A double-break switch plug

Abstract

This utility model relates to the field of plug technology and discloses a double-break switch plug, including a housing. The upper surface of the housing is equipped with a power-off button, a power-on button, and an indicator light. Both the power-off button and the power-on button can be pressed down and reset upwards. The lower surface of the housing is equipped with a PE pin arranged in a triangular pattern and two power-on pins. The power-off button, power-on button, indicator light, PE pin, and power-on pins are all connected to the wiring assembly inside the housing. This utility model achieves safe start-stop control. Pressing down the power-on button drives the slider to rise, causing the conductive spring to contact the power-on terminal and energize it. Pressing down the power-off button causes its lower wedge-shaped block to push the locking piece to release the power-on button. The power-on button resets under the action of a third spring, de-energizing it. This double-button mechanism avoids accidental operation, ensuring that power is only connected under clear instructions, improving safety. The operation process is also clear and easy for users to quickly master.

Description

Technical Field

[0001] This utility model relates to the field of plug technology, specifically a double-break switch plug. Background Technology

[0002] In everyday electricity use scenarios such as homes and offices, the safety hazards and operational inconveniences of traditional double-break switch plugs are quite prominent, specifically in the following aspects:

[0003] 1. The safety protection mechanism is simplistic, making it easy to accidentally energize the device.

[0004] Traditional double-pole switch plugs often use a single-button design, lacking a clear start / stop locking mechanism, making them prone to accidental power-on due to misoperation or external impact. For example, in a home environment, children may accidentally press the power button out of curiosity, causing the plug to be connected to the power supply without confirming safety, increasing the risk of electric shock. In addition, traditional plugs may self-reset due to button loosening in vibrating environments (such as frequent movement of office equipment), causing abnormal power outages and affecting data security.

[0005] 2. Poor contact stability can easily lead to circuit failure.

[0006] Traditional plugs often use simple crimping or welding to fix the conductive contacts and power terminals. After long-term use, wear and tear from plugging and unplugging can lead to poor contact and increase safety hazards.

[0007] The above problems highlight the shortcomings of traditional plugs in terms of safety and stability, and there is an urgent need to improve protection capabilities through structural innovation. Therefore, this application proposes a double-break switch plug. Utility Model Content

[0008] To address the technical problems existing in the background art, this utility model proposes a double-break switch plug.

[0009] The present invention discloses a double-break switch plug, including a housing. The upper end face of the housing is equipped with a power-off button, a power-on button and an indicator light. Both the power-off button and the power-on button can be pressed down and reset upward. The lower end face of the housing is equipped with a PE pin arranged in a triangular pattern and two power pins. The power-off button, the power-on button, the indicator light, the PE pin and the power pins are all connected to the wiring assembly inside the housing.

[0010] The wiring assembly includes terminal blocks, PE connecting pieces, conductive springs, a fixing bracket, a slider, and a locking piece;

[0011] The mounting bracket is installed inside the front end of the housing. The lower ends of the power off button and the power on button both extend into the housing and are slidably assembled with the mounting bracket. The slider is slidably assembled at the rear end of the mounting bracket and is driven to rise by the power on button. The power on button is manually reset upwards by driving the power off button to the power on button.

[0012] The terminal block is installed inside the rear end of the housing and has three terminals that are respectively connected to the PE connecting piece and two conductive spring pieces. The free end of the PE connecting piece extends into the front end of the housing and is connected to the PE pin. The free end of the conductive spring piece is respectively connected to the ends of the slider extending to both sides of the fixing frame.

[0013] Both sides of the rear end of the mounting bracket have power terminals that are electrically connected to the adjacent power pins, and the two power terminals are respectively located above the free ends of the two conductive springs.

[0014] As a further optimization of this utility model, the lower end of the power button extends vertically downward and slides into the rear end of the slider. An L-shaped locking piece is installed at the front end of the slider. The short side of the L-shape of the locking piece is opposite to the front end face of the slider and is connected by a first spring. The long side of the L-shape slides horizontally backward through the slider and is movably fitted onto the lower end of the power button and engages with the slot on the rear side of the lower end of the power button.

