Patent Publication Number: US-2022234868-A1

Title: Buffer type speed difference falling protector

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a Continuation-In-Part Application of PCT Application No. PCT/CN2020/073565 filed on Jan. 21, 2020, which claims the benefit of Chinese Patent Application No. 201911111202.2 filed on Nov. 14, 2019. All the above are hereby incorporated by reference in their entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention belongs to the technical field of safety tools, and particularly relates to a buffer type speed difference falling protector. 
     BACKGROUND OF THE INVENTION 
     Speed difference falling protectors can quickly brake and lock falling objects within a limited distance, which are suitable for cargo hoisting, can protect the life safety of operators on the ground and prevent damage to the lifted workpieces. It is suitable for safety protection to prevent the lifted workpieces from falling accidentally, and can effectively protect the life safety of operators on the ground and prevent damage to the lifted workpieces. It is used in high-altitude workplaces in the fields of metallurgy, automobile manufacturing, petrochemical industry, engineering construction, electricity, ships, communications, pharmaceuticals, and bridge engineering, etc. 
     The existing speed difference falling protectors have the following advantages: firstly, the speed difference falling protectors the markets realize the braking functions by using a pawl and a ratchet limit. Since a pawl is used for braking, all the gravity will be applied to the pawl. At this time, the impact force applied on the pawl is large, its braking effect is unstable, and it is prone to slippage or pawl breakage, with a low safety; secondary, the brake friction lining and reel of the speed difference falling protector on the markets are integrated together with screws. The friction resistance of the friction lining is completely determined by the tightening force of the screws. The size of the friction force is not easy to control, which causes the buffer force of the buffer type speed difference falling protector not to be easily controlled; thirdly, since the conventional speed difference falling protector uses only one pawl for braking, a buffer pack is designed to reduce the impact; however, with the design of the buffer pack, the falling protector has an increased volume and is inconvenient to carry; in addition, due to dependence on the performance of buffer pack, the safety is low. 
     SUMMARY OF THE INVENTION 
     In order to overcome the defects in the prior art, the present invention provides a buffer type speed difference falling protector with good multi-braking effect and high safety. 
     In order to achieve the above object, the present invention adopts the following technical solution. A buffer type speed difference falling protector comprises: 
     a shell which is provided with an opening; 
     a frame body which is arranged in the shell; 
     a winding device which is arranged on the frame body, wherein a rope body can be wound when the winding device rotates in the forward direction, and the rope body is released when the winding device rotates in the reverse direction; 
     an elastic resetting piece which is used for driving the winding device to rotate in the forward direction; 
     a braking device which is arranged on the frame body and comprises a locking seat with a plurality of ratchets, a fixing piece capable of rotating synchronously with the winding device, a plurality of pawls rotationally arranged on the fixing piece and elastic pieces connected with the pawls, wherein when the fixing piece rotates to enable the centrifugal force generated by the pawls to be larger than the elastic force of the elastic pieces, the pawls are meshed with the ratchets to brake the winding device; and 
     a braking piece which is matched with the winding device through a multi-thread structure, wherein the braking piece rotates synchronously with the winding device and is tightly attached to the braking device. 
     In the present invention, the plurality of pawls are arranged on the fixing piece, thus when the braking device rotates, the pawls are thrown out synchronously to be contacted with the ratchets at the same time, the pawls and the ratchets are limited at the same time to achieve the braking effect, the braking speed is high, and the reliability during braking is high. In addition, the pawls are arranged to form multiple protection, even if one pawl is loosened or broken, the other pawls make contact with the fixing piece, the braking effect is good, and the safety is improved in a multiplied mode. The pawls bear impact force equally, so that vibration formed on parts in the shell is small, and the stability of the parts after being connected is high. The pawls are adopted for synchronous locking, thus the pawls bear pull force equally with the rope, the force borne by each pawl is small, and the service life of the pawls is prolonged. Due to the fact that the plurality of pawls are provided, when the pawls are thrown out, the pawls can balance centrifugal force mutually, the fixing piece cannot bear the pull force towards one side, the fixing piece cannot be loosened even after being used for multiple times, the firmness and stability of the fixing piece after being mounted can be improved, and then the safety of the braking device during braking is improved. The pressure between the braking piece and the braking device is kept constant under the fixing of a multi-thread structure, so that in the process that the winding device is driven by gravity to rotate slowly, the friction force between the braking piece and the braking device of each falling protector is constant, the rotating speed of the winding device is constant when each set of falling protectors slips, objects hung on the falling protectors are put down slowly, and the high safety of the falling protectors produced by mass in the using process is guaranteed. 
