82413 ⎘
Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes with jibs mounted for jibbing or luffing movements and adapted to move the loads in predetermined paths the paths being substantially horizontal; Level-luffing jib-cranes with means for automatically varying the effective length of the hoisting rope or cable