US 7,549,242 B2
Multiple boom for excavators
Ralf Schmeling, Berlin (Germany); Bernhard Willaredt, Berlin (Germany); Holger Oertel, Berlin (Germany); and Birgit Ditz, Potsdam (Germany)
Assigned to CNH Baumaschinen GmbH, Berlin (Germany)
Appl. No. 10/556,197
PCT Filed Apr. 24, 2004, PCT No. PCT/DE2004/000862
§ 371(c)(1), (2), (4) Date Aug. 04, 2006,
PCT Pub. No. WO2004/101901, PCT Pub. Date Nov. 25, 2004.
Claims priority of application No. 103 21 070 (DE), filed on May 10, 2003.
Prior Publication US 2007/0157491 A1, Jul. 12, 2007
Int. Cl. E02F 3/32 (2006.01)
U.S. Cl. 37—443  [37/379; 414/694; 414/685] 6 Claims
OG exemplary drawing
 
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.