Device for harvesting timber

A device for timber harvesting having a hydraulically controlled felling head attachable to the boom arm of a vehicle and comprises:

• a gripper and saw unit and a tilting device, wherein the gripper and saw unit has at least one pair of two gripper arms for the harvested material, actuatable by a first hydraulic cylinder and pivotable between an open and closed state, and a cutting element for cutting through the harvested material pivotable out by a second hydraulic cylinder, and pivotable from a depositing position into a cutting position for the harvested material by the tilting device that is actuatable by a third hydraulic cylinder,
• wherein the first hydraulic cylinder is connected to a first hydraulic line for opening the gripper arms and to a second hydraulic line for closing the gripper arms,
• a first hydraulic valve with a non-return valve is connected on the input side to the first hydraulic line, and is connected on the output side to a second hydraulic valve, which is connected to the third hydraulic cylinder configured as a single-acting hydraulic cylinder, and to a third hydraulic valve, via which the second hydraulic valve is connected to the first hydraulic line,
• wherein the third hydraulic valve is configured to block when pressure is applied to the first hydraulic line and to open when pressure is applied to the second hydraulic line, and the second hydraulic valve is configured to conduct hydraulic fluid from the first hydraulic valve to the third hydraulic cylinder when a switch is actuated by the gripper arms pivoted into their open state, and to conduct hydraulic fluid from the third hydraulic cylinder to the third hydraulic valve when the switch is not actuated when the gripper arms are closed.