59results about How to "Fast braking" patented technology

The utility model discloses a novel impulse turbine brake device which is characterized in that the center of a power generation rotating wheel disc is connected with a main shaft of a generator, a plurality of power generation water buckets are arranged around the power generation rotating wheel disc, an annular water distribution pipe is arranged on the outer sides of the power generation water buckets in the circumferential direction, and a plurality of power generation water spraying devices are arranged on the inner side of the annular water distribution pipe; a plurality of brake water buckets are arranged on the brake rotating wheel disc in a surrounding mode, a water pipe is arranged on one side of the end of the annular water distribution pipe, and a brake spray pipe is arranged at the tail end of the water pipe. When the power generation water turbine works, the braking water turbine shrinks in the concave cavity of the power generation rotating wheel disc, and power generation is not affected; when the power generation water wheel stops or breaks down, the brake shaft is controlled by the hydraulic operating mechanism to extend and drive the brake water turbine to enter a brake station, and the hydraulic needle valve on the brake spray pipe is opened, so that the impulse water turbine is quickly braked. The device effectively improves the braking efficiency and the operation stability of the impulse turbine, and is worthy of being vigorously popularized in future impulse power stations.

The invention discloses an anti-tilting pressure container tilter which comprises a base frame and a container bracket, supporting vertical frames are symmetrically and fixedly installed on the left side and the right side of the base frame, the upper ends of the supporting vertical frames are rotationally connected with the container bracket, a hydraulic pushing and lifting mechanism is installed on the side face of the base frame, holding devices are symmetrically installed on the container bracket, and side face guiding assemblies are symmetrically installed on the two sides of the base frame. A lower tight brake pressing plate and an upper tight brake pressing plate are arranged between the interlayer and the clamping plate. The hydraulic lifting mechanism drives the rotating arm to rotate by 90 degrees anticlockwise, the container bracket rotates by 90 degrees anticlockwise, the pressure container is arranged in the container bracket, then the pressure container is turned over from the transverse direction to the vertical direction, and the whole device is integrated and more flexible in practical application; the telescopic end is prevented from deviating due to overlarge stress; and certain safety is improved.

The invention discloses a brake device for preventing fault inversion of an induced draft fan, and particularly relates to the technical field of braking, the brake device comprises a support, a sleeve frame, a concave frame and a peripheral synchronous embedded brake mechanism, and further comprises a lateral synchronous meshing brake mechanism and a timely proofreading detection assembly; wherein the peripheral synchronous embedded brake mechanism comprises a gear motor, a rotating shaft, a driving gear, a driven gear, a rotating ring, a linkage ring, a positioning ring, a brake wheel, a butt joint shaft, a plurality of anti-inversion grooves and a plurality of inclined sliding frames. According to the invention, the brake mechanism is synchronously embedded at the periphery, so that the brake wheel has the advantages of realizing embedded brake for a plurality of anti-inversion grooves outside the brake wheel, quickly performing brake and being better in brake timeliness, thereby solving the problem that once the torque force of shaft body inversion is greater than the brake friction force, the inversion is still generated, and the service life of the brake wheel is prolonged. Braking is difficult in time to achieve rapid anti-reverse braking, and the braking timeliness is poor.

The utility model discloses a variable displacement piston pump with a compound control function, a control valve and an oil supplementing pump (8) are integrated on the variable displacement piston pump, a driving electromagnetic valve mechanism (3) is integrated on the control valve, the oil supplementing pump (8) is connected with a variable displacement cavity in the variable displacement piston pump through the driving electromagnetic valve mechanism (3), a switch valve mechanism (7) is arranged on a rear cover (20) of the variable displacement piston pump, and the switch valve mechanism (7) is connected with the control valve. A branch oil way is arranged in a rear cover (20) of the variable displacement piston pump, the branch oil way is provided with an oil inlet end and two oil outlet ends, the oil inlet end of the branch oil way is connected with an oil supplementing pump (8), the two oil outlet ends of the branch oil way are connected with an active electromagnetic valve mechanism (3) and a switch valve mechanism (7) respectively, and the switch valve mechanism (7) is connected with a shell cavity of the variable displacement piston pump. The utility model has the advantage of high safety.

