and the user-inserted barrier compound, when the gland nut 180 is attached to the hub body 110, the path of least resistance for the escaping gases is through the spacing gap formed between the external threads on the hub body 110 and the internal threads of the gland nut 180. After the gases pass through the spacing gap, they can be exhausted to the surrounding environment (see arrow "F"). The labyrinth joint and tortuous path formed by the mating threads of the gland nut 180 and the hub body 110 are configured to reduce the volatility (e.g., temperature and pressure) of the gases escaping from the housing 250. The repeated turns and small openings tend to dissipate the energy of the escaping gases to a level that can be safely released into the harsh environment outside the housing 250. It is contemplated that the labyrinth joint can be 0.04 inches or smaller to help dissipate the energy of the escaping gases.

[0047] Thus, the present device provides a cable gland with reduced components compared to heretofore known cable glands configured for use in harsh environments. The present device also allows for rapid assembly by providing grounding and retention of the cable in the cable gland in one twisting motion of the gland nut.

[0048] It will be apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit and scope of the claimed invention.

Claims

1. A cable gland for use in a hazardous environment, the cable gland comprising: a hub body having a first end, a second end, and an opening extending between the first end and the second end of the hub body; a gland nut configured to engage the second end of the hub body to define an inner cavity between the hub body and the gland nut, the gland nut having a first inner annular step portion and a second inner annular step portion spaced apart from the first inner annular step portion; a sealing member disposed in the inner cavity and having a first end portion positioned adjacent to the first inner annular step portion and a second end portion facing oppositely; an annular member disposed in the inner cavity and adjacent to the second end of the sealing member, the annular member having a first surface facing the sealing member and a second surface facing opposite to the first surface; as well as a spring disposed in the inner cavity between the second surface and an oppositely facing frustoconical surface fixed in the inner cavity, in, When the gland nut is in a first position a first distance from the first end of the hub body, the first inner annular step engages the first end of the seal and the second inner annular step is spaced apart from the first surface of the annular member, When the gland nut is in a second position at a second distance from the first end of the hub body, the second distance being less than the first distance, the second inner annular step engages the first surface of the annular member, and the seal is compressed by the first inner annular step and the first surface of the annular member and deflected radially inward, and When the gland nut is in a third position at a third distance from the first end of the hub body, the third distance being less than the second distance, the spring is radially inwardly biased by the second surface of the annular member and the oppositely facing frustoconical surface.

2. The cable gland according to claim 1, wherein: The oppositely facing frusto-conical surfaces are formed on a first end of a chamber portion configured to be at least partially received in the opening of the hub body.

3. The cable gland according to claim 2, wherein: A labyrinth joint is defined between the chamber portion and the hub body.

4. The cable gland according to claim 3, wherein: The labyrinth joint has a first end and a second end. The first end of the labyrinth joint is in communication with the opening of the hub body, and the second end of the labyrinth joint leads to a space defined by the gland nut, the chamber portion, and the hub body.

5. The cable gland according to claim 3, wherein: The labyrinth joint is at least partially defined between an annular tongue formed on the chamber portion and an annular groove formed in the hub body, the annular groove being sized to receive the annular tongue.

6. The cable gland according to claim 1, wherein: The spring is a coil of wire formed into a loop.

7. The cable gland according to claim 1, wherein: The annular member has a rectangular cross section.

8. The cable gland according to claim 1, wherein: The first end of the hub body is configured to engage a mating hole in the housing, and the second end of the hub body has external threads formed thereon.

9. The cable gland according to claim 8, wherein: The gland nut includes internal threads configured to engage the external threads on the hub body.

10. The cable gland according to claim 1, wherein: An annular groove is formed on the outer cylindrical surface of the sealing member.

11. A method for assembling a cable to a housing via a cable gland, the cable gland comprising: a hub body having a first end, a second end, and an opening extending between the first end and the second end of the hub body; a gland nut configured to engage the second end of the hub body to define an inner cavity between the hub body and the gland nut, the gland nut having a first inner annular step portion and a second inner annular step portion spaced apart from the first inner annular step portion; a sealing member disposed in the inner cavity and having a first end portion positioned adjacent to the first inner annular step portion and a second end portion facing oppositely; an annular member disposed in the inner cavity and adjacent to the second end of the sealing member, the annular member having a first surface facing the sealing member and a second surface facing opposite to the first surface; as well as a spring disposed in the inner cavity between the second surface of the annular member and an oppositely facing frustoconical surface fixed in the inner cavity, the method comprising: inserting a cable through the gland nut and the hub; positioning the gland nut in a first position a first distance from a first end of the hub body, wherein the first inner annular step engages the first end of the seal and the second inner annular step is spaced from the first surface of the annular member; moving the gland nut to a second position a second distance from the first end of the hub body, the second distance being less than the first distance, wherein the second inner annular step engages the first surface of the annular member and the seal is compressed by the first inner annular step and the first surface of the annular member and deflected radially inwardly toward an outer surface of the cable; and The gland nut is moved to a third position a third distance from the first end of the hub body, the third distance being less than the second distance, wherein the spring is radially deflected inwardly toward the outer surface of the cable by the second surface of the annular member and the oppositely facing frustoconical surface.

12. The method according to claim 11, wherein: The step of moving the gland nut to the second position secures the cable within the inner cavity.

13. The method according to claim 11, wherein: The step of moving the gland nut to the third position causes the spring to at least partially penetrate the outer surface of the cable.

14. The method according to claim 11, wherein: The hub body has external threads formed on the second end thereof, and the gland nut includes internal threads configured to engage the external threads, and a method of moving the gland nut to the first position or the second position includes twisting the gland nut relative to the hub body.

15. A cable gland for use in a hazardous environment, the cable gland comprising: a hub body having a first end, a second end, and an opening extending between the first and second ends of the hub body, the first end of the hub body being configured to engage a mating hole in the housing, and the second end of the hub body having external threads formed thereon; a gland nut configured to engage the external threads on the hub body to define an inner cavity between the hub body and the gland nut, the gland nut having a first inner annular step portion and a second inner annular step portion spaced apart from the first inner annular step portion; a seal disposed in the inner cavity and having a first end portion positioned adjacent to the first inner annular step portion, a second end portion facing oppositely, and an annular groove formed on an outer cylindrical surface of the seal; an annular member disposed in the inner cavity and adjacent to the second end of the sealing member, the annular member having a first surface facing the sealing member and a second surface facing opposite to the first surface; as well as a spring disposed in the inner cavity between the second surface of the annular member and an oppositely facing frustoconical surface fixed in the inner cavity, wherein When the gland nut is in a first position a first distance from the first end of the hub body, the first inner annular step engages the first end of the seal and the second inner annular step is spaced apart from the first surface of the annular member, When the gland nut is in a second position at a second distance from the first end of the hub body, the second distance being less than the first distance, the second inner annular step engages the first surface of the annular member, and the seal is compressed by the first inner annular step and the second surface of the annular member and deflected radially inwardly, and When the gland nut is in a third position at a third distance from the first end of the hub body, the third distance being less than the second distance, the spring is radially inwardly biased by the second surface of the annular member and the oppositely facing frustoconical surface.

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