40results about How to "Guarantee a safe landing" patented technology

The invention discloses a high-reliability unmanned aerial vehicle with tilt rotors. The high-reliability unmanned aerial vehicle comprises a rack, wherein a flight control system is arranged at the center of the rack, the rack is a Y-shaped rack formed by abutting three same arms, and one group of electric power units which is electrically connected with the flight control system and can set angle by rotating is arranged at the end part of each arm. Each electric power unit comprises a motor base rotatably connected to the end part of each arm, a permanent magnet brushless direct current motor fixed on the motor base, a rotor connected to an output shaft of the permanent magnet brushless direct current motor, and a motor steering server which is connected to one side of the motor base and used for driving the motor base to rotate by taking the arm as a shaft, and the input ends of the permanent magnet brushless direct current motor and the motor steering server are electrically connected with the output end of the flight control system. The high-reliability unmanned aerial vehicle has a capacity of keeping the attitude stable after certain rotor fails, and is variable in structure, for example, a three-rotor horizontal structure can be converted into a dual-rotor vertical structure so that the projection area can be reduced, thereby being suitable for flight in a limited space.

The invention discloses an electronic control system and control method for an electricity-oil hybrid unmanned aerial vehicle energy system. The energy system comprises an engine, a power generator, astandby battery and a lift motor, and the power generator is connected with the engine which is connected with an oil tank. The electronic control system comprises an engine operating condition acquisition module, a power generator voltage and current sampling module, an electric energy mixing module, a bidirectional rectifying module and an engine control unit. The engine control unit comprisesan engine throttle opening control module and an engine injection quality control module. Accurate control of the electricity-oil hybrid unmanned aerial vehicle energy system can be realized, energy conversion efficiency is improved, fault redundancy is provided, and stability and reliability of the energy system can be remarkably improved.

The invention relates to an emergency landing method of an unmanned aerial vehicle based on radio and laser guiding. Equipment in the method comprises a laser scanner, laser receivers and a data processor; the laser scanner is arranged at the end of one end of a runway, a scanning center aligns to the center line of the runway, and a flake laser beam is emitted out in a scanning range of plus-minus five degrees to plus-minus ten degrees; two laser receivers are arranged at both ends of the wings of the unmanned aerial vehicle, and are connected with the data processor through cables; and the data processor is arranged inside an equipment compartment of the unmanned aerial vehicle. When a flight control system of the unmanned aerial vehicle judges that received GPS (Global Positioning System) data is in failure, the emergency landing of the unmanned aerial vehicle is realized through the combination of long-distance radio guiding and short-distance laser guiding.

The invention discloses a landing buffering device for an unmanned aerial vehicle. The landing buffering device comprises an outer bag and an inner bag which is composed of an inflation framework. After being inflated, the inflation framework of the inner bag comprises four cylindrical main air columns in the same shape, the top surfaces of the main air columns are located on the top plane, and the bottom surfaces of the main air columns are located on the bottom plane. The main air columns are connected through side air columns and the projections of the side air columns on the top plane are distributed along the sides of a rectangle. The outer bag is used for wrapping the inner bag and is in a rectangular solid shape or a cube shape after being inflated, the height of the outer bag is larger than or equal to that of the main air columns, and the projection of the outer bag on the top plane covers the projections of the main air columns and the side air columns. The landing buffering device for the unmanned aerial vehicle can be in a fixed square shape after being inflated, the fixed shape of the unmanned aerial vehicle can be guaranteed in the landing process of the unmanned aerial vehicle, even though the unmanned aerial vehicle is affected by air resistance, the unmanned aerial vehicle does not impact on the ground directly, and therefore the good unmanned aerial vehicle protection effect can be achieved.

The invention discloses a liquid rocket. The liquid rocket comprises a first sub-stage of the rocket, a power tail cabin section, a parachute bag and an explosion separation structure, wherein the power tail cabin section is connected with the first sub-stage of the rocket through the explosion separation structure; an explosion separation surface is positioned between the bottom of a storage tankof the first sub-stage of the rocket and the power tail cabin section; the parachute bag is arranged on the power tail cabin section in a folding manner; after separation of the first sub-stage of the rocket, the explosion separation structure is detonated, so that the power tail cabin section is separated from the bottom of the storage tank along the explosion separation surface; and the parachute bag is opened to reduce the descending speed of the power tail cabin section. Compared with the prior art, the structure has the advantages of convenience in control, safety, reliability, low costand the like; and after the power tail cabin section is recycled, the power tail cabin section can be overhauled, tested, cleaned and reused.

