掩护支架经常采用四连杆机构,对这种机构提出了多种要求:顶梁与掩护梁铰点的轨迹一般应尽可能呈铅垂线;必须保证掩护支架有一定的调高范围;连杆的铰点位置及长度都要遵守几何学方面的约束规则。此外,连杆机构必须能传递一定大小的力,特别要指出的是,四连杆机构的结构长度对于掩护支架的总长度以及重量有重大影响,应尽可能小。事实上如果能够找到一种结构方案,满 Shield support often use four-bar linkage mechanism, put forward a variety of requirements for this mechanism: Roof beam and shield beam hinge point trajectory should generally be as vertical as possible; must ensure that the shield bracket has a certain range of adjustment; connecting rod The hinge point position and length must comply with the geometric constraint rules. In addition, the linkage mechanism must be able to transmit a certain amount of force, in particular, pointed out that the four-bar linkage structure length of the overall length of the shield bracket and weight have a significant impact should be as small as possible. In fact, if we can find a structural solution, full