Single-pole double-throw microswitch

Abstract

The invention belongs to the technical field of micro-switches, and particularly discloses a single-pole double-throw micro-switch, which comprises a fixed contact assembly comprising a first port contact and a second port contact; the switching contact is arranged between the first port contact and the second port contact, and the switching contact has a first working state in which the switching contact is in contact with the first port contact and a second working state in which the switching contact is in contact with the second port contact; the switching mechanism comprises a switching block and a switching piece, the switching block is elastically connected with the switching piece, the switching contact is arranged on the switching piece, and the switching block can be used for driving the switching contact to swing and driving the switching point to be switched between the first working state and the second working state. According to the invention, the switch is prevented from being turned off by mistaken touch under the condition of frequent vibration, the possibility of mistaken touch of the microswitch is reduced, and the overall anti-vibration performance of the microswitch is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of microswitches, and particularly to a single-pole double-throw microswitch. Background Art

[0002] A single-pole double-throw microswitch is a switch device having one moving contact and two stationary contacts. It has a small contact interval and a fast response action, and supports various functions such as signal switching, limit control, and status detection, and has mature applications in industries, automobiles, medical fields, etc.

[0003] A small single-pole double-throw microswitch disclosed in Chinese Patent No. CN203406188U includes a base, a reed assembly, and upper / lower contact pieces that respectively form normally closed / normally open contacts with the reed assembly. The reed assembly includes a reed, a spring, and a transmission rod, and the reed is disposed between the transmission rod and the spring; Covers are respectively provided on both sides of the base, and a pressing rod for limiting and applying force to the transmission rod in the reed assembly is hinged between the two covers. In the prior art, the single-pole double-throw microswitch generally uses the elastic action of the reed to switch the position of the common contact to change the switch state.

[0004] For special environments, such as the nuclear power field, it is required that the microswitch has properties such as high temperature resistance, radiation resistance, and earthquake resistance, and can be reliable for a long time. Since the existing microswitch designs do not have a design action margin, they are prone to mis-triggering under conditions of strong vibration and earthquake, and therefore cannot be reliably used in the nuclear power field. In view of this, the applicant has proposed a single-pole double-throw microswitch. Summary of the Invention

[0005] In view of the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide a single-pole double-throw microswitch to solve the problem of insufficient seismic strength of the single-pole double-throw microswitch in the prior art.

[0006] To achieve the above object and other related objects, the present invention provides a single-pole double-throw microswitch, comprising:

[0007] A fixed contact assembly, the fixed contact assembly including a first port contact and a second port contact;

[0008] A switching contact, the switching contact being disposed between the first port contact and the second port contact, the switching contact having a first working state in contact with the first port contact and a second working state in contact with the second port contact;

[0009] Switching mechanism, the switching mechanism includes a conversion block and a switching piece, the conversion block is elastically connected to the switching piece, the switching contact is arranged on the switching piece, the conversion block is provided with a contact part for receiving a power source, and the conversion block can be used to drive the switching piece to swing through the contact part and drive the switching contact to switch between the first working state and the second working state.

[0010] Optionally, the switching mechanism further includes a common terminal, the conversion block and the switching piece are both fixed on the common terminal, an elastic member is arranged between the conversion block and the switching terminal, and the conversion block and the switching piece are respectively abutted against the common terminal through the elastic member.

[0011] Optionally, the common terminal is provided with a first card slot, the conversion block is provided with a card block, the card block and the first card slot have a first abutting part that abuts against each other, and the conversion block can swing around the first abutting part.

[0012] Optionally, the common terminal is provided with a second card slot, the switching piece is provided with a connecting part, the connecting part and the second card slot have a second abutting part that abuts against each other, and the switching piece can swing around the second abutting part.

[0013] Optionally, the single-pole double-throw micro switch further includes a housing assembly and a button, and the fixed contact assembly, the switching contact and the switching mechanism are all arranged in the housing assembly.

[0014] Optionally, the housing assembly includes an outer shell, an inner shell and a base, the base is arranged at the bottom of the outer shell, the inner shell is arranged inside the outer shell and the inner shell abuts against the base.

