TOWER CRANE BOOM Russian patent published in 2004 - IPC

FIELD: mechanical engineering; materials handling facilities. SUBSTANCE: invention relates to tower cranes with articulated sectional booms which can be turned, when in inoperative position, relative to each other. Proposed tower crane boom has root and end sections with lower chords butt jointed through lugs of sections connected by pin and section brackets in holes of which mounting pin is fitted. Lug of root section is formed by rigidly interconnected middle plate and two extreme plates, and lug of end section consists of two plates. Middle plate of lug of root section is arranged between plates of end section lug. End face surfaces of extreme plates of root section lug end face surfaces of plates on end section lug are provided with cavities. Holes are made in middle plate of root section lug, one of said holes is oval and arranged in end part of plate, and other hole of said plate is aligned with cavities in end face of extreme plates. Axle is fitted in this hole and in said cavities. Axle is fixed from side displacements of lug of root section by means of cover plates rigidly secured on outer sides of extreme plates of root section lug. EFFECT: improved reliability of boom in operation, convenience and safety at mounting and demounting. 11 dwg