CN111228718B

CN111228718B - Force lifting equipment capable of braking in falling process

Info

Publication number: CN111228718B
Application number: CN202010069669.1A
Authority: CN
Inventors: 单林娜; 杨春
Original assignee: Tangshan Normal University
Current assignee: Tangshan Normal University
Priority date: 2020-01-09
Filing date: 2020-01-09
Publication date: 2021-05-18
Anticipated expiration: 2040-01-09
Also published as: CN111228718A

Abstract

The invention provides a force lifting device capable of braking in a falling process, which comprises a lifting rod, a supporting structure and a braking device, wherein the lifting rod is connected with the supporting structure; the supporting structure comprises a pair of stand columns, and the upper ends of the stand columns are fixedly provided with a first mounting seat of the braking device; a pair of supporting vertical plates arranged in opposite directions are fixedly arranged on the front end face and the rear end face of the mounting seat I, and a mounting seat II of the braking device is fixedly arranged at the upper end of each supporting vertical plate; the braking devices are oppositely arranged in the mounting grooves of the first mounting seat and the second mounting seat respectively; a rotating chain wheel is arranged in the braking device, a chain is connected between the chain wheels of the first mounting seat and the second mounting seat, and two ends of the lifting rod are respectively fixed on two chains close to the rear side supporting vertical plate; a weight lifting rod placing bearing plate is fixedly arranged between the pair of vertical supporting plates; the invention can greatly reduce and offset the falling speed and impact force of the barbell when the barbell suddenly falls out of control, thereby eliminating the danger of lifting equipment.

Description

Force lifting equipment capable of braking in falling process

Technical Field

The invention relates to the technical field of sports fitness equipment, in particular to a strength lifting equipment capable of braking in a falling process.

Background

Strength lifting is carried out by using barbell load, and long-term adherence to training of lifting the barbell can not only enable muscles to be developed, but also enhance the endurance of the muscles; in the process of body building or strength lifting, sometimes the load reaches the limit or the force of a body building person or an athlete is exhausted due to overload, so that the hand-off error is caused, the barbell is very easy to be struck by the gravity, and the danger of injury or even death is caused. Therefore, although the strength lifting exercise has good body building effect, great exercise risks exist, and sufficient safety protection is required. However, there is no effective force lifting safety protection device currently, and in the current fitness training or force lifting competition, under the care of professionals, the danger cannot be completely avoided, and even the injury to the caretakers can be caused at the same time.

Disclosure of Invention

In order to solve the problems, the invention provides a force lifting device capable of braking in a falling process, which can rapidly reduce the gravity of a barbell through a braking device when the barbell suddenly falls out of control, greatly reduce and offset the falling speed and impact force of the barbell, and solve the problem that fitness personnel or athletes have injuries and even fatal risks.

The technical scheme adopted by the invention is as follows: a strength lifting apparatus capable of braking in a falling process comprises a lifting rod, a supporting structure and a braking device; the supporting structure comprises a pair of upright posts, and the upper ends of the upright posts are fixedly provided with a first mounting seat of the braking device; a pair of supporting vertical plates arranged oppositely is fixedly arranged on the front end face and the rear end face of the mounting seat I, and a mounting seat II of the braking device is fixedly arranged at the upper end of each supporting vertical plate; the braking devices are respectively oppositely arranged in the mounting grooves of the first mounting seat and the second mounting seat; a rotating chain wheel is arranged in the braking device, a chain is connected between the chain wheels in the braking device between the first mounting seat and the second mounting seat, and the plane of the two chains is vertical to the plane of the supporting vertical plate; two ends of the weight lifting rod are respectively fixed on the two chains close to the rear side supporting vertical plate; between a pair of support riser, the top level of mount pad one has set firmly and lifts the heavy pole and place the bearing plate, is equipped with the trompil that can supply the chain to pass on the bearing plate.