[0015] Optionally, the single-pole double-throw micro switch further includes a button, the inner shell is provided with an avoidance opening, the bottom of the button is provided with a trigger rod that can pass through the avoidance opening, and the trigger rod can be used to drive the conversion block to swing.

[0016] Optionally, the inner shell is provided with a reset rod, the button is provided with a reset groove, and a reset spring that penetrates into the reset groove is sleeved on the reset rod.

[0017] Optionally, the inner shell is provided with a plurality of guiding holes, the bottom of the button is provided with guiding rods corresponding to the guiding holes, and the guiding rods penetrate into the guiding holes.

[0018] Optionally, the single-pole double-throw microswitch further includes a first terminal and a second terminal. The first port contact is disposed on the first terminal, the second port contact is disposed on the second terminal. The base is provided with a first slot, a second slot and a third slot. The first terminal is fixedly connected to the first slot, the second slot is fixedly connected to the second terminal, and the common terminal is fixedly connected to the third slot.

[0019] As described above, a single-pole double-throw microswitch proposed by the present invention has the following beneficial effects:

[0020] In the present invention, through the fixed contact assembly and the switching contact provided, the switching contact can change the position of the switching contact under the action of the switching mechanism to realize the first working state and the second working state of the switching contact. The switching mechanism adopts a combination of a conversion block and a switching piece, and an elastic connection is adopted between the two, so that the switching contact needs to reach a certain pressure condition to swing to realize the switching of the working state. Compared with the prior art, when the present invention is applied to special fields, such as nuclear power environment and working environments with frequent vibrations, the seismic strength is high, the possibility of accidental contact of the microswitch is reduced, and the overall performance of the microswitch is improved. Description of the Drawings

[0021] Figure 1 Showing a schematic structural diagram of an embodiment of the present invention;

[0022] Figure 2 Showing a structural sectional view of an embodiment of the present invention;

[0023] Figure 3 Showing a schematic internal structure diagram of an embodiment of the present invention;

[0024] Figure 4 Showing a schematic structural diagram of the base in an embodiment of the present invention;

[0025] Figure 5 Showing another schematic structural diagram of the base in an embodiment of the present invention;

[0026] Figure 6 Showing a schematic structural diagram of the switching mechanism in an embodiment of the present invention;

[0027] Figure 7 Showing a schematic connection structure diagram of the conversion block and the switching piece in an embodiment of the present invention;

[0028] Figure 8 Showing a schematic structural diagram of the conversion block in an embodiment of the present invention.

[0029] Description of the Reference Numerals:

[0030] Outer shell 1, inner shell 2, avoidance opening 201, guiding hole 202, reset rod 203, reset spring 204, button 3, reset groove 303, trigger rod 301, guiding rod 302, base 4, first terminal 5, second terminal 6, first port contact 7, second port contact 8, common terminal 9, first card slot 901, second card slot 902, first abutting portion 903, second abutting portion 904, conversion block 10, card block 1001, contact portion 1002, switching piece 11, mounting hole 1101, switching contact 12, elastic member 13, first connection end 1301, second connection end 1302. Detailed implementation manners

[0031] The following uses specific specific examples to illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0032] It should be noted that the diagrams provided in this embodiment only illustrate the basic concept of the present invention in a schematic manner. Therefore, only the components related to the present invention are shown in the diagrams, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in actual implementation can be arbitrarily changed, and the component layout type may also be more complex. The structures, ratios, sizes, etc. shown in the diagrams of this specification are only used to cooperate with the content disclosed in the specification for those skilled in this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Therefore, they do not have technical substantive significance. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope that the technical content disclosed by the present invention can cover. At the same time, the terms such as "upper", "lower", "left", "right", "middle", and "one" cited in this specification are only for the convenience of clear description and are not used to limit the scope for the implementation of the present invention. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope within which the present invention can be implemented.

[0033] As Figures 1-8 shown, the present invention proposes a single-pole double-throw microswitch.

