Closing equipment

Abstract

The utility model relates to the technical field of high-voltage power distribution cabinets, in particular to closing equipment, which comprises a ball spline shaft assembly, a front-back driving mechanism, a rotary driving mechanism and a tool head, the driving end of the front-back driving mechanism is connected with one end of the ball spline shaft assembly and used for controlling the ball spline shaft assembly to reciprocate in the axis direction of the ball spline shaft assembly. The driving end of the rotation driving mechanism is connected with the other end opposite to one end of the ball spline shaft assembly and is used for controlling the ball spline shaft assembly to circumferentially rotate along the axis direction of the ball spline shaft assembly, so that when switching-on operation needs to be carried out, only the position of the pressing button or the rotation button needs to be in butt joint with a tool head of the equipment; after butt joint is completed, the personnel evacuate from the high-voltage power distribution cabinet to reach a safe distance, and then the front-back driving mechanism and the rotary driving mechanism can be controlled by equipment such as an industrial tablet computer to drive the ball spline shaft assembly to rotate, advance and retreat, so that automatic closing is realized.

Description

Technical Field

[0001] This utility model relates to the field of high-voltage switchgear technology, and in particular to a closing device. Background Technology

[0002] In existing switchgear (such as high-voltage distribution cabinets or electrical control cabinets), local closing is performed manually by directly touching the buttons on the switchgear. Generally, ultra-high voltage electrical control cabinets in power distribution plants only require manual closing when a fault occurs. Since the electrical control cabinet is still energized when closing, direct manual contact can easily result in being knocked down by extremely high voltage (because the electrical control cabinet is faulty at this time), which creates a safety hazard. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a closing device that can realize automatic closing.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0005] A closing device includes a ball spline shaft assembly, a front and rear drive mechanism, a rotary drive mechanism, and a tooling head that connects to the closing switch of a high-voltage distribution cabinet. The tooling head is installed at one end of the ball spline shaft assembly. The drive end of the front and rear drive mechanism is connected to one end of the ball spline shaft assembly to control the reciprocating motion of the ball spline shaft assembly along its axial direction. The drive end of the rotary drive mechanism is connected to the other end of the ball spline shaft assembly opposite to one end to control the circumferential rotation of the ball spline shaft assembly along its axial direction.

[0006] Furthermore, it also includes a first mounting plate and a second mounting plate, the first mounting plate being vertically mounted on one side of the second mounting plate, the rotary drive mechanism being mounted on the first mounting plate, and the front-rear drive mechanism being mounted on the second mounting plate.

[0007] Furthermore, the rotary drive mechanism includes a first stepper motor, a first synchronous pulley, a second synchronous pulley, and a first synchronous belt. The first stepper motor is mounted on a first mounting plate, and the output shaft of the first stepper motor passes through the first mounting plate and is fixedly connected to the first synchronous pulley. The second synchronous pulley is sleeved on the outside of one end of the ball spline shaft assembly and the other end is connected to the ball spline shaft assembly. The first synchronous pulley and the second synchronous pulley are connected by the first synchronous belt.

[0008] Furthermore, the front and rear drive mechanism includes a second stepper motor, a third synchronous pulley, a fourth synchronous pulley, a second synchronous belt, and a slider. The third synchronous pulley, the fourth synchronous pulley, the second synchronous belt, and the slider are located on one side of the second mounting plate, and the second stepper motor is mounted on the second mounting plate and located on the opposite side of the second mounting plate.

[0009] The line connecting the third and fourth synchronous pulleys is parallel to the axis of the ball spline shaft assembly, and the third synchronous pulley is positioned close to the first mounting plate. The output shaft of the second stepper motor passes through the second mounting plate and is fixedly connected to the third synchronous pulley. The fourth synchronous pulley is rotatably connected to the second mounting plate. The third and fourth synchronous pulleys are connected by a second synchronous belt. The slider is fixedly connected to the second synchronous belt. The slider is connected to one end of the ball spline shaft assembly and is slidably connected to the second mounting plate.

[0010] Furthermore, the front and rear drive mechanism also includes a slide rail, which is mounted on a second mounting plate. The slider is mounted on the slide rail and is slidably connected to the slide rail.

