Abstract: A control unit controls a tree stem processing tool pivotably mounted to an articulated boom in such a way that orientation of the tool is changed when the tool is controllably rotated about a rotation axis that is oriented substantially vertically. the articulated boom being rotatably connected to a mobile work machine, The control unit is adapted to automatically apply a control mode in the control unit in which control mode a power-driven operation is controlled according to a predetermined dependency in such a way that one or more operating parameters influencing the power-driven operation vary as a function of a prevailing separation or a prevailing distance determined in relation relating to a predetermined hazard direction or predetermined hazard trajectory associated with the tool.

Abstract: A load control device includes a camera to capture information of objects of load handled by a load handling device to forward such information to a computer, which compares load data derived therefrom with reference data in a data source and emits a signal to an output device in the case of a certain conflict between the data.

Abstract: A load control device includes a camera to capture information of objects of load handled by a load handling device to forward such information to a computer, which compares load data derived therefrom with reference data in a data source and emits a signal to an output device in the case of a certain conflict between the data.

Abstract: A control system for controlling a moveable device includes at least one hydraulic actuator associated with the moveable device, at least one position sensing device to determine the position of the moveable device or the actuator, or both, and a hydraulic control system, including an electronic control unit, for controlling the actuator. For performing a control method, the hydraulic control system is configured to deliver pressurized hydraulic fluid to the actuator, the hydraulic fluid being pressurized at most to a predetermined maximum pressure, and the control system is adapted to regulate the predetermined maximum pressure based on the determined position. According to an example, the moveable device is a boom of a working machine. According to a further example, the actuator is a hydraulic cylinder or motor.

Abstract: A system and a method for controlling a tool pivotably mounted to an articulated boom connected to a work machine having a control unit. The solution: 1) determining the direction a predetermined point of the boom or the tool is moving to, i.e. the moving direction, and 2) controlling orientation of the tool as a function of one or several predetermined dependencies, the predetermined dependencies defining at least the orientation of the tool in relation to the moving direction. According to an example the work machine is a forest machine.

Abstract: A control system for controlling a moveable device includes at least one hydraulic actuator associated with the moveable device, at least one position sensing device to determine the position of the moveable device or the actuator, or both, and a hydraulic control system, including an electronic control unit, for controlling the actuator. For performing a control method, the hydraulic control system is configured to deliver pressurized hydraulic fluid to the actuator, the hydraulic fluid being pressurized at most to a predetermined maximum pressure, and the control system is adapted to regulate the predetermined maximum pressure based on the determined position. According to an example, the moveable device is a boom of a working machine. According to a further example, the actuator is a hydraulic cylinder or motor.

Abstract: A system and a method for controlling a tool pivotably mounted to an articulated boom connected to a work machine having a control unit. The solution: 1) determining the direction a predetermined point of the boom or the tool is moving to, i.e. the moving direction, and 2) controlling orientation of the tool as a function of one or several predetermined dependencies, the predetermined dependencies defining at least the orientation of the tool in relation to the moving direction. According to an example the work machine is a forest machine.

Abstract: A transformer unit for sawing, wherein the transformer unit comprises: a first machine element for performing a continuous rotational motion, and a second machine element for performing a limited alternating rotational motion, wherein the transformer unit can be coupled to an arrangement supplying driving energy for the transformer unit, wherein the first and the second machine elements are coupled to a chain saw with a guide bar, wherein the first machine element is for rotating the chain saw, wherein the second machine element is for feeding the guide bar and for returning the guide bar to the starting point of the sawing after the sawing. The second machine element is a wing torsion device operated by pressurized medium, comprising an annular space for the pressurized medium.

Abstract: The invention relates to a delimbing apparatus for processing elongated pieces, particular tree trunks (S), which apparatus (1) comprises a frame structure (2) to be suspended at the end of a boom assembly in a working machine, at least one means, articulated in relation to said frame structure, for processing the trunk (S), and actuators (31a, 31c, 51a, 51b) for controlling the position and force effect (F) of said means. In the invention, said actuators comprise at least one joint (100) driven by a pressurized medium and comprising a joint frame (101), a joint arm (103) swivelled in said joint frame, and a blade structure (105, 106) fitted in said joint, by means of which blade structure the pressure effect of the pressurized medium produces said swivelling.

