Patent ID: 6997221
Filing Date: 2006-02-14
Classification: 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 a proximal end pivoted to the distal end of the hoist boom; 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 circuit for operatively supplying hydraulic oil to said cylinders, wherein said hydraulic circuit comprises an oil flow path between working ends of said hoist and stick cylinders so as to transfer hydraulic oil between said working ends; and means for producing reach, comprising pump means connected to control said transfer of hydraulic oil between said working ends.