In this paper calculating method of lead angle of helical gear by measuring span length of length bar and base tangent length is put forward and lead angle calculating formula is deducel.
With the limitations of the maximal bearable bending moment and the positive lifting force, the controlling parameter curves of span and lifting Angle are then acquired to guide the safety operation.
以长桩结构能够承受的最大弯矩和吊点力不为负值作为限制条件，得出安全作业跨距和倾角参数控制曲线。
3
The rounded angle at the base of the doors of the furniture allows for a continual reading of space from one door to another to the very span of the space.