TWI894087B - Feedback device - Google Patents

Abstract

A feeder device comprises a housing structure, at least one adapter unit, at least one signal conductor unit, and a protective cover. The adapter unit includes a first adapter and a second adapter mounted in the housing structure at a front-to-rear spacing. The signal conductor units are located within the housing structure and connected to the adapter units, respectively, with each signal conductor unit mounted between the first and second adapters of the corresponding adapter unit. The protective cover is mounted on the housing structure and is operable to switch between a retracted state and an extended state. With the above design, when the protective cover is in the extended state, the protective cover extends backward from the housing structure and shields the second adapter, thereby protecting the plug-in assembly plugged into the second adapter and preventing the plug-in assembly from falling off due to unexpected external force.

Description

Feedback device

The present invention relates to a feeding device, and more particularly to a feeding device with a movable protective cover.

Feedback devices are typically used to airtightly route a large number of signal conductors, such as optical fibers or electrical conductors, between two areas under various environmental conditions. However, in some existing structures, feedback devices can be susceptible to external impact during use, affecting the stability of plug-in components or even causing them to become detached.

In addition, Chinese Patent Publication No. CN110326176B (U.S. counterpart No. US10008362B1) discloses a feeding device mounted on one wall of a vacuum chamber. This device allows several signal conductors to pass airtightly from the chamber to the surrounding environment, enabling the transmission of various signals carried by these conductors between the chamber and the surrounding environment. However, the portion of these signal conductors exposed to the surrounding environment is susceptible to external forces, causing them to be pulled and displaced. This displacement can also cause damage due to friction, which in turn affects the quality and stability of signal transmission.

Therefore, the object of the present invention is to provide a feeding device that can improve at least one disadvantage of the prior art.

Therefore, in some embodiments of the present invention, the feed-through device includes a housing structure, at least one adapter unit, at least one signal conductor unit, and a protective cover. The adapter unit includes a first adapter and a second adapter installed in the housing structure at a front and rear interval. The signal conductor unit is located in the housing structure and connected between the first adapter and the second adapter. The protective cover is installed in the housing structure and can be operated to change between a retracted state and an extended state. When the protective cover is in the retracted state, the protective cover is sleeved on the outer periphery of the housing structure. When the protective cover is in the extended state, the protective cover extends backward from the housing structure and shields the second adapter.

In some embodiments, the second adapter can be inserted into a plug-in assembly and extend rearwardly. When the protective cover is in the extended state, the plug-in assembly is at least partially located in the protective cover and is shielded by the protective cover.

In some embodiments, the protective cover has a slide groove extending in the front-to-rear direction, the shell structure includes a shell unit for mounting the adapter units, and a limit member passing through the slide groove and fixed to the shell unit, the limit member restricts the protective cover from sliding relative to the shell unit along the extension direction of the slide groove.

In some embodiments, the limit member has an operating portion that can be operated and rotated, a threaded section locked to the housing unit, and a rod section connecting the operating portion and the threaded section, the rod section passes through the slide groove, and the operating portion can be used to press against the protective cover; the slide groove is formed with an insertion hole at a middle position between the two ends, the diameter of which is larger than the outer diameter of the threaded section of the limit member but smaller than the outer diameter of the operating portion, and the width of the slide groove is larger than the outer diameter of the rod section but smaller than the outer diameter of the threaded section.

In some embodiments, the housing unit has a front frame, a rear frame mounted behind the front frame, and a sealing partition mounted between the front frame and the rear frame, the sealing partition having a plurality of through holes extending front to rear for the signal conductor units to pass through respectively, each of the signal conductor units including a plurality of signal conductor modules extending front to rear, and a sealing member for positioning the signal conductor modules and airtightly filling the corresponding through holes.

In some embodiments, each of the seals has several positioning grooves extending from front to back, and each of the signal conductor modules has a signal conductor extending from front to back, a first plug connected to the front end of the signal conductor and mounted on the corresponding first adapter, a second plug connected to the rear end of the signal conductor and mounted on the corresponding second adapter, and at least one positioning member integrally wrapped around the signal conductor, wherein the positioning member is used to be embedded in the positioning groove of the seal.

In some embodiments, the rear frame includes two rear half frames mounted on the front frame and assembled facing each other, and a rear plate mounted on the rear ends of the rear half frames and for mounting the second adapters; the two rear half frames are identical and hermaphroditic.

