31results about How to "Prevent sudden power failure" patented technology

The invention discloses an amplifier back panel, which comprises a panel main body (1) and an installing part (2) fixed on the outer periphery of the panel body (1) in a surrounding way. The amplifier back panel is characterized in that the panel main body (1) is provided with a wireless microphone receiving area (3), a signal input control area (4) consisting of a Bluetooth interface (4.1.1), an SD (Secure Digital) interface (4.1.2), a USB (Universal Serial Bus) interface (4.1.4), a 3.5mm socket (4.2.1) and an RCA socket (4.2.2) and a multifunctional socket (4.3.1), and an input power supply control area (5) in sequence from top to bottom. By adopting the structure of the amplifier back panel, a plurality of sound source input ways can be realized, and high universality is achieved; moreover, a plurality of amplifiers can be used together through an arranged signal output interface, so that the length of a connecting circuit is reduced. Moreover, a storage battery is provided, so that work without an external power supply can be realized.

The invention discloses an air dust removing device comprising a receiving cavity which is arranged in a wall and has a rightward opening, a power distribution cabinet which is arranged in the receiving cavity through a pushing component and a plug head which is electrically connected to a dust remover. Insertion grooves with rightward notches are symmetrically arranged up and down in the power distribution cabinet. First sliding grooves which are between the two insertion grooves and have notches facing the insertion grooves are symmetrically arranged up and down in the power distribution cabinet. A first motor is installed between the two first sliding grooves. First sliding arms are slidingly installed in the first sliding grooves. End faces of the first sliding arms facing the insertion grooves are provided with first inclined surfaces. The first sliding arms are internally provided with first spiral grooves with notches facing the first motor, first spiral rods which are in powerconnection with the first motor are matched and installed in the first spiral grooves, and end walls of the insertion grooves far from the first sliding grooves are internally provided with second sliding grooves and third sliding grooves whose notches face the insertion grooves.

The invention discloses an informatization consulting device. The informatization consulting device comprises a turntable which is fixedly arranged on the ground, a device body which is arranged on the turntable through a rotating component, a plug which is electrically connected with the device body through a cable, and a socket which matches the plug and is fixedly arranged in a wall. Insertionslots are symmetrically arranged up and down in the socket, wherein the ports of the insertion slots face the right. First sliding slots located between two insertion slots are symmetrically arrangedup and down in the socket, wherein the ports of the first sliding slots face the insertion slots. A first drive is arranged between two first sliding slots. A first sliding arm is slidably arranged ineach first sliding slot. A first inclined surface is arranged on the end face, which faces an insertion slot, of each first sliding arm. A first spiral slot is arranged in each first sliding arm, wherein the port of the first spiral slot faces the first drive. A first screw rod in power connection with the first drive is threadedly fitted in each first spiral slot.

The present invention provides a lithium secondary battery comprising: a positive electrode comprising aluminum-doped bimodal lithium cobalt oxide which comprises a first lithium cobalt oxide and a second lithium cobalt oxide having different average particle sizes (D50) from each other; a negative electrode comprising a bimodal graphite which comprises a first graphite and a second graphite having different average particle sizes (D50) from each other; and a first additive which is a nitrile-based compound, wherein the first lithium cobalt oxide and the second lithium cobalt oxide each independently comprise aluminum with a concentration of 2500 to 4000 ppm.

The invention discloses a novel welding device, which comprises a plug pin seat and a plug pin head connected with a welding machine, wherein the left end face of the plug pin seat is provided with fixing blocks in a vertically corresponding manner, each fixing block is internally provided with a fixing hole, the plug pin seat is internally provided with jacks with the opening facing towards the right in a vertically corresponding manner, the front and rear end walls of each jack are internally provided with power connecting pieces respectively, the plug pin seat is internally provided with aleft sliding cavity and a right sliding cavity which are located between the two jacks, a motor is fixedly installed between the left sliding cavity and the right sliding cavity, the end walls, whichare close to the left sliding cavity, of the jacks are provided with first sliding slots with the opening facing towards the corresponding jacks in a vertically corresponding manner, the right half section of each first sliding slot is intercommunicated with the left sliding cavity, the left sliding cavity is internally provided with a left sliding plate capable of smoothly sliding left and right,the left sliding plate is internally provided with a left screw extending left and right in a matched manner, the left end of the left screw is rotatably installed in the left end wall of the left sliding cavity, and the right end is in power connection with the motor.

