Arm joint for truss arm, truss arm, and crane with truss arm

The present invention provides a lattice boom arm section, comprising an arm body section, provided at the top of the top of the connection structure of the arm body section, and a connecting structure provided at the bottom of the bottom section of the arm body, the arm body section truss structure the arm body section having an axis extending in the lattice boom arm section further comprises a pulling plate disposed on both sides of the arm body section, said upper pull plate extending from the body section of the arm to the lower portion thereof, an extending direction said arm body section and extending substantially parallel to the axis. The present invention also provides a crane having the lattice boom and a lattice arm. The present invention is lattice boom jib section, and a lattice boom crane with a lattice of the arm, the arm truss may be under pressure and to be in tension.