Rotating head of screen printing machine

The rotating head of the screen printing machine comprises a supporting seat, a main shaft, a connecting shaft, a limiting sleeve, a connecting block and a limiting plate, supporting lugs are arranged at the two ends of the top of the supporting seat, the main shaft is connected between the two supporting lugs in a rotating mode, a movable hole is formed in one end of the main shaft, the connecting shaft is arranged on the movable hole, and the limiting sleeve is arranged on the main shaft in a sleeving mode. A first avoiding groove and a second avoiding groove are formed in the side wall of the main shaft, a connecting sleeve is installed at one end of the limiting sleeve and connected to the connecting shaft in a sleeving mode, the connecting block is fixed to one end of the limiting sleeve, the limiting plate is fixed to the main shaft, limiting bolts are installed on the two sides of the connecting block, and the limiting plate is adjacently connected between the two limiting bolts. Due to the fact that t