The invention relates to a remote control mechanical transportation device, in particular to remote control equipment for grabbing and transporting building materials in a building site. The remote control equipment comprises a walking mechanism, a grabbing mechanism, a motor driving mechanism and a remote control commanding mechanism, and is characterized in that the walking mechanism is composed of walking wheels, servo steering engines, a remote control unit and a pushing handle, the walking wheels are arranged at the bottom of a rack, the servo steering engine is arranged at the bottom of the rack and sealed, the two servo steering engines are arranged on the two sides of the bottom of the walking mechanism respectively and used for driving the four walking wheels on the two sides respectively, and the pushing handle is arranged on the rack to from a frame of the equipment. The remote control equipment can automatically grab and transport the building materials, machines, electronics, chemicals, apparatuses, instruments and other heavy equipment in a workshop. Remote control commanding can be carried out, and the operation is convenient. Universal wheels with stopping mechanisms are designed, and a self-locking mechanism is arranged between a hoisting sliding block and the rack.

The invention discloses a crash-proof logic circuit and a notebook computer. The crash-proof logic circuit comprises a charge chip, a first power supply module, a CPU (Central Processing Unit), a first resistor, a second resistor, a capacitor and a driving module, wherein a first end of the capacitor is connected with a first end of the first resistor and a signal output end of the charge chip respectively; a second end of the capacitor is connected with a first end of the second resistor and a signal input end of the driving module respectively; a signal output end of the driving module is connected with the input end of the CPU; the first power supply module is connected with a second end of the first resistor and a second end of the second resistor respectively; the charge chip is used for outputting indication signals when power is supplied power current is suddenly reduced; the capacitor is used for receiving the indication signals; the signal output end of the driving module is controlled according to the second resistor and the capacitor to output low-level signals firstly, then the frequency of the CPU is reduced, and high-level signals are further output. By adopting the crash-proof logic circuit, the notebook computer can be prevented from power off in high-speed operation or crash down if an adaptor is plugged out, and the service life of a battery is prolonged.

The invention discloses a novel power device, which comprises an electric connection socket fixedly arranged in a wall and an electric connection plug connected with equipment, wherein inserting grooves of which openings are toward the right are longitudinally symmetrically arranged in the electric connection socket; power supply sheets are arranged in front and rear end walls of each inserting groove; a left sliding cavity and a right sliding cavity located between the two inserting grooves are arranged in the electric connection socket; a drive motor is fixedly arranged between the left sliding cavity and the right sliding cavity; first sliding grooves of which the openings are toward the corresponding inserting groove are longitudinally symmetrically arranged in the end wall, close to the left sliding cavity, of each inserting groove; the right half segment of each first sliding groove communicates with the left sliding cavity; a left sliding plate capable of sliding from left to right is arranged in the left sliding cavity; a left threaded rod which extends from left to right is arranged in the left sliding plate in a screw-thread fit manner; and the left end of the left threaded rod is rotationally arranged in the left end wall of the left sliding cavity and the right end is in power connection with the drive motor.

The invention discloses an improved air dust removing device. The device comprises a dust removing box body, a winding assembly arranged in the dust removing box body, a plug and a socket which matches the plug and is fixedly arranged in a wall. Plug-in slots are symmetrically arranged up and down in the socket, wherein the openings of the plug-in slots face the right. Electric connecting pieces are arranged in front and rear end walls of each plug-in slot. A left sliding chamber and a right sliding chamber are arranged in the socket, and are between two plug-in sockets. A first motor is fixedly arranged between the left sliding chamber and the right sliding chamber. First sliding slots are symmetrically arranged up and down in the end wall, which is close to the left sliding chamber, of each plug-in slot, wherein the opening of each first sliding slot face the plug-in slot. The right half section of each first sliding slot is connected with the left sliding chamber. A left sliding plate capable of sliding left and right is arranged in the left sliding chamber. A left spiral rod which extends left and right is arranged in the left sliding plate in a matched manner.