The braking device consists of an external shell, a central shaft fixed in the shell and components arranged on the central shaft side by side, wherein the components sequentially comprise a rotating wheel, an external thread cylinder, a double-spring-seat wheel sheet, a compression spring, a sleeve, a friction wheel sheet I, a chain wheel, a chain, a ratchet wheel, a pawl, a tension spring and a friction wheel sheet II from left to right; the shell consists of a left cover body on the left side, a cylindrical body in the middle part and a sealing cover on the right side; the left cover body consists of a first disk, a second disk and two connecting beams, wherein the first disk and the second disk are arranged in parallel at intervals on the left and right, and the two connecting beams are symmetrically arranged up and down; the central shaft mounting hole I is formed in the central position of the first disc; a threaded hole is formed in the center of the second disc; the center of the sealing cover is provided with a second central shaft mounting hole; the part of the cylinder wall of the cylinder body of the shell, which corresponds to the position of the chain wheel, is provided with a pair of long-strip-shaped openings which are symmetrical front and back in the axial direction vertical to the cylinder body, and the chain can pass through the long-strip-shaped openings and is connected with the chain wheel; the external thread of the external thread cylinder is matched with the thread of the threaded hole of the second disc; the left end of the external thread cylinder is fixedly provided with a rotating wheel; the external thread cylinder is sleeved on the central shaft and is in threaded connection with the threaded hole of the second disc; a compression spring is arranged between the double-spring seat wheel sheets; the center part of the double-spring-seat wheel sheet is provided with a first through hole for a central shaft to pass through, and the wall of the double-spring-seat wheel sheet in the first through hole is symmetrically provided with sliding blocks; the double spring seat wheel sheet and the compression spring are sleeved on the central shaft; the left half wall of the central shaft is symmetrically provided with sliding chutes; the sliding block is embedded into the sliding groove, and the double-spring seat wheel sheet is connected in the sliding groove on the central shaft in a sliding way to limit the rotation of the double-spring seat wheel sheet around the central shaft; the sleeve is sleeved on the central shaft and can rotate around the central shaft; two ends and the middle part of the outer wall of the sleeve are respectively and symmetrically provided with a first key groove and a second key groove; a through hole II for the sleeve to pass through is formed in the center of the first friction wheel sheet; two ends of the sleeve are respectively provided with a first friction wheel sheet in interference fit through two through holes; the wall of the friction wheel piece I in the through hole II is symmetrically provided with a key groove III, the friction wheel piece I is matched and fixed at two ends of the sleeve through the key groove I and a flat key, and the outer surface of the friction wheel piece I and the end surface of the sleeve are on the same plane; the chain wheel is in interference connection with the middle part of the sleeve through a bearing and is fixed on the sleeve through a flat key and a key groove II in a matched mode, and the chain wheel is in rotational connection with the sleeve; protective contours are arranged on two sides of the chain wheel; a pawl is rotatably connected to the right side surface of the chain wheel through a fixed shaft, and a tension spring is arranged on the pawl; the ratchet wheel is sleeved on the central shaft and can rotate around the central shaft, the ratchet wheel is arranged right below the pawl, and the pawl is meshed with the ratchet wheel under the action of the tension spring; a third through hole for a central shaft to pass through is formed in the central part of the second friction wheel sheet; a fourth key groove is symmetrically formed in the wall of the second friction wheel sheet in the third through hole; a key groove V is symmetrically formed in the right end wall of the central shaft; and the second friction wheel sheet is fixed at the right end of the central shaft through the cooperation of the key groove IV, the key groove V and the flat key.

The external thread cylinder, the double spring seat wheel sheet, the sleeve, the friction wheel sheet I, the chain wheel, the ratchet wheel and the friction wheel sheet II are arranged on the central shaft or the sleeve without gaps.

The compression spring has certain pre-tightening pressure after being installed.

The diameter of the protective profile of the chain wheel is larger than that of the first friction wheel sheet; the diameters of the first friction wheel sheet and the second friction wheel sheet are the same; the diameter of the ratchet wheel is smaller than the diameters of the first friction wheel sheet and the second friction wheel sheet.

