A multi-stage safety brake hand chain block

Abstract

This utility model relates to the field of mechanical technology and discloses a multi-stage safety braking hand chain hoist, including a hook, a connecting strip fixedly connected to the bottom of the hook, a shell fixedly connected to the outer side of the connecting strip, a circular plate fixedly connected to the bottom of the connecting strip, a spiral column slidably connected to the inner side of the circular plate, a pull plate rotatably connected to the top of the spiral column, a plurality of evenly distributed locking holes on the outer side of the pull plate, a chain slidably connected to the outer side of the pull plate, a ratchet fixedly connected to the bottom of the circular plate, a pawl fixedly connected to the bottom of the circular plate, and a spring sleeved on the outer bottom of the pawl. In this utility model, the core braking adopts a ratchet and pawl structure to achieve the first stage of mechanical self-locking. When this braking fails and the speed reaches a threshold, a brake block is thrown out and engages with a limit block, providing redundant safety protection. The anti-slip rubber coating on the chain effectively improves the anti-slip performance of the chain in humid environments, significantly enhancing the overall safety and reliability.

Description

Technical Field

[0001] This utility model relates to the field of mechanical technology, and in particular to a multi-stage safety braking hand chain hoist. Background Technology

[0002] A hand chain hoist is an extremely common and practical small, manual lifting device. Its core purpose is to safely and efficiently lift, lower, or pull heavy objects vertically or horizontally using human power. Its biggest advantage is that it requires no electricity or other power source, making it particularly suitable for use in environments without power, field operations, confined spaces, or situations requiring frequent movement. In factory workshops, it is commonly used for equipment installation, maintenance, and parts replacement; on construction sites, it is used for hoisting building materials and equipment or for positioning; in warehouses, it is used for loading, unloading, and stacking goods. In shipbuilding and vehicle repair, it is used for lifting heavy components such as engines, and it even has applications in agricultural production. Hand chain hoists are easy to operate and carry, making them a reliable tool for lifting, pulling, and positioning small to medium tonnage objects, especially suitable for work scenarios requiring precise control of the object's position or intermittent lifting. Safe operation is paramount; overloading and carrying passengers are strictly prohibited. The core components of a hand chain hoist include: a hand chain, a sprocket system, a lifting sprocket and lifting chain, a crucial braking system, upper and lower hooks, and a protective casing. Its working principle essentially utilizes gear reduction to amplify torque. When the hand chain is pulled down, the force is transmitted through the sprocket to the gear set, significantly reducing the pulling force and converting it into a large torque that drives the lifting sprocket to wind the chain, thereby lifting the load. Crucially, it features automatic safety braking: once pulling stops or the load shows signs of falling, the pawl immediately engages with the ratchet teeth under spring action, locking the system like a mechanical "clamp" to prevent the load from falling accidentally. To lower the load, the hand chain must be pulled up. This action first lifts the pawl, disengaging it from the ratchet, and then, under manual control, the lifting sprocket rotates in the opposite direction to release the chain, achieving controlled descent. This characteristic of achieving force amplification and inherent safety self-locking without external power, relying solely on a purely mechanical structure, is the core value of the hand chain hoist. While existing multi-stage safety brake hand chain hoists achieve lifting and fall protection for heavy objects, their safety protection system is singular. There is no backup plan when one safety brake fails, and the chain slips in rainy weather, so the safety redundancy needs to be improved. Therefore, a multi-stage safety brake hand chain hoist is proposed to solve the above problems. Utility Model Content