The invention discloses a power device, which comprises an electric connection socket fixedly arranged in a wall and an electric connection plug connected with equipment, wherein inserting grooves ofwhich openings are toward the right are longitudinally symmetrically arranged in the electric connection socket; power supply sheets are arranged in front and rear end walls of each inserting groove;a left sliding cavity and a right sliding cavity located between the two inserting grooves are arranged in the electric connection socket; a drive motor is fixedly arranged between the left sliding cavity and the right sliding cavity; first sliding grooves of which the openings are toward the corresponding inserting groove are longitudinally symmetrically arranged in the end wall, close to the left sliding cavity, of each inserting groove; the right half segment of each first sliding groove communicates with the left sliding cavity; a left sliding plate capable of sliding from left to right isarranged in the left sliding cavity; a left threaded rod which extends from left to right is arranged in the left sliding plate in a screw-thread fit manner; and the left end of the left threaded rodis rotationally arranged in the left end wall of the left sliding cavity and the right end is in power connection with the drive motor.

The invention discloses an improved electric power device. The improved electric power device comprises a power connection seat fixedly mounted in a wall and a power connection head connected with equipment; plugging slots with rightwards-facing openings are formed in the power connection seat, wherein the plugging slots are in longitudinal symmetry; power supply sheets are arranged at the front end walls and rear end walls of the plugging slots; a left sliding cavity and a right sliding cavity located between the two plugging slots are formed in the power connection seat; a driving motor is fixedly mounted between the left sliding cavity and the right sliding cavity; first sliding slots of which the openings face the plugging slots are formed in end walls of the plugging slots, wherein the first sliding slots are in longitudinal symmetry, and the end walls of the plugging slots are adjacent to the left sliding cavity; the right half segments of the first sliding slots are communicatedwith the left sliding cavity; a left sliding plate which can slide leftwards and rightwards is mounted in the left sliding cavity; a left threaded rod which extends leftwards and rightwards is mounted in the left sliding plate in a screw-thread fit manner; the left end of the left threaded rod is rotationally mounted in the left end wall of the left sliding cavity; and the right end of the left threaded rod is in power connection with the driving motor.

The invention discloses a novel air dust removal device. The device comprises a power distribution cabinet and a plug electrically connected with a dust remover, wherein the power distribution cabinetis arranged in a wall, has an opening facing rightwards and is arranged in an accommodating cavity through a push assembly, wherein plug-in slots with notches facing rightwards are vertically and symmetrically formed in the power distribution cabinet, first sliding chutes which are located between the two plug-in slots and have the notches facing the plug-in slots are vertically and symmetricallyformed in the power distribution cabinet, a first electrical motor is mounted between the two first sliding chutes, first sliding arms are glidingly mounted in the first sliding chutes, first obliquesurfaces facing the end surfaces of the plug-in slots are arranged on the first sliding arms, first spiral slots with notches facing the first motor are formed in the first sliding arms, first spiralrods in power connection with the first electric motor are mounted in the first spiral slots in a thread fit manner, and second sliding chutes and third sliding chutes which have notches facing the plug-in slots are formed in the end walls, far away from the first sliding chutes, of the plug-in slots.

The invention discloses an air dust removal device. The air dust removal device comprises a dust removal box body, a winding assembly, a power plug and a power socket, wherein the winding assembly isarranged in the dust removal box body, the power socket is matched with the power plug and is fixedly arranged in a wall, insertion grooves are vertically and symmetrically formed in the power socketand are provided with rightward groove openings, power connection sheets are arranged in a front end wall and a rear end wall of each insertion groove, a left sliding cavity and a right sliding cavityare formed in the power socket and are arranged between the insertion grooves, a first motor is fixedly arranged between the left sliding cavity and the right sliding cavity, first sliding grooves are vertically and symmetrically formed in end walls, near to the left sliding cavity, of the insertion grooves and are provided with groove openings facing the insertion grooves, right half segments ofthe first sliding grooves communicate with the left sliding cavity, a left sliding plate is arranged in the left sliding cavity and can slide leftwards and rightwards, and a left spiral rod is arranged in the sliding plate in a matching way and extends leftwards and rightwards.