[0011] Furthermore, the front and rear drive mechanism also includes an abutment block, which abuts the second synchronous belt against the slider to fix the slider to the second synchronous belt.

[0012] Furthermore, a bearing is fixedly sleeved on one end of the ball spline shaft assembly, and the slider is fixedly connected to the bearing.

[0013] Furthermore, the first mounting plate is also provided with a magnetic attraction mechanism, which is used to attract the closing device onto the high-voltage distribution cabinet after the tool head is connected to the closing switch of the high-voltage distribution cabinet.

[0014] Furthermore, the magnetic attraction mechanism includes an electromagnet and an insulating component, the insulating component being mounted on a first mounting plate, and the electromagnet being mounted on the insulating component.

[0015] Furthermore, the number of electromagnets is three, and the insulating assembly includes an insulating pad and an insulating block. The insulating block is mounted on the first mounting plate, and the insulating pad is mounted on the insulating block. The insulating pad is L-shaped, and the three electromagnets are respectively mounted on the three ends of the insulating pad.

[0016] The beneficial effects of this utility model are as follows:

[0017] This solution involves setting up a ball spline shaft assembly, a front and rear drive mechanism, a rotary drive mechanism, and a tooling head that connects to the closing switch of the high-voltage distribution cabinet. The tooling head is installed at one end of the ball spline shaft assembly. The drive end of the front and rear drive mechanism is connected to one end of the ball spline shaft assembly to control the reciprocating motion of the ball spline shaft assembly along its axial direction. The drive end of the rotary drive mechanism is connected to the other end of the ball spline shaft assembly to control its circumferential rotation along its axial direction. When a closing operation is required, simply align the press or rotate button with the tooling head of this device. After alignment, personnel should evacuate the high-voltage distribution cabinet to a safe distance. Then, the front and rear drive mechanisms and the rotary drive mechanism can be controlled via an industrial tablet PC or similar device to rotate, advance, and retreat the ball spline shaft assembly, thereby achieving automatic closing and protecting personal safety. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the closing device of this utility model;

[0019] Figure 2 This is a schematic diagram of the closing device of this utility model;

[0020] Figure 3 This is a schematic diagram of the closing device of this utility model;

[0021] Label Explanation:

[0022] 1. Ball spline shaft assembly; 11. Spline shaft; 12. Bushing; 13. Bearing; 2. Front and rear drive mechanism; 21. Second stepper motor; 22. Third synchronous pulley; 23. Fourth synchronous pulley; 24. Second synchronous belt; 25. Slider; 26. Slide rail; 27. Abutment block; 3. Rotary drive mechanism; 31. First stepper motor; 32. First synchronous pulley; 33. Second synchronous pulley; 34. First synchronous belt; 4. Tooling head; 5. First mounting plate; 6. Second mounting plate; 7. Magnetic attraction mechanism; 71. Electromagnet; 72. Insulating gasket; 73. Insulating block; 8. Controller; 9. Handle. Detailed Implementation

[0023] To explain in detail the technical content, objectives, and effects of this utility model, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0024] Please refer to Figure 1 The technical solution adopted by this utility model is as follows:

[0025] A closing device includes a ball spline shaft assembly, a front and rear drive mechanism, a rotary drive mechanism, and a tooling head that connects to the closing switch of a high-voltage distribution cabinet. The tooling head is installed at one end of the ball spline shaft assembly. The drive end of the front and rear drive mechanism is connected to one end of the ball spline shaft assembly to control the reciprocating motion of the ball spline shaft assembly along its axial direction. The drive end of the rotary drive mechanism is connected to the other end of the ball spline shaft assembly opposite to one end to control the circumferential rotation of the ball spline shaft assembly along its axial direction.

[0026] As can be seen from the above description, the beneficial effects of this utility model are as follows:

[0027] This solution involves setting up a ball spline shaft assembly, a front and rear drive mechanism, a rotary drive mechanism, and a tooling head that connects to the closing switch of the high-voltage distribution cabinet. The tooling head is installed at one end of the ball spline shaft assembly. The drive end of the front and rear drive mechanism is connected to one end of the ball spline shaft assembly to control the reciprocating motion of the ball spline shaft assembly along its axial direction. The drive end of the rotary drive mechanism is connected to the other end of the ball spline shaft assembly to control its circumferential rotation along its axial direction. When a closing operation is required, simply align the press or rotate button with the tooling head of this device. After alignment, personnel should evacuate the high-voltage distribution cabinet to a safe distance. Then, the front and rear drive mechanisms and the rotary drive mechanism can be controlled via an industrial tablet PC or similar device to rotate, advance, and retreat the ball spline shaft assembly, thereby achieving automatic closing and protecting personal safety.