The invention discloses an earthquake-induced high-speed train derailment whole process state test simulation system. A vehicle-track-lower foundation structure model comprises a lower foundation structure model, a track system model and a vehicle model; the acceleration system is located at one end of the track system model; the braking system is located at the other end of the track system model; the earthquake simulation device is connected to the lower foundation structure model; the monitoring system comprises a vehicle-mounted monitoring subsystem and a trackside monitoring subsystem. And the data acquisition system is used for acquiring and processing monitoring data of the monitoring system. The method is used for solving the problem that in the prior art, accurate reproduction of the whole derailment process of the high-speed train under the earthquake condition and effective assessment of the damage of the post-earthquake track structure system cannot be achieved, and the purposes of accurate reproduction of the whole derailment process of the high-speed train induced by the earthquake and effective assessment of the damage of the post-earthquake track structure system are achieved.

The utility model discloses a safety brake device for a pneumatic motor, which comprises a motor, a connecting port is arranged above the motor, a mounting seat is arranged on the motor, a first brake pad and a second brake pad are arranged on the mounting seat, and the first brake pad and the second brake pad are respectively positioned on two sides of an output end of the motor. A cylinder barrel is arranged on the mounting seat, an air inlet and an air outlet are formed in the cylinder barrel, air entering the motor from the connecting port is reduced while the motor needs to be braked, air enters the cylinder barrel through the air inlet, and the pushing plug is assisted to slide until the pushing plug pushes the first brake pad to the output end of the motor; the pneumatic motor is braked at the same time from two aspects, the braking speed is increased, loss caused by friction between the output end of the motor and the brake pad is reduced, meanwhile, the second brake pad is used for assisting the first brake pad to brake the output end of the motor, the braking effect of the braking device is guaranteed, and braking failure is avoided.

The monorail personnel transportation device for the coal mine tunnel comprises a rail assembly and a transportation vehicle advancing on the rail assembly, the transportation vehicle comprises a driving part, a cabin and a bearing trolley, the rail assembly comprises a rail, the driving part comprises a hydraulic motor and a friction wheel, the friction wheel can roll on the rail, and the cabin is arranged on the rail. Through driving of the hydraulic motor and friction wheels on the two sides, the running speed is increased, the driving force is larger, the gradeability is higher, running is more stable, a rail is clamped through a brake block of a brake assembly, rapid braking can be achieved, the transport capacity of a single train can be improved according to the needs of personnel through the modular marshalling design, and the situation that the train does not need to turn around to go back and forth is achieved through the two-way cockpit configuration; the air spring damping and rotation structure enables operation to be more stable, the track structure supports rapid extension, and the narrow fuselage design enables the device to be suitable for a complex narrow roadway network of a mine.

The utility model discloses a medical lathe with automatic transfer function, including base, transfer mechanism and brake mechanism, its upper end is equipped with the liftable bed board, transfer mechanism: it includes moving plate, receiving roller, guide roller no. 1, guide roller no. The receiving rollers are arranged at the upper end and the lower end of the left side of the base correspondingly, the first guide roller is rotationally connected to the left side of the upper end of the base, the second guide roller is rotationally connected to the right end of the base, and the two receiving rollers are in transmission connection through the transfer belt. Through cooperation of the moving plate and the transfer belt, a patient can be transferred easily, stably and rapidly, the burden of medical staff is relieved, the safety of the patient is guaranteed, the two brake pads move relatively to make contact with the rotating shaft, huge friction force can be avoided, then the medical lathe is effectively braked, and the medical lathe is prevented from deviating in the transfer process.

The utility model discloses a hydraulic pressure test device for intelligent pressure vessel equipment, which comprises a rack and a human-computer interface touch screen, automatic brake mechanisms are fixed on two sides of the bottom of the rack, each automatic brake mechanism comprises a hydraulic telescopic cylinder, a thread installation clamping column and an anti-skid rubber supporting leg, a water storage tank is fixed in the rack, and a water pump is fixed in the water storage tank. And a fixed seat is welded on the rack. According to the utility model, the sound insulation protective cover, the sound pickup and the like are arranged, so that when the device is used, the sound pickup arranged on the sound insulation protective cover can be used for automatically monitoring sound generated in a water pressure test and then sending the sound to the human-computer interface touch screen, and the result of the water pressure test can be intuitively displayed after the result is calculated based on water sound analysis; and the sound insulation protective cover can effectively solve the interference of external environment noise on the sound pick-up, so that the test precision is improved.