     Optionally, a ratchet groove allowing each pawl to be inserted is formed between every two adjacent ratchets, each pawl is provided with a cantilever section extending in the direction away from the rotating center of the pawl, each cantilever section is provided with a first side edge and a second side edge, and a plane perpendicular to the axis of a fixing piece serves as a reference plane. The end, away from the rotating center of the corresponding pawl, of each cantilever section is provided with a tip capable of being clamped into the corresponding ratchet groove, each tip is provided with a first cut edge connected with the corresponding first side edge, and the included angle between the projection of each first cut edge on the reference plane and the projection of each first side edge on the reference plane is set to be β1. The inner wall of each ratchet groove is of a polygonal structure, a first guide edge, a second guide edge, a third guide edge and a flange are sequentially arranged on each ratchet groove in the reverse rotating direction of the fixing piece, and each ratchet is composed of the flange and the first guide edge of the adjacent ratchet groove. The included angle between the projection of each first guide edge on the reference plane and the projection of each second guide edge on the reference plane is set to be β2, the included angle between the projection of each second guide edge on the reference plane and the projection of each third guide edge on the reference plane is set to be 03, wherein 90°&lt;β1&lt;β2&lt;β3. 
     Optionally, 0&lt;(β2−β1)≤30°, 0&lt;(β3−β1)≤45°. 
     Optionally, the second cut edges capable of abutting against the ratchets are arranged at the tips, the plane perpendicular to the axis of the fixing piece serves as a reference plane, the included angle between the projection of each second cut edge on the reference plane and the projection of each second side edge on the reference plane is set to be θ, wherein 140°≤θ&lt;180°. 
     Optionally, a gasket is arranged between the locking seat and the frame body, the thickness of the locking seat in the axis direction of the fixing piece is D1, the thickness of each pawl in the axis direction of the fixing piece is D2, wherein D1: D2=(1-3): 1. 
     Optionally, the plane perpendicular to the axis of the fixing piece serves as the reference plane, the included angle between the projections of the two side walls of the ratchets on the reference plane is α, wherein 25°≤α≤45°. 
     Optionally, a protruding portion used for limiting the pawls is arranged on the fixing piece, the plane perpendicular to the axis of the fixing piece serves as the reference plane, the projection of the axis of the fixing piece on the reference plane serves as a center point C1, the projections of the two ends of the protruding portion on the reference plane serve as the connecting line C1C2 and the connecting line C1C3 with the center point C1, the included angle between C1C2 and C1C3 is γ, wherein 10°≤γ≤70°. 
     Optionally, the winding device comprises a shaft body connected with the fixing piece and a winding structure in anti-rotation connection with the shaft body, and the shaft body is movably connected with the frame body; and/or the winding structure comprises a shaft sleeve arranged on the shaft body in a sleeved manner and a limiting disc used for limiting the rope body, and the limiting disc is connected with the shaft body; and/or the shaft body is provided with a first cutting face, and the shaft sleeve is provided with a second cutting face abutting against the first cutting face. 
     Optionally, the fixing piece is provided with a friction piece, and the braking piece is tightly attached to the friction piece; and/or the multi-thread structure comprises a multi-thread external thread arranged on the shaft body and a multi-thread internal thread matched with the multi-thread external thread, and the multi-thread internal thread is arranged on the braking piece. 