The invention discloses a new sky landing method as well as sky landing equipment, namely a sky landing safe chair. Sky landing comprises landing on a star, the moon or the earth. The sky landing method comprises the following steps: gas is produced by igniting in the landing process, a gas protective layer is inflated, friction force is generated between the gas protective layer carrying a landing person and the atmospheric layer when landing under the inflated state, the landing is at a low speed, the gas protective layer is separated between the landing person and the earth, the moon or the star when the landing person lands on the surface of the earth, the moon or the star, that is the landing person lands on the gas protective layer, and the landing person is protected in an omnibearing manner, when ignition is conducted on the water surface or underwater, the gas protective layer carries the landing person to float on the water surface or float out the water surface. The sky landing safe chair has the characteristics that the gas protective layer is lapped to be annular like a swim ring to be encircled on the purpose-made chair; an electrical appliance controls the ignition in landing, so that the gas protective layer is inflated, and the landing person is wrapped to the core to fall instantaneously. The equipment is safe, quick, universal and all-weather, safely falls at all heights greater than 1 second altitude difference from the ground, and can save the person's life in 1 second.

The invention provides a rocket fairing recovery system and method, and belongs to the technical field of rocket sublevel recovery. The rocket fairing recovery system provided by the invention comprises a deceleration system, a control system and an aerial grabbing system, wherein the deceleration system comprises a controllable parafoil and a thrust reverser which are arranged on a fairing; the control system is used for controlling operation of the controllable parafoil and the thrust reverser; and the aerial grabbing system comprises an air vehicle which is provided with a mechanical arm for conducting aerial grabbing on the fairing. According to the rocket fairing recovery system, the fairing grabbed in the air does not need to be received on the ground, the aerial grabbing mode has better maneuverability compared with other receiving modes, safe landing of the fairing can be ensured, and secondary use of the fairing is ensured.

The invention discloses a device and method suitable for a fixed-wing unmanned aerial vehicle to land on a field crop canopy. The device comprises a fixed supporting frame, a load buffering device and a pay-off and take-up device, wherein the fixed supporting frame comprises an underframe and a plurality of hanging brackets; the landing device is mounted under the unmanned aerial vehicle through the hanging brackets; the underframe comprises front end brackets, supporting side arms, a supporting front rod, a supporting middle rod and a supporting rear rod; one ends of the front end brackets are connected with the supporting side arms end to end; the other ends of the front end brackets are vertically connected with the supporting front rod; the supporting middle rod is respectively connected with front ends of the supporting side arms at the two ends; the two ends of the supporting rear rod are respectively connected with the tail ends of the supporting side arms on the two sides; the load buffering device comprises a glass fibre mesh and a sliding rod; one end of the glass fibre mesh is fixed on the supporting middle rod; the other end of the glass fibre mesh is fixed on the sliding rod; the sliding rod is parallel to the supporting front rod; and the sliding rod moves forwards and backwards along the supporting side arms under the driving of the pay-off and take-up device. The invention can ensure that the fixed-wing unmanned aerial vehicle can safely land on the field crop canopy without affecting the normal flight of the fixed-wing unmanned aerial vehicle.

The present invention is a self-rotating wing rain-enhancing and hail-proof rocket, comprising a sowing cabin (20), an umbrella cabin (21), an engine (22) and an empennage (23). The umbrella cabin is located in the middle of the rocket, through a base (5) and an adapter (15) are respectively connected with the sowing cabin and the engine; the umbrella rope of the small umbrella (11) is tied in the guide post (10) hole, and is connected with the big umbrella (13) by pulling the umbrella rope (19). The small umbrella brings out the big umbrella; the folding tail is adopted and launched through the launch tube; the slope on the surface of the leading edge of the wing creates a pressure difference in the airflow, which makes the rocket rotate during flight to increase flight stability and improve shooting accuracy; deep groove The inner ring and the outer ring of the ball bearing (14) are closely matched with the mandrel (16) and the inner hole of the adapter cylinder respectively, which eliminates the synchronous rotation between the rocket and the big umbrella line, and prevents the big umbrella canopy from being disturbed , to ensure the safe landing of the anti-rotation device, the engine and the empennage, with high reliability and safety.