The invention discloses a welding device. The device comprises a bolt seat and bolt head connected to a welding machine. The left side end surface of the bolt seat is vertically and correspondingly provided with fixing blocks. Fixing holes are arranged in the fixing blocks. The bolt seat is vertically and correspondingly provided with jacks whose opening portions face towards the right. The frontand rear end walls of the jacks are provided with electrical connection sheets. The bolt seat is provided with a left slide chamber and a right slide chamber which are located between the two jacks. Amotor is fixedly arranged between the left slide chamber and the right slide chamber. The jack, which is close to the end wall of the left slide chamber, is vertically and correspondingly provided with a first chute whose opening portion faces towards the jack. The right half segment of the first chute is interconnected with the left slide chamber. A left slide plate which can slide towards the left and the right is installed in the left slide chamber. A left screw which is extended towards the left and the right is cooperatively arranged in the left slide plate. The left end of the left screw is rotatably arranged in the left end wall of the left slide chamber. A right end is connected to the motor in a power connection mode.

The present invention discloses an improved information-based consultation device. The device comprises a rotary seat, a device main body, a plug and a socket; the rotary seat is fixedly disposed on the ground; the device main body is disposed on the rotary seat through a rotation assembly; the plug is electrically connected with the device main body through a cable; the socket is matched with theplug and is fixedly mounted in a wall; tight insertion slots with rightwards-facing end openings are formed in the socket, wherein the tight insertion slots are in longitudinal symmetry; power connection sheets are arranged in the front end walls and rear end walls of the tight insertion slots; a left sliding cavity and a right sliding cavity located between the two tight insertion slots are formed in the socket; a first driving machine is fixedly mounted between the left sliding cavity and the right sliding cavity; first sliding slots of which the end openings face the tight insertion slotsare formed in end walls of the tight insertion slots, wherein the end walls of the tight insertion slots are closed to the left sliding cavity, and the first sliding slots are in longitudinal symmetry; the right half segments of the first sliding slots are communicated with the left sliding cavity; a left sliding plate which can slide rightwards and leftwards is installed in the left sliding cavity; and a left screw rod which extends leftwards and rightwards is installed in the left sliding plate in a matched manner.

The invention discloses a battery connector and electronic equipment. The battery connector comprises an insulating body and at least two conductive terminals, wherein each conductive terminal comprises a head part, an intermediate part and a tail part which are conductive and sequentially connected, the intermediate part is contained and fixed in the insulating body; the head part and the tail part are arranged on both ends of the insulating body in a protruding way; the head part of each conductive terminal is provided with at least two contact parts which are conductive and mutually spaced, and all contact parts of each conductive terminal are eclectically connected through the connection parts of corresponding intermediate part or tail part positions. With such a mode, the invention has the advantages of enhancing the connection stability between a battery and the conductive terminals of the battery connector and effectively preventing the sudden power failure phenomenon of the electronic equipment.

The invention discloses a welding device which comprises an electric linkage seat and a linkage electric head, wherein the electric linkage seat is fixedly mounted in a wall; the linkage electric headis electrically connected with a welding machine; fixed blocks are correspondingly arranged on the left end face of the electric linkage seat up and down; fixed holes are formed in the fixed blocks;jacks with rightward ports are correspondingly arranged in the electric linkage seat up and down; first sliding chutes are correspondingly formed in the electric linkage seat up and down, the first sliding chutes are formed between the two jacks, and the ports of the first sliding chutes are towards the jacks; a first motor is mounted between the two first sliding chutes; first slide arms are smoothly mounted in the first sliding chutes; first oblique sliding surfaces are arranged on the end faces, towards the jacks, of the first slide arms;first screw grooves are formed in the first slide arms, and the ports of the first screw grooves are towards the first motor; first screws in power connection with the first motor are mounted in the first screw grooves in a screw-thread fit manner; anda second sliding chute and a third sliding chute are formed in the end walls, far away from the first sliding chutes, of the jacks, and the ports of the second sliding chute and the third sliding chute are towards the jacks.

The invention discloses an improved welding device. The improved welding device comprises an electric seat and an electric head, wherein the electric seat is fixedly arranged in a wall, the electric head is electrically connected with a welding machine, fixing blocks are correspondingly arranged on the left side end face of the electric seat, fixing holes are formed in the fixing blocks, through holes towards the right are correspondingly arranged in the electric seat up and down, first sliding grooves which are located between the two inserting holes and face towards the inserting holes are correspondingly formed in the electric seat in an up-down mode, a first motor is arranged between the two first sliding grooves, first sliding arms are arranged in the first sliding grooves in a smoothmode, first inclined sliding faces are arranged on the end faces, facing the inserting holes, of the first sliding arms, the through holes are formed in the first sliding arms, first screw grooves facing the first motor are formed in the first sliding arms, first screw rods which are in power connection with the first motor are arranged in the first screw grooves in a matched mode, an second sliding grooves and third sliding grooves are formed in the end walls, far away from the first sliding grooves, of the inserting holes.