The left cover body and the right cover are respectively fixedly connected with the two ends of the middle cylindrical body through screws and screw holes; and the two ends of the central shaft are provided with threads, and the central shaft penetrates through the first mounting hole and the second mounting hole and then is fixed on the shell through nuts.

The gravity centers of the braking devices are on the same plane and are symmetrically arranged up and down and left and right.

The weight lifting rod is connected with the chain through a fixing piece.

The invention has the beneficial effects that:

the invention has the advantages of simple structure, strong mechanical property, wear resistance, impact resistance and long service life.

Secondly, the invention solves the problem that when the barbell suddenly falls out of control, the gravity of the barbell is rapidly reduced through the braking device, the falling speed and impact force of the barbell are greatly reduced and offset, and the danger that body-building personnel or athletes are injured or even fatal is solved.

Thirdly, the braking device of the invention has wide application range, can be used for various forms of strength lifting in fitness and sports equipment, has strong safety, and does not need professional coaches for on-site nursing.

Drawings

FIG. 1 is a schematic diagram of the main structure of the present invention;

FIG. 2 is a schematic view of the present invention shown in FIG. 1 with a support structure added;

FIG. 3 is a side view of FIG. 2 of the present invention;

FIG. 4 is a cross-sectional view of the braking device of the present invention;

FIG. 5 is an exploded view of the brake apparatus of the present invention;

fig. 6 is an exploded view of the housing of the braking device of the present invention.

Wherein: a weight lifting rod 1; a support structure 2; a column 201; a first mounting seat 202; a vertical plate 203; a second mounting seat 204; a bearing plate 205; a braking device 3; a housing 301; a central axis 302; a rotating wheel 303; an externally threaded barrel 304; a double spring-loaded wheel piece 305; a compression spring 306; a sleeve 307; a first friction wheel sheet 308; a sprocket 309; a chain 310; a ratchet 311; a pawl 312; a tension spring 313; a second friction wheel plate 314; a left cover body 3011; cylindrical body 3012; a cover 3013; a first disc 3014; a second disc 3015; a connecting beam 3016; a first mounting hole 3017; a threaded hole 3018; a second mounting hole 3019; elongated openings 3020; a first through hole 3021; a slider 3022; a chute 3023; a first key groove 3024; a second key groove 3025; a second through hole 3026; a third keyway 3027; a flat key 3028; a bearing 3029; a protective contour 3030; a through hole three 3031; a keyway four 3032; a keyway five 3033; and a nut 3034.

Detailed Description

As shown in fig. 1 to 6: a strength that the dropping process can be braked lifts the apparatus, including lifting the heavy pole 1, supporting structure 2 and arresting gear 3; the supporting structure 2 comprises a pair of upright columns 201, and the upper ends of the upright columns 201 are fixedly provided with a first mounting seat 202 of the braking device 3; a pair of supporting vertical plates 203 arranged oppositely is fixedly arranged on the front end face and the rear end face of the first mounting seat 202, and a second mounting seat 204 of the braking device 3 is fixedly arranged at the upper ends of the supporting vertical plates 203; the braking devices 3 are oppositely arranged in the mounting grooves of the first mounting seat 202 and the second mounting seat 203 respectively; the gravity centers of the braking devices 3 are on the same plane and are symmetrically arranged up and down and left and right; a rotating chain wheel 309 is arranged in the braking device 3, a chain 310 is connected between the chain wheels 309 in the braking device 3 between the first mounting seat 202 and the second mounting seat 203, and the plane where the two chains 310 are located is vertical to the plane of the supporting vertical plate 203; two ends of the weight lifting rod 1 are respectively fixed on two chains 310 close to the rear side supporting vertical plate 203; the weight lifting rod 1 is connected with the chain 310 through a fixing piece; a bearing plate 205 for placing the weight lifting rod 1 is horizontally and fixedly arranged above the first mounting seat 202 between the pair of vertical supporting plates 203, and an opening through which the chain 310 can pass is formed in the bearing plate 205.

