Can the overload protection device of the hand chain hoist prevent heavy objects from falling?

Analysis of the protection of hand chain hoist overload protection device to prevent heavy objects from falling

I. Introduction
As a common manual lifting equipment, hand chain hoists are widely used in factories, mines, construction sites, docks, docks, warehouses and other places to install machines and lift goods, especially for open-air and powerless operations. However, during use, if overload occurs, it may lead to serious consequences, such as equipment damage, heavy objects falling, etc., endangering the safety of personnel and property. Therefore, the overload protection device of the hand chain hoist is crucial to prevent heavy objects from falling.

II. Working principle of hand chain hoist
The hand chain hoist pulls the manual chain and the hand chain wheel to rotate, presses the friction plate ratchet and the brake seat into one body and rotates together, and the tooth long axis rotates the plate gear, the tooth short axis and the spline hole gear. In this way, the lifting sprocket installed on the spline hole gear drives the lifting chain, thereby lifting the heavy object smoothly. The ratchet friction plate type one-way brake can brake itself under load. The ratchet engages with the ratchet under the action of the spring, and the brake works safely.

3. Principle and function of overload protection device
Working principle
The overload protection device of the hand chain hoist usually includes brake nut, sleeve, lock nut, disc spring, pressure plate, friction plate and other components. During normal operation, the hand chain drives the hand chain wheel to rotate. The torque of the hand chain wheel is less than the friction between the friction plate and the hand chain wheel. The torque is transmitted to the long shaft through the brake nut, and the hand chain wheel rotates with the brake nut and the long shaft. When working under overload, the torque applied to the hand chain wheel is greater than the friction force, and slip occurs between the hand chain wheel and the friction plate. The torque cannot be effectively transmitted to the brake nut, thereby avoiding working under overload.
Function
Prevent overload lifting: The overload protection device has been prefabricated before leaving the factory. When the prefabricated overload limit, that is, 1.2 times the load, is exceeded, the protection device is activated. At this time, the hand chain will be locked, lifting will be blocked, and only lowering is possible.
Protect equipment safety: The overload protection device can effectively prevent destructive damage to the equipment caused by overloading, such as the lifting chain reaching its limit and breaking, etc., protect the safety of the equipment and extend the service life of the equipment.
Ensure personnel safety: The overload protection device can detect overloading in time and issue a warning to remind the operator to take immediate measures to avoid casualties caused by heavy objects falling.

4. Can the overload protection device of the hand chain hoist prevent heavy objects from falling?
Mechanism to prevent heavy objects from falling
Instant braking of the brake: The hand chain hoist adopts a ratchet friction plate one-way brake, which can brake automatically under load. The ratchet engages with the ratchet under the action of the spring to make the brake work safely. When overloaded, the brake will brake immediately to prevent heavy objects from falling.
Slip protection of the load limit protection device: When the overload protection device is overloaded, slippage occurs between the hand chain wheel and the friction plate, and the torque cannot be effectively transmitted to the brake nut, thereby avoiding work under overload conditions. At this time, the heavy object will not continue to be lifted, nor will it fall.
Performance in practical applications
In practical applications, the overload protection device of the hand chain hoist can effectively prevent the heavy object from falling. For example, the hook of the Falcon Heavy Industry National Standard HS-C hand chain hoist is forged with high-quality alloy materials and has excellent overload protection performance. When facing a situation where the rated load exceeds the rated load, the hook will not break suddenly, but will give the operator an intuitive safety warning in the form of deformation and bending, which will escort the safety of on-site operations.

V. Precautions for using hand chain hoists
Pre-operation inspection
Check whether the hook, chain and shaft are deformed or damaged, whether the pins at the end of the chain are firm and reliable, whether the transmission part is flexible, whether the brake part is reliable, and whether the hand chain has slippage and chain drop.
Check whether the lifting chain has kinks, and if so, it should be adjusted before use.
Operation specification
When operating a hand chain hoist, first pull the hand chain back and loosen the lifting chain to allow it to have sufficient lifting distance, then slowly lift it. After the chain is tightened, check whether there are any abnormalities in each part and whether the hook is suitable. Only after confirming that it is normal can you continue to work.
Do not pull the hand chain obliquely or too hard. When used in an inclined or horizontal direction, the zipper direction should be consistent with the sprocket direction to avoid chain jams and chain drops.
The number of zippers should be determined according to the lifting capacity of the hoist. If it cannot be pulled, check whether it is overloaded, whether it is connected, and whether the hoist is damaged. It is strictly forbidden to increase the number of zippers for strong pulling.
Maintenance
After use, the hoist should be cleaned and coated with anti-rust grease, and stored in a dry place to prevent the hand chain hoist from rusting and corrosion due to moisture.
In order to ensure the safe use of the hand chain hoist, a dedicated person must do regular inspections. The inspection can be done once a year, and if there are unfavorable conditions, it will take a shorter time to check. Check whether the components of the lifting equipment are damaged, worn, corroded or have some unconventional damage. All safety devices must be thoroughly and effectively checked. The brakes and rated loads must be tested for lifting. If necessary, the hoist should be disassembled to check for worn parts.

VI. Summary
The overload protection device of the hand chain hoist can brake in time when overloaded to prevent the heavy objects from being lifted further, thereby effectively preventing the heavy objects from falling and ensuring the safety of personnel and equipment. In actual use, operators should strictly follow the operating specifications, regularly check and maintain the hand chain hoist, and ensure the normal operation of the overload protection device to reduce the possibility of accidents.