Patent ID: 7549242
Filing Date: 2009-06-23
Classification: E02F

Abstract:
1. A multiple boom for excavators having a frame and a revolving superstructure, the multiple boom comprising: a main boom having a front end and a rear end: a back boom having a lower end and an upper end, the lower end attached to a drag link mounted on the frame of the revolving superstructure; the upper end of the back boom is inserted into the main boom from below, the main boom designed as a downward-opening fork accepting the upper end of the back boom; an articulated joint located close to an upper edge of the main boom, connecting the upper end of the back boom directly with the downward opening fork of the main boom at a distance from the rear end of the main boom, such that a portion of the back boom is located within the main boom; a boom cylinder having a first end directly connected to the articulated joint and a second end acting on a knuckle on the frame; and an adjustment cylinder located between an articulation pin mounted at the rear end of the main boom and a fixed pivot located near the lower end of the back boom.