The braking device 3 comprises an external shell 301, a central shaft 302 fixed in the shell 301 and components arranged on the central shaft 302 side by side, wherein the components comprise a rotating wheel 303, an external thread cylinder 304, a double-spring seat wheel sheet 305, a compression spring 306, a sleeve 307, a friction wheel sheet I308, a chain wheel 309, a chain 310, a ratchet wheel 311, a pawl 312, a tension spring 313 and a friction wheel sheet II 314 in turn from left to right; the shell 301 is composed of a left cover 3011 at the left side, a cylinder 3012 at the middle part and a right cover 3013; the left cover body 3011 is composed of a first disk 3014 and a second disk 3015 which are arranged in parallel at intervals on the left and right, and two connecting beams 3016 which are arranged symmetrically up and down; the first disc 3014 and the second disc 3015 are fixedly connected together by two connecting beams 3016, and the left cover body 3011 is a one-time forming structure; the left cover body 3011 forms two large arc-shaped windows which are symmetrical front and back, so that the rotating wheel 303 is placed in the left cover body 3011 for installation; the central position of the first disc 3014 is provided with a first central shaft 302 mounting hole 3017; a threaded hole 3018 is formed in the center of the second disc 3015; the central position of the sealing cover 3013 is provided with a second mounting hole 3019 of the central shaft 302; a pair of long openings 3020 which are symmetrical in the front-back direction are formed in the position, corresponding to the position of the sprocket 309, on the cylindrical wall of the cylindrical body 3012 of the housing 301 in the axial direction perpendicular to the cylindrical body 3012, so that the chain 310 can pass through and be connected with the sprocket 309; the external thread of the external thread barrel 304 is matched with the thread of the threaded hole 3018 of the second disc 3015; the left end of the external thread cylinder 304 is fixedly provided with a rotating wheel 303; the external thread cylinder 304 is sleeved on the central shaft 302 and is screwed in the threaded hole 3018 of the second disc 3015, and the external thread cylinder 304 retracts on the central shaft 302 by rotating the rotating wheel 303; a compression spring 306 is arranged between the double-spring seat wheel sheets 305; a through hole 3021 through which the central shaft 302 can pass is formed in the central part of the double spring seat wheel piece 305, and sliding blocks 3022 are symmetrically arranged on the wall of the double spring seat wheel piece 305 in the through hole 3021; the double spring seat wheel sheet 305 and the compression spring 306 are sleeved on the central shaft 302; the compression spring 306 has a certain pre-tightening pressure after being installed; the left half wall of the central shaft 302 is symmetrically provided with sliding chutes 3023; the slide block 3022 is embedded in the slide groove 3023, and the double spring seat wheel piece 305 is slidably connected in the slide groove 3023 on the central shaft 302 to limit the rotation of the double spring seat wheel piece around the central shaft 302; the sleeve 307 is sleeved on the central shaft 302 and can rotate around the central shaft 302; two ends and the middle part of the outer wall of the sleeve 307 are respectively and symmetrically provided with a first key groove 3024 and a second key groove 3025; a second through hole 3026 for the sleeve 307 to pass through is formed in the center of the first friction wheel piece 308; two ends of the sleeve 307 are respectively provided with a friction wheel piece I308 in interference fit through a through hole II 3026; a third key groove 3027 is symmetrically formed in the wall of the first friction wheel piece 308 in the second through hole 3026, and is fixed at two ends of the sleeve 307 through the first key groove 3024 and the flat key 3028 in a matching manner, and the outer surface of the first friction wheel piece 308 and the end surface of the sleeve 307 are on the same plane, so that the double spring seat wheel piece 305 and the first friction wheel piece 308 are completely attached; the chain wheel 309 is in interference connection with the middle of the sleeve 307 through a bearing 3029 and is fixed on the sleeve 307 through a flat key 3028 and a key groove two 3025 in a matching manner, and the chain wheel 309 is in rotational connection with the sleeve 307; two sides of the chain wheel 309 are provided with protective contours 3030 to prevent chain jumping, groove falling and chain clamping; a pawl 312 is rotatably connected to the right side surface of the chain wheel 309 through a fixed shaft, and a tension spring 313 is arranged on the pawl 312; the ratchet wheel 311 is sleeved on the central shaft 302 and can rotate around the central shaft 302, the ratchet wheel 311 is arranged right below the pawl 312, and the pawl 312 is meshed with the ratchet wheel 311 under the action of the tension spring 313; the tail end of the pawl 312 is bent inwards, so that the pawl 312 is conveniently and fully meshed with the ratchet wheel 311; a through hole III 3031 through which the central shaft 302 can pass is arranged at the central part of the second friction wheel piece 314; a key groove four 3032 is symmetrically arranged on the wall of the friction wheel piece two 314 in the through hole three 3031; a key slot five 3033 is symmetrically arranged on the right end wall of the central shaft 302; the second friction wheel piece 314 is matched and fixed at the right end of the central shaft 302 through a key groove four 3032, a key groove five 3033 and a flat key 3028.

