Tree Felling with a Drill Cone

Motor-manual timber felling is one of the most dangerous operations in forest and cannot be completely replaced by fully mechanized harvesting a harvester when dealing with large deciduous trees. Shifting center gravity tree ready to felled beyond its tipping line using conventional wedges because worker directly behind stem under crown until just before falls. The can hit trunk itself, but also falling parts crown. In preliminary study for development new type head, drill cone that open cut help an applied torque was investigated. A does not require any special cutting technique, no counter forces tree, works without impulses, it self-retaining unscrewed again.In order determine required as function parameters, mathematical equation framework established practical experiments were used friction parameters verify calculations. bend intact fibers hinge, shift direction fall, overcome on cut. effects forward or backward leaning trees quantified. It has been shown efficiency low, this compensated high internal lift ratio. maximum measured input diameter up 55 centimeter 100 Nm.