[0034] In an exemplary embodiment, a single-pole double-throw microswitch includes:

[0035] A fixed contact assembly, the fixed contact assembly includes a first port contact 7 and a second port contact 8;

[0036] The switching contact 12 is arranged between the first port contact 7 and the second port contact 8. The switching contact 12 has a first working state in contact with the first port contact 7 and a second working state in contact with the second port contact 8;

[0037] A switching mechanism, which includes a conversion block 10 and a switching piece 11. The conversion block 10 is elastically connected to the switching piece 11. The switching contact 12 is arranged on the switching piece 11. A contact part 1002 for receiving a power source is provided on the conversion block 10. The conversion block 10 can drive the switching piece 11 to swing through the contact part 1002 and drive the switching contact 12 to switch between the first working state and the second working state.

[0038] In this embodiment, by setting the fixed contact assembly and the switching contact 12, the position of the switching contact 12 can be changed under the action of the switching mechanism to realize the first working state and the second working state of the switching contact 12. The switching mechanism adopts a combination of the conversion block 10 and the switching piece 11, and the two are elastically connected, so that the switching contact 12 needs to reach a certain pressure condition to swing and realize the switching of the working state. Compared with the prior art, when the present invention is applied to special fields, such as nuclear power environments and working environments with frequent vibrations, the seismic resistance is high, the possibility of accidental contact of the microswitch is reduced, and the overall performance of the microswitch is improved.

[0039] Exemplarily, the microswitch in this embodiment is a normally open microswitch. Correspondingly, the first port contact 7 is a normally open contact, and the second port contact 8 is a normally closed contact. The switching contact 12 is in contact with the normally open contact under normal circumstances, and the microswitch is in the normally open state. When it needs to be closed, the working state of the microswitch is switched through the switching mechanism to make it switch to the second working state, and the switching contact 12 is in contact with the normally closed contact, and the microswitch is closed.

[0040] Exemplarily, the microswitch in this embodiment can also be a normally closed microswitch. Correspondingly, the first port contact 7 is a normally closed contact, and the second port contact 8 is a normally open contact. The switching contact 12 is in contact with the normally closed contact under normal circumstances, and the microswitch is in the normally closed state. When it needs to be opened, the working state of the microswitch is switched through the switching mechanism to make it switch to the second working state, and the switching contact 12 is in contact with the normally open contact, and the microswitch is opened.

[0041] It should be noted that in this embodiment, the first working state can be set adaptively as a normally open state or a normally closed state according to the specific needs of the user to achieve the required functions.

[0042] It should also be noted that in this embodiment, the first port contact 7 and the second port contact 8 are respectively located on the upper and lower sides of the switching contact 12.

[0043] In an exemplary embodiment, the switching mechanism further includes a common terminal 9. Both the conversion block 10 and the switching piece 11 are fixed on the common terminal 9. An elastic member 13 is provided between the conversion block 10 and the switching terminal. The conversion block 10 and the switching piece 11 are respectively in abutting connection with the common terminal 9 through the elastic member 13.

[0044] As Figures 3-8 shown, in this embodiment, the provided common terminal 9 provides an installation environment for the conversion block 10 and the switching piece 11. The conversion block 10 and the switching piece 11 are fixed to the common terminal 9 through the stretching action of the elastic member 13. The connection method is abutting connection. Under the stretching action of the elastic member 13, a force balance is achieved among the common terminal 9, the conversion block 10, and the switching piece 11.

[0045] Exemplarily, in this embodiment, an installation hole 1101 is formed in the switching piece 11, and a pair of contact portions 1002 are provided on the conversion block 10. The elastic member 13 is a tension spring. One end of the tension spring passes through the installation hole 1101, and the other end passes through the gap between the contact portions 1002. Therefore, both ends of the tension spring respectively pull the switching piece 11 and the conversion block 10, and the tension spring is in a first stretched state. At this time, the tension spring exerts a force on the switching piece 11 from the lower left to the upper right. The switching piece 11 is in an inclined state, and the switching contact 12 mounted on the switching piece 11 tilts up to contact the first port contact 7, realizing the normally open / normally closed state of the microswitch. In a specific embodiment, the tension spring has a first connection end 1301 connected to the conversion block 10 and a second connection end 1302 connected to the switching piece 11. In the natural state where the conversion block 10 is not stressed, the horizontal height of the first connection end 1301 is higher than that of the second connection end 1302. This setting method can increase the descending margin of the conversion block 10. The conversion block 10 needs to descend a greater height to drive the switching contact 12 on the switching piece 11 to move into contact with the second port contact 8, improving the seismic resistance of this application.