[0028] Furthermore, it also includes a first mounting plate and a second mounting plate, the first mounting plate being vertically mounted on one side of the second mounting plate, the rotary drive mechanism being mounted on the first mounting plate, and the front-rear drive mechanism being mounted on the second mounting plate.

[0029] Furthermore, the rotary drive mechanism includes a first stepper motor, a first synchronous pulley, a second synchronous pulley, and a first synchronous belt. The first stepper motor is mounted on a first mounting plate, and the output shaft of the first stepper motor passes through the first mounting plate and is fixedly connected to the first synchronous pulley. The second synchronous pulley is sleeved on the outside of one end of the ball spline shaft assembly and the other end is connected to the ball spline shaft assembly. The first synchronous pulley and the second synchronous pulley are connected by the first synchronous belt.

[0030] As can be seen from the above description, when the first stepper motor starts, it drives the first synchronous pulley to rotate. The rotation of the first synchronous pulley drives the second synchronous pulley to rotate, and the rotation of the second synchronous pulley drives the ball spline shaft assembly to rotate.

[0031] Furthermore, the front and rear drive mechanism includes a second stepper motor, a third synchronous pulley, a fourth synchronous pulley, a second synchronous belt, and a slider. The third synchronous pulley, the fourth synchronous pulley, the second synchronous belt, and the slider are located on one side of the second mounting plate, and the second stepper motor is mounted on the second mounting plate and located on the opposite side of the second mounting plate.

[0032] The line connecting the third and fourth synchronous pulleys is parallel to the axis of the ball spline shaft assembly, and the third synchronous pulley is positioned close to the first mounting plate. The output shaft of the second stepper motor passes through the second mounting plate and is fixedly connected to the third synchronous pulley. The fourth synchronous pulley is rotatably connected to the second mounting plate. The third and fourth synchronous pulleys are connected by a second synchronous belt. The slider is fixedly connected to the second synchronous belt. The slider is connected to one end of the ball spline shaft assembly and is slidably connected to the second mounting plate.

[0033] As can be seen from the above description, the second stepper motor starts, driving the third synchronous pulley to rotate. The rotation of the third synchronous pulley drives the second synchronous belt to rotate, and the rotation of the second synchronous belt drives the ball spline shaft assembly to move forward and backward.

[0034] Furthermore, the front and rear drive mechanism also includes a slide rail, which is mounted on a second mounting plate. The slider is mounted on the slide rail and is slidably connected to the slide rail.

[0035] As can be seen from the above description, by setting a slide rail, the slider can slide stably along the slide rail, thereby further improving the stability of the ball spline shaft assembly in both forward and backward movements.

[0036] Furthermore, the front and rear drive mechanism also includes an abutment block, which abuts the second synchronous belt against the slider to fix the slider to the second synchronous belt.

[0037] Furthermore, a bearing is fixedly sleeved on one end of the ball spline shaft assembly, and the slider is fixedly connected to the bearing.

[0038] Furthermore, the first mounting plate is also provided with a magnetic attraction mechanism, which is used to attract the closing device onto the high-voltage distribution cabinet after the tool head is connected to the closing switch of the high-voltage distribution cabinet.

[0039] Furthermore, the magnetic attraction mechanism includes an electromagnet and an insulating component, the insulating component being mounted on a first mounting plate, and the electromagnet being mounted on the insulating component.

[0040] As can be seen from the above description, by setting up an electromagnet, when a closing operation is required, the position where the button to be pressed or rotated needs to be aligned with the tooling head of the equipment. After alignment, the electromagnet is energized, which can attract the entire equipment to the door of the high-voltage distribution cabinet, further improving the stability of closing.