     Optionally, the frame body is provided with an anti-scraping structure matched with the rope body, the anti-scraping structure is a rotating roller corresponding to the opening, and the rotating roller is arranged on the lower portion of the frame body; and/or at least three pawls are provided. 
     In summary, a plurality of pawls are arranged on the fixing piece, when the braking device rotates, the plurality of pawls are thrown out synchronously to be contacted with the ratchets, the braking speed is high, the braking reliability is high, the plurality of pawls can equally divide the impact force during braking, thus, the impact force borne by the interior of the speed difference falling protector is small, and the stability of all parts of the speed difference falling protector is high. The multi-thread external thread structure is used for fixing the braking piece, compared with a traditional screw or single-thread fixing mode, the pressure of the braking piece and the braking device is constant, thus, when the winding device rotates, the rotating speed of the winding device is constant, and the pressure between the braking piece and the friction piece of speed difference falling protectors produced by mass is consistent. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of the present invention. 
         FIG. 2  is a cross-sectional view of the present invention. 
         FIG. 3  is the enlarged view of A in  FIG. 2 . 
         FIG. 4  is an exploded view of the present invention. 
         FIG. 5  is a partial schematic view  1  of the present invention. 
         FIG. 6  is a partial schematic view  2  of the present invention. 
         FIG. 7  is a schematic view of a braking device of the present invention. 
         FIG. 8  is a front view of  FIG. 7 . 
         FIG. 9  is a partial schematic view of  FIG. 8 . 
         FIG. 10  is an exploded view of a braking device of the present invention. 
         FIG. 11  is a schematic view of a winding structure of the present invention. 
         FIG. 12  is a schematic view of a shaft body and a braking piece of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     In order to enable those skilled in the art to have a better understanding of the solutions of the present invention, the technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention. 
     As shown in  FIGS. 1 to 12 , a speed difference falling protector comprises a shell  1 , a frame body  2 , a winding device  3 , an elastic resetting piece  4  and braking device  5 , wherein the shell  1  comprises a first shell  11  and a second shell  12 , the first shell  11  is a metal shell, and the second shell  12  is also a metal shell. The first shell  11  and the second shell  12  are connected together by screws to form a hollow shell; the frame body  2  is arranged inside the shell  1 , the frame body  2  is an n-shaped metal plate, the upper part of the frame body  2  is connected with a joint  22 , and the upper end of the joint  22  is provided with a circular shackle  220 , and the shackle  220  is convenient to wind wire ropes or belt ropes. The lower part of the joint  22  is provided with a convex ring  221 , the frame body  2  is provided with a circular hole, the lower part of the joint  22  is inserted into the circular hole, the convex ring  221  and the frame body  2  are limited at the same time, such that the joint  22  will not be disengaged upwardly. A circlip  222  is sleeved on the joint  22 , the circlip  222  is located on the upper part of the frame body  2 , and a plug  223  is inserted into the joint  22 . The plug  223  is located on the upper part of the circlip  222 , so that the plug  223  limits the circlip  222  to achieve the anti-falling effect. 
     In some embodiments, the winding device  3  is used for winding a rope body, and the rope body is a belt rope or a wire rope, and the winding device  3  can rotate relative to the frame body  2  in a forward direction and a reverse direction. When the winding device  3  rotates in a forward direction, the rope body can be wound on the winding device  3 , and when the winding device  3  rotates in a reverse direction, the rope body will be released; the winding device  3  comprises a shaft body  31  and a winding structure that is sleeved on the shaft body  31 , wherein the shaft body  31  is a metal shaft, the shaft body  31  passes through the through hole on the frame body  2 , and the shaft body  31  can rotate relative to the frame body  2 ; the winding structure is located in the middle of the frame body  2 , the winding structure  32  is in anti-rotation matching with the shaft body  31 ; specifically, the winding structure  32  comprises a shaft sleeve  321  and two limiting discs  322 , the shaft sleeve  321  is a metal sleeve, and the shaft sleeve  321  is sleeved on the shaft body  31 . A first cutting face  310  is arranged on the shaft body  31 , and the first cutting face  310  is a plane, and a second cutting face  320  is arranged on the shaft sleeve  321 , and the second cutting face  320  is also a plane; the first cutting face  310  is in contact with the second cutting face  320 , so as to realize the anti-rotation connection between the shaft sleeve  321  and the shaft body; the limiting disc  322  is a metal disc, and two limiting discs  322  are connected with the shaft sleeve  321  respectively, such that the rope body will be located between the two limiting discs  322  when the rope body is wound around the shaft sleeve  321 , which ensures that the belt rope is in a neat state when wound on the winding structure, to facilitate the releasing and winding of the rope body. The rope body is simple in structure and long in service life. 