[0046] In some embodiments, the common terminal 9 is provided with a first card slot 901, and the conversion block 10 is provided with a card block 1001. The card block 1001 and the first card slot 901 have a first abutting portion 903 that abuts against each other, and the conversion block 10 can swing around the first abutting portion 903. In this embodiment, the provided first card slot 901 provides an installation environment for the conversion block 10. Due to the provision of the tension spring, one end thereof generates a pulling force on the conversion block 10, such that the conversion block 10 abuts against the first card slot 901 through the card block 1001. The card block 1001 is provided at one end of the conversion block 10, and it can cooperate with the first card slot 901. When the other end of the conversion block 10 is stressed, due to the limiting effect of the first card slot 901 on the card block 1001, the conversion block 10 can swing around the portion where the card block 1001 abuts against the first card slot 901 (i.e., the first abutting portion 903), synchronously driving one end of the tension spring to move downward.

[0047] In some embodiments, the common terminal 9 is provided with a second card slot 902, and the switching piece 11 is provided with a connecting portion. The connecting portion and the second card slot 902 have a second abutting portion 904 that abuts against each other, and the switching piece 11 can swing around the second abutting portion 904. In this embodiment, the provided second card slot 902 provides an installation environment for the switching piece 11. One end of the provided tension spring generates a pulling force on the conversion block 10, and the other end also generates a pulling force on the switching piece 11, such that the connecting portion of the switching piece 11 is firmly fixed in the second card slot 902, improving the stability of the switching piece 11. During the process of pressing down one end of the conversion block 10, after pressing down a certain distance, the distance between the first connecting end 1301 and the second connecting end 1302 of the tension spring increases, and the elastic deformation of the tension spring increases. After reaching the maximum stroke of the contact portion 1002, the conversion block 10 drives the switching piece 11 to descend, and the switching contact 12 on the switching piece 11 contacts the second port contact 8 below, and the switch switches from the first working state to the second working state.

[0048] It should be noted that the tension spring in this embodiment can adopt other elastic elements, which can firmly fix the conversion block 10 and the switching piece 11 on the common terminal 9 while connecting them.

[0049] In an exemplary embodiment, the single-pole double-throw microswitch further includes a housing assembly and a button 3. The fixed contact assembly, the switching contact 12, and the switching mechanism are all arranged inside the housing assembly.

[0050] In this embodiment, through the provided housing assembly, the internal fixed contact assembly, the switching contact 12, and the switching mechanism can be covered and protected.

[0051] In some embodiments, the housing assembly includes an outer housing 1, an inner housing 2, and a base 4. The base 4 is disposed at the bottom of the outer housing 1, and the inner housing 2 is disposed inside the outer housing 1 and abuts against the base 4.

[0052] In this embodiment, the provided outer housing 1, inner housing 2, and base 4 provide an installation environment for the above-mentioned fixed contact assembly, switching contact 12, and switching mechanism.

[0053] Exemplarily, in this embodiment, the side wall of the base 4 is provided with a fixing portion which is inclined and flanged outward. During installation, it is installed from bottom to top. There is a bayonet on the inner wall of the outer housing 1, and the size of the bayonet corresponds to that of the fixing portion. The bayonet can limit the fixing portion. During the upward movement of the fixing portion, it is limited by the inner wall of the outer housing 1 and slightly deformed until it abuts against the top of the bayonet and cannot move upward any further. In a specific embodiment, the base 4 can also be threadedly connected to the outer housing 1 to achieve a stable connection with the outer housing 1, or a detachable connection method using bolts or screws can be adopted to achieve a quick connection between the outer housing 1 and the base 4.

[0054] It is worth noting that in this embodiment, after the base 4 is installed, the inner housing 2 is installed on the upper surface of the base 4, and the outer wall of the inner housing 2 fits against the inner wall of the outer housing 1.

