Abstract: The present invention concerns a method and an apparatus for defrosting frozen wood prior to debarking. The defrosting method of logs of the invention is based on bringing heat zone-specifically to logs in transfer motion on a conveyor according to their heat receiving capacity immediately from the moment of starting of the defrosting, and at the end of the defrosting process, the heat volume per time unit, supplied at a higher temperature, is only a part of the heat volume of the starting phase of the defrosting process. For instance, it is possible to spray water on the wood to be defrosted so that the row interval of the showers in the initial part of the piping is a fraction of the row Interval in the tail end of the piping. In the tall end of the defrosting conveyor steam can also be supplied.

Abstract: This invention relates to a wood chip recovery system which removes bark from roundwood or wood chips. It is desirable for such structures of this type to recover the wood chips from the bark without introducing contaminants, such as metal ions like iron, into the debarked roundwood or wood chips.

Abstract: High powered lasers are used to score the bark on logs before they are mechanically debarked. Typical of the lasers employed are multi-kilowatt CO.sub.2 industrial lasers. A high powered laser beam is brought to a focus just above the surface of the bark on the log. A jet of compressed air is blown coaxially with the beam and facilitates the beam's formation of a narrow slot in the surface of the bark. Logs are advanced and rotated by a plurality of parallel augers extending across the base of a trough. The lasers are positioned in a gap beneath and in between sets of augers. The beam's focus may be adjustable with respect to the bark's surface.

Abstract: Fungi which grow white/colorless and reduce pitch are used to protect structural wood before or after cutting from logs against color staining by staining fungi. The fungus Phanerochaete gigantea is also useful to facilitate debarking.

Abstract: A tree felling attachment apparatus for a farm tractor having connections for rear mounting the attachment onto the hydraulic lift arms and stabilizer bar of the tractor. The attachment includes an elongated longitudinal beam extending rearward behind the tractor that terminates at its distal end in a gripper operable between open and closed positions to receive and grip a tree trunk to be felled. In response to rearward driving of the tractor, the gripper effects felling of the tree disposed therein while enabling the tractor to remove the felled tree to a suitable disposal site.

Abstract: An apparatus and method for the hot water treatment of debarked logs to eliminate infestation and fungi in the logs is presented. The present invention utilizes a water tank and a heat generation source to raise the temperature of the center of the logs above a predetermined level for a sufficient time to accomplish this purpose.

Abstract: A steam distributing valve in contact with the log feed end of a rotatable debarking drum is supported in such a manner that it is capable of moving slightly parallel to the drum axis in response to axial displacement of the drum. Full contact between the valve header and the drum end is maintained for sequentially providing pressurized steam to hollow longitudinal staves on the inner circumferential surface of the drum for thawing frozen logs for debarking.

Abstract: A method for the debarking of logs is disclosed, which comprises treating the logs with enzymes to weaken the bonds between the bark and wood. An apparatus is also disclosed for the debarking of logs, comprising a conveyor for conveying the logs to a debarker, a piping system with nozzles for spraying the logs with an enzyme solution, a device for separating the enzyme solution from the logs and conducting it back into the piping system, and a feed device for supplying enzyme solution into the circulation system.

Abstract: An improved boom construction on a tree delimber. The boom construction has a boom support and a boom assembly pivotally connected to the boom support. Locking means are provided for locking the boom assembly to the boom support in a working position of the delimber. The locking means are movable to an unlocked position allowing the boom assembly to pivot relative to the boom support in setting the delimber up in a travel position. Moving means are provided for both moving the locking means between locked and unlocked positions and for pivoting the boom assembly relative to the boom support. Means are also provided for preventing lateral movement between the boom assembly and the boom support when in the working position.

Abstract: A barking method, and an apparatus for utilization of the method, wherein a log (6) during a substantially linear feeding movement is brought to pass one or a number of barking devices (1; 4,4'), arranged to perform a surrounding rotary movement in relation to the log (6), the barking devices (1; 4, 4') are pressed into a contact position against the log by centrifugal force during the surrounding rotary movement in relation to the log, and the contact pressure of the barking devices (1; 4, 4') is continuously variable by increasing/decreasing the rotary speed of the barking devices (1; 4, 4') and the cutters are arranged inclined at an angle in relation to the feed direction of the log (6), to produce a feeding movement for the log (6) in a direction through the barking device (1; 4, 4').

Abstract: An apparatus for pretreating and debarking logs wherein the log is debarked by a plurality of cutting elements disposed at an angle to the longitudinal extent of the log and offset with respect to each other. The cutting elements include top and bottom cutting elements between which the log is rolled, imparting helical slits thereto.

Abstract: For supplying pressurized steam into a rotating barking drum during the barking of tree trunks in order to thaw and warm the bark, steam is supplied into the barking drum from the periphery of the drum in a substantially radial direction through a distribution ring on the periphery of the drum and a stationary member in sliding contact with the ring.

Abstract: A procedure and an apparatus for barking timber, wherein the timber is barked by the frictional barking method, and it is pretreated prior to barking in order to render the friction barking more efficient. In the pretreatment the timber is patched, that is partly barked, in that bare patches are produced in the bark of the timber, that is spots from which the bark has been removed, preferably by at least one water jet directed against the bark.