The invention discloses a special shock-absorbing tripod for an aerial camera, which comprises a primary shock-absorbing device, an intermediate connecting piece and a secondary shock-absorbing device sequentially connected from bottom to top, and is characterized in that the secondary shock-absorbing device includes a top The connecting piece, the top connecting piece is cylindrical, the bottom surface of the top connecting piece is provided with three expansion assemblies along the circumference, and the expansion assemblies are provided with connecting assemblies between each two, and the expansion assemblies and the connecting assemblies form As for the shock-absorbing sleeve, one end of the intermediate connecting piece is connected to the primary shock-absorbing device, and the shock-absorbing head at the other end of the intermediate connecting piece is set in the shock-absorbing sleeve and can move along the axial direction of the shock-absorbing sleeve. The present invention adopts the arrangement of the primary shock absorbing device and the secondary shock absorbing device, wherein the secondary shock absorbing device adopts the mode of wrapping the shock absorbing head with the shock absorbing sleeve, and realizes two shock absorbing for landing through two different structures, which is very good It solves the problem of excessive impact force when landing, and ensures the safe landing of the drone.

The invention relates to an output structure of an unmanned helicopter engine adopting overrunning one-way clutches. The output structure comprises a main reducer which is provided with two power input ends and a power output end. Each power input end of the main reducer is sequentially connected with the corresponding overrunning one-way clutch, a flexible coupler and a turboshaft engine. The power output end of the main reducer is connected with a main rotor wing of an unmanned helicopter. According to the output structure of the unmanned helicopter engine adopting the overrunning one-way clutches, the unmanned helicopter adopts a double-power device and is provided with the two turboshaft engines, the output end of each turboshaft engine is provided with the corresponding overrunning one-way clutch, and the problem that a power output part and a power source part are asynchronous is solved by using the overrunning one-way clutches.

The invention relates to a novel oil-electricity combined four-rotor transport unmanned aerial vehicle, and belongs to the technical field of unmanned aerial vehicles. The novel oil-electricity combined four-rotor transport unmanned aerial vehicle aims to solve the problems of the short runtime and the poor stability in the prior art. The novel oil-electricity combined four-rotor transport unmanned aerial vehicle includes a vehicle body, a shock absorbing mounting table arranged on the vehicle body, four sets of flying devices arranged at the four corners of the upper end of the vehicle body,a gripping device connected to the shock absorbing mounting table and a power and transmission device arranged on the shock absorbing mounting table; the power and transmission device comprises an electrification start unit and an oil-to-electricity unit, wherein the electrification start unit drives the oil-to-electricity unit to be started, and the oil-to-electricity unit supplies power to the overall unmanned aerial vehicle. The novel oil-electricity combined four-rotor transport unmanned aerial vehicle can realize oil-electricity combined drive four-rotor flight, can realize electrification start of the unmanned aerial vehicle, solves the problems about flight stability and the runtime, can convert the drive mode into electric drive under the condition that oil in an oil tank is used up, and ensures safe landing of the unmanned aerial vehicle.

The invention relates to a non-time-limit ground power and pesticide supply plant protection unmanned aerial vehicle. The non-time-limit ground power and pesticide supply plant protection unmanned aerial vehicle comprises a power supply module, a pesticide supply module, a power transmission and pesticide conveying cable, a movable lifting platform, a tension induction line reeling and unreeling device and a plant protection unmanned aerial vehicle body. The power supply module converts the alternating current of an electric generator into the high-voltage direct current through an alternating and direct current electric transducer and transmits the high-voltage direct current to a high-voltage direct current line. The pesticide supply module uses an anti-corrosive high-pressure pump for pumping pesticide in a pesticide matching barrel into a pesticide conveying pipe. The power transmission and pesticide conveying cable is composed of the high-voltage direct current line and the pesticide conveying pipe and connected with the plant protection unmanned aerial vehicle body through the tension induction line reeling and unreeling device. The non-time-limit ground power and pesticide supply plant protection unmanned aerial vehicle is flexible in control and convenient to operate, and the working time is not limited.

