Will the electric hoist fall and injure someone?
1. The difference between electric hoist and crane
The electric hoist is similar to the single-beam crane, and the main difference from the single-beam crane is the size and load-bearing capacity. The electric hoist is a small lifting equipment. The lifting capacity of the electric hoists commonly used in workshops is mostly 0.5t-3t.
2. Classification and main components of electric hoists
Electric hoists are usually divided into wire ropes and chains according to the different lifting rigging. The main components of chain electric hoists include:
① Motor: Provides electric drive for electric hoists.
② Hook.
③ Lifting mechanism and running mechanism: The lifting mechanism is used to control the lifting height up and down, and the running mechanism is used to control the forward and backward movement.
④ Braking: Used to stop or slow down.
⑤ Chain.
⑥ Limiting: Corresponding to the lifting mechanism and the running mechanism, the electric hoist is equipped with the maximum range of upward, downward and moving trajectories. If the limit is exceeded, the brake will be automatically braked to ensure the safe operation of the electric hoist.
⑦ Electrical circuits and buttons: Used to control the operation of the motor of the electric hoist.
3. Key points for safety inspection of electric hoists
The consequences of accidents that may be caused by electric hoists in abnormal conditions are mainly classified as lifting injuries. However, in specific accident cases, it is found that electric hoists have their own particularities when causing harm to people. For example, the most common accident of electric hoists is the fall of the body, that is, the entire electric hoist derails and falls and injures people. Therefore, in addition to paying attention to the operating specifications during the lifting process, some unsafe conditions of the components of the electric hoist itself will be listed and introduced.
(1) The chain electric hoist should have a travel limit function: when the limit fails, the lifting height and shape of the electric hoist are not restricted, which will cause the goods to be lifted too high and hit the ceiling or the walking track is too large to hit the wall. To a certain extent, it may also cause the electric hoist to become unstable and fall.
(2) The rated lifting capacity should be marked in a conspicuous place on the hook group: The purpose of marking the lifting capacity is to enable the operator to intuitively identify the lifting capacity of the electric hoist and subjectively avoid the occurrence of overload lifting.
(3) The lifting hook should be equipped with a hook locking device, which is what we often call an anti-unhooking device.
(4) For chain hoists with a rated lifting capacity of ≥0.5t, the lifting mechanism should be equipped with a lifting capacity limiter: This is also an important safety measure to prevent the electric hoist from becoming unstable and falling. An important reason for the electric hoist to become unstable and fall is overload lifting. Through the lifting capacity limiter interlock start and stop, the power supply of the electric hoist is directly disconnected when overload occurs, effectively preventing the occurrence of falling accidents.
(5) The operating control device should be equipped with an emergency stop switch: that is, the emergency stop on the button. The biggest function of the emergency stop is to quickly suspend the operation when it is found that the hoist is about to collide with a person or equipment during the lifting process, or the hoisted object is suddenly in a relatively dangerous state.