[0015] As a further optimization of this utility model, the rear end of the slider is provided with a movable hole that matches the lower end of the power button, and the bottom of the front end face of the slider is provided with a groove for installing the first spring. A sleeve is installed in the groove, one end of the first spring is fitted into the sleeve and fixed to the inner wall of the groove, and the other end of the first spring is fixed to the inner side of the L-shaped short side of the locking piece.

[0016] As a further optimization of this utility model, the lower end of the power button is wedge-shaped, and the rear end of the L-shaped long side of the locking piece is provided with a through hole that matches the lower end of the power button. In the initial state, the rear end of the through hole is connected to the movable hole and the width of the connection is greater than the width of the flat bottom of the wedge-shaped lower end of the power button.

[0017] As a further optimization of this utility model, the lower end of the power-off button is connected to the bottom surface of the inner cavity of the housing through a second spring. A wedge block is installed on the rear side of the lower end of the power-off button. The wedge block has an inclined surface, and the inclined surface is vertically set above the short side of the L-shaped locking plate.

[0018] As a further optimization of this utility model, a limiting bracket is installed on the front end of the terminal block. The upper end of the limiting bracket has a slot and a circuit board is inserted therein. The lower end of the circuit board abuts against the conductive spring, and the upper end of the circuit board is electrically connected to the indicator light.

[0019] As a further optimization of this utility model, the lower end of the fixing frame is equipped with a support column arranged in a triangle and connected to the PE pin and two power-conducting pins respectively. The free end of the PE connecting piece extends to the bottom of the front support column and is engaged with the upper end of the PE pin by a snap ring.

[0020] As a further optimization of this utility model, the upper end of the terminal block has a mounting groove that matches the end of the conductive spring. The end of the conductive spring away from the slider is snapped into the mounting groove and fixed by fasteners, allowing for direct wiring output without intermediate connections, resulting in better reliability.

[0021] As a further optimized solution of this utility model, the power button includes a button end and a button rod at its bottom. The button end is arranged parallel to the upper rear end of the fixing frame. The lower end of the button rod is assembled with the slider. The upper end of the button rod is fitted with a third spring, and the two ends of the third spring are respectively fixed to the lower surface of the button end and the upper rear end of the fixing frame.

[0022] The double-break switch plug proposed in this utility model has the following beneficial effects:

[0023] (I) This utility model achieves safe start and stop control through the linkage design of the power off button and the power on button. When the power on button is pressed down, it drives the slider to rise, so that the conductive spring contacts the power on terminal to conduct electricity. When the power off button is pressed down, the wedge block at its lower end pushes the locking piece to release the power on button. The power on button is reset and de-energized under the action of the third spring. This dual-button mechanism avoids misoperation and ensures that the power is connected only under clear instructions, thereby improving the safety of use. At the same time, the operation process is clear and easy for users to master quickly.

[0024] (ii) The locking plate is connected to the slider through the first spring. When the power button is pressed down, the lower end of the wedge pushes open the locking plate. After the slot aligns with the locking plate, the spring resets to achieve locking, so that the power button is stably in the pressed state, ensuring that the conductive spring contact the power terminal continuously. This elastic locking structure can withstand slight vibrations in daily use, avoid poor contact or accidental power failure caused by plug shaking, improve power stability, and is especially suitable for application scenarios with frequent plugging and unplugging or vibration.

[0025] (iii) The conductive spring is tightly attached to the circuit board through the protrusions, and the terminal block is directly snapped and fixed to the conductive spring. There are no additional connecting parts in the middle, which reduces contact resistance and fault points. The PE connecting piece is fixed to the PE pin through the snap ring to ensure reliable grounding. This design reduces the risk of poor circuit contact, improves the electrical reliability of the double-break switch plug, meets safety standards, and reduces the risk of leakage or short circuit caused by loose connection.

[0026] (iv) The power-off button is reset by the second spring and the power-on button is reset by the third spring, ensuring that the conductive spring can quickly disengage from the power-on terminal after the power-off is triggered, thus cutting off the power supply. The spring reset system has a short response time and can act quickly when leakage or abnormality is detected. Combined with the circuit status display of the indicator light, it realizes fault visualization and improves the power safety guarantee capability.

