Abstract:
Method and apparatus for preventing or releasing a blockage occurring in a flow of tree trunks supplied to a wood chipper via a feed hopper and for securing an uninterrupted flow of timber to the chipper. At least one lifting arm is insertable to project through an opening defined in a hopper. The lifting arm is inserted to raise tree trunks wedged in the hopper and release blockages. The duration of the lifting arm insertion is controlled momentarily for limiting the amount of tree trunks supplied to the chipper.