The invention discloses an airport bird repelling system, including a HD camera array, bird-repelling loudspeaker, desktop computer, bird repelling system software, and a signal line, the high-definition camera array is mounted on both ends of the airport runway, bird-repelling loudspeaker is arranged at both ends of a runway entrance, the desktop computer is installed in the airport monitoring room, the bird repelling system software is installed on a desktop computer, the signal line is buried under the airport concrete, for communication connections between components of the system. The invention adopts the high-definition camera array to collect the space image of the take-off and landing route of the aircraft, then the bird driving system software is used to read the big data of birdappearance and walking path in space flight, and the analysis is made to intelligently identify which kind of bird it belongs to, and then the bird-repelling loudspeaker is used to emit the sound aiming at expelling this kind of bird, so as to repell the birds to ensure the safe landing of the plane.

The invention discloses an aerial camera capable of safely landing. The aerial camera comprises an aerial camera body and a camera arranged at the bottom portion of the aerial body, wherein plural groups of vibration reducing foot frames are arranged below the aerial camera body, the vibration reducing foot frame comprises a first-stage vibration reducing device, a middle connection member and a second-stage vibration reducing device, the second-stage vibration reducing device comprises a top portion connection member, the top portion connection member is cylindrical, the bottom surface of thetop portion connection member is provided with three expansion assemblies, connection assemblies are arranged between the two expansion assemblies, the expansion assembly and the connection assemblyform a vibration reducing sleeve, one end of the middle connection member is connected to the first-stage vibration reducing device, and the vibration reducing head on the other end of the middle connection member is sleeved in the vibration reducing sleeve and can move along the axial direction of the vibration reducing sleeve. According to the present invention, the vibration reducing foot frameis arranged into the first-stage vibration reducing device and the second-stage vibration reducing device, and the second-stage vibration reducing device uses the vibration reducing sleeve to coat the vibration reducing head, such that the vibration reducing is performed on the landing through different structures, the problem of too high impact force during the landing is well solved, and the safe landing of the aerial camera is ensured.

The invention provides an unmanned aerial vehicle landing control method and device, an unmanned aerial vehicle and a storage medium, and relates to the field of flight control of unmanned aerial vehicles. The method is applied to the composite wing unmanned aerial vehicle, the composite wing unmanned aerial vehicle comprises a fixed wing and a rotor wing, and the method comprises the steps that whether the current deceleration distance of the composite wing unmanned aerial vehicle is smaller than or equal to a deceleration distance threshold value is judged; if yes, the composite wing unmanned aerial vehicle is set to be in a horizontal-to-vertical mode; when the forward speed of the composite wing unmanned aerial vehicle is smaller than or equal to the hovering speed threshold value, thecomposite wing unmanned aerial vehicle is set to be in a tail end hovering mode; whether the current hovering time is greater than or equal to the tail end hovering time or not is judged; if yes, thecomposite wing unmanned aerial vehicle is set to be in a tail end descending mode; and under the condition that the composite wing unmanned aerial vehicle meets the preset to-be-flied condition, thecomposite wing unmanned aerial vehicle is set to be in the to-be-flying mode from the tail end descending mode. By setting different judgment thresholds, the landing behavior of the unmanned aerial vehicle is divided into multiple modes to be controlled, and it is guaranteed that the unmanned aerial vehicle can safely land to a designated landing point.

The invention provides an escapement transmission type high building escape device. The device comprises a fixing support, a main shaft, a winding drum, a steel wire rope, a ratchet wheel mechanism, an escapement mechanism, a ball bearing and a small chain wheel shaft. The two ends of the main shaft are supported and positioned to the fixing support. The ball bearing and a pawl base are mounted onthe main shaft in a sleeving manner. The two ends of the winding drum are fixedly and coaxially connected with the outer race of the ball bearing and a ratchet wheel correspondingly. The steel wire rope is wound on the outer side of the winding drum. The escapement mechanism comprises a first shaft, a second shaft, an escapement wheel, an escapement fork, a support and a balance wheel. The firstshaft is rotationally supported on the fixing support and located on the lateral side of the main shaft. A gear transmission mechanism is arranged between the first shaft and the main shaft. An escapement transmission mechanism is arranged between the first shaft and the second shaft. The escapement wheel is mounted on the first shaft in a sleeving mode. The escapement fork is mounted at the firstend of the second shaft in a sleeving mode. The other end of the second shaft is sleeved with the balance wheel. According to the escapement transmission type high building escape device, the gravitational potential energy of a human body is uniformly released by means of alternating engagement of the escapement wheel and the escapement fork, so that the human body falls at a certain uniform speed, thereby guaranteeing that the human body lands safely.

