The safety requirements of chain hoists for high-altitude operations are also relatively high due to factors such as the field of operation. The main safety protection devices include rope breakage protection, safe parking, load capacity limit, upper limit stop, lower limit stop, buffer, and communication signal devices. Here is a detailed introduction for you:

　　(1) Rope break protection device

　　When the rated load capacity of the chain hoist is loaded and the rope is broken during suspension or operation, the rope breaking protection device must reliably brake the chain hoist on the guide rail, and the maximum braking sliding distance should not exceed 1m, and should not cause permanent damage to the structural components.

　　(2) Safe docking device

　　A device that can securely support the chain hoist on the frame when it is parked on a certain layer. Prevent the basket from falling when the brake fails due to sudden fracture of the steel wire rope. There are two types of devices: braking and manual. When the chain hoist is in place, it is controlled by springs or manually moved to extend the support rod onto the support frame of the frame. The load is fully borne by the support frame, and the steel wire rope is not under force. When the chain hoist is loaded with 125% of the rated load capacity and operates to load and unload at each floor position, the stopping device should be able to reliably position the chain hoist.

　　(3) Load capacity limiting device

　　When the load inside the chain hoist reaches 90% of the rated load capacity, an alarm signal should be issued; When the load inside the chain hoist reaches 100% -110% of the rated load capacity, the working power supply of the hoist should be cut off.

　　(4) Upper limit limiter

　　The upper limit limiter should be installed at the highest allowable working position of the chain hoist, and the overtravel of the chain hoist should not be less than 3m. When the chain hoist reaches the specified height, the limiter acts to cut off the power supply.

　　(5) Lower limit limiter

　　The lower limit limiter should be able to operate before the chain hoist encounters the buffer device. When the chain hoist descends to the lower limit, the limiter should automatically cut off the power supply to stop the chain hoist from descending.

　　(6) Buffer

　　The buffer should be installed in the bottom pit of the frame, and when the chain hoist acts on the buffer at the rated load and specified speed, it should be able to withstand the corresponding impact force. The buffer can be in the form of springs or elastic entities.

　　(7) Communication signal device

　　A signal device is a type of audio device controlled by the driver, with a volume that can be clearly heard by personnel using elevators to load and unload materials on each floor. The driver and operators can communicate with each other.