Patent ID: 8573420

Claim:
A crawler crane ( 1 ) comprising: two crawler supports ( 9 ) having rotating crawlers ( 8 ), at least one transversal bridge ( 10 ) connecting the two crawler supports ( 9 ), wherein the at least one transversal bridge ( 10 ) comprises a transversal-bridge plane ( 38 ), a crane structure ( 3 ) having at least one crane boom ( 4 , 5 ) connected to the transversal bridge ( 10 ) so as to be able to pivot about a vertical axis ( 7 ), a pivot articulation ( 6 ) that pivotally connects the transversal bridge ( 10 ) to the crane structure ( 3 ), wherein at least one of the crawler supports ( 9 ) is connected to the transversal bridge ( 10 ) via a double link ( 11 ) comprising: a lower link ( 12 ) that is articulated on the crawler support ( 9 ) via a crawler support lower pivot shaft ( 13 ) and on the transversal bridge ( 10 ) via a transversal bridge lower pivot shaft ( 14 ), an upper link ( 15 ) that is articulated on the crawler support ( 9 ) via a crawler support upper pivot shaft ( 16 ) and on the transversal bridge ( 10 ) via a transversal bridge upper pivot shaft ( 17 ), and an adjustment drive ( 20 ) for pivotally displacing at least one of the two links ( 12 , 15 ) about at least one of the pivot shafts with which said link is articulated to the crawler support ( 9 ) and the transversal bridge ( 10 ), wherein said double link ( 11 ) enables compensation of a roll inclination about an axis longitudinal to a driving direction defined by the two crawler supports ( 9 ), such that the roll inclination is provided between a foot print plane ( 18 ) of the crawler support ( 9 ) and the transversal-bridge plane ( 38 ), wherein the crane structure ( 3 ) has no roll inclination relative to the transversal-bridge plane ( 38 ), wherein the adjustment drive ( 20 ) has a reduction gear, wherein the adjustment drive ( 20 ) has a threaded rod ( 22 ) connected to the crawler support ( 9 ) and a nut ( 24 ) connected to the driven lower link ( 12 ), the nut being complementary to the thread of the threaded rod ( 22 ), wherein the threaded rod ( 22 ) has a trapezoidal external thread and the nut ( 24 ) has a trapezoidal internal thread complementary thereto, wherein the nut ( 24 ) is connected to the lower link ( 12 ) in a manner so as to be unable to rotate relative to the crawler support ( 9 ) by means of connecting pieces ( 25 ), wherein the connecting pieces ( 25 ) define a parallel key guidance for the nut ( 24 ).