Why elevator door clip from?

Why elevator door clip from? 

 

According to incomplete statistics, personal elevator, about 70 percent of the casualties occur due to the level of quality door installation, maintenance and passenger caused by improper use. When the elevator door is exposed to the passenger elevator in the first part of the elevator is a very important safety feature. Thus, in the landing doors and locks open and close is a prerequisite to ensure the safety of users of the elevator. To prevent the elevator doors closing clip in when people shut the safety device, a common anti-pinch safety edge safety device, infrared light curtains and ultrasound monitoring devices. 

Elevator doors appear clip human phenomenon, generally have the following situations: 

An elevator door closing speed is too fast; 

2, Layer Door Safety Edge, infrared light curtains, ultrasonic monitoring equipment damage or human theft; 

3, when the passenger in the car by hand, foot, body or sticks, small carts and other direct action to prevent off, resulting in an artificial layer door system damage. 

4, installation quality elevator doors, elevator maintenance and parts quality problems caused. 

5. Elevator parts quality, but off