In some embodiments, the protective cover includes a top wall, a bottom wall, and two side walls connecting the top wall and the bottom wall. Each of the top wall and the bottom wall is provided with a slide groove. The shell structure includes two limiting members, which are respectively used to pass through the slide grooves of the top wall and the bottom wall and be fixed to the shell unit.

In some embodiments, the housing unit has a front frame and a rear frame mounted behind the front frame. The rear frame has two rear half frames that are roughly U-shaped and mounted on the front frame in a group facing each other left and right. Each of the rear half frames includes a side panel and a top panel and a bottom panel extending in the same direction from the side panel and spaced apart from each other up and down. The two rear half frames are connected with their top panels facing each other and their bottom panels facing each other. One limiting member is fixed to the top panel of one of the rear half frames, and the other limiting member is fixed to the bottom panel of the other rear half frame.

In some embodiments, the rear edge of each side wall of the protective cover is recessed forward relative to the top wall and the bottom wall to form a wire outlet notch.

The effectiveness of the present invention lies in: through the provision of the protective cover, it is designed to be operable to change between the retracted state and the extended state. When the protective cover is in the extended state, the protective cover shields and protects the second adapter and the plug-in component inserted into the second adapter, preventing the plug-in component from being impacted by unexpected external forces. Moreover, when the protective cover is in the retracted state, it does not affect the insertion and removal of the plug-in component.

Referring to Figures 1 to 3 , one embodiment of the feeder device of the present invention is adapted to provide a first plug assembly 91 (see Figure 11 ) of a first device for plugging into a second plug assembly 92 (see Figure 11 ) of a second device. In this embodiment, the first device is located within a vacuum chamber, and the second device is located in an external environment. However, in practice, the first and second devices can be located in different environments without limitation. Furthermore, the number of first and second plug assemblies 91 and 92 provided in this embodiment is shown as an example, but multiple plug assemblies of each can be provided in practice.

The feeding device includes a shell structure 1, at least one adapter unit 2, at least one signal conductor unit 3, and a protective cover 4. In this embodiment, there are multiple adapter units 2 and signal conductor units 3, but the present invention is also applicable to the state where there is only one adapter unit 2 and signal conductor unit 3. The protective cover 4 is mounted on the shell structure 1 and can be operated to move relative to the shell structure 1 and change between a retracted state and an extended state. For the convenience of explanation, in the various figures of this embodiment, the direction in which the protective cover 4 can move relative to the shell structure 1 is defined as the front-rear direction D1 (the direction of the arrow is forward, and the reverse direction is rear), and the left-right direction D2 (the direction of the arrow is right, and the reverse direction is left) and the up-down direction D3 (the direction of the arrow is up, and the reverse direction is down) are defined accordingly.

The housing structure 1 includes a housing unit 11 and two stoppers 12 mounted on the upper and lower sides of the housing unit 11. The housing unit 11 has a front frame 13, a rear frame 14 mounted behind the front frame 13, and a sealing partition 15 mounted between the front frame 13 and the rear frame 14. The front frame 13 has a surrounding hollow front frame wall 132 and a rim 131 extending laterally outward from the front end of the front frame wall 132. The front end of the front frame wall 132 defines a front opening 133 (see Figure 1). The front frame 13 can be fixed to the first device via the rim 131. Referring to Figures 1 and 11 together, the front frame 13 also has a front panel 134, which is exposed forward and disposed in the front opening 133. The front panel 134 is configured to be recessed rearward relative to the edge 131 of the front frame 13, so that a first adapter 21 of each adapter unit 2 fixed on the front panel 134 can also be recessed rearward relative to the edge 131, thereby allowing the plug-in portion of the first plug-in assembly 91 inserted in the first adapter 21 to be accommodated in the recess, reducing the height of the first plug-in assembly 91 protruding forward, thereby saving internal space of the first device.

Referring also to FIG. 4 , in this embodiment, the sealing plate 15 is located at the rear end of the front frame 13 and between the front frame 13 and the rear frame 14 . The sealing plate 15 has a plurality of through holes 151 extending from front to rear and arranged in an array. Furthermore, in this embodiment, the sealing plate 15 is a separate component mounted on the front frame 13 .