This invention discloses an electric ball valve, a braking system, and a rail vehicle. The electric ball valve includes a ball valve unit and an actuator unit. The ball valve unit includes a valve body and a valve core disposed within the valve body. The valve body has a first valve port and a second valve port. The actuator unit includes a housing and a transmission assembly, at least one rotary energy storage assembly, and a control assembly disposed within the housing. The transmission assembly is connected to the valve core, and the control assembly is connected to the transmission assembly and is used to control the transmission assembly and the rotary energy storage assembly to drive the valve core to rotate and open, thereby connecting the first valve port and the second valve port. According to the electric ball valve provided by this invention, the control assembly controls the transmission assembly and the rotary energy storage assembly to drive the valve core to rotate and open to exhaust air via the transmission assembly, enabling rapid braking in response to exhaust air from the brake pipe.

The invention relates to the technical field of safety protection of industrial equipment, and particularly discloses an anti-falling device of a die-casting edge trimmer. The problem that a middle base of the edge casting and cutting machine falls off in the overhauling process is solved. Comprising a fixed base, an abutting plate, a push ring and a transmission connecting rod mechanism, the base comprises two semi-annular fixed shells which are detachably connected, and the two fixed shells can be jointly clamped and fixed to a guide column of the edge trimmer; an annular groove is formed in the top of the fixed shell, and the abutting plate is arranged in the annular groove in a sliding mode and can slide in the radial direction of the guide column; the push ring is arranged above the annular groove; the transmission connecting rod mechanism is arranged between the push ring and the abutting plate, and when the push ring is subjected to pressure of falling of the edge trimmer middle base, the transmission connecting rod mechanism drives the abutting plate to abut against and lock the guide column. According to the die-casting edge trimmer, the situation that the middle base falls in the overhauling process is reduced.

An integrated self-locking brake system and method, the system includes a motor assembly, a main housing, a transmission mechanism, a master cylinder, and a fluid storage pot; the motor assembly includes a motor and a motor control unit, and the motor control unit is integrated at the rear of the motor; the transmission mechanism includes a worm, a worm wheel, a worm wheel shaft, and a master cylinder push rod, wherein the worm and the worm wheel mesh to form a worm wheel transmission pair, the worm wheel shaft and the master cylinder push rod and the ball constitute a ball screw transmission pair, and the worm wheel is fixedly matched with the worm wheel shaft; the master cylinder is fixedly connected to the main housing by bolts, and a master cylinder piston is matched in the master cylinder, the master cylinder piston is slidably matched with the master cylinder body and is sealed with a sealing ring, the interior of the master cylinder piston is a master cylinder high-pressure chamber, and the exterior of the master cylinder piston is in contact with the master cylinder push rod; the output torque of the motor pushes the master cylinder piston through the worm wheel transmission pair and the ball screw transmission pair, so that it can be telescopically moved in the master cylinder to generate and release braking pressure.

This disclosure relates to a variable frequency motor controller and a garment processing device. The variable frequency motor controller includes a rectifier module, an energy discharge module, a voltage regulator module, a control module, a selector switch module, and a power module. The control module is connected to the selector switch module, which is connected to both the energy discharge module and the voltage regulator module. When the garment processing device is in an energy-dissipating braking state, the control module controls the selector switch module to connect the energy discharge module across the DC bus and disconnect the voltage regulator module from the DC bus, thereby allowing the energy discharge module to discharge the regenerative energy generated during braking. According to embodiments of this disclosure, rapid braking and extended lifespan of the voltage regulator module can be achieved. Furthermore, since no additional mechanical devices are required, mechanical friction and vibration are avoided, thus saving costs and reducing noise.

The invention provides a dual-motor anti-backlash heavy-load numerical control rotary table, and belongs to the field of numerical control machine tools, the dual-motor anti-backlash heavy-load numerical control rotary table comprises a main base body, a base protection top block is fixedly connected to the top surface of the main base body through a horizontal bolt, and a working platform is horizontally arranged on the top surface of the base protection top block. The rotary table can accurately rotate and position according to a preset angle, and a high-precision machining reference is provided for a workpiece, so that the size precision and the shape precision of a machined part are remarkably improved, and the requirement for high-precision machining is met. For example, in the machining process of aerospace parts, the rotary table can ensure that the machining precision reaches the micron level for machining of some holes, contours and other characteristics with extremely high precision requirements, the quality and performance of the parts are effectively improved, overall workpiece machining can be more accurate and efficient, and the machining efficiency is improved. And multiple directions can be expanded to meet the machining requirement, the bearing capacity is greatly improved, and the range of the types of machined workpieces is further widened.

