TECHNIQUE FOR CHANGING TAKE-OFF OF ARM OF PORTABLE CRANE Russian patent published in 2008 - IPC B66C23/06 

FIELD: construction.

SUBSTANCE: changing the take-off of the arm of a portable crane is based on converting rotation of the outlet axle of the electrical drive of the mechanism of changing take-off of the arm, into rectilinear displacement of a rod and into repeated displacement of the arm. When strain in the rod reaches a value corresponding to 0.64-0.67 of the power used by the mechanism for changing take-off of the arm, the angular velocity of the electrical drive is lowered until the maximum permissible strain is attained in the rod, after which the angular velocity of the electrical drive is not lowered anymore.

EFFECT: lower power consumption by the portable crane.

5 dwg