[0055] In a specific embodiment, the single-pole double-throw microswitch further includes a button 3. The inner housing 2 is provided with an avoidance opening 201, and the bottom of the button 3 is provided with a trigger rod 301 that can pass through the avoidance opening 201. The trigger rod 301 can be used to drive the conversion block 10 to swing. By providing the button 3, the button 3 can be pressed down, so that the trigger rod 301 at the bottom of the button 3 presses down the contact portion 1002 to drive the conversion block 10 to press down and realize the swing of the conversion block 10.

[0056] It is worth noting that in this embodiment, the inner housing 2 is further provided with a plurality of guide holes 202, and the bottom of the button 3 is provided with a plurality of guide rods 302. The guide rods 302 are inserted into the guide holes 202. In this embodiment, both the guide holes 202 and the guide rods 302 are two. By providing the guide rods 302, the movement of the button 3 can be guided to ensure its stable movement. At the same time, it can prevent the button 3 from turning around and avoid the trigger rod 301 from deviating from the contact portion 1002 and being unable to trigger.

[0057] It should also be noted that in this embodiment, the side wall of the button 3 is provided with a first step surface, and the inner wall of the outer housing 1 is provided with a second step surface. The second step surface can be used to limit the first step surface in the height direction to prevent the button 3 from coming out of the outer housing 1.

[0058] In an exemplary embodiment, the inner housing 2 is provided with a reset rod 203, the button 3 is provided with a reset groove 303, and a reset spring 204 that passes through the reset groove 303 is sleeved on the reset rod 203.

[0059] In this embodiment, through the arranged reset rod 203, when the button 3 is continuously pressed down, the reset spring 204 enters the reset groove 303 and presses the reset spring 204, and the reset spring 204 is compressed. When the button 3 is released, the reset spring 204 resets, and the button 3 resets synchronously.

[0060] In an exemplary embodiment, the single-pole double-throw micro switch further includes a first terminal 5 and a second terminal 6. The first port contact 7 is arranged on the first terminal 5, the second port contact 8 is arranged on the second terminal 6, and the base 4 is provided with a first slot 901, a second slot 902 and a third slot. The first terminal 5 is fixedly connected to the first slot 901, the second slot 902 is fixedly connected to the second terminal 6, and the common terminal 9 is fixedly connected to the third slot.

[0061] In this embodiment, through the arranged first terminal 5 and second terminal 6, an installation environment is provided for the first port contact 7 and the second port contact 8. Among them, the shapes of the first terminal 5 and the second terminal 6 are both L-shaped, the size of the first terminal 5 is larger than that of the second terminal 6, the first port contact 7 is fixedly installed on the first terminal 5, and the second port contact 8 is installed on the second terminal 6. Among them, the working end of the first port contact 7 faces downward, the working end of the second terminal 6 faces upward, and both sides of the switching contact 12 are working ends.

[0062] In some embodiments, the first terminal 5, the second terminal 6 and the common terminal 9 are all provided with step portions. Through the arranged step portions, the first terminal 5 is in interference fit with the first installation groove, the second terminal 6 is in interference fit with the second installation groove, and the common terminal 9 is in interference fit with the third installation groove. The first terminal 5 passes through the first installation groove and is exposed outside the base 4, the second terminal 6 passes through the second installation groove and is exposed outside the base 4, and the common terminal 9 passes through the third installation groove and is exposed outside the base 4. The arrangement of each terminal passing through the base 4 makes it convenient to disassemble each terminal.

[0063] Specific implementation steps:

[0064] During use, it is stipulated that the first port contact 7 is a normally open contact. The switching contact 12 is in contact with the normally open contact, and the switch is in the normally open state. When it is necessary to close the switch, the button 3 is pressed down. At this time, the return spring 204 is compressed, and the trigger rod 301 at the bottom of the button 3 moves downward synchronously in the avoidance groove until it contacts the contact portion 1002. Continuously pressing down the contact portion 1002, the conversion block 10 swings up and down around the first abutting portion 903. During the continuous descent of the contact portion 1002 of the conversion block 10, it will finally drive the elastic member 13 to generate elastic deformation and be in a large tensile state, pulling the switching piece 11 to swing up and down around the second abutting portion 904 until the switching contact 12 on the switching piece 11 contacts the second port contact 8, and the switch is closed. Release the button 3, and the return spring 204 resets, pushing up the button 3, and the button 3 resets, and the switch returns to the normally open state. Therefore, when it is necessary to close the switch, the elastic member 13 needs to reach a certain elastic deformation to achieve the function of pulling down the switching contact 12 at the end of the switching piece 11, thus avoiding the switch being accidentally touched and closed under frequent vibration and improving the anti-vibration performance of the switch.

