Overhead cranes are mechanical equipment that are horizontally mounted above workshops, warehouses and open storage yards, and are used to lift various objects. They are usually called "overhead cranes" or "traveling cranes". It is the most widely used lifting machine in the mechanical, metallurgical and chemical industries. In modern industrial enterprises, it is one of the important equipment to realize the mechanization and automation of the production process, reduce heavy physical labor, and improve production efficiency. When using bridge cranes, pay attention to the following safety matters:
1. The crane must be in a normal state, especially the safety devices, such as the braking mechanism, sound and light, signals, interlocking devices, etc. must be sensitive and intact.
2. During the work, the operator should concentrate on the work, and then idling before lifting, and then lifting. If the lifting object is 100 to 150 mms off the ground, it should be re-bound when it is found that the lifting object is not tightly bound. A signal bell should be issued before driving; hanging objects must not be passed over the head. When the crane is running, it is strictly forbidden to repair, inspect, refuel and wipe the test parts. When the fault is found during operation, it must be stopped immediately.
3. When the work is terminated, the crane should be parked on the parking line, and the hook should be raised in place. No heavy objects should be hung on the hook. Put all the controllers and joysticks to the zero position, pull off the power switch, and lock the cab door.
4. Bridge cranes must be equipped with reliable and sensitive safety devices. Generally equipped with a buffer, a limiter (stroke limiter, lifting limiter), a lifting limiter, windproof rail clamp.
5. The shell of all live parts of the crane should be reliably grounded to avoid accidental electric shock to the operator. When the trolley track is not welded on the main beam, welding grounding should also be adopted, and the step-down transformer should be grounded on the low voltage side according to regulations.
6. Bridge cranes must not be hoisted under the following conditions:
(1) Unmanned command or command signal is incorrect.
(2) Defective driving equipment or failure of safety devices.
(3) Overload lifting or equipment quality is unclear.
(4) A person is standing on or under the lifting object, and is hoisted by a crane hook.
(5) The light is dim and the vision is unclear.
(6) The hoisting object has sharp edges or diagonals, and no safety measures have been taken.