The invention discloses a novel air dust collector, which comprises a dust collecting box body, a wrapping component arranged in the dust collecting box body, an electric plug and an electric socket,wherein the electric socket is matched with the electric plug and fixedly arranged in a wall; inserting grooves of which openings are toward the right are symmetrically arranged in the electric socketfrom top to bottom; electric connection sheets are arranged on front and rear end walls of the inserting grooves; a left sliding cavity and a right sliding cavity located between the two inserting grooves are arranged in the electric socket; a first motor is fixedly arranged between the left sliding cavity and the right sliding cavity; first sliding grooves of which the openings are toward the inserting grooves are symmetrically arranged in the end walls, close to the left sliding cavity, of the inserting grooves from top to bottom; the right half segments of the first sliding grooves communicate with the left sliding cavity; a left sliding plate capable of sliding from left to right is arranged in the left sliding cavity; and a left spiral rod which extends from left to right is arrangedin the left sliding plate in a matched manner.

The present invention discloses a novel welding device. The device comprises an electrical connection seat fixed arranged in a wall and an electrical connection head electrically connected with a welding machine. Two positions, near the left end face of the electrical connection seat, are provided with fixing blocks, wherein the fixing blocks form up-and-down correspondence, and each fixing blockis provided with a fixing hole. Inserting holes are arranged in the electrical connection seat, wherein the inserting holes form up-and-down correspondence, and the opening of each inserting hole is arranged towards the right. The electrical connection seat is provided with first sliding slots, wherein the first sliding slots form up-and-down correspondence, the first sliding slots are located between the two inserting holes, and the opening of each first sliding slot is arranged towards the corresponding inserting hole. A first motor is arranged between the two first sliding slots, each firstsliding arm is smoothly arranged in the corresponding first sliding slot, and the end face, extending towards the corresponding inserting hole, of each first sliding arm is provided with a first slanted sliding surface. Each first sliding arm is provided with a first screw slot, wherein the opening of each first screw slot is arranged towards the first motor. Each first screw slot is provided with a first screw rod, wherein each first screw rod forms threaded fit with the corresponding first screw slot, and each first screw rod is dynamically connected with the first motor. The end wall, farfrom the corresponding first sliding slot, of each inserting hole is provided with a second sliding slot and a third sliding slot, wherein the openings of each second sliding slot and each third sliding slot are arranged towards the corresponding inserting hole.

The invention discloses novel information consultation equipment, which comprises a rotating seat, an equipment main body, a plug and a socket, wherein the rotating seat is fixedly arranged on the ground; the equipment main body is arranged on the rotating seat through a rotating component; the plug is electrically connected with the equipment main body through a cable; the socket is matched withthe plug and is fixedly arranged in a wall; inserting grooves of which ports are toward the right are longitudinally symmetrically arranged in the socket; electric connection sheets are arranged in front and rear end walls of each inserting groove; a left sliding cavity and a right sliding cavity located between the two inserting grooves are arranged in the socket; a first driving machine is fixedly arranged between the left sliding cavity and the right sliding cavity; first sliding grooves of which the ports are toward the corresponding inserting groove are longitudinally symmetrically arranged in the end wall, close to the left sliding cavity, of each inserting groove; the right half segment of each first sliding groove communicates with the left sliding cavity; a left sliding plate capable of sliding from left to right is arranged in the left sliding cavity; and a left screw rod which extends from left to right is arranged in the left sliding plate in a matched manner.

The invention discloses an improved electric power device. The improved electric power device comprises a power connection seat fixedly mounted in a wall and a power connection head connected with equipment; plugging slots with rightwards-facing openings are formed in the power connection seat, wherein the plugging slots are in longitudinal symmetry; first sliding slots of which the openings facethe plugging slots are formed in the power connection seat, wherein the first sliding slots are in longitudinal symmetry and are located between the two plugging slots; a first driving motor is mounted between the two first sliding slots; first sliding arms are slidingly mounted in the first sliding slots; end surfaces of the first sliding arms are provided with first inclined surfaces, wherein the end surfaces of the first sliding arms face the plugging slots; first threaded slots of which the openings face the first driving motor are formed in the first sliding arms; first threaded rods which are in power connection with the first driving motor are mounted in the first threaded slots through screw-thread fit; and a second sliding slot and third sliding slot of which the openings face theplugging slot are formed in an end wall of the plugging slot, wherein the end wall of the plugging slot is far away from the corresponding first sliding slot.

