Device for extracting tree stumps

A device for extracting tree stumps split into several parts, comprising a vehicle-carried crane boom having an adjustable effective length, and a gripping unit rigidly connected to the end of said crane boom for pulling out such stumps with associated roots, one by one, from the earth in a direction substantially corresponding to the extension of the roots, said unit also containing means for shaking the pulled-out stump parts and means for cutting the associated roots, and wherein said unit comprises a flat frame in which are mounted a first hydraulic jack, a swing arm pivoted in said frame to be actuated by said first jack for urging such stump part against a fixed counter-arm for firmly clamping such stump part so that it can be pulled out from the earth, a second hydraulic jack having a longitudinally vibrating piston acting on said swing arm for shaking such pulled-out stump part and rubbing it between said swing arm and said fixed counter-arm, a third hydraulic jack, and a knife pivoted in said frame to be actuated by said third jack for cutting off roots of such pulled-out stump part.