Often go to the mall people must know that the mall elevator is divided into passenger elevators and freight elevators, some customers in the elevator when they found the passenger ladder full, want to take the shopping malls of the freight elevator, but the staff of the mall is always refused the request of passengers. Why is that?
Because elevators are divided into drag-and-push-driven. The passenger ladder belongs to the traction elevator, the two ends of the elevator wire rope are connected with the weight of the car and the same weights, in order to maintain the balance. There is a rope trough between the two, depending on the friction between the wire rope and the rope groove to drive the car. Because the friction is uniform, so the strength of the elevator up and down, the speed is uniform, there will be no rapid and slow situation, will not be stuck in the skid.
and used to use only a wire rope different, now traction elevators generally have five or six wire rope, some even up to 10. and the national standard stipulates that the diameter of wire rope is more than 8mm, generally do not worry about when the wire rope will suddenly break off when riding.
But the shopping malls, the construction site is generally used to drive the elevator, the principle of the elevator and water wells, that is, through crank, rotating Lu, will pull up the bucket, not only a wire rope, and the wire rope easy to slip, resulting in a sudden fall of the car, or suddenly stuck. This is why the freight elevator will be "prohibited to take the passenger ladder" sign.