[0003] To overcome the above shortcomings, this utility model provides a multi-stage safety braking hand chain hoist, which aims to improve the problems of single safety protection and chain slippage in rainy weather in the existing technology.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A multi-stage safety brake hand chain hoist includes a hook, a connecting strip fixedly connected to the bottom of the hook, a housing fixedly connected to the outer side of the connecting strip, a circular plate fixedly connected to the bottom of the connecting strip, a spiral column slidably connected to the inner side of the circular plate, a pull plate rotatably connected to the top of the spiral column, a plurality of evenly distributed locking holes opened on the outer side of the pull plate, a chain slidably connected to the outer side of the pull plate, a ratchet fixedly connected to the bottom of the circular plate, a pawl fixedly connected to the bottom of the circular plate, and a spring sleeved on the outer bottom of the pawl. As a further description of the above technical solution: A small gear 1 is fixedly connected to the bottom of the spiral column. Large gears are meshed with both sides of the small gear 1. A transmission column is fixedly connected to the inner side of the large gear. A small gear 2 is fixedly connected to the bottom of the transmission column. A large gear is meshed with the right side of the small gear 2. As a further description of the above technical solution: A transmission column is fixedly connected to the bottom of the large gear, and a cable pulley is fixedly connected to the bottom of the transmission column; As a further description of the above technical solution: An iron cable is slidably connected to the outer side of the cable pulley, a ring is fixedly connected to the bottom of the iron cable, and a locking hook is slidably connected to the inner side of the ring; As a further description of the above technical solution: A connecting post is fixedly connected to the bottom of the second pinion, and a mounting plate is fixedly connected to the bottom of the connecting post; As a further description of the above technical solution: A connecting block is fixedly connected to the top of the mounting plate, and a braking block is rotatably connected to the outside of the connecting block; As a further description of the above technical solution: The top of the cable wheel has round holes on both the left and right sides; As a further description of the above technical solution: Multiple limiting blocks are fixedly connected to the inner side of the top of the cable wheel.

[0005] This utility model has the following beneficial effects: 1. In this utility model, the operator pulls the chain to drive the pull plate to rotate, which in turn drives the spiral column fixedly connected to it to rotate. The spiral column drives the small gear one at its bottom, and through multi-stage gear meshing, the small gear one meshes with the large gear. The small gear two at the bottom of the transmission column of the large gear meshes with the large gear on the other side to transmit power to the cable pulley to wind up and unwind the iron cable. At the same time, the ratchet under the pull plate and the pawl under the action of the spring form the core braking structure. When the pulling stops or the heavy object tends to fall, the pawl automatically engages with the ratchet tooth groove under the action of the spring force to form the first stage of mechanical self-locking, effectively preventing the heavy object from falling accidentally and achieving a basic safety braking effect. If the basic safety braking fails, when the speed reaches a certain level, the brake block is thrown out and locks with the limit block to form a limit, so that the safety protection can be guaranteed by multiple layers and solve the problem of single safety protection.

[0006] 2. In this utility model, the gear reduction system consisting of the small gear, large gear, and transmission column on the transmission path, as well as the anti-slip adhesive sprayed on the outer side of the chain, makes it less prone to slippage even when there is water accumulation on the chain surface. At the same time, the locking hole on the cable pull plate significantly increases the anti-slip performance between the iron cable and the pull plate, solving the problem of lack of redundant protection when the single safety braking mechanism fails in the prior art, and effectively overcoming the risk of the iron cable slipping easily in rainy weather, greatly improving the overall safety and working reliability of the hand chain hoist. Attached Figure Description

[0007] Figure 1 A three-dimensional schematic diagram of a multi-stage safety braking hand chain hoist proposed in this utility model; Figure 2 This is a schematic diagram of the circular plate structure of a multi-stage safety braking hand chain hoist proposed in this utility model; Figure 3 This is a schematic diagram of the ratchet structure of a multi-stage safety braking hand chain hoist proposed in this utility model; Figure 4 This is a schematic diagram of the structure of the large gear in a multi-stage safety braking hand chain hoist proposed in this utility model. Figure 5 This is a schematic diagram of the brake block structure of a multi-stage safety brake hand chain hoist proposed in this utility model; Figure 6 This is a schematic diagram of the locking hook structure of a multi-stage safety braking hand chain hoist proposed in this utility model.