The external thread cylinder 304, the double spring seat wheel sheet 305, the sleeve 307, the friction wheel sheet I308, the chain wheel 309, the ratchet wheel 311 and the friction wheel sheet II 314 are arranged on the central shaft 302 or the sleeve 307 without gaps, the external thread cylinder 304 extrudes the double spring seat wheel sheet 305 by rotating the rotating wheel 303, and the tension formed by contraction of the compression spring 306 is sequentially transmitted to the friction wheel sheet I308, the ratchet wheel 311 and the friction wheel sheet II 314 to form a whole which is extruded with each other and has certain friction force.

The diameter of the protective contour 3030 of the chain wheel 309 is larger than that of the first friction wheel piece 308; the diameters of the first friction wheel piece 308 and the second friction wheel piece 314 are the same; the diameter of the ratchet wheel 311 is smaller than the diameters of the first friction wheel piece 308 and the second friction wheel piece 314, so that the arrangement is that the hanging shaft of the pawl 312 on the chain wheel 309 passes over the first friction wheel piece 308 and is arranged right above the ratchet wheel 311, and meanwhile, a natural groove is formed between the first friction wheel piece 308, the second friction wheel piece 314 and the ratchet wheel 311, so that the pawl 312 is limited, the pawl 312 is prevented from being displaced, twisted and deformed under the impact force of the ratchet wheel 311, and the burden of the hanging shaft of the pawl 312 is relieved.

The left cover body 3011 and the right cover body 3013 are respectively connected with two ends of the cylindrical body 3012 at the middle part together by screws and screw holes; the two ends of the central shaft 302 are provided with threads, and the central shaft is fixed on the shell 301 through a nut 3034 after passing through the first mounting hole 3017 and the second mounting hole 3019.

The working principle and the using method are as follows:

the working principle is as follows: the external thread cylinder 304 is made to extrude the double spring seat wheel piece 305 by rotating the rotating wheel 303, the compression spring 306 contracts to form certain tension, and the certain tension is sequentially transmitted to the first friction wheel piece 308, the sleeve 307, the ratchet 311 and the second friction wheel piece 314 to form a whole which is extruded mutually and has certain friction force, and the whole is in a relatively static state when the lifting rod 1 moves upwards to drive the chains 310 at the two ends to move upwards and the chain wheel 309 rotates anticlockwise; the pawl 312 beats rhythmically along the ratchet groove of the ratchet 311 under the action of the tension spring 313; when the weight lifting rod 1 falls, the chain wheel 309 rotates clockwise, the pawl 312 is clamped into the ratchet groove of the ratchet wheel 311 under the action of the tension spring 313, the chain wheel 309, the ratchet wheel 311, the sleeve 307 and the first friction wheel piece 308 synchronously rotate clockwise around the central shaft 302 under the action of friction force, the friction force generated between the first friction wheel piece 308 and the static double-spring seat wheel piece 305 and the friction force generated between the ratchet wheel 311 and the static second friction wheel piece 314 overcome the gravity of the weight lifting rod 1 on the chain 310, and the impact force and the danger of the barbell on a human body are reduced.

