... brake, and the middle articulated frame.It is mainly used in stone yards, sand yard, coal yards, harbor and store houses ... .Suitable for non-antiexplosion job of 2.5m coal seam in low gas mines, it can promote efficiency obviously. 3.SG920 lower ... non-antiexplosion job of 2.3-2.5m coal seam in low gas coal mines, it can promote efficiency obviously. Technical Specifications ...