... 2,Strict quality and self-design 3,Column and boom , with safety device, heavy type 4,Anti ... and strength. 2. To ensure safety, the boom lifting device uses a ratchet-and-pawl structure and ... manipulator. 4. The front end of the boom is manufactured with a cross adjustment structure which ... locked with double nuts. Fixed Welding Manipulator (Column Boom Manipulator) 6. The column rotation can be carried ...