The rear frame 14 comprises two roughly U-shaped rear halves 141 that are mounted side-by-side on the front frame 13, and a rear plate 142 mounted to the rear ends of the two rear halves 141. The two rear halves 141 are preferably identical and hermaphroditic, allowing them to be snapped together without distinguishing left from right during assembly, thereby saving mold costs and facilitating assembly. Each of the rear half frames 141 includes a side panel 141a and a top panel 141b and a bottom panel 141c extending in the same direction from the side panel 141a and spaced apart from each other. The edges 141d and 141e of each of the top panel 141b and the bottom panel 141c extending in the front-to-back direction are stepped buckle protrusions and are thinner than other positions of the top panel 141b and the bottom panel 141c. The two rear half frames 141 are formed with the top panels 141b facing each other and the bottom panels 141c facing each other. The top plate 141b of one rear half frame 141 and the bottom plate 141c of the other rear half frame 141 are joined together to form a hollow structure. The stepped structures of the plate edge 141d of the top plate 141b of one rear half frame 141 and the snap-fitting protrusions of the plate edge 141d of the top plate 141b of the other rear half frame 141 complement each other and can be joined together. The stepped structures of the plate edge 141e of the bottom plate 141c of one rear half frame 141 and the snap-fitting protrusions of the plate edge 141e of the bottom plate 141c of the other rear half frame 141 also complement each other and can be joined together. The rear plate 142 is fixed to the rear ends of the two rear half frames 141 and covers the opening formed in the rear end of the rear frame 14. The rear plate 142 is preferably completely identical to the front plate 134 to facilitate interchangeability between the two components.

Referring to Figures 3 and 9, in this embodiment, the two limiting members 12 are respectively mounted and fixed on the rear half frames 141 and are located near the rear ends of the rear half frames 141. One limiting member 12 is located on the top plate 141b of one rear half frame 141, and the other limiting member 12 is located on the bottom plate 141c of the other rear half frame 141. Each limiting member 12 can be specifically a screw structure, each limiting member 12 having an operating portion 123 for operation and rotation, a threaded section 121 for locking to the housing unit 11, and a rod section 122 connecting the operating portion 123 and the threaded section 121. The rod section 122 is preferably a smooth round rod without threads.

Referring to Figures 5 to 7 and 9, the adapter units 2 are mounted in an array on the housing unit 11. Each adapter unit 2 includes a first adapter 21 mounted on the front end of the front frame 13 and a second adapter 22 mounted on the rear plate 142 of the rear frame 14 and spaced from the first adapter 21 in front and back. The first adapter 21 is exposed from the front opening 133 of the front frame 13 (as shown in Figure 1) to allow the first plug-in assembly 91 to be inserted therein. The second adapter 22 is exposed from the rear plate 142 of the rear frame 14 to allow the second plug-in assembly 92 to be inserted therein and extends rearward.

The signal conductor units 3 are disposed within the housing unit 11 along the front-to-back direction and are respectively installed and connected between the first adapter 21 and the second adapter 22 by passing through the through-holes 151 of the sealing diaphragm 15. Each signal conductor unit 3 includes a signal conductor module 31 extending front-to-back and a sealing member 32 that is positioned in the corresponding through-hole 151 to ensure airtightness and allows the signal conductor module 31 to extend through. The sealing member 32 is generally a block-shaped structure that can be filled in the corresponding through-hole 151 of the sealing diaphragm 15. The sealing member 32 has a plurality of positioning grooves 321 formed by a recessed side thereof, the function of which will be described later. By providing the sealing member 32 , the signal conductor module 31 can be positioned in the housing unit 11 . In this embodiment, after each sealing member 32 is filled in the through hole 151 , a curing glue is further filled around the sealing member 32 to improve airtightness.

Furthermore, each signal conductor module 31 has a signal conductor 311 extending forward and backward, a first plug 312 connected to the front end of the signal conductor 311 and inserted into the first adapter 21, and a second plug 313 connected to the rear end of the signal conductor 311 and inserted into the second adapter 22. In this embodiment, each signal conductor 311 is an optical fiber ribbon.

In addition, in order to enhance the stability of the signal conductor module 31 extending through the seal 32 and prevent it from being easily displaced, while also taking into account that the signal conductor 311 will not be damaged, in this embodiment, each of the signal conductor modules 31 further has two positioning members 314 spaced apart in front and rear and integrally wrapped around the signal conductor 311. Each of the positioning members 314 can be, for example, a block structure that is injection molded and wrapped around the signal conductor 311. When the signal conductor module 31 extends through the seal 32, the positioning members 314 of each signal conductor module 31 are embedded in the positioning groove 321 of the seal 32, thereby tightly positioning the signal conductor module 31 within the seal 32. The embedding of the positioning members 314 in the positioning groove 321 of the seal 32 is primarily designed to achieve airtightness. Furthermore, the positioning members 314 are bonded to the signal conductor 311 in a manner that prevents the signal conductor 311 from being damaged by friction with the seal 32 or other surroundings when pulled or displaced.