[0008] Legend: 1. Hook; 2. Connecting bar; 3. Outer shell; 4. Round piece; 5. Spiral column; 6. Pull plate; 7. Lock hole; 8. Chain; 9. Ratchet; 10. Pawl; 11. Spring; 12. Pinion I; 13. Large gear; 14. Drive column; 15. Brake block; 16. Connecting column; 17. Iron chain; 18. Lock hook; 19. Connecting block; 20. Limiting block; 21. Cable pulley; 22. Round hole; 23. Mounting piece; 24. Ring; 25. Pinion II. Detailed Implementation

[0009] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0010] Reference Figures 1-3 This utility model provides an embodiment of a multi-stage safety braking hand chain hoist, including a hook 1 suspended from a fixed support point, bearing the weight of the entire hoist and its load. A connecting strip 2 is fixedly connected to the bottom of the hook 1, serving to transmit force and fix the main structure. A shell 3 is fixedly connected to the outside of the connecting strip 2, protecting internal precision components such as gears and brakes from dust and collision damage, while also enhancing overall rigidity. A circular plate 4 is fixedly connected to the bottom of the connecting strip 2, serving as a core support platform. The key component of the braking system is a spiral column 5 slidably connected to the inner side of the disc 4. The spiral column 5 drives the gear system. A pull plate 6 is rotatably connected to the top of the spiral column 5. The pull plate 6 transmits the power source. Multiple evenly distributed locking holes 7 are opened on the outer side of the pull plate 6. The locking holes 7 are used for locking and limiting. A chain 8 is slidably connected to the outer side of the pull plate 6. The chain 8 works with the locking holes 7 to limit the movement and drive the pull plate 6 to rotate, providing the main lifting power source. A ratchet 9 and a pawl 10 are fixedly connected to the bottom of the disc 4. The ratchet 9 and the pawl 10 cooperate to allow the pull plate 6 to rotate in one direction to lift the load, and to self-lock in the opposite direction to prevent falling, thus forming an automatic braking system. A spring 11 is sleeved on the bottom outer side of the pawl 10. One end of the spring 11 is placed inside the through hole in the pawl 10 to provide the pawl 10 with a continuous elastic force that presses against the ratchet 9, ensuring a rapid and reliable braking response.

[0011] Reference Figures 2-4A small gear 12 is fixedly connected to the bottom of the spiral column 5. The small gear 12 cooperates with the spiral column 5 to realize power transmission. Large gears 13 are meshed on both sides of the small gear 12. The large gears 13 mesh with the small gear 12 to reduce the speed and increase the torque. A transmission column 14 is fixedly connected to the inner side of the large gear 13. The transmission column 14 is connected to the large gear 13 and transmits rotational power to the load mechanism. A small gear 25 is fixedly connected to the bottom of the transmission column 14. The large gear 13 is meshed on the right side of the small gear 25. The transmission column 14 is fixedly connected to the bottom of the large gear 13. A cable pulley 21 is fixedly connected to the bottom of the transmission column 14. The cable pulley 21 is wound around the chain 8 to control the lifting and lowering of the load and directly drive the core component of the load.

[0012] Reference Figures 3-6 A cable 17 is slidably connected to the outer side of the sheave 21. A ring 24 is fixedly connected to the bottom of the cable 17. A locking hook 18 is slidably connected to the inner side of the ring 24. The cable 17 is a load-bearing rigging that suspends the load. One end is fixed to the sheave 21, and the other end is connected to the ring 24 and the locking hook 18. A connecting post 16 is fixedly connected to the bottom of the pinion 12. The connecting post 16 serves as the main connecting structure for the secondary brake. A mounting plate 23 is fixedly connected to the bottom of the connecting post 16. The function of the mounting plate 23 is to install the brake structure. A connecting block 19 is fixedly connected to the top of the mounting plate 23. The outer side of the connecting block 19 is rotatably connected to... The brake block 15 is connected to the connecting block 19, which allows the brake block 15 to rotate. The end of the brake block 15 that is not connected to the connecting block 19 is connected by the magnetic connection of the connecting post 16. When the rotation speed exceeds a certain threshold, it disengages from the connecting post 16 to achieve safe braking. The top left and right sides of the cable wheel 21 are provided with round holes 22. The function of the round holes 22 is to allow the mounting plate 23 to rotate inside the cable wheel 21. Multiple limit blocks 20 are fixedly connected to the inner side of the top of the cable wheel 21. The function of the limit blocks 20 is to allow the brake block 15 to be locked in the limit blocks 20 when the secondary safety braking is triggered.