The invention discloses a personal air vehicle, discloses a sport device challenging limit sports, and particularly relates to the personal air vehicle. Both sides of a main wing bone are each provided with a gasoline engine, and each engine is provided with a propeller; the main wing bone is provided with a main wing bone cloth cape; a tail wing bone is provided with a tail wing cloth cape; during use, a passenger body is tied firmly by a tying belt and a passenger soft seat, a passenger holds a joystick by hand, the gasoline engines are started to drive the propellers to rotate, when a certain speed is reached, air is pushed to flow downward, an overall upward pushing force is generated, and the air vehicle gets off the ground to complete taking-off. The personal air vehicle is used as the athletic sports device challenging the limit, is novel in style and strong in challenge, can bring enjoyment of flying pleasure to a sporter, has the characteristics of small volume and light weight, and does not need special specifications and large-area places. With the joystick, a vehicle body is flexible to steer. The passenger is allowed to fly with various postures, the air retention time is long, the fuel consumption is low, and the problems existing in a conventional air vehicle are solved.

The invention provides a centrifugal high-rise escape device and a working method thereof. The centrifugal high-rise escape device comprises a support, a first shaft, a second shaft, a third shaft, afirst gear, a second gear, a third gear, a fourth gear, a winding drum, a steel wire rope, a ratchet mechanism, a centrifugal speed regulating mechanism, a friction disc mechanism and a lever drivingmechanism; and the centrifugal speed regulating mechanism comprises a centrifugal seat, a centrifugal rod, a flying ball, a shaft ring and a connecting rod, wherein one end of the centrifugal rod is hinged to the centrifugal seat, the other end of the centrifugal rod is fixedly connected with the flying ball, the shaft ring is coaxially arranged on the first shaft in a sliding mode, and the two ends of the connecting rod are hinged to the shaft ring and the centrifugal rod correspondingly. According to the centrifugal high-rise escape device, the centrifugal speed regulating mechanism and thefriction disc mechanism are innovatively adopted, the axial driving force to a fixed friction disc is generated by utilizing the centrifugal speed regulating mechanism, the axial driving force is amplified through the lever driving mechanism, and a compression spring is used for adjusting displacement and transmitting the axial driving force to the fixed friction disc, so that the friction resistance moment is promoted to be generated between the fixed friction disc and a movable friction disc, and a human body can be prevented from falling down rapidly.

The invention discloses a special shock-absorbing tripod for an aerial camera, which comprises a shock-absorbing base body, on which a connecting piece for connecting with the aerial camera body is arranged, and a shock-absorbing bracket is arranged under the shock-absorbing base body, and the shock-absorbing bracket includes a horizontal The main bracket with a circular cross-section is equipped with multiple groups of sub-supports evenly on the outer circumference of the main bracket. The sub-supports include a primary shock absorber, an intermediate connector and a secondary shock absorber. The secondary shock absorber includes a top connector. The top connecting piece is cylindrical, and the bottom surface of the top connecting piece is provided with three expansion assemblies along the circumference, and a connecting assembly is arranged between two expansion assemblies, and the expansion assembly and the connecting assembly form a shock absorbing sleeve. The other end of the intermediate connector is provided with a shock-absorbing head adapted to the shock-absorbing sleeve. The shock-absorbing head is set in the shock-absorbing sleeve and can move along the axial direction of the shock-absorbing sleeve; the invention solves the problem very well. It solves the problem of excessive impact force when landing, and ensures the safe landing of the drone.

The invention discloses an aerial camera with a professional tripod. The aerial camera comprises an aerial camera main body and a camera arranged at the bottom of the aerial camera main body, wherein multiple sets of wings with propellers are arranged on the aerial camera main body; a damping device is arranged at the bottom at one end of the wings; the damping device comprises a connecting plate and a damping tripod; the connecting plate is connected with the bottom of the wings; the damping tripod comprises three sets of adjusting components which are distributed along the peripheral direction of the connecting plate; each adjusting component comprises a base; a left expansion link and a right expansion link are hinged on the base; the left expansion link and the right expansion link are arranged in V shape; and the other ends of the left expansion link and the right expansion link are both hinged with the connecting plate. According to the invention, the damping device is arranged, the V-shaped damping tripod is arranged and a triangular structure is formed between the damping tripod and the connecting plate, so that the damping and stabilizing functions are achieved and the safe landing of the aerial camera is guaranteed.