The invention discloses an improved air dust removing device. The device comprises an accommodation cavity which is arranged in a wall body, a power distribution cabinet which is arranged in the accommodation cavity through a push assembly, and a plug which is electrically connected with the dust removing device, wherein the opening of the accommodation cavity faces the right. Plug-in slots are symmetrically arranged up and down in the power distribution cabinet, wherein the openings of the plug-in slots face the right. First sliding slots which are arranged between two plug-in slots are symmetrically arranged up and down in the power distribution cabinet, wherein the opening of each first sliding slot faces a plug-in slot. A first motor is arranged between two first sliding slots. A firstsliding arm is slidably arranged in each first sliding slot. A first inclined surface is arranged on the end face, which faces a plug-in slot, of each first sliding arm. A first spiral slot is arranged in each first sliding arm, wherein the opening of the first spiral slot faces the first motor. A first spiral rod in power connection with the first motor is arranged in each first spiral slot, wherein the first spiral rod is in screw-thread fit with the first spiral slot. A second sliding slot and a third sliding slot are arranged in the end wall, which is away from a first sliding slot, of each plug-in slot, wherein the openings of the second sliding slot and the third sliding slot face the plug-in slot.

The invention discloses an electric power device. The electric power device comprises a power connection seat fixedly mounted in a wall and a power connection head connected with equipment; plugging slots with rightwards-facing openings are formed in the power connection seat, wherein the plugging slots are in longitudinal symmetry; first sliding slots of which the openings face the plugging slotsare formed in the power connection seat, wherein the first sliding slots are in longitudinal symmetry and are located between the two plugging slots; a first driving motor is mounted between the twofirst sliding slots; first sliding arms are slidingly mounted in the first sliding slots; end surfaces of the first sliding arms are provided with first inclined surfaces, wherein the end surfaces ofthe first sliding arms face the plugging slots; first threaded slots of which the openings face the first driving motor are formed in the first sliding arms; first threaded rods which are in power connection with the first driving motor are mounted in the first threaded slots through screw-thread fit; and a second sliding slot and third sliding slot of which the openings face the plugging slot areformed in an end wall of the plugging slot, wherein the end wall of the plugging slot is far away from the corresponding first sliding slot.

The invention discloses novel information consulting equipment, comprising a turntable fixedly arranged on the ground, an equipment main body arranged on the turntable through a loop component, a plugelectrically connected to the equipment main body through a cable, and a socket that is matched with the plug and is fixedly mounted in a wall, wherein insertion slots with rightward ports are symmetrically arranged in the socket up and down, first sliding slots that are located between the two insertion slots and have rightward ports are symmetrically arranged in the socket up and down, a firstdriving machine is arranged between the two first sliding slots, a first sliding arm is slidably arranged in each first sliding slot, the end surfaces of the first sliding arms facing towards the insertion slots are provided with first inclined surfaces, a first spiral slot of which the port faces towards the first driving machine is arranged in each first sliding arm, and a first screw rod in power connection with the first driving machine is arranged in each first spiral slot in a screw-thread fit manner.

The invention discloses a novel electric power device. The novel electric power device comprises a power connection seat fixedly mounted in a wall and a power connection head connected with equipment;plugging slots with rightwards-facing openings are formed in the power connection seat, wherein the plugging slots are in longitudinal symmetry; first sliding slots of which the openings face the plugging slots are formed in the power connection seat, wherein the first sliding slots are in longitudinal symmetry and are located between the two plugging slots; a first driving motor is mounted between the two first sliding slots; first sliding arms are slidingly mounted in the first sliding slots; end surfaces of the first sliding arms are provided with first inclined surfaces, wherein the end surfaces of the first sliding arms face the plugging slots; first threaded slots of which the openings face the first driving motor are formed in the first sliding arms; first threaded rods which are in power connection with the first driving motor are mounted in the first threaded slots through screw-thread fit; and a second sliding slot and third sliding slot of which the openings face the plugging slot are formed in an end wall of the plugging slot, wherein the end wall of the plugging slot is far away from the corresponding first sliding slot.