E02F 3/3408

Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm {, i.e. there is either one arm or a pair of arms}, e.g. dippers, buckets with bucket-arms {, i.e. a pair of arms, e.g. manufacturing processes, form, geometry, material of bucket-arms } directly pivoted on the frames of tractors or self-propelled machines {and comprising an additional linkage mechanism of the parallelogram-type}