E02F3/28—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
E02F3/30—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 a dipper-arm pivoted on a cantilever beam, i.e. boom
E02F3/627—Devices to connect beams or arms to tractors or similar self-propelled machines, e.g. drives therefor
E02F3/6273—Devices to connect beams or arms to tractors or similar self-propelled machines, e.g. drives therefor using legs to support the beams or arms on the ground during the connecting process