The utility model relates to a circular arc track is installed on the jar wall through support connecting, and the adjusting screw who rotates on supporting can adjust the track, and vertical orbital motion working condition motion down is difficult for dropping and directional accurate, the simple to operate's of target adjustable T convex track structure that appears, the convex track of T shape with support one end and be connected, the motion is located the T convex track that appears. Jar wall linking bridge on wherein supporting installs on the jar wall, and track linking bridge and the convex orbital round arc rib plate of T shape are connected, establishes ties through adjusting screw and both, and adjustment adjusting screw makes the track and the clearance of jar wall keep unanimously, adjusts and screws up lock nut after the completion. Because the cutting all can make convex track deformation with the welding, for better control deflection, can use adjusting screw to carry out the drawing of being out of shape to the track in addition, improve the circular arc precision.