The control principle of manual hoists (including chain hoists and lever hoists) is achieved through the coordination of mechanical transmission, braking systems, and safety devices, ensuring smooth lifting, lowering, and safe locking of heavy objects. The following is a detailed analysis of the core principles:

1. Principle of mechanical transmission

Hand chain hoist:

By manually pulling the hand zipper strip, the hand chain wheel is driven to rotate clockwise/counterclockwise, and through a two-stage spur gear transmission system (such as plate gears, short shafts, and spline hole gears), the lifting chain wheel is driven to rotate, thereby pulling the heavy chain to achieve lifting and lowering of heavy objects. The transmission system adopts a symmetrical structure design, combined with a chain pulley system, to achieve force amplification and smooth movement. The lifting height is usually 2.5-3 meters, and the lifting capacity is 0.5-30 tons. It can be used alone or as a lifting mechanism for bridge cranes.

Hand hoist:

By pulling the handle to drive the sprocket to rotate, the chain movement drives the hook to lift or move horizontally. The lifting capacity of the ring chain is ≤ 3 tons, and the steel wire rope is alternately clamped by clamps to achieve diagonal/horizontal traction. The operation is flexible and suitable for scenarios where the direction is frequently adjusted.

2. Braking system design

Ratchet and pawl one-way brake:

Core safety devices. When the pulling stops, the pawl engages with the ratchet under the action of the spring, preventing the sprocket from reversing and preventing heavy objects from falling freely. Self locking design under load, without external intervention, ensuring reliable braking.

Friction pad brake:

By pressing the friction plate against the brake seat, friction is generated to enhance the braking effect. The weight of heavy objects increases friction, forming a self-locking mechanism to ensure safety.

Self locking function:

The braking system is designed to be self-locking, automatically locking after stopping operation to prevent heavy objects from sliding, especially suitable for outdoor or non powered work scenarios.

3. Safety protection device

Overload protection:

When the monitoring load exceeds the rated value, the power will be automatically cut off or the transmission will be stopped to prevent equipment damage and falling accidents.

Braking performance maintenance:

Regularly check the wear of the brake friction plate and replace it when it exceeds the limit; The chain needs to be cleaned and lubricated to avoid jamming or deformation. Stop immediately when the brake fails to prevent accidents.

Zero protection:

The controller is equipped with a zero position protection device to prevent accidental operation from causing the equipment to suddenly start.

Grounding protection:

Prevent the metal parts of the equipment from being electrified and ensure the safety of operators.

Emergency switch and isolation switch:

In emergency situations, power can be quickly cut off. During maintenance, disconnect the main isolation switch to ensure personnel safety.

4. Operating standards and maintenance

Operation requirements:

When operating, stand on the same plane as the bracelet wheel and pull the bracelet evenly to avoid the chain jumping or getting stuck due to strong pulling.

Before lifting, confirm that the hook is securely fastened and the lifting chain is vertical without distortion. It is strictly prohibited to use diagonal pulling, overloading, or non-human power.

Personnel are prohibited from working or walking under heavy objects. When descending, slowly pull the chain to avoid impact.

Maintenance and upkeep:

Clean the gourd after use, apply rust proof grease, and store it in a dry and ventilated place.

Regularly inspect components such as chains, gears, and brakes, and replace worn parts in a timely manner.

Lubricate bearings and transmission components to ensure smooth operation.

5. Type differences and applicable scenarios

Hand chain hoist:

Vertical lifting is the main method, suitable for scenarios such as factories, mines, and construction sites, especially for operations without power supply.

Hand hoist:

Ring chain is suitable for vertical lifting, while wire rope can achieve horizontal/diagonal traction, with flexible operation, suitable for scenarios that require frequent adjustment of direction (such as material lifting on construction sites).

The main equipment produced by Hebei Makita: stage electric hoist, electric chian hoist, wire rope electric hoist，Hand chain hoist, lever hoist, pneumatic hoist and other lifting equipment