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: A method for binding logging waste or small timber material by using an automatic binding device, wherein the material is collected in a continuous bundle of brushwood and fed in the longitudinal direction. The material of the bundle of brushwood is compressed further in the binding device by tensioning the band which is fed in a continuous manner around the bundle of brushwood, and the band is finally locked as a strap which keeps the bundle of brushwood together.

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: A sawing device and a chain for it, comprising at least two adjacent sequences of connecting links, of which at least some are cutting teeth; and a sequence of drive links fitted between two adjacent connecting link sequences, wherein an opening at the rear end of the drive link is centered at an opening in the front end of the connecting links, wherein an opening in the front end of the drive link is centered at an opening of the rear end of the connecting links, and wherein a binding pin extending through the whole width of the chain is fitted in the openings. To increase the sawing width, a bush ring is fitted between two adjacent connecting link sequences, around the pin, and placed in the opening of the drive link, and on at least one side of said drive link, a collar is fitted whose diameter is formed greater than the opening in said drive link.

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: In a control method of a tree harvesting machine, the tree harvesting machine comprises a tree-supporting part (1) with a feeding means (2) for feeding the tree in its longitudinal direction and a cross-cutting saw (5) for cutting the tree at selected locations. The part (1) is supported by a boom assembly (6) or the like. At the moment of action of the cross-cutting saw (5), the tree-supporting part (1) is moved by means of the control automatics of the tree harvesting machine in such a way that the force caused by the weight of the tree, tending to bend the tree at the cutting point and thereby tending to cleave the tree, is compensated at least partly.

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: An apparatus for adjusting the rotation speed of a cross-cutting saw of a tree handling machine, especially grapple harvester is provided. The apparatus is arranged to control a hydraulic cylinder connected to the guide bar of the cross-cutting saw in a power transmitting way. A line communicating with the source of pressure medium and having an adjusting unit for adjusting the pressure of the cylinder is connected to the hydraulic cylinder. The system further includes a computing unit, and a rotation speed sensor in conjunction with the cross-cutting saw for measuring the rotational speed of the cross-cutting saw. The rotational speed sensor has a data transmitting connection with the computing unit arranged to control the adjusting unit according to the measured speed.

Abstract: A tree feeding device of a tree handling machine has a saw (8) for cross-cutting of a tree trunk, a conveying unit (2) for moving the tree trunk, an actuator (4) for positioning the conveying unit (2) as well as delimbing blades (6) for delimbing the tree trunk. The conveying unit (2) has a rotatable structure with peripheral, substantially rigid surface adapted to support a continuous contact member, which transmits force between the rotatable structure and the tree trunk. The force acting between the rotatable structure and the tree trunk is adapted to be transmitted directly between the peripheral surface and the continuous contact member of elastic material, which is in direct contact with the peripheral surface and capable of moving freely in relation thereto in a manner determined by the load acting on the elastic material.

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.