[0027] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0028] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0029] Figure 2 This is a schematic diagram of the internal structure of the housing of this utility model;

[0030] Figure 3 This utility model Figure 2 A schematic diagram of a partial cross-sectional structure;

[0031] Figure 4 This utility model Figure 2 A schematic diagram of the side sectional structure;

[0032] Figure 5 This utility model Figure 4 A schematic diagram of the assembly structure of the middle slider and the locking plate;

[0033] Figure 6 This is a three-dimensional assembly structure diagram of the slider and locking piece of this utility model;

[0034] Figure 7 This utility model Figure 6 A schematic diagram of a partial cross-sectional structure.

[0035] Figure Descriptions: 1. Housing; 2. Power-off button; 3. Power-on button; 4. Indicator light; 5. PE pin; 6. Power-on pin; 7. Terminal block; 8. PE connecting piece; 9. Conductive spring; 10. Fixing bracket; 11. Slider; 111. Movable hole; 112. Sleeve post; 12. Locking piece; 121. Through hole; 13. First spring; 14. Second spring; 15. Wedge block; 16. Slot; 17. Third spring; 18. Limiting bracket; 19. Circuit board. Detailed Implementation

[0036] The embodiments of this utility model are described in detail below. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar symbols denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0037] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0038] like Figure 1-7 As shown, a double-break switch plug includes a housing 1. The upper end face of the housing 1 is equipped with a power-off button 2, a power-on button 3, and an indicator light 4. Both the power-off button 2 and the power-on button 3 can be pressed down and reset upwards. The lower end face of the housing 1 is equipped with a PE pin 5 arranged in a triangular pattern and two power pins 6. The power-off button 2, the power-on button 3, the indicator light 4, the PE pin 5, and the power pins 6 are all connected to the wiring assembly inside the housing 1.

[0039] The wiring assembly includes a terminal block 7, a PE connecting piece 8, a conductive spring 9, a fixing bracket 10, a slider 11, and a locking piece 12;

[0040] The fixing frame 10 is installed inside the front end of the housing 1. The lower ends of the power off button 2 and the power on button 3 both extend into the housing 1 and are slidably assembled with the fixing frame 10. The slider 11 is slidably assembled at the rear end of the fixing frame 10 and is driven to rise by the power on button 3. The power on button 3 is manually reset upward by driving the power off button 2.

[0041] The terminal block 7 is installed inside the rear end of the housing 1 and has three terminals that are respectively connected to the PE connecting piece 8 and the two conductive spring pieces 9. The free end of the PE connecting piece 8 extends into the front end of the housing 1 and is connected to the PE pin 5. The free end of the conductive spring piece 9 is connected to the ends of the slider 11 that extend to both sides of the fixing frame 10.

[0042] The rear sides of the mounting bracket 10 have power terminals that are electrically connected to the adjacent power pins 6, and the two power terminals are respectively located above the free ends of the two conductive springs 9.

[0043] This design improves operational safety through a dual-button mechanism. When the power button 3 is pressed down, it drives the slider 11 to rise, causing the conductive spring 9 to contact the power terminal and energize. When the power off button 2 is pressed down, it forces the power button 3 to reset and de-energize through mechanical linkage.

[0044] For example, users need to manually press the power button 3 to connect the power supply to avoid accidental contact. When the power is off, users only need to press the power off button 2 to force the connection between the conductive spring 9 and the power terminal through the mechanical structure on the fixing frame 10, ensuring a complete power off. The PE pin 5 is directly grounded through the PE connecting piece 8. The conductive spring 9 and the slider 11 are linked to ensure stable contact when the power is on, solving the problems of easy accidental contact and poor contact of traditional plugs with a single button.

[0045] Specifically, such as Figure 3 and Figure 4 As shown, the power button 3 includes a button end and a button rod at its bottom. The button end is arranged parallel to the upper rear end of the fixing frame 10. The lower end of the button rod is assembled with the slider 11. The upper end of the button rod is fitted with a third spring 17, and the two ends of the third spring 17 are respectively fixed to the lower surface of the button end and the upper rear end of the fixing frame 10.

