Circular inspection shaft opening appurtenance for laying -out

The utility model relates to a circular inspection shaft opening appurtenance for laying -out, include main pole setting and subordinate to the pole, wherein: main pole setting bottom is equipped withand is used for the awl point fixed, and the lower part is equipped with vertical sliding tray and 2 at least locking holes, it is the telescopic link to subordinate to the pole, and one end is rotationally connected in main pole setting sliding tray through the round pin axle, round pin axle can slide in the sliding tray, subordinate to still be equipped with on the pole with locking hole complex locking mechanism, it is the free end to subordinate to the pole other end, and the end is equipped with marking off mechanism. This appurtenance has solved the scarce specialized tool of circular inspection shaft opening laying -out construction leads to among the prior art inconvenient, the big problem of circle compliance error through new design, has positive technical meaning. 本实用新型涉及种圆形检查井开口放样用辅助工具，包括主立杆和从属杆，其中：所述