The principle of mechanical balance weight is adopted, that is, the balance between the shaft body and the weight block, to realize the lifting action of the shaft, without external power assistance such as motor drive, boost spring, air support, etc., so the operation is easy, simple, convenient and safe. No broken movies, no maintenance.

      The principle of mechanical balance counterweight is adopted, i.e. the balance between the shaft body and counterweight, so as to realize the lifting and closing of the shaft. The operation is easy, simple, convenient and safe without external power assistance such as motor drive, boost spring, air support, etc. No broken movies, no maintenance. It is suitable for the occasion with few load-bearing contents and space requirements.