Patent ID: 7007728
Filing Date: 2006-03-07
Classification: A01G,B66C

Abstract:
1. A knuckle boom apparatus, comprising: a machine base; a hoist boom having a proximal end pivoted to the machine base, and a distal end remote therefrom; a stick boom having an intermediate pivot pinned to pivot on the distal end of the hoist boom, a distal end configured to carry a working tool and a proximal end having a suitable cylinder push point; at least one hydraulic hoist cylinder mounted between said machine base and said hoist boom; at least one hydraulic stick cylinder mounted between said hoist boom and said stick boom; a hydraulic reach cylinder mounted above said hoist boom between said hoist boom and said suitable push point at said stick boom proximal end, whereby when said hydraulic reach cylinder is actuated by supplying oil to its base end, said distal end of said stick boom is withdrawn towards said machine base; and a hydraulic circuit for operatively supplying hydraulic oil to said hoist, stick and reach cylinders, wherein said hydraulic circuit comprises at least one hydraulic conduit line connecting respective base end ports of said hoist and stick cylinders so as to allow hydraulic oil to shunt between base ends of said hoist and stick cylinders.