     In some embodiments, the elastic resetting piece  4  is a coil spring, and the elastic resetting piece  4  is used to drive the shaft body  31  to rotate forward, so that the winding structure  32  can wind the rope body; the frame body  2  is connected with a protective cover  40  by bolts. The protective cover  40  is a metal cover with a circular chamber. The elastic resetting piece  4  is located in the protective cover  40 . One end of the elastic resetting piece  4  is connected to the protective cover  40 , and the other end of the elastic resetting piece  4  is connected to the shaft body  31 ; specifically, the shaft body  31  is provided with a notch  317 , and the elastic resetting piece  4  is inserted into the notch  317  as the other end, so as to realize the connection between the elastic resetting piece  4  and one end of the shaft body  31 . 
     In some embodiments, in order to prevent the person on the rope body from falling quickly and hurting due to the sudden and rapid rotation when the winding device  3  rotates in a direction, a braking device  5  is arranged on the frame body  2  for locking the winding device  3 . Specifically, the braking device  5  comprises a locking seat  51 , a fixing piece  52 , a pawl  53  and an elastic piece  54 ; the locking seat  51  is a metal sheet, and the locking seat  51  is connected with the frame body  2  through bolts; a circular hole is formed on the locking seat  51 . A plurality of ratchets  510  is provided on the locking seat  51 , and the ratchets  510  are directly cut out of the locking seat  51 , and a ratchet groove  511  for pawl insertion is formed between the adjacent ratchets  510 ; the fixing piece  52  is a metal disc, the fixing piece  52  is connected with the shaft body  31 ; a plurality of pawls  53  are provided and are metal pawls. The pawls  53  are connected with the fixing piece  52  through bolts and nuts; in this embodiment, specifically, three pawls  53  are provided, and the three pawls  53  are movably connected to the fixing piece  52  at equal spacing, and the braking effect is three times that of the conventional pawls. Therefore, the winding device can be quickly braked, with a good braking effect; the elastic piece  54  is a torsion spring, one end of the elastic piece  54  is connected with the fixing piece  52 , and the other end is connected with the pawl  53 , the pawl  53  is pulled by the elastic force of the elastic piece  54  to a position that is not in contact with the ratchet  510 . 
     When the rope body is quickly pulled down due to the gravity of the human body, the winding structure drives the shaft body to rotate in the reverse direction. At this time, since the fixing piece is tightly connected with the shaft body, the fixing piece will rotate synchronously with the winding structure at the initial period, at this time, due to the fast rotating speed of the fixing piece, the centrifugal force on the pawl is greater than the elastic force of the elastic piece, so the pawl will be thrown out, and the pawl will be in contact with the ratchet, thereby locking the fixing piece to restrict the fixing piece from continuing to rotate. Thus, the downward movement of the rope body is restricted. By setting a plurality of pawls on the fixing piece, when the braking device rotates, the plurality of pawls are thrown out synchronously to contact the ratchets at the same time, so the plurality of pawls and the ratchets will be limited at the same time, to achieve the braking effect. The braking speed is fast and the reliability is high during braking; Moreover, the plurality of pawls is provided to form multiple protections. Even if a pawl is loosened or broken, there is a plurality of other pawls in contact with the fixing piece, the braking effect is good, and the safety is doubled; furthermore, the plurality of pawls receives the impact force equally, so the vibration to the components inside the shell is small, and the stability of each component after connection is high; and the plurality of pawls is used for synchronous locking, so the plurality of pawls will equally share the tension on the rope body, and the force acted on each pawl is small, which improves the service life of the pawl; and because there are multiple pawls, when the pawls are thrown out, the plurality of pawls will balance the centrifugal force with each other, so the fixing piece will not be pulled towards one side. Therefore, the fixing piece will not be loosened even after multiple uses, which can improve the firmness and stability of the fixing piece after installation, thereby improving the safety of the braking device during braking. In addition, due to the multi-pawl design, multiple protections are formed. In this application, the design of the buffer pack is cancelled, so the falling protector is more compact in overall structure, occupies a small space and is easy to use; and the multi-pawl design achieves the structural stability and high safety. 
