Mechanical part of top plate displacement monitor

The utility model relates to a mechanical part of a roof displacement monitor, and belongs to the technical field of mining safety monitoring equipment. The mechanical part comprises a bottom shell and a cover plate which are oppositely combined, the bottom shell and the cover plate are connected through screws, four pull boxes are arranged in the bottom shell side by side, reels are arranged in the pull boxes, a rotating shaft is arranged in the center of each reel along the axis, the rotating shafts are connected with coil springs, the back side of the bottom plate is connected with four scale boxes, and the scale boxes are connected with the four scale boxes. A connecting pipe is integrally formed in the middle of the upper side shell wall of the bottom shell, four sliding blocks are arranged in the connecting pipe, pull wires are fixedly wound on winding wheels of the pull wire boxes, and the pull wires of the four pull wire boxes are connected with the four sliding blocks in the connecting pipe respectiv