The utility model relates to the technical field of railway transportation equipment and safety, and particularly discloses an external brake device of a track inspection tester, which comprises a supporting mechanism, the supporting mechanism comprises a supporting assembly, and a clamping assembly, a braking assembly and a driving assembly are installed on the supporting assembly. The supporting assembly and the clamping assembly are combined and fixed to a train track inspection vehicle, and the driving assembly is rotationally clamped and embedded in the supporting assembly and drives the brake assembly to abut against a train track. The torsion spring drives the connecting shaft rod to rotate, so that the brake pad is far away from a train track, and normal running of a train is guaranteed; when braking is needed, an operator only needs to rotate the handle, the first push block can be pushed to move through the second push block, then the brake pad abuts against a train track, and rapid and effective braking is achieved. In addition, a first spring in the brake assembly can drive a first push block to be away from a second fixing plate after braking, so that a brake pad leaves a rail in time, and excessive abrasion is avoided.

A pirate ship braking device comprises a foundation support, a braking frame is vertically installed on the foundation support through a power driving device, a vertical support is installed on the braking frame, a transverse support is installed on the vertical support, a braking groove used for being matched with a pirate ship in a braking mode is formed in the transverse support, and braking leather is arranged in the braking groove. The bottom of the vertical support is installed on the brake frame through a plurality of vertically-arranged vertical buffers, the two sides of the transverse support are fixedly connected with the vertical support through a plurality of transversely-arranged transverse buffers, a transverse sliding block is further arranged at the bottom of the transverse support, and a transverse sliding rail matched with the transverse sliding block is arranged on the vertical support. Vertical sliding rails are arranged on the two sides of the brake frame, and vertical sliding blocks vertically installed on the vertical sliding rails in a sliding mode are arranged on the two sides of the vertical support. The bearing is safe and reliable, friction loss and extra stress can be effectively reduced through the improved design, and the durability and reliability of the bearing can be improved.

The invention relates to the technical field of machine tool fixture testing, in particular to a numerical control machine tool fixture stability vibration testing device which comprises a detection bed frame, a detection component and a brake component. A gravity center adjusting screw rod in the counterweight assembly is rotated, so that two gravity center adjusting slide blocks are driven to move along two straight grooves in the direction far away from the test rod under the action of thread thrust between the gravity center adjusting screw rod and an inner thread pipe, and the two gravity center adjusting slide blocks further drive two gravity weights to move together; at the moment, the overall gravity center of the counterweight assembly, the counterweight block and the test rod deviates from the circle center of the test rod, the right end of the test rod vibrates, and the overall gravity center position of the counterweight assembly, the counterweight block and the test rod can be adjusted by adjusting the moving distance of the internal thread pipe, so that the test rod can rotate in the rotating period of the test rod. The right end generates vibration of different amplitudes, the clamping stability of the numerical control machine tool clamp can be tested according to different vibration intensities, the detection range is widened, and the detection intensity is improved.

The invention belongs to the field of antigens and antibodies, particularly relates to an antigen and antibody storage device, and aims to solve the problems of inconvenience in taking and placing, difficulty in control of storage conditions and incapability of meeting the requirements of classified storage and quick taking of various antigens and antibodies in an existing storage mode. A round hole is formed in the middle of the top of the storage box, a rotating bottom plate is rotatably connected to the inner wall of the bottom of the storage box, a plurality of rectangular shells are fixedly connected to the top of the rotating bottom plate, and the rectangular shells are divided into two groups. According to the device, classified storage of various antigens and antibodies is achieved, rapid braking and plugging of the rotating bottom plate and the rectangular shell are achieved through the design of the braking assembly and the plugging assembly, the structural design of sliding connection, spring supporting and the like is adopted, and stable connection and reliable supporting between all components are ensured.