     Referring to  FIG. 2  and  FIG. 3 , in some embodiments, a gasket  55  is arranged between the locking seat  51  and the frame body  2 , and the relative position of the locking seat  51  and the pawl can be adjusted by adjusting the thickness of the gasket  55  to ensure that the ratchet is completely aligned with the pawl; the thickness of the locking seat  51  in the axis direction of the fixing piece is D1, the thickness of the pawl  53  in the axis direction of the fixing piece is D2, wherein D1: D2=(1-3): 1; preferably, D1:D2=(1.5-2.5):1; most preferably, D1:D2=2:1; by defining the relationship between D1 and D2, the margin for adjustment of the locking seat  51  is reserved, so that the locking seat  51  can be specifically adjusted according to the position of the pawl  53 , to ensure that the pawl  53  can make full contact with the ratchet  510 . 
     Referring to  FIG. 8 , in some embodiments, the plane perpendicular to the axis of the fixing piece  52  serves as the reference plane, wherein the included angle between the projections of the two side walls of the ratchets on the reference plane is α, 25°≤α≤45°; preferably, 30°≤α≤40°; most preferably, α=35°. The structural strength of the ratchet  510  is ensured to avoid breakage by the impact of the pawl  53 , and the ratchet groove  511  has enough space for snapping-in of the pawl. 
     Referring to  FIG. 8  and  FIG. 9 , in some embodiments, the pawl  53  is provided with a cantilever section  531  extending in the direction away from the rotating center of the pawl  53 , the cantilever section  531  is provided with a first side edge  5311  and a second side edge  5312 , and a plane perpendicular to the axis of a fixing piece  52  serves as a reference plane. Wherein, the distance between the projection of the first side edge  5311  and the projection of the second side edge  5312  on the reference plane gradually decreases in the direction away from the rotation center of the pawl  53 , which is beneficial for the pawl  53  to be snapped into the ratchet groove  511 . 
     Referring to  FIG. 8  and  FIG. 9 , in some embodiments, the end, away from the rotating center of the corresponding pawl  53 , of the cantilever section  531  is provided with a tip  532  capable of being clamped into the corresponding ratchet groove  511 , each tip  532  is provided with a first cut edge  5321  connected with the corresponding first side edge  5311 , and the included angle between the projection of each first cut edge  5321  on the reference plane and the projection of each first side edge  5311  on the reference plane is set to be β1; the inner wall of the ratchet groove  511  is of a polygonal structure, a first guide edge  5111 , a second guide edge  5112 , a third guide edge  5113  and a flange  5114  are sequentially arranged on each ratchet groove  511  in the reverse rotating direction of the fixing piece (the rotation direction when the winding device is released), wherein the ratchet  510  is composed of the flange  5114  and the first guide edge  5111  of the adjacent ratchet groove  511 . The included angle between the projection of each first guide edge  5111  on the reference plane and the projection of each second guide edge  5112  on the reference plane is set to be β2, the included angle between the projection of each second guide edge  5112  on the reference plane and the projection of each third guide edge  5113  on the reference plane is set to be β3, wherein 90°&lt;β1&lt;β2&lt;β3. The first guide edge  5111 , the second guide edge  5112 , the third guide edge  5113  guide the pawl stuck in ratchet groove  511 , and then remove the impact force of pawl in stages, thereby reducing the impact on ratchets and pawl  53 , to prevent breakage and improve safety; by setting β1&lt;β2&lt;β3, the tip is prevented from being stuck in the inner wall of ratchet groove  511 , to ensure that the tip can slide smoothly along the first guide edge  5111 , second guide edge  5112 , third guide edge  5113  until it abuts against the flange  5114 ; in addition, β1, β2 and β3 are all set to obtuse angles, to ensure that the tip  532  is not stuck in the inner wall of the ratchet groove  511 , reduce the farthest distance between the inner wall of the ratchet groove  511  and the axis of the fixing piece, ensure that the locking seat  51  has sufficient structural strength and reduce the projected area of the locking seat on the reference plane, so that the braking device is more compact, thereby reducing the overall volume of the falling protector. Thus, the falling protector of the present application is convenient to receive and occupies less space, and is convenient to carry. 