In this embodiment, two positioning members 314 are provided. However, in practice, as long as the corresponding signal conductor module 31 is tightly positioned within the sealing member 32, only one positioning member 314 may be provided. Furthermore, although the two positioning members 314 are spaced apart in this embodiment, in practice, the two positioning members 314 can be placed tightly together and epoxy resin can be filled into the positioning groove 321 of the sealing member 32 on one side of the two positioning members 314 to enhance the seal.

Referring to Figures 3, 8, and 11, the protective cover 4 is sleeved around the outer periphery of the rear frame 14 and can be operated to change between a retracted state (shown in Figures 8 and 9) and an extended state (shown in Figures 10 and 11) in which it protrudes rearward relative to the rear frame 14. In this embodiment, the protective cover 4 is generally hollow and cylindrical and includes a top wall 43, a bottom wall 44, two side walls 45 connecting the top wall 43 and the bottom wall 44, and two sliding grooves 41 provided on the top wall 43 and the bottom wall 44, respectively, extending in the direction in which the protective cover 4 can slide forward and backward. The rear edge of each side wall 45 is recessed forward relative to the top wall 43 and the bottom wall 44 to form a wire outlet notch 42. Each of the wire outlet recesses 42 is used to allow a signal wire connected to the second plug assembly 92 to extend laterally.

Each of the slide grooves 41 is formed with an insertion hole 411 at the middle position between the two ends, the diameter of which is larger than the outer diameter of the threaded section 121 of the limiting member 12 but smaller than the outer diameter of the operating portion 123. The width of each of the slide grooves 41 is preferably set to be larger than the outer diameter of the rod section 122 but smaller than the outer diameter of the threaded section 121. When the protective cover 4 is sleeved on the rear frame 14, the limiting members The rods 12 pass through the insertion holes 411 of the slide grooves 41 and are respectively locked to the top plate 141b and the bottom plate 141c of the rear frame 14 by the threaded sections 121. The rod sections 122 are respectively able to slide within the slide grooves 41, thereby limiting the sliding movement of the protective cover 4 relative to the rear frame 14 to the extension direction of the slide grooves 41. In addition, the position of the limiting members 12 on the top wall 43 and the bottom wall 44 is staggered in vertical direction, which can provide more stable guidance and sliding of the protective cover 4 relative to the rear frame 14. To remove each of the stoppers 12 from the protective cover 4, it is necessary to shift each stopper 12 to a position aligned with the corresponding insertion hole 411, first unlock the threaded section 121 from the rear frame 14 by rotating it, and then pull the threaded section 121 of the stopper 12 outward through the insertion hole 411. This prevents the operator from excessively unlocking and rotating the stopper 12 when changing the retracted or extended state of the protective cover 4, causing it to inadvertently fall out of the chute 41.

8 and 9 , when it is necessary to expose the second adapters 22 from the rear plate 142 of the rear frame 14, the protective cover 4 is slid forward so that the protective cover 4 is in the retracted state where the entire protective cover is substantially overlapped and sleeved on the outer periphery of the rear frame 14. This exposes the second adapters 22 and provides plugging and unplugging of the second plug assembly 92. At this time, each of the limiting members 12 is located at the rear end of the corresponding slide 41. Furthermore, by rotating the operating portion 123 of each limiting member 12, the two limiting members 12 are respectively locked until their operating portions 123 press against the top wall 43 and the bottom wall 44 of the protective cover 4, thereby preventing the protective cover 4 from easily sliding backward. When it is necessary to prevent the second plug assembly 92 connected to the second adapter 22 from being hit by external force, or when it is necessary to protect the second adapters 22, as shown in Figures 10 and 11, the protective cover 4 is slid backward so that the protective cover 4 extends backward relative to the rear frame 14 and is in the extended state, so that the second adapters 22 can be shielded in the protective cover 4, and the second plug assembly 92 is at least partially located in the protective space 40 of the protective cover 4 and is protected by the protective cover. The protective cover 4 shields the second plug-in assembly 92 connected to the second adapter 22, thereby preventing it from being hit by external forces or protecting the second adapters 22. At this time, each of the limiting members 12 is located at the front end of the corresponding slide 41. Furthermore, by rotating the operating portion 123 of the limiting member 12, the two limiting members 12 are locked respectively until the operating portion 123 presses against the top wall 43 and the bottom wall 44 of the protective cover 4, which can also prevent the protective cover 4 from sliding forward easily.