The application discloses an electric control mechanical brake and air brake train brake control system and method, which comprises a brake signal generator, an EPB switch, an EMB controller, an EMB electric push rod assembly, a wheel brake, a trailer controller, a trailer actuating valve, an air pressure sensor, a trailer valve, an air cylinder, an air compressor, a red / yellow spiral air pipe electric connection line and a trailer air pressure brake system; the EMB controller is electrically connected with the brake signal generator and the EPB switch respectively, and the EMB controller controls the wheel brake through the EMB electric push rod assembly; the trailer controller is electrically connected with the brake signal generator, the EPB switch, the trailer actuating valve and the air pressure sensor respectively; the trailer actuating valve is electrically connected with the air pressure sensor, the trailer actuating valve and the trailer valve are connected through a pipeline, and the trailer valve is electrically connected with the trailer air pressure brake system through the red / yellow spiral air pipe electric connection line; and the air compressor is connected with the trailer actuating valve through the air cylinder.

The utility model discloses a kind of robot chassis stretch deformation mechanism, including first chassis, second chassis and stretch structure, second chassis is movably connected above first chassis;Stretch structure includes output gear and rack, output gear is set inside first chassis and partially exposes the upper surface of first chassis, output gear is connected with driving element, rack is set on the lower surface of second chassis and is engaged in output gear, output gear rotation drives rack to move to make first, second chassis stretch / stack each other.The utility model technical scheme aims at optimizing the deformation structure of robot, reduce friction, deformation is more smooth and rapid.

This invention discloses a magnetic levitation circular conveying device and method, comprising: a mounting base, a controller, a circular magnetic levitation stator rail, a material conveying mechanism, a braking mechanism, a fixing frame, a linear motion module, and a vision recognition module; the controller is disposed on the front side of the mounting base; the circular magnetic levitation stator rail is mounted on the top of the mounting base; several material conveying mechanisms are spaced apart on the inner side of the circular magnetic levitation stator rail; the braking mechanism is disposed below the circular magnetic levitation stator rail; the fixing frame is mounted on the rear side of the mounting base; and the linear motion module is disposed on the top left side of the fixing frame along the front-rear direction. This magnetic levitation circular conveying device and method can achieve rapid braking during high-speed magnetic levitation circular conveying, shortening the braking distance, and can achieve precise braking during the conveying of heavier materials, making the material movement position more accurate.

The utility model discloses an integral frame rubber-tyred vehicle retarding device which comprises an integral frame, a front drive axle, a rear drive axle, a gearbox, a front transmission shaft, a coupler, a retarder and a rear transmission shaft, the front drive axle and the rear drive axle are fixed on the front portion and the rear portion of the integral frame respectively, and the gearbox is fixed in the middle of the integral frame. The gearbox is in transmission connection with the front drive axle through a front transmission shaft, the gearbox is further connected with the retarder through a coupler, the retarder is in transmission connection with the rear drive axle through a rear transmission shaft, and the retarder adopts two control modes of foot brake linkage and a hydraulic handle. By means of the mode, the hydraulic retarder can avoid the phenomena of brake abrasion and overheating caused by long-time or frequent brake treading to a certain degree, and stable braking of a vehicle is achieved.

The utility model provides a frozen meat cutting device. The frozen meat cutting device comprises a rack, a cutting assembly and an emergency stop assembly, the rack comprises a machine body and a machine head, the machine body is provided with a cutting table top, and the machine head is connected with the machine body and located above the cutting table top; the cutting assembly comprises a power element, a driving wheel, a driven wheel and a band saw, the power element is arranged in the machine body, the driving wheel is in transmission connection with the power element, the driven wheel is arranged in the machine head, and the band saw is connected with the driving wheel and the driven wheel; the emergency stop assembly comprises a detection assembly and a brake assembly, the detection assembly is installed on the machine head and faces the intersection of the cutting table top and the band saw, the detection assembly is connected with the power element and the brake assembly, the brake assembly is installed in the machine body and connected with the detection assembly, and the brake assembly comprises a brake rod; the brake rod is used for being inserted into the brake hole to brake the band saw when the detection assembly detects the signal. According to the emergency stop device, braking is faster and more effective during emergency stop, the safety can be improved, and fool-proof is effectively achieved.