Abstract: The invention relates to a transformer unit, particularly for sawing, wherein the transformer unit (M) comprises a first machine element (1), particularly a shaft, performing a continuous rotational movement during the use of the transformer unit, and a second machine element (2) performing a limited alternating rotational motion on a part of the transformer unit, particularly a wing torsion device driven by pressurized medium. The transforming unit (M) is arranged to be coupled to an arrangement to supply driving energy for the transformer unit (M), such as a hydraulic pump unit. The first and second machine element (1, 2) of the transformer unit are preferably coupled to a device performing the same work.

Abstract: A hydraulic boom control system has two valves controlling linear hydraulic actuators, one for pivoting a hoist boom relative to a machine and one for pivoting a stick boom relative to the hoist boom. The bore sides of the actuators are hydraulically connected and the rod side of the hoist actuator is connected to the first port of the first valve and to the second port of the second valve. Operating the first valve moves the boom end generally horizontally and operating the second valve moves it generally vertically.

Abstract: A hydraulic boom control system has two valves controlling linear hydraulic actuators, one for pivoting a hoist boom relative to a machine and one for pivoting a stick boom relative to the hoist boom. The bore sides of the actuators are hydraulically connected and the rod side of the hoist actuator is connected to the first port of the first valve and to the second port of the second valve. Operating the first valve moves the boom end generally horizontally and operating the second valve moves it generally vertically.

Abstract: The invention relates to a method for adjusting supply pressure (ps) in a hydraulic system. The method comprises a feeder pump (23) for producing the supply pressure (ps), at least two hydraulic actuators (8a, 8b, 8c), measuring means for measuring the pressure levels of the actuators (8a, 8b, 8c), and a pressurized medium flow channel system. In the method, it is examined, in which actuators (8a, 8b, 8c) the load pressure is caused by moving a load (positive work). From the pressure levels of the actuators (8a, 8b, 8c) performing load-moving work, the highest is selected, and the supply pressure (ps) is adjusted on the basis of the selected pressure level.

Abstract: An actuator particularly for accomplishing the swinging motion of a swinging arm comprises two cylinders using a pressurized medium, the piston rods of the cylinders being connected to a structure rotatable in relation to the swinging arm for the purpose of rotating the swinging arm around a rotation axis by the effect of movements of the pistons of the cylinders. The actuator comprises two control valves, of which one control valve is arranged to guide the pressurized medium either to both cylinders while they are coupled in parallel, or solely to one cylinder where its piston rod chamber and piston chamber are coupled together. This results in a movement of the piston outwards, because the pressure is directed to the whole work area of the piston on the side of the piston chamber and on the side of the piston rod chamber only to the work area which is the difference between the cross-sectional areas of the piston and the piston rod.

Abstract: A leg mechanism for moving a body comprising an upper arm pivotably connected to the body by a hip joint, and a lower arm pivotably connected to the opposite end of the upper arm by a knee joint. The lower end of the lower arm comprises a walk element for contacting a surface over which the body is moved. Between the upper arm and the body at the hip joint, and between the upper arm and the lower arm at the knee joint, respectively, there is an actuator for effecting the pivotal movement of the corresponding joint. At one of the joints there is, in addition to an active actuator, also a passive force-transmitting element arranged to transmit a change in a pivoting angle taking place at the joint under the effect of the active actuator and an external load. The passive force-transmitting element transforms the change into a force which is transmitted to a receiving actuator which effects a change in the position of the lower end of the lower arm to compensate for the change in the pivoting angle.

Abstract: In the grapple of a tree harvesting machine, the feeding means (14, 15) and/or delimbing means (1, 2) are pairwise coupled in a way that the movement of the actuator (6) is transmitted to one swinging arm (5) of the pair directly and to the other one by means of a drive arm (7) and a torsion spring (18).

Abstract: Load-bearing swinging arm which causes an advance movement of a mobile device by means of its pivoting movement is pivotally connected to a supporting structure in a pivotal relationship thereto about an axis of rotation, and a pair of actuators for effecting the pivoting movement is provided between the swinging arm and the supporting structure. The points of action acting on the supporting structure by way of the actuators are provided on both sides of the axis of rotation. The points of action effect moment simultaneously about the axis of rotation, and they will also effect a force couple at least in some position, for example, in a position critical in view of the load, the forces acting through the points of action being parallel, of equal magnitude and having opposite senses in the force couple.