[0041] Furthermore, the number of electromagnets is three, and the insulating assembly includes an insulating pad and an insulating block. The insulating block is mounted on the first mounting plate, and the insulating pad is mounted on the insulating block. The insulating pad is L-shaped, and the three electromagnets are respectively mounted on the three ends of the insulating pad.

[0042] Please refer to Figures 1 to 3 As shown, Embodiment 1 of this utility model is as follows:

[0043] Please refer to Figures 1 to 3 A closing device includes a ball spline shaft assembly 1, a front and rear drive mechanism 2, a rotary drive mechanism 3, and a tooling head that is connected to the closing switch of a high-voltage distribution cabinet. The tooling head is installed at one end of the ball spline shaft assembly 1. The drive end of the front and rear drive mechanism 2 is connected to one end of the ball spline shaft assembly 1 to control the reciprocating motion of the ball spline shaft assembly 1 along the axial direction of the ball spline shaft assembly 1. The drive end of the rotary drive mechanism 3 is connected to the other end opposite to one end of the ball spline shaft assembly 1 to control the circumferential rotation of the ball spline shaft assembly 1 along the axial direction of the ball spline shaft assembly 1.

[0044] Please refer to Figures 1 to 3 It also includes a first mounting plate 5 and a second mounting plate 6. The first mounting plate 5 is vertically mounted on one side of the second mounting plate 6. The rotary drive mechanism 3 is mounted on the first mounting plate 5, and the front and rear drive mechanism 2 is mounted on the second mounting plate 6.

[0045] Please refer to Figures 1 to 3 The rotary drive mechanism 3 includes a first stepper motor 31, a first synchronous pulley, a second synchronous pulley, and a first synchronous belt. The first stepper motor 31 is mounted on a first mounting plate 5. The output shaft of the first stepper motor 31 passes through the first mounting plate 5 and is fixedly connected to the first synchronous pulley. The second synchronous pulley is sleeved on the outside of one end of the ball spline shaft assembly 1 and the other end is connected to the ball spline shaft assembly 1. The first synchronous pulley and the second synchronous pulley are connected by the first synchronous belt.

[0046] Please refer to Figures 1 to 3The front and rear drive mechanism 2 includes a second stepper motor 21, a third synchronous pulley 22, a fourth synchronous pulley 23, a second synchronous belt 24, and a slider 25. The third synchronous pulley 22, the fourth synchronous pulley 23, the second synchronous belt 24, and the slider 25 are located on one side of the second mounting plate 6. The second stepper motor 21 is mounted on the second mounting plate 6 and is located on the opposite side of the second mounting plate 6.

[0047] The line connecting the third synchronous pulley 22 and the fourth synchronous pulley 23 is parallel to the axis of the ball spline shaft assembly 1, and the third synchronous pulley 22 is positioned close to the first mounting plate 5. The output shaft of the second stepper motor 21 passes through the second mounting plate 6 and is fixedly connected to the third synchronous pulley 22. The fourth synchronous pulley 23 is rotatably connected to the second mounting plate 6. The third synchronous pulley 22 and the fourth synchronous pulley 23 are connected by a second synchronous belt 24. The slider 25 is fixedly connected to the second synchronous belt 24. The slider 25 is connected to one end of the ball spline shaft assembly 1 and is slidably connected to the second mounting plate 6.

[0048] Please refer to Figure 1 The front and rear drive mechanism 2 also includes a slide rail 26, which is mounted on the second mounting plate 6. The slider 25 is mounted on the slide rail 26 and is slidably connected to the slide rail 26.

[0049] Please refer to Figure 1 The front and rear drive mechanism 2 also includes an abutment block 27, which abuts the second synchronous belt 24 against the slider 25 so that the slider 25 is fixedly connected to the second synchronous belt 24.

[0050] Please refer to Figure 2 One end of the ball spline shaft assembly 1 is externally fitted with a bearing 13, and the slider 25 is fixedly connected to the bearing 13.

[0051] Please refer to Figure 2 The ball spline shaft assembly 1 includes a spline shaft 11 and a bushing 12. The bearing 13 is sleeved on one end of the spline shaft 11, and the inner ring of the bearing 13 is fixedly connected to one end of the spline shaft 11. The bushing 12 is rotatably mounted on the first mounting plate 5. The bushing 12 is fixedly connected to the second synchronous pulley. The bushing 12 is sleeved on the other end of the spline shaft 11, and the spline shaft 11 and the bushing 12 are slidably connected.

