LOAD-LIFTING CRANE BOOM Russian patent published in 1995 - IPC

FIELD: materials handling facilities. SUBSTANCE: boom has hook hanger pulley block secured by means of quickly removable pin on bracket of extending section and operating from crane winch, and additional bracket with catchers-pilots on ends, bracket being secured on fixed section of boom. When telescoping the sections and when hook hanger is in extreme upper position, upper and lower sheaves of pulley block get into catchers-pilots and are thus get tied by pulley block cable and fixed on additional bracket. When pin holding extending section of pulley block upper sheave on bracket is pulled out, extending section gets released without dismounting of winch. EFFECT: enlarged operating capabilities. 5 dwg