A hydraulic drive for feed rollers of a head of a complete timber harvester includes two radial piston motors coupled for conjoint rotation to the feed rollers. One radial piston motor has only one displacement volume and the other radial piston motor has two displacement volumes, between which it is possible to switch. A tree trunk clamped between the feed rollers can thus be moved at two speeds. At the higher speed, pressure medium circulates under a control pressure in the second displacement volume of the switchable radial piston motor.

A curved blade for a delimbing head operable to cut branches from a felled tree is disclosed. The curved blade comprises a cutting rim, at least one portion of which comprises a continuous flange defining a continuous cutting edge, as well as at least one row of ribs that are straight and parallel to each other, extending in the direction of at least one face of the cutting rim from the continuous flange. The continuous cutting edge of the blade having these straight parallel ribs reduces the lateral load of the continuous cutting edge during the operation of cutting branches from a felled tree.

A sensor mount for use with a timber-working device includes a monolithic structure having a base portion configured to be secured to a frame of a timber-working device, and a sensor mounting portion including a cavity configured to receive a contactless sensor. The cavity has a sensor mounting surface for securing the contactless sensor thereto.

A sensor mount for use with a timber-working device includes a monolithic structure having a base portion configured to be secured to a frame of a timber-working device, and a sensor mounting portion including a cavity configured to receive a contactless sensor. The cavity has a sensor mounting surface for securing the contactless sensor thereto.

This invention concerns a feed wheel arrangement intended to be used in a timber working head for at least one of felling, trimming, bark-peeling and cutting of a tree or tree trunk, comprising a frame to which feed wheels and grip fittings are mounted either fixed or in a manner that allows them to be removed. The feed wheel arrangement comprises a feed wheel with a power transfer arrangement lowered centrally in a jacket of the feed wheel, a motor arranged at a distance from the feed wheel, and a power transfer arrangement for the transfer of rotational force from the motor to the feed wheel, for the feed of the tree or trunk through the timber working head. The invention concerns also a timber working head, a crane and a timber working machine.

This invention concerns a feed wheel arrangement intended to be used in a timber working head for at least one of felling, trimming, bark-peeling and cutting of a tree or tree trunk, comprising a frame to which feed wheels and grip fittings are mounted either fixed or in a manner that allows them to be removed. The feed wheel arrangement comprises a feed wheel with a power transfer arrangement lowered centrally in a jacket of the feed wheel, a motor arranged at a distance from the feed wheel, and a power transfer arrangement for the transfer of rotational force from the motor to the feed wheel, for the feed of the tree or trunk through the timber working head. The invention concerns also a timber working head, a crane and a timber working machine.

A method for controlling operation of a wood-handling device in a work machine. The wood-handling device is attached through a rotation device to an end of a set of booms of the work machine to create a desired orientation of the wood-handling device for the operation. The orientation of the wood-handling device using the rotation device is tied on the basis of the operation to be performed using the set of booms. The orientation of the wood-handling device is tied to the position of the end of the set of booms. The position of the end of the set of booms is defined while performing the operation, on the basis of the position of the end of the set of booms. The wood-handling device is oriented using the rotation device, according to the said tie.

A method for controlling operation of a wood-handling device in a work machine. The wood-handling device is attached through a rotation device to an end of a set of booms of the work machine to create a desired orientation of the wood-handling device for the operation. The orientation of the wood-handling device using the rotation device is tied on the basis of the operation to be performed using the set of booms. The orientation of the wood-handling device is tied to the position of the end of the set of booms. The position of the end of the set of booms is defined while performing the operation, on the basis of the position of the end of the set of booms. The wood-handling device is oriented using the rotation device, according to the said tie.

A hydraulic system and method for service mode on a work machine is operatively coupled to a cutting element for felling trees. The hydraulic system comprises a hydraulic motor, a hydraulic pump, a feed actuator, a feed line, a directional control valve, a voltage battery, and a controller. The hydraulic motor is coupled to the hydraulic circuit for operating the cutting element. The hydraulic pump is operable to supply pressurized fluid to the hydraulic motor. The feed actuator extends or retracts the cutting element. The feed line is coupled to the hydraulic actuator. The directional control valve is located on the feed line of the feed actuator. The controller receives a cutting element service mode signal, moves the directional control valve to pressure the feed line for extending the cutting element where the valve is powered by the voltage battery upon receiving the cutting element service mode signal.

A method for controlling operation of a wood-handling device in a work machine. The wood-handling device is attached through a rotation device to an end of a set of booms of the work machine to create a desired orientation of the wood-handling device for the operation. The orientation of the wood-handling device using the rotation device is tied on the basis of the operation to be performed using the set of booms. The orientation of the wood-handling device is tied to the position of the end of the set of booms. The position of the end of the set of booms is defined while performing the operation, on the basis of the position of the end of the set of booms. The wood-handling device is oriented using the rotation device, according to the said tie.