[0052] Please refer to Figure 1 The first mounting plate 5 is also provided with a magnetic attraction mechanism 7, which is used to attract the closing device onto the high-voltage distribution cabinet after the tool head is connected to the closing switch of the high-voltage distribution cabinet.

[0053] In this embodiment, there are two magnetic attraction mechanisms 7, which are respectively disposed at opposite ends on one side of the first mounting plate 5.

[0054] Please refer to Figures 1 to 3 The first mounting plate 5 has handles 9 at opposite ends of one side and the other side.

[0055] Please refer to Figure 1 and Figure 2 The magnetic attraction mechanism 7 includes an electromagnet 71 and an insulating component. The insulating component is mounted on the first mounting plate 5, and the electromagnet 71 is mounted on the insulating component.

[0056] Please refer to Figure 2 The number of electromagnets 71 is three. The insulating assembly includes an insulating pad 72 and an insulating block 73. The insulating block 73 is mounted on the first mounting plate 5. The insulating pad 72 is mounted on the insulating block 73. The insulating pad 72 is L-shaped. The three electromagnets 71 are respectively mounted on the three ends of the insulating pad 72.

[0057] Please refer to Figure 1 and Figure 2 The closing device also includes a controller 8, which is electrically connected to the first stepper motor 31, the second stepper motor 21, and the electromagnet 71. The controller 8 is also equipped with three buttons: a first button, a second button, and a third button. When the third button is pressed and held for three seconds, the six electromagnets 71 are energized and will be attracted to the high-voltage distribution cabinet. In knob mode, the first button is used to adjust the left rotation of the ball spline shaft assembly 1, and the second button is used to adjust the right rotation of the ball spline shaft assembly 1. In button mode, the first button is used to adjust the forward movement of the ball spline shaft assembly 1, and the second button is used to adjust the backward movement of the ball spline shaft assembly 1.

[0058] The closing device designed using this solution can be aligned with the tooling head (which is insulated) at the location where a button needs to be pressed or rotated. After alignment, the electromagnet 71 on the device is energized, attracting the entire device to the door of the high-voltage distribution cabinet. Personnel can then evacuate the high-voltage distribution cabinet 30 meters away (to reach a safe distance) and remotely control the closing operation via wireless connection to the device's controller 8 through an industrial tablet computer, ensuring personal safety. This device is also suitable for various other devices that require remote automatic button pressing or rotation. All functions are integrated into one device, making it simple to operate and easy to carry.

[0059] In knob mode, the tooling head is a rotating tooling head. The controller 8 of the device is wirelessly connected to the industrial tablet computer. The controller 8 controls the first step motor 31 to start, which drives the first synchronous pulley to rotate. The rotation of the first synchronous pulley drives the second synchronous pulley to rotate. The rotation of the second synchronous pulley drives the bushing 12 to rotate. The rotation of the bushing 12 drives the spline shaft 11 to rotate.

[0060] In button mode, the working head is a button tooling head. It is wirelessly connected to the controller 8 of the device via an industrial tablet computer. The controller 8 controls the second stepper motor 21 to start, which drives the third synchronous pulley 22 to rotate. The rotation of the third synchronous pulley 22 drives the second synchronous belt 24 to rotate. The rotation of the second synchronous belt 24 drives the slider 25 to slide along the slide rail 26, thereby driving the spline shaft 11 to move forward and backward.

[0061] In summary, the closing device provided by this utility model comprises a ball spline shaft assembly, a front and rear drive mechanism, a rotary drive mechanism, and a tooling head that connects to the closing switch of the high-voltage distribution cabinet. The tooling head is installed at one end of the ball spline shaft assembly. The drive end of the front and rear drive mechanism is connected to one end of the ball spline shaft assembly to control the reciprocating motion of the ball spline shaft assembly along its axial direction. The drive end of the rotary drive mechanism is connected to the other end of the ball spline shaft assembly to control its circumferential rotation along its axial direction. When a closing operation is required, simply align the press or rotate button with the tooling head of the device. After alignment, personnel should evacuate the high-voltage distribution cabinet to a safe distance. Then, the front and rear drive mechanism and the rotary drive mechanism can be controlled via an industrial tablet PC or similar device to rotate, advance, and retreat the ball spline shaft assembly, thereby achieving automatic closing and protecting personal safety.