[0046] The third spring 17 provides a reset force for the power button 3. The end of the button is set parallel to the fixing bracket 10, which is ergonomic and makes it easy for the thumb to press vertically, reducing the torque deviation during operation. For example, when plugging or unplugging a plug in a narrow space, the parallel design can ensure that the pressing force is applied vertically to the button rod, avoiding jamming or poor reset caused by tilting the press, thus improving the convenience of operation and structural stability.

[0047] Specifically, such as Figures 3-5 As shown, the lower end of the power button 3 extends vertically downward and slides into the rear end of the slider 11. An L-shaped locking piece 12 is installed at the front end of the slider 11. The short side of the L-shape of the locking piece 12 is opposite to the front end face of the slider 11 and is connected by the first spring 13. The long side of the L-shape slides horizontally backward through the slider 11 and is movably fitted onto the lower end of the power button 3 and engages with the slot 16 on the rear side of the lower end of the power button 3.

[0048] The locking plate 12 and the first spring 13 form an elastic locking structure. When the power button 3 is pressed down, its wedge-shaped lower end pushes open the L-shaped long side of the locking plate 12. When the slot 16 moves to align with the locking plate 12, the first spring 13 pushes the locking plate 12 into the slot 16, keeping the power button 3 in the pressed state. This design can prevent the plug from automatically disconnecting when vibrating or being hit by external force. For example, during the movement of office equipment, the locking structure can effectively resist vibration and ensure that the conductive spring 9 continues to contact the power terminal, avoiding abnormal power outages caused by poor contact.

[0049] Furthermore, such as Figure 5As shown, the rear end of the slider 11 is provided with a movable hole 111 that matches the lower end of the power button 3. The bottom of the front end face of the slider 11 is provided with a groove for installing the first spring 13. A sleeve post 112 is installed in the groove. One end of the first spring 13 is fitted into the sleeve post 112 and fixed to the inner wall of the groove. The other end of the first spring 13 is fixed to the inner side of the L-shaped short side of the locking piece 12.

[0050] The movable hole 111 provides a sliding guide for the lower end of the power button 3, ensuring the assembly accuracy between it and the slider 11. The sleeve 112 fixes the first spring 13, preventing the spring from shifting or winding when under force, and ensuring that the locking action of the locking piece 12 is stable and reliable. For example, after pressing the power button 3 multiple times, the sleeve 112 can still maintain the verticality of the spring, maintain the effectiveness of the locking structure, and extend the mechanical life of the plug.

[0051] Specifically, such as Figure 5 As shown, the lower end of the power button 3 is wedge-shaped, and the L-shaped locking piece 12... The long side of the power button 3 has a through hole 121 at its rear end, which is adapted to the lower end of the power button 3. In the initial state, the rear end of the through hole 121 is connected to the movable hole 111 and the width of the connection is greater than the width of the flat bottom of the wedge-shaped lower end of the power button 3. When the power button 3 is pressed down, the wedge-shaped inclined surface of the power button 3 contacts the rear edge of the through hole 121, thereby pushing the locking piece 12 backward. When the slot 16 moves to be flush with the long side of the locking piece 12, the locking piece 12 moves forward and resets under the elastic action of the first spring 13, so that the rear edge of the through hole 121 is inserted into the slot 16, realizing the assembly between the lower end of the power button 3 and the slider 11. Then, through the upward reset function of the power button 3, the power button 3 drives the slider 11 and the conductive spring 9 on it to move upward, so that the free end of the conductive spring 9 contacts the power terminal of the power pin 6 to realize power supply.

[0052] The wedge-shaped lower end and the through hole 121 form a mechanical linkage guide. When the power button 3 is pressed, the wedge-shaped inclined surface pushes the locking piece 12 backward. The mechanical properties of the inclined surface reduce the pressing force and improve the operating feel. When the slot 16 is aligned with the locking piece 12, the spring returns to achieve automatic locking. The power-on state can be maintained without additional operation. This design combines mechanical movement with elastic reset to ensure a smooth and stable power-on process, which is especially suitable for elderly people or users with less strength.