[0065] In summary, when the present invention is applied to special fields, such as nuclear power environments and working environments with frequent vibrations, the elastic member 13 needs to reach a certain elastic deformation to achieve the function of pulling down the switching contact 12 at the end of the switching piece 11 to contact the second port contact 8, thus avoiding the switch being accidentally touched and closed under frequent vibration, reducing the possibility of accidental touch of the microswitch, and improving the overall anti-vibration performance of the microswitch.

[0066] The above embodiments are only illustrative of the principles and effects of the present invention, and are not used to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A single-pole double-throw microswitch, characterized in that, Comprising: A fixed contact assembly, said fixed contact assembly including a first port contact and a second port contact; A switching contact, said switching contact being arranged between the first port contact and the second port contact, said switching contact having a first working state in contact with the first port contact and a second working state in contact with the second port contact; A switching mechanism, said switching mechanism including a conversion block and a switching piece, the conversion block being elastically connected to the switching piece, the switching contact being arranged on the switching piece, a contact portion for receiving a power source being provided on the conversion block, the conversion block being capable of driving the switching piece to swing through the contact portion and being capable of driving the switching contact to switch between the first working state and the second working state.

2. The single-pole double-throw microswitch according to claim 1, characterized in that: The switching mechanism further includes a common terminal, the conversion block and the switching piece are both fixed on the common terminal, an elastic member is provided between the conversion block and the switching terminal, and the conversion block and the switching piece are respectively abutted against the common terminal through the elastic member.

3. The single-pole double-throw microswitch according to claim 2, wherein: The common terminal is provided with a first card slot, the conversion block is provided with a clamping block, the clamping block and the first card slot have a first abutting portion for mutual abutment, and the conversion block can swing around the first abutting portion.

4. The single-pole double-throw microswitch according to claim 2, wherein: The common terminal is provided with a second card slot, the switching piece is provided with a connecting portion, the connecting portion and the second card slot have a second abutting portion for mutual abutment, and the switching piece can swing around the second abutting portion.

5. The single-pole double-throw microswitch according to claim 2, characterized in that: The single-pole double-throw microswitch further includes a housing assembly and a button, and the fixed contact assembly, the switching contact and the switching mechanism are all arranged in the housing assembly.

6. The single-pole double-throw microswitch according to claim 5, wherein: The housing assembly includes an outer shell, an inner shell and a base, the base is arranged at the bottom of the outer shell, the inner shell is arranged inside the outer shell and the inner shell abuts against the base.

7. The single-pole double-throw microswitch according to claim 6, wherein: The single-pole double-throw microswitch further includes a button, an avoidance opening is provided on the inner shell, a trigger rod capable of passing through the avoidance opening is provided at the bottom of the button, and the trigger rod can be used to drive the conversion block to swing.

8. The single-pole double-throw microswitch according to claim 7, wherein: A reset rod is provided on the inner shell, a reset groove is provided on the button, and a reset spring sleeved on the reset rod penetrates into the reset groove.

9. The single-pole double-throw microswitch according to claim 8, wherein: A plurality of guiding holes are provided on the inner shell, guiding rods corresponding to the guiding holes are provided at the bottom of the button, and the guiding rods penetrate into the guiding holes.

10. The single-pole double-throw microswitch according to claim 6, characterized in that: The single-pole double-throw microswitch further includes a first terminal and a second terminal, the first port contact is arranged on the first terminal, the second port contact is arranged on the second terminal, a first card slot, a second card slot and a third card slot are provided on the base, the first terminal is fixedly connected to the first card slot, the second card slot is fixedly connected to the second terminal, and the common terminal is fixedly connected to the third card slot.

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