The utility model discloses a conveyor belt breakage protection device which comprises a brake assembly, the brake assembly is arranged on a return stroke section of a belt and is composed of a first roller and a second roller, and the first roller and the second roller are rollers with damping and are arranged above and below the belt respectively. The first roller is connected to one end of the first reversing frame, the other end of the first reversing frame is hinged to the rack, and a first driving part is connected between the first reversing frame and the rack; the second roller is installed at one end of the first sliding frame, the first sliding frame is provided with a sliding block, and the sliding block is matched with a guide rail groove in the first base to form a sliding pair; a second driving piece is further arranged between the first sliding frame and the first base. When the belt is broken, clamping protection can be formed on the belt, meanwhile, materials on the belt are prevented from driving the belt to operate due to inertia, secondary damage can be prevented, and the device has the advantages of being good in reliability and high in safety.

The utility model belongs to metallurgical casting technical field discloses a molten iron ladle overturning and dumping device for molten iron production, including installation base and hydraulic cylinder, the top outer wall of installation base is opened with rectangular through slot, and the bottom four corners of installation base all are installed with foot brake universal wheel, the both ends of installation base top outer wall all are fixed with arc guide rail through bolt, and the inner wall sliding insertion of arc guide rail has guide wheel shaft, install fixed clamp seat between two guide wheel shafts, and the top outer wall welding of fixed clamp seat has bearing rectangular plate. The utility model through the cooperation of L type fixed frame, C type guide shell and adjusting plug, servo cylinder can drive arc sleeve shell flexible expansion, adapt to different diameter, volume's molten iron ladle, guide sliding slot and guide sliding block ensure that adjusting plug slides accurately, avoid deviation, pressure sensor real -time monitoring arc sleeve shell and the contact pressure of molten iron ladle, ensure that the fixed strength is moderate, cooperate with the mechanical self -lock of self -lock wedge and inclined surface wedge groove, prevent slack in operation.

This utility model belongs to the field of linear motor technology, specifically a novel damping structure for a Z-axis linear motor. It includes a housing, a stator assembly at the bottom of the housing, an oscillator assembly inside the housing, and a damping assembly on the top side of the housing's interior. This utility model designs a damping assembly composed of a copper block and a magnetic ring, combined with the structural cooperation between the oscillator assembly and the stator assembly. After the motor is powered off, the relative motion of the magnet and the copper block cuts magnetic lines of force to generate electromagnetic induction. Simultaneously, the magnetic force of the coil, the iron core inside the coil, and the magnet jointly forms a damping force to consume the oscillator's kinetic energy, achieving rapid braking. This structure does not rely on magnetic fluid or physical contact, significantly improving braking stability, quietness, and consistency.

The utility model discloses a kind of automatic locking support of ship hoisting bracket, it is related to ship field, including the support plate for being fixed on ship board, further include: rotatably installed on support plate support frame;Rotatably installed in support frame inside pay-off reel;Automatic locking assembly is set in the one side of support frame, wherein, automatic locking assembly includes rotatably installed in the one side of support frame bottom turntable, and turntable side is fixedly connected with pay-off reel, and is inserted with the limit ring of being fixed in the one side of support frame. The utility model controls the stall rotation of pay-off reel by automatic locking assembly, improves the security and stability of hoisting operation, pay-off reel is fixedly connected with turntable, when reel stall rotation, turntable synchronous operation, make outer clamping plate extend and insert into limit ring under centrifugal force effect, realize automatic locking emergency stop, effectively prevent cargo falling due to traction rope stall, the design does not need manual intervention, improve the security, reliability and overall efficiency of hoisting operation.

The utility model relates to the field of cantilever cranes, and particularly discloses an electric cantilever crane which comprises a cantilever, a swing seat mounted at one end of the cantilever, a rotating base arranged below the swing seat, rotating teeth mounted on the outer side of the lower end of the swing seat, and a second ratchet ring arranged below the rotating teeth. A first ratchet ring is mounted on the outer side of the swing seat between the second ratchet ring and the rotating teeth, a first brake mechanism is mounted on one side of the second ratchet ring and located in the rotating base, a second brake mechanism is mounted on one side of the first ratchet ring and located in the rotating base, and the first brake mechanism comprises a pawl, a winding roller and a brake motor. And an elastic rotating shaft is connected between the pawl and the rotating base. The tooth punching directions of the first ratchet ring and the second ratchet ring are opposite, the first ratchet ring and the second ratchet ring are matched with the action of the first brake mechanism and the second brake mechanism, so that no influence is generated during normal swinging, and when braking is needed, the purpose of quick braking can be achieved under the action of the overall brake and the pawl of the device.