Device for timber harvesting having a felling head (H) which includes a gripper and saw unit and a tilting device. The gripper and saw unit have gripper arms which can be actuated by a first hydraulic cylinder and a cutting element which can be pivoted out by a second hydraulic cylinder, and can be pivoted from a depositing position into a cutting position for the harvested material with the aid of the tilting device, which can be actuated by a third hydraulic cylinder. 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. The It is proposed that the tilting device can be pivoted from its cutting position into its depositing position by pressurizing the second hydraulic line in a pressure range in which the cutting element remains in an inactive state.

Device for timber harvesting having a felling head (H) which includes a gripper and saw unit and a tilting device. The gripper and saw unit have gripper arms which can be actuated by a first hydraulic cylinder and a cutting element which can be pivoted out by a second hydraulic cylinder, and can be pivoted from a depositing position into a cutting position for the harvested material with the aid of the tilting device, which can be actuated by a third hydraulic cylinder. 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. The It is proposed that the tilting device can be pivoted from its cutting position into its depositing position by pressurizing the second hydraulic line in a pressure range in which the cutting element remains in an inactive state.

Disclosed is a new type of dosing device in a tree-processing device and a method for using it. The dosing device comprises a pump (2) to be attached to the processing device and a feed hose (15) connected to the pump (2) for leading the treatment agent fed by the pump (2) to the point of use. In the device is a replaceable treatment-agent cartridge (7) and the treatment-agent cartridge contains treatment agent. The cartridge is attached to the inlet port of the pump (2) by means of an adapter (4).

Device for timber harvesting having a felling head which includes a gripper and saw unit and a tilting device. The gripper and saw unit has gripper arms which can be actuated by a first hydraulic cylinder and a cutting element which can be pivoted out by a second hydraulic cylinder, and can be pivoted from a depositing position into a cutting position for the harvested material with the aid of the tilting device which can be actuated by a third hydraulic cylinder. 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. Through interaction of a first hydraulic valve, a second hydraulic valve and a third hydraulic valve, the gripper and saw unit maintains its position even when the hydraulic lines are not pressurized and enables precise positioning on the harvested material.

Device for timber harvesting having a felling head which includes a gripper and saw unit and a tilting device. The gripper and saw unit has gripper arms which can be actuated by a first hydraulic cylinder and a cutting element which can be pivoted out by a second hydraulic cylinder, and can be pivoted from a depositing position into a cutting position for the harvested material with the aid of the tilting device which can be actuated by a third hydraulic cylinder. 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. Through interaction of a first hydraulic valve, a second hydraulic valve and a third hydraulic valve, the gripper and saw unit maintains its position even when the hydraulic lines are not pressurized and enables precise positioning on the harvested material.

A hydraulic system for a felling saw head includes a hydraulic motor, operatively coupled to a saw disc of the saw head, a hydraulic variable displacement pump, operatively coupled to the hydraulic motor to supply pressurized fluid to the motor, and a controller configured to control the pump. To provide a target operating speed of the saw disc, the motor is configured to operate at a first displacement corresponding to a first flow rate of hydraulic fluid through the motor During at least a part of a saw recovery operation, the controller controls the pump to operate at a current pump displacement that results in a flow rate of hydraulic fluid through the pump that exceeds the first flow rate through the motor. Saw recovery time may be reduced without overspeeding the saw by including a metered flow control device between the pump and the motor.

A hydraulic system for a felling saw head includes a hydraulic motor, operatively coupled to a saw disc of the saw head, a hydraulic variable displacement pump, operatively coupled to the hydraulic motor to supply pressurized fluid to the motor, and a controller configured to control the pump. To provide a target operating speed of the saw disc, the motor is configured to operate at a first displacement corresponding to a first flow rate of hydraulic fluid through the motor During at least a part of a saw recovery operation, the controller controls the pump to operate at a current pump displacement that results in a flow rate of hydraulic fluid through the pump that exceeds the first flow rate through the motor. Saw recovery time may be reduced without overspeeding the saw by including a metered flow control device between the pump and the motor.

A forestry machine configured to cut timber, where the forestry machine comprises a felling head including a support frame having an accumulation pocket, an accumulating arm, and a harvest arm. The forestry machine further comprises a stator having coils thereon adapted to produce a time varying stator magnetic field, a rotor having at least either a set of slots or a set of permanent magnets mounted thereon facing the stator and adapted to produce a radially directed flux or an axially directed flux. The rotor is rotatably coupled to the stator in axial alignment therewith by the time varying stator magnetic field. The rotor comprises a saw blade.

A forestry machine configured to cut timber, where the forestry machine comprises a felling head including a support frame having an accumulation pocket, an accumulating arm, and a harvest arm. The forestry machine further comprises a stator having coils thereon adapted to produce a time varying stator magnetic field, a rotor having at least either a set of slots or a set of permanent magnets mounted thereon facing the stator and adapted to produce a radially directed flux or an axially directed flux. The rotor is rotatably coupled to the stator in axial alignment therewith by the time varying stator magnetic field. The rotor comprises a saw blade.

The present invention concerns a method for the indication of the sharpness of the teeth at a harvesting head at a forestry machine, an arrangement for the execution of the method, and a forestry machine for the use of the arrangement during execution of the method.