The using method comprises the following steps: during the specific use, the friction force needs to be set according to the training requirement, if the fitness requirement is met, the barbell needs to be frequently lifted up and down, and the sum of the friction forces of the four braking devices 3 is smaller than the weight of the barbell to be lifted; if the weight lifting match is carried out, under the condition that the friction forces on the upper, lower, left and right braking devices 3 are equal, the sum of the friction forces is equal to or slightly larger than the weight of the limit value of the self weight lifting; when the total friction force is larger than the weight of the weight, the user can pull down slowly with strong force. The magnitude of the frictional force can be set according to the weight required by the user. Before lifting weight, putting the barbell assembled with a certain weight on the bearing plate 205, rotating the rotating wheels 303 on the four braking devices 3 anticlockwise to ensure that the tension of the compression spring 306 is just zero (the weight lifting rod 1 can freely move up and down without counterweight), then rotating the rotating wheels 303 on the four braking devices 3 clockwise with the same number of rotating turns until the barbell is lifted by two hands on the chain 309, and after finding out the balance point, the friction force can be adjusted freely, so as to reduce or increase or decrease the barbell plates.

The invention is not limited to the above-described embodiments, and from the above description, obvious modifications may be made by those skilled in the art, which modifications are within the scope of the claims of the invention.

Claims

1. A strength lifting apparatus capable of braking in a falling process comprises a lifting rod, a supporting structure and a braking device; the brake device is characterized in that the supporting structure comprises a pair of stand columns, and the upper ends of the stand columns are fixedly provided with a first mounting seat of the brake device; a pair of supporting vertical plates arranged oppositely is fixedly arranged on the front end face and the rear end face of the mounting seat I, and a mounting seat II of the braking device is fixedly arranged at the upper end of each supporting vertical plate; the braking devices are respectively oppositely arranged in the mounting grooves of the first mounting seat and the second mounting seat; a rotating chain wheel is arranged in the braking device, a chain is connected between the chain wheels in the braking device between the first mounting seat and the second mounting seat, and the plane of the two chains is vertical to the plane of the supporting vertical plate; two ends of the weight lifting rod are respectively fixed on the two chains close to the rear side supporting vertical plate; a lifting rod is horizontally and fixedly arranged above the first mounting seat between the pair of supporting vertical plates for placing a bearing plate, the bearing plate is provided with a hole through which a chain can pass, the braking device consists of an external shell, a central shaft fixed in the shell and assemblies arranged on the central shaft side by side, and each assembly sequentially comprises a rotating wheel, an external thread cylinder, a double-spring-seat wheel sheet, a compression spring, a sleeve, a first friction wheel sheet, a chain wheel, a chain, a ratchet wheel, a pawl, a tension spring and a second friction wheel sheet from left to right; the shell consists of a left cover body on the left side, a cylindrical body in the middle part and a sealing cover on the right side; the left cover body consists of a first disk, a second disk and two connecting beams, wherein the first disk and the second disk are arranged in parallel at intervals on the left and right, and the two connecting beams are symmetrically arranged up and down; the central shaft mounting hole I is formed in the central position of the first disc; a threaded hole is formed in the center of the second disc; the center of the sealing cover is provided with a second central shaft mounting hole; the part of the cylinder wall of the cylinder body of the shell, which corresponds to the position of the chain wheel, is provided with a pair of long-strip-shaped openings which are symmetrical front and back in the axial direction vertical to the cylinder body, and the chain can pass through the long-strip-shaped openings and is connected with the chain wheel; the external thread of the external thread cylinder is matched with the thread of the threaded hole of the second disc; the left end of the external thread cylinder is fixedly provided with a rotating wheel; the external thread cylinder is