     Referring to  FIG. 8  and  FIG. 9 , in some embodiments, 0&lt;(β2−β1)≤30°), 0&lt;(β3−β1)≤45°, preferably, 10°≤(β2−β1)≤20°, 20°≤(β3−β1)≤35°; most preferably, the (β2−β1)=16.7°, (β3−β1)=30°; while ensuring that tip  532  is not stuck with the inner wall of ratchet groove  511 , it is possible to achieve sufficient contact area between the tip  532  and ratchet groove  511 , to maximize the dispersion of the impact force generated when the tip  532  is in contact with the ratchet groove  511 . 
     Referring to  FIG. 8  and  FIG. 9 , in some embodiments, a second cut edge  5322  is arranged on the tip  532 , and the second cut edge  5322  abuts against a ratchet when the pawl  53  is stuck in the ratchet groove  511 . The plane perpendicular to the axis of the fixing piece  52  serves as a reference plane, the included angle between the projection of each second cut edge  5322  on the reference plane and the projection of each second side edge  5312  on the reference plane is set to be θ, wherein 140°≤θ&lt;180°; preferably, 150°≤θ≤170°; most preferably, θ=160°; by defining the included angle between the second cut edge and the second side edge, the tip protrudes in the direction away from the first side edge  5311 , which improves the impact strength of the pawl and makes the pawl not to break easily. 
     In some embodiments, in order to ensure that the pawl will not move in a reserve direction excessively when the pawl is in contact with the ratchet  510 , a plurality of protruding portions  520  are arranged on the fixing piece  52 , and the protruding portions  520  correspond to the pawls  53  one to one, thereby limiting the rotation angle of the pawls  53  and ensuring that the winding structure  32  will not continue to rotate; when the pawl  53  is thrown out, the pawl  53  will abut against the protruding portion  520 , so the pawl  53  cannot continue to move outwards. Thus, when the pawl  510  is in contact with the ratchets  510 , the pawl  53  will not be loosened during the braking, with a high stability; in this embodiment, three protruding portions are provided, and the three protruding portions  520  are arranged in equal spacing along the circumferential direction of the fixing piece. 
     Referring to  FIG. 8 , in some embodiments, the protruding portion  520  is set as an arc, and is located at the edge of the fixing piece  52 . The plane perpendicular to the axis of the fixing piece  52  serves as the reference plane, the projection of the axis of the fixing piece  52  on the reference plane serves as a center point C1, the projections of the two ends of the protruding portion  520  on the reference plane serve as the connecting line C1C2 and the connecting line C1C3 with the center point C1, the included angle between C1C2 and C1C3 is γ, and 10°≤γ≤70°; preferably, 20°≤γ≤40°; most preferably, γ=30°. By setting the included angle γ to limit the arc length of the protruding portion  520  on the fixing piece  52 , the structural strength of the protruding portion is ensured, and the protruding portion is prevented from being broken by impact; in addition, there is sufficient spacing between the adjacent protruding portions to prevent the pawl from interfering with the protruding portion that is matched with the adjacent pawl during the rotation. 