[0053] Furthermore, such as Figure 3 and Figure 4 As shown, the lower end of the power-off button 2 is connected to the bottom surface of the inner cavity of the housing 1 through the second spring 14. A wedge block 15 is installed on the rear side of the lower end of the power-off button 2. The wedge block 15 has an inclined surface, and the inclined surface is vertically arranged above the short side of the L-shaped locking piece 12.

[0054] The power-off button 2 is automatically reset by the second spring 14. When the power-off button 2 is pressed, the inclined surface of the wedge block 15 at its lower end pushes the short side of the L-shaped locking piece 12 backward, forcibly releasing the locking piece 12 from the slot 16. For example, in the event of leakage or emergency, when the power-off button 2 is pressed, the wedge block 15 quickly pushes open the locking piece 12, and the power-on button 3 is quickly reset under the action of the third spring 17, cutting off the power supply. The response time is less than 0.1 seconds, ensuring safe power-off.

[0055] Specifically, such as Figures 2-4 As shown, a limit bracket 18 is installed on the front end of the terminal 7. The upper end of the limit bracket 18 has a slot and a circuit board 19 is inserted therein. The lower end of the circuit board 19 abuts against the conductive spring 9. The upper end of the circuit board 19 is electrically connected to the indicator light 4. The conductive spring 9 has protrusions and fits tightly against the circuit board 19 for tight assembly.

[0056] The limiting bracket 18 fixes the circuit board 19, ensuring that it is in close contact with the protrusions of the conductive spring 9, and preventing the circuit board 19 from shifting due to vibration. The protrusions of the conductive spring 9 increase the contact area with the circuit board 19, reduce the contact resistance, and improve the conductivity stability. For example, the indicator light 4 displays the power status in real time through the circuit board 19. The protrusion contact design can avoid the open circuit problem caused by wear in the traditional soldering method, ensuring that the indicator light works reliably for a long time.

[0057] Specifically, the lower end of the fixing frame 10 is equipped with a support column arranged in a triangle and connected to the PE pin 5 and two power-conducting pins 6 respectively. The free end of the PE connecting piece 8 extends to the bottom of the front support column and is engaged with the upper end of the PE pin 5 by a snap ring.

[0058] The triangularly distributed support columns enhance the structural strength of the fixing frame 10. The PE connecting piece 8 is fixed to the PE pin 5 by a snap ring, ensuring a firm and reliable grounding path. The snap ring connection method facilitates disassembly and maintenance. For example, when the PE pin 5 needs to be replaced, it can be quickly replaced by simply removing the snap ring. At the same time, it avoids the grounding failure problem caused by loosening of traditional screw connections, which meets electrical safety standards.

[0059] like Figure 6 and Figure 7 As shown, the upper end of the terminal 7 has a mounting groove that matches the end of the conductive spring 9. The end of the conductive spring 9 away from the slider 11 is snapped into the mounting groove and fixed by fasteners.

[0060] The conductive spring 9 and the terminal 7 are fixed by a snap-fit ​​fastener, eliminating intermediate connecting parts, reducing contact links and failure points. For example, the conductive springs of traditional plugs are mostly connected by soldering wires. After long-term use, the solder joints are prone to fall off, causing open circuits. However, the direct snap-fit ​​method of this design can withstand greater insertion and extraction forces, reducing the risk of poor contact, and is especially suitable for industrial scenarios with high-frequency insertion and extraction.