[0062] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent modifications made based on the content of this utility model specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A closing device, characterized in that The ball spline shaft assembly, front and rear driving mechanism, rotary driving mechanism and tool head opposite to the closing switch of the high-voltage distribution cabinet are provided, the tool head is installed at one end of the ball spline shaft assembly, the driving end of the front and rear driving mechanism is connected with one end of the ball spline shaft assembly for controlling the reciprocating movement of the ball spline shaft assembly along the axial direction of the ball spline shaft assembly, and the driving end of the rotary driving mechanism is connected with the other end opposite to one end of the ball spline shaft assembly for controlling the circumferential rotation of the ball spline shaft assembly along the axial direction of the ball spline shaft assembly.

2. The closing device according to claim 1, characterized in that The first mounting plate and the second mounting plate are further provided, the first mounting plate is vertically installed on one side of the second mounting plate, the rotary driving mechanism is installed on the first mounting plate, and the front and rear driving mechanism is installed on the second mounting plate.

3. The closing device according to claim 2, characterized in that The rotary driving mechanism comprises a first stepper motor, a first synchronous pulley, a second synchronous pulley and a first synchronous belt, the first stepper motor is installed on the first mounting plate, the output shaft of the first stepper motor is fixedly connected with the first synchronous pulley through the first mounting plate, the second synchronous pulley is sleeved outside the other end opposite to one end of the ball spline shaft assembly, and the second synchronous pulley is connected with the ball spline shaft assembly, and the first synchronous pulley and the second synchronous pulley are connected through the first synchronous belt.

4. The closing device according to claim 2, characterized in that The front and rear driving mechanism comprises a second stepper motor, a third synchronous pulley, a fourth synchronous pulley, a second synchronous belt and a sliding block, the third synchronous pulley, the fourth synchronous pulley, the second synchronous belt and the sliding block are located on one side of the second mounting plate, the second stepper motor is installed on the second mounting plate and located on the other side opposite to one side of the second mounting plate; The connecting line between the third synchronous pulley and the fourth synchronous pulley is parallel to the axis of the ball spline shaft assembly, the third synchronous pulley is arranged close to the first mounting plate, the output shaft of the second stepper motor is fixedly connected with the third synchronous pulley through the second mounting plate, the fourth synchronous pulley is rotationally connected with the second mounting plate, the third synchronous pulley and the fourth synchronous pulley are connected through the second synchronous belt, the sliding block is fixedly connected with the second synchronous belt, the sliding block is connected with one end of the ball spline shaft assembly, and the sliding block is slidingly connected with the second mounting plate.

5. The closing device according to claim 4, characterized in that The front and rear driving mechanism further comprises a sliding rail, the sliding rail is installed on the second mounting plate, the sliding block is installed on the sliding rail, and the sliding block is slidingly connected with the sliding rail.

6. The closing device according to claim 4, characterized in that The front and rear driving mechanism further comprises an abutting block, the abutting block abuts the second synchronous belt on the sliding block to fixedly connect the sliding block with the second synchronous belt.

7. The closing device according to claim 4, characterized in that, A bearing is fixedly sleeved outside one end of the ball spline shaft assembly, and the sliding block is fixedly connected with the bearing.

8. The closing device according to claim 2, characterized in that, A magnetic attraction mechanism is further arranged on the first mounting plate, and the magnetic attraction mechanism is used for attracting the closing device to the high-voltage distribution cabinet after the tool head is opposite to the closing switch of the high-voltage distribution cabinet.

9. The closing device according to claim 8, characterized in that The magnetic attraction mechanism comprises an electromagnet and an insulation assembly, the insulation assembly is installed on the first mounting plate, and the electromagnet is installed on the insulation assembly.

10. The closing device according to claim 9, characterized in that The number of electromagnets is three, the insulating assembly comprises insulating pads and insulating blocks, the insulating blocks are installed on the first mounting plate, the insulating pads are installed on the insulating blocks, the insulating pads are L-shaped, and the three electromagnets are respectively installed at the three ends of the insulating pads.

Images