     In some embodiments, after the rope body is locked by the ratchet  510  and the pawl  53 , the rope body can still slowly fall down. A friction piece  522  is pasted on the back of the fixing piece  52 , and the friction piece  522  is a disc; the friction piece  522  is sleeved on the shaft body  31  together with the fixing piece  52 ; a braking piece  312  is sleeved on the shaft body  31 , and the braking piece  312  is a nut with a convex cross section. The braking piece  312  is screwed with the shaft body  31 , and the braking piece  312  abuts against the friction piece  522 . The “abut against” means that the braking piece is tightly attached to the friction piece  522 . The fixing piece  52  rotates synchronously with the shaft body  31  under the action of static friction between the braking piece and the friction piece  522 . By setting a friction piece, after the winding structure is braked by the braking piece, the winding device will still rotate slowly to slowly put down the materials on the rope body since the lower end of the rope body is still subject to weight, while the friction piece increases the force of friction between the fixing piece and the braking piece, so the winding structure rotates slowly when pulled by the rope body. In addition, when a person hanging on the rope body falls, the pawl will be stuck on the ratchet under the action of a centrifugal force. Due to the action of gravity and inertia, together with the sudden stop by falling up and down, the impact on the human body is very large. In this application, through the cooperation between the braking piece and the friction piece, after the pawl  53  is locked by the ratchet  510 , the braking piece will move toward the direction of the fixing piece relative to the shaft body under the action of friction piece, until the position of braking piece is completely locked, thus, the pawl  53  of the braking piece will continue to rotate with the winding device after locked by the ratchet  510 , to buffer a certain distance, and reduce the impact force on the human body when falling, with a high safety; in addition, buffering is carried out through the cooperation of the braking piece and the friction piece, and the buffer structure is integrated into the braking device, which further improves the safety protection effect and can replace the buffer pack on the conventional falling protector. 
     In some embodiments, in order to ensure a constant pressure of the braking piece  312  on the friction piece  522 , the shaft body  31  and the braking piece  312  are connected together by a multi-thread structure. The multi-thread structure comprises a multi-thread external thread  319  arranged on the shaft body  31  and a multi-thread internal thread  318  arranged on the braking piece  312 . When the braking piece  312  is connected with the shaft body  31 , the multi-thread external thread  319  is engaged with the multi-thread internal thread  318 . The pressure between the braking piece and the braking device is kept constant under the fixation of the multi-thread structure, thus, during the slow rotation of the winding device driven by gravity, the frictional force between each braking piece of the failing protector and the braking device is constant. Therefore, when each group of falling protector slips, the rotation rate of the winding device is constant, and the objects hung on the falling protector can be put down slowly, which ensures the high safety of the falling protector during use. 
     In some embodiments, an opening  10  is provided on the shell  1 , and the opening  10  is used for the rope body to protrude from the shell  1 ; in order to ensure that the service life of the rope body is affected by the friction between the rope body and the opening  10  when the rope body is protruding from the opening  10 , an anti-scraping structure is arranged at the position corresponding to the opening  10 . By setting the anti-scraping structure, it ensures that the rope body will not be in contact with the opening when the rope body is pulled down, so the rope body will not be worn, prolonging the service life of the rope body; and the rope body is not scratched, so the rope body will not be disconnected, and its stability is high. In this embodiment, the anti-scraping structure is a rotating roller  21 , the rotating roller  21  is sleeved on a metal bolt; the rotating roller  21  is arranged at the lower part of the frame body  2 , and the rope body will be in contact with the rotating roller  21 ; by setting the anti-scraping structure as a rotating roller, the structure is simple. When the rope body is pulled down, the rotating roller will rotate, and the friction between the rotating roller and the rope body is small, with a good protection effect on the rope body. 
     Apparently, embodiments described are only a part of embodiments of the present invention, and are not all of embodiments thereof. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.