Timber working device and method for controlling a timber working device and a working vehicle

A method of controlling a timber working device, the timber working device comprising,

• a frame, having a feed axis,
• a controller, adapted to control the timber working device,
• a stem drive system, configured to feed at least one stem along the feed axis, at least a pair of upper knives and a pair of lower knives movably attached to the frame,
• wherein the pair of upper knives and the pair of lower knives are each configured to be controllable by an actuator to open and close around a stem,
• a tilt mechanism comprising, a controllable tilt bracket pivotably attached to the frame, to control a tilt angle of the frame in relation to the tilt bracket, angle detection equipment adapted to sense or calculate a tilt angle of the tilt bracket and/or the movement of the timber working device,
• wherein the controller is
• receives a signal from the angle detection equipment,
• adjusts, based on the signal from the angle detection equipment, one or more of the upper pair of knives, the lower pair of knives, a tilt torque, and the stem drive system, wherein the adjustment comprises one or more of (a) increasing a closing force of the upper pair of knives or the lower pair of knives based on the sensed or calculated tilt angle and (b) increasing a pressure of the stem drive system based on the sensed or calculated tilt angle.

A working vehicle for forestry application comprising

• a crane, the crane being outfitted with a timber working device, comprising,
• a frame, having a feed axis,
• a controller, adapted to control the timber working device,
• a stem drive system, configured to feed at least one stem along the feed axis,
• at least a pair of upper knives or lower knives movably attached to the frame,
• wherein the knives are configured to be controllable each by an actuator to open and close around a stem,
• a tilt mechanism comprising, a controllable tilt bracket pivotably attached to the frame, to control a tilt angle of the frame in relation to the tilt bracket, angle detection equipment adapted to sense or calculate the tilt angle of the tilt bracket and/or the movement of the crane or the timber working device,
• wherein the controller
• receives a signal from the angle detection equipment,
• adjusts, based on the signal from the angle detection equipment, one or more of the upper pair of knives, the lower pair of knives, a tilt torque, and the stem drive system, wherein the adjustment comprises one or more of (a) increasing a closing force of the upper pair of knives or the lower pair of knives based on the sensed or calculated tilt angle and (b) increasing a pressure of the stem drive system based on the sensed or calculated tilt angle.