sleeved on the central shaft and is in threaded connection with the threaded hole of the second disc; a compression spring is arranged between the double-spring seat wheel sheets; the center part of the double-spring-seat wheel sheet is provided with a first through hole for a central shaft to pass through, and the wall of the double-spring-seat wheel sheet in the first through hole is symmetrically provided with sliding blocks; the double spring seat wheel sheet and the compression spring are sleeved on the central shaft; the left half wall of the central shaft is symmetrically provided with sliding chutes; the sliding block is embedded into the sliding groove, and the double-spring seat wheel sheet is connected in the sliding groove on the central shaft in a sliding way to limit the rotation of the double-spring seat wheel sheet around the central shaft; the sleeve is sleeved on the central shaft and can rotate around the central shaft; two ends and the middle part of the outer wall of the sleeve are respectively and symmetrically provided with a first key groove and a second key groove; a through hole II for the sleeve to pass through is formed in the center of the first friction wheel sheet; two ends of the sleeve are respectively provided with a first friction wheel sheet in interference fit through two through holes; the wall of the friction wheel piece I in the through hole II is symmetrically provided with a key groove III, the friction wheel piece I is matched and fixed at two ends of the sleeve through the key groove I and a flat key, and the outer surface of the friction wheel piece I and the end surface of the sleeve are on the same plane; the chain wheel is in interference connection with the middle part of the sleeve through a bearing and is fixed on the sleeve through a flat key and a key groove II in a matched mode, and the chain wheel is in rotational connection with the sleeve; protective contours are arranged on two sides of the chain wheel; a pawl is rotatably connected to the right side surface of the chain wheel through a fixed shaft, and a tension spring is arranged on the pawl; the ratchet wheel is sleeved on the central shaft and can rotate around the central shaft, the ratchet wheel is arranged right below the pawl, and the pawl is meshed with the ratchet wheel under the action of the tension spring; a third through hole for a central shaft to pass through is formed in the central part of the second friction wheel sheet; a fourth key groove is symmetrically formed in the wall of the second friction wheel sheet in the third through hole; a key groove V is symmetrically formed in the right end wall of the central shaft; the friction wheel piece II is fixed at the right end of the central shaft through the key groove IV, the key groove V and the flat key in a matched mode, the external thread cylinder extrudes the double-spring seat wheel piece through the rotating wheel, the compression spring contracts to form certain tension, the tension is sequentially transmitted to the friction wheel piece I, the sleeve, the ratchet wheel and the friction wheel piece II, and a whole which is extruded mutually and has certain friction force is formed.

2. The force lifting apparatus according to claim 1, wherein the externally threaded cylinder, the double spring seat wheel piece, the sleeve, the first friction wheel piece, the sprocket, the ratchet wheel and the second friction wheel piece are mounted on the central shaft or the sleeve without any gap therebetween.

3. A force lifting apparatus as claimed in claim 2 wherein the compression spring is mounted with a pre-tensioning force.

4. A force lifting apparatus as claimed in claim 3 wherein the guard profile of the sprocket wheel has a diameter greater than the diameter of the first friction wheel; the diameters of the first friction wheel sheet and the second friction wheel sheet are the same; the diameter of the ratchet wheel is smaller than the diameters of the first friction wheel sheet and the second friction wheel sheet.

5. A force lifting apparatus with a brake during falling process as claimed in claim 1, wherein the left cover and the right cover are respectively fixed to the two ends of the middle cylindrical body by screws and screw holes; and the two ends of the central shaft are provided with threads, and the central shaft penetrates through the first mounting hole and the second mounting hole and then is fixed on the shell through nuts.

6. A force lifting apparatus as claimed in claim 1, wherein the braking means has a centre of gravity in the same plane and is symmetrically arranged up and down and left and right.

7. A force lifting apparatus as claimed in claim 1 wherein the weight lifting bar is connected to the chain by a fixing member.