Regarding the retracted state and the extended state of the protective cover 4, the retracted state is mainly to prevent the plugging and unplugging of the second plug-in component 92 and the corresponding second adapter 22, while the extended state is to block external forces from hitting the second plug-in component 92 and affecting its signal connection or even falling off, or hitting the second adapters 22 to avoid damage.

When the feeder device of the present invention is used to transmit signals between the first device and the second device, the front frame 13 of the housing unit 11 is first mounted on the wall of the first device (e.g., a vacuum chamber), the first connector 91 is inserted into one of the first adapters 21 of the adapter unit 2, and the second connector 92 is inserted into one of the second adapters 22 of the adapter unit 2. Subsequently, the protective cover 4 is extended rearward relative to the rear frame 14. The protective cover 4 and the rear frame 14 cooperate to define the protective space 40, thereby protecting the second connector 92 and preventing it from being damaged or even falling off due to unexpected external forces.

In summary, the present invention is designed to be operable to change between the retracted state and the extended state by providing the protective cover 4. When the protective cover 4 is in the extended state, the protective cover 4 extends backward from the shell structure 1 and covers the second adapters 22, thereby protecting the second plug-in assembly 92 inserted in the second adapter 22, thereby preventing the second plug-in assembly 92 from being hit by unexpected external forces. Moreover, when the protective cover 4 is in the retracted state, it does not affect the plugging and unplugging of the second plug-in assembly 92. Therefore, the purpose of the present invention can be achieved.

In addition, the positioning grooves 321 are provided through the sealing member 32 of each signal conductor unit 3, and each signal conductor module 31 is designed with the positioning members 314. The positioning members 314 of each signal conductor module 31 can be embedded and positioned in the corresponding positioning grooves 321, so that each signal conductor module 31 is not easily damaged by sliding and displacement due to external forces, which helps maintain the transmission quality of the signal.

However, the above description is merely an example of the present invention and should not be used to limit the scope of the present invention. All simple equivalent changes and modifications made according to the scope of the patent application and the content of the patent specification of the present invention are still within the scope of the present patent.

1: Housing structure 11: Housing unit 12: Stopper 121: Threaded section 122: Rod section 123: Operating section 13: Front frame 131: Edge 132: Front frame wall 133: Front opening 134: Front panel 14: Rear frame 141: Rear half frame 141a: Side panel 141b: Top panel 141c: Bottom panel 141d, 141e: Panel edges 142: Rear panel 15: Sealing plate 151: Through hole 2: Adapter unit 21: First adapter 22: Second adapter 3: Signal conductor unit 31: Signal conductor module 311: Signal conductor 312: First plug 313: Second plug 314: Positioning member 32: Seal 321: Positioning slot 4: Protective cover 40: Protective space 41: Slide slot 411: Insertion hole 42: Cable outlet notch 43: Top wall 44: Bottom wall 45: Side wall 91: First connector 92: Second connector D1: Front-to-back direction D2: Left-to-right direction D3: Up-down direction

Other features and functions of the present invention will be clearly presented in the embodiments with reference to the drawings, in which: Figure 1 is a perspective view illustrating an embodiment of the feeder device of the present invention, and illustrating a protective cover of the embodiment in a retracted state; Figure 2 is a view similar to Figure 1 but viewed from another angle; Figure 3 is a perspective exploded view illustrating a rear frame of the embodiment comprising two rear half frames; Figure 4 is a perspective view illustrating a sealing baffle coupled to a front frame of the embodiment; Figure 5 is a perspective view illustrating one of the signal conductor units of the embodiment; Figure 6 is a perspective exploded view illustrating one of the signal conductor units of the embodiment; Figure 7 is a cross-sectional view illustrating the positioning member of the signal conductor unit of the embodiment embedded in the positioning groove of the sealing member; Figure 8 is a side view illustrating the protective cover of this embodiment in the retracted state; Figure 9 is a cross-sectional view taken along line VIII-VIII in Figure 8; Figure 10 is a perspective view illustrating the protective cover of this embodiment in the extended state; and Figure 11 is a cross-sectional view illustrating the protective cover of this embodiment in the extended state.