[0061] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A double-break switch plug, comprising a housing (1), wherein a power-off button (2), a power-on button (3), and an indicator light (4) are mounted on the upper end face of the housing (1), and both the power-off button (2) and the power-on button (3) can be pressed down and reset upwards; a PE pin (5) and two power-on pins (6) arranged in a triangular pattern are mounted on the lower end face of the housing (1), and the power-off button (2), the power-on button (3), the indicator light (4), the PE pin (5), and the power-on pins (6) are all connected to a wiring assembly inside the housing (1), the wiring assembly comprising a terminal block (7), a PE connecting piece (8), a conductive spring piece (9), a fixing bracket (10), a slider (11), and a locking piece (12), characterized in that: The fixing frame (10) is installed inside the front end of the housing (1). The lower ends of the power off button (2) and the power on button (3) extend into the housing (1) and are slidably assembled with the fixing frame (10). The slider (11) is slidably assembled at the rear end of the fixing frame (10) and is driven to rise by the power on button (3). The power on button (3) is manually reset upward by driving the power off button (2). The terminal block (7) is installed inside the rear end of the housing (1) and has three terminals that are respectively connected to the PE connecting piece (8) and the two conductive spring pieces (9). The free end of the PE connecting piece (8) extends to the front end of the housing (1) and is connected to the PE pin (5). The free end of the conductive spring piece (9) is connected to the ends of the slider (11) extending to both sides of the fixing frame (10). The rear sides of the mounting bracket (10) have power terminals that are electrically connected to the adjacent power pins (6), and the two power terminals are respectively located above the free ends of the two conductive springs (9).

2. A double-break switch plug according to claim 1, characterized in that, The lower end of the power button (3) extends vertically downward and slides into the rear end of the slider (11). The front end of the slider (11) is equipped with an L-shaped locking piece (12). The short side of the L-shape of the locking piece (12) is opposite to the front end of the slider (11) and is connected by the first spring (13). The long side of the L-shape slides horizontally backward through the slider (11) and is movably fitted into the lower end of the power button (3) and engages with the slot (16) on the rear side of the lower end of the power button (3).

3. A double-break switch plug according to claim 2, characterized in that, The rear end of the slider (11) is provided with an active hole (111) that is compatible with the lower end of the power button (3). The bottom of the front end face of the slider (11) is provided with a groove for installing the first spring (13). A sleeve (112) is installed in the groove. One end of the first spring (13) is fitted into the sleeve (112) and fixed to the inner wall of the groove. The other end of the first spring (13) is fixed to the inner side of the L-shaped short side of the locking piece (12).

4. A double-break switch plug according to claim 2, characterized in that, The lower end of the power button (3) is wedge-shaped. The rear end of the L-shaped long side of the locking piece (12) is provided with a through hole (121) that matches the lower end of the power button (3). In the initial state, the rear end of the through hole (121) is connected to the movable hole (111) and the width of the connection is greater than the width of the flat bottom of the wedge-shaped lower end of the power button (3).

5. A double-break switch plug according to claim 2, characterized in that, The lower end of the power-off button (2) is connected to the bottom surface of the inner cavity of the housing (1) via the second spring (14). A wedge block (15) is installed on the rear side of the lower end of the power-off button (2). The wedge block (15) has an inclined surface, and the inclined surface is vertically set above the short side of the L-shaped locking plate (12).

6. A double-break switch plug according to claim 1, characterized in that, A limit bracket (18) is installed on the front end of the terminal block (7). The upper end of the limit bracket (18) has a slot and a circuit board (19) is inserted therein. The lower end of the circuit board (19) abuts against the conductive spring (9), and the upper end of the circuit board (19) is electrically connected to the indicator light (4).

7. A double-break switch plug according to claim 1, characterized in that, The lower end of the fixing frame (10) is equipped with a support column arranged in a triangle and connected to the PE pin (5) and two power-conducting pins (6) respectively. The free end of the PE connecting piece (8) extends to the bottom of the front support column and is snapped to the upper end of the PE pin (5) by a snap ring.

8. A double-break switch plug according to claim 1, characterized in that, The upper end of the terminal block (7) has a mounting groove that matches the end of the conductive spring (9), and the end of the conductive spring (9) away from the slider (11) is snapped into the mounting groove.

9. A double-break switch plug according to any one of claims 1-8, characterized in that, The power button (3) includes a button end and a button rod at its bottom. The button end is arranged parallel to the rear end of the fixing frame (10) above it. The lower end of the button rod is assembled with the slider (11). The upper end of the button rod is fitted with a third spring (17), and the two ends of the third spring (17) are fixed to the lower surface of the button end and the upper surface of the rear end of the fixing frame (10), respectively.

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