本文指出四连杆掩护或支撑掩护式支架存在的主要问题是,在一定条件下支架对梁前顶板存在着破坏作用,而且在支架承载时会在四连杆机构内产生很大的内力,因而使支架额外增加了很大重量。本文提出了采用自卸载掩护机构来改善梁前顶板的控制和消除四连杆掩护机构的内力,使支架的性能得到改善。 This paper points out that the main problem existing in the four-link shield or supporting shield is that under certain conditions, the support has a damaging effect on the front roof of the beam and will generate a great internal force in the four-bar linkage when the support is carried The bracket adds an extra amount of weight. In this paper, the self-unloading protection mechanism is adopted to improve the control of the roof of the beam and to eliminate the internal force of the four-bar shield mechanism so that the performance of the bracket is improved.