The invention discloses a recovery device for a fixed-wing unmanned aerial vehicle. The device comprises a wind power generation device (1), a rectifying device (2), a control unit (3), an unmanned aerial vehicle recovery bin (4), a camera unit (5), an unmanned aerial vehicle storage chamber (7) and the like, and the wind power generation device (1) is used for generating wind energy, buffering an unmanned aerial vehicle, absorbing energy and reducing the speed; the rectifying device (2) is fixedly connected to the wind power generation device through screws and used for smoothing airflow and preventing turbulent flow; the control unit (3) adjusts the rotating speed of an axial flow fan of the wind power generation device (1) and the left-right and up-down swing angles of guide vanes (9) according to the flight attitude and speed, and applies wind resistance to the unmanned aerial vehicle; and a flow guide groove (11) and an air outlet (10) which are formed in the upper portion of the unmanned aerial vehicle recovery bin (4) apply wind power to the upper portion of the unmanned aerial vehicle, the unmanned aerial vehicle is forced to land, and finally the unmanned aerial vehicle is recovered into the unmanned aerial vehicle storage chamber (7). The recovery process is completed mainly by applying wind power to the unmanned aerial vehicle, the process is safe and reliable, the automation degree is high, and the device can be suitable for recovery of fixed-wing unmanned aerial vehicles in different fields.

The invention provides a centrifugal high-rise escape device and a working method thereof. The centrifugal high-rise escape device comprises a support, a first shaft, a second shaft, a third shaft, afirst gear, a second gear, a third gear, a fourth gear, a winding drum, a steel wire rope, a ratchet mechanism, a centrifugal speed regulating mechanism, a friction disc mechanism and a lever drivingmechanism; and the centrifugal speed regulating mechanism comprises a centrifugal seat, a centrifugal rod, a flying ball, a shaft ring and a connecting rod, wherein one end of the centrifugal rod is hinged to the centrifugal seat, the other end of the centrifugal rod is fixedly connected with the flying ball, the shaft ring is coaxially arranged on the first shaft in a sliding mode, and the two ends of the connecting rod are hinged to the shaft ring and the centrifugal rod correspondingly. According to the centrifugal high-rise escape device, the centrifugal speed regulating mechanism and thefriction disc mechanism are innovatively adopted, the axial driving force to a fixed friction disc is generated by utilizing the centrifugal speed regulating mechanism, the axial driving force is amplified through the lever driving mechanism, and a compression spring is used for adjusting displacement and transmitting the axial driving force to the fixed friction disc, so that the friction resistance moment is promoted to be generated between the fixed friction disc and a movable friction disc, and a human body can be prevented from falling down rapidly.

The invention discloses an audio-recognition lift type lightning rod for apron. The audio-recognition lift type lightning rod for apron comprises a noise picker, a noise storage, a central processingunit, a step motor and a lightning rod, wherein the noise picker is used for picking up the sound of thunder in a thunderstorm day, the noise storage is used for storing thunderstorm noise data, the central processing unit is a central controller of the whole system and is used for collecting and comparing the noise data and controlling positive rotation and negative rotation of the step motor, and the lightning rod is mounted on the apron and is used for preventing lightning stroke from devices on the apron in the thunderstorm day. According to the audio-recognition lift type lightning rod for apron, the sound of thunder in the thunderstorm day is intelligently recognized so as to control the lift of the lightning rod, specifically the lightning rod is shrunk in the days without thunderstorm and is lifted up in the thunderstorm day so that the devices on the apron are effectively prevented from damages of the thunder stroke.

The invention discloses a building with multifunctional rope unwinding equipment. The building with the multifunctional rope unwinding equipment comprises the multifunctional rope unwinding equipmentarranged on a roof or a refuge storey or an upper storey of the building, wherein the multifunctional rope unwinding equipment comprises a motor, a reel and a pull rope; the motor, the reel and the pull rope are arranged on the roof storey or the refuge storey or the upper storey; the motor is capable of driving the reel to rotate; a circular ring sleeves the reel; a stopping surface is arranged on the circular ring; a stopping element is arranged on the reel; one end of the pull rope is connected to the circular ring; the pull rope extends out from the circular ring and is wound on the reel,and then extends out from the reel and is connected with a heavy object; and a cable connected with the motor extends downwards to reach a place below the building or reach the outside of the buildingand is connected with a power supply through a main contact of a contactor.