Patent ID: 7380677

Claim:
Crane comprising a rotating platform ( 4 ) structured and arranged to rotate on a vertical axle ( 3 ), a boom ( 5 ) connected with the rotating platform ( 4 ) and structured and arranged to luff on a luffing axle ( 6 ), a guy support ( 9 ) structured and arranged to pivot on an axle ( 10 ) parallel to the luffing axle ( 6 ) of the boom ( 5 ), guying ( 8 ) connected with an upper end of the boom ( 5 ) at one end thereof and an upper end or top of the guy support ( 9 ) opposite the pivoting axle ( 10 ) at an opposite end, adjustment cabling ( 11 ) structured and arranged for luffing the boom ( 5 ) and connected with the upper end of the guy support ( 9 ) and rotating platform ( 4 ), and an angle adjustment mechanism ( 12 ) installed along said guying ( 8 ) between ends of said guying ( 8 ) respectively connected to the upper end of the boom ( 5 ) and upper end or top of the guy support ( 9 ) and structured and arranged for adjusting, through adjusting length of said guying ( 8 ), an angle of the guy support ( 9 ) relative to the boom ( 5 ), such that when the boom ( 5 ) is positioned along the ground before raising, the guy support ( 9 ) is positioned to form an acute angle with the boom ( 5 ), said angle adjustment mechanism ( 12 ) then positions the guy support ( 9 ) to form an obtuse angle with the boom ( 5 ) positioned along the ground by slackening or increasing length of said guying ( 8 ), the boom ( 5 ) is raised to position the guy support ( 9 ) adjacent the rotating platform ( 4 ), and said angle adjustment mechanism ( 12 ) then shortens the length of said guying ( 8 ) to form an acute angle between the guy support ( 9 ) and boom ( 5 ), with said angle adjustment mechanism ( 12 ) positioned along said guying ( 8 ) constituting the primary mechanism for adjusting the angle of said guy support ( 9 ) relative to the boom ( 5 ).