[0013] Working principle: When the operator pulls the chain 8 clockwise, the chain 8, with the assistance of the lock hole 7, drives the pull plate 6 to rotate. The pull plate 6 then drives the spiral column 5 to rotate. The small gear 12 fixedly connected to the bottom of the spiral column 5 transmits the rotational power to the large gear 13. The bottom of the large gear 13 is connected to the cable pulley 21 through the transmission column 14, driving the cable pulley 21. The cable pulley 21 drives the outer iron cable 17 to rotate, thereby realizing the movement of the lock hook 18. The small gear 25 at the bottom of each large gear 13 is engaged with the large gear 13. The torque increases or decreases. The thread on the spiral column 5 allows the ratchet 9 and pawl 10 to work when pulled clockwise. The spring 11 installed on the pawl 10 allows the pawl 10 to cooperate with the spring force of the spring 11 to rotate with the ratchet 9. When it is necessary to lower it, the pull plate 6 is pulled to the bottom of the spiral column 5 and it fits against the disc 4. The ratchet 9 and pawl 10 cannot be triggered, allowing the iron cable 17 to be pulled down. When the main brake fails and causes an overspeed fall, the brake block 15 and the limit block 20 are automatically triggered to mechanically engage, achieving instantaneous and forced locking.

[0014] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A multi-stage safety brake hand hoist comprising a hook (1), characterized in that: The bottom of the hook (1) is fixedly connected to a connecting strip (2), the outer side of the connecting strip (2) is fixedly connected to a shell (3), the bottom of the connecting strip (2) is fixedly connected to a disc (4), the inner side of the disc (4) is slidably connected to a spiral column (5), the top of the spiral column (5) is rotatably connected to a pull plate (6), the outer side of the pull plate (6) is provided with multiple evenly distributed lock holes (7), the outer side of the pull plate (6) is slidably connected to a chain (8), the bottom of the disc (4) is fixedly connected to a ratchet (9), the bottom of the disc (4) is fixedly connected to a pawl (10), and the bottom of the pawl (10) is sleeved with a spring (11).

2. A multi-stage safety brake rope hoist according to claim 1, characterized in that: The bottom of the spiral column (5) is fixedly connected to a small gear (12), and large gears (13) are meshed on both the left and right sides of the small gear (12). A transmission column (14) is fixedly connected to the inside of the large gear (13), and a small gear (25) is fixedly connected to the bottom of the transmission column (14). A large gear (13) is meshed on the right side of the small gear (25).

3. A multi-stage safety brake rope hoist according to claim 2, characterized in that: The bottom of the large gear (13) is fixedly connected to a transmission column (14), and the bottom of the transmission column (14) is fixedly connected to a cable pulley (21).

4. A multi-stage safety brake rope hoist according to claim 3, characterized in that: The outer side of the sheave (21) is slidably connected to an iron cable (17), the bottom of the iron cable (17) is fixedly connected to a ring (24), and the inner side of the ring (24) is slidably connected to a locking hook (18).

5. A multi-stage safety brake rope hoist according to claim 2, characterized in that: The bottom of the pinion 2 (25) is fixedly connected to a connecting post (16), and the bottom of the connecting post (16) is fixedly connected to a mounting plate (23).

6. A multi-stage safety brake rope hoist according to claim 5, characterized in that: The top of the mounting plate (23) is fixedly connected to a connecting block (19), and a brake block (15) is rotatably connected to the outside of the connecting block (19).

7. A multi-stage safety brake rope hoist according to claim 3, characterized in that: The top left and right sides of the cable wheel (21) are provided with round holes (22).

8. A multi-stage safety brake rope hoist according to claim 3, characterized in that: Multiple limiting blocks (20) are fixedly connected to the inner side of the top of the cable wheel (21).

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