1: Shell structure

11: Shell unit

12: Limiter

13: Front frame

14: Back frame

141: Back half of the frame

142: Back panel

2: Adapter unit

22: Second adapter

4: Protective cover

40: Protect space

41: Chute

411: Insertion hole

42: Cable outlet notch

43:top wall

44: Bottom wall

D1: Front and back direction

D2: Left and right direction

D3: up and down direction

Claims (10)

A feeder device comprises: a housing structure; at least one adapter unit, the adapter unit comprising a first adapter and a second adapter mounted in the housing structure with a front-to-rear spacing; at least one signal conductor unit, located within the housing structure and connected between the first adapter and the second adapter; and a protective cover, mounted on the housing structure and operable to change between a retracted position and an extended position. When in the retracted position, the protective cover is positioned around the outer periphery of the housing structure. When in the extended position, the protective cover extends rearward from the housing structure and shields the second adapter. The feed-through device as described in claim 1, wherein the second adapter can accommodate a plug-in assembly and extend rearward, and when the protective cover is in the extended state, the plug-in assembly is at least partially located within the protective cover and is shielded by the protective cover. A feeding device as described in claim 1, wherein the protective cover has a slide groove extending in the front-to-rear direction, the shell structure includes a shell unit for mounting the adapter units, and a limiting member passing through the slide groove and fixed to the shell unit, the limiting member restricting the protective cover from sliding relative to the shell unit along the extension direction of the slide groove. A feed-through device as described in claim 3, wherein the limit member has an operating portion that can be operated and rotated, a threaded section locked to the housing unit, and a rod section connecting the operating portion and the threaded section, the rod section passes through the slide groove, and the operating portion can be used to press against the protective cover; the slide groove is formed with an insertion hole at a middle position between the two ends, the diameter of which is larger than the outer diameter of the threaded section of the limit member but smaller than the outer diameter of the operating portion, and the width of the slide groove is larger than the outer diameter of the rod section but smaller than the outer diameter of the threaded section. A feed-through device as described in claim 3, wherein the housing unit has a front frame, a rear frame mounted behind the front frame, and a sealing partition mounted between the front frame and the rear frame, the sealing partition having a plurality of through holes extending front to back and for the signal conductor units to pass through respectively, each of the signal conductor units including a plurality of signal conductor modules extending front to back, and a seal for positioning the signal conductor modules and airtightly filling the corresponding through holes. A feed-through device as described in claim 5, wherein each of the seals has a plurality of positioning grooves extending front to back, and each of the signal conductor modules has a signal conductor extending front to back, a first plug connected to the front end of the signal conductor and mounted on the corresponding first adapter, a second plug connected to the rear end of the signal conductor and mounted on the corresponding second adapter, and at least one positioning member integrally covering the signal conductor, wherein the positioning member is used to be embedded in the positioning groove of the seal. A feed-through device as described in claim 5, wherein the rear frame includes two rear half frames mounted on the front frame and assembled facing each other, and a rear plate mounted on the rear ends of the rear half frames and for mounting the second adapters; the two rear half frames are identical and hermaphroditic. A feeding device as described in claim 3, wherein the protective cover includes a top wall, a bottom wall, and two side walls connecting the top wall and the bottom wall, each of the top wall and the bottom wall is provided with a slide groove, and the shell structure includes two limiting members, which are respectively used to pass through the slide grooves of the top wall and the bottom wall and be fixed to the shell unit. A feeder device as described in claim 8, wherein the housing unit has a front frame and a rear frame mounted behind the front frame, the rear frame has two rear half frames that are roughly U-shaped and mounted on the front frame in a group facing each other left and right, each of the rear half frames includes a side panel and a top panel and a bottom panel extending in the same direction from the side panel and spaced apart from each other up and down, the two rear half frames are connected with their top panels facing each other and their bottom panels facing each other, one of the limit members is fixed to the top panel of one of the rear half frames, and the other limit member is fixed to the bottom panel of the other rear half frame. A feed-through device as described in claim 8, wherein the rear edge of each side wall of the protective cover is recessed forward relative to the top wall and the bottom wall to form a wire outlet notch.