US 4,485,861 AGranted

Method and apparatus for processing logs having a nonuniform profile

AssigneeKockums Industri AB

InventorsPhilip Nilsson, deceased, Urban Eklund, Jan-Erik Gasslander

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Abstract

A flat reducing and sawing installation for processing tapering logs includes a reducing section and a sawing section through which logs pass in sequence. The reducing section includes two reducing disks which can each be moved outwards by respective positioning devices. The sawing section includes at least two laterally movable saw blades. The position of the reducing disks is controlled by an electronic evaluation and control unit on the basis of profile data fed in about the log, which indicates that at least one of the disks is about to grind sufficient material from one side of the log to form a plank of a minimum acceptable thickness, length and width. Under these circumstances, the control unit moves the appropriate reducing disk outwardly by at least the minimum acceptable thickness to allow the outermost saw of the sawing section to saw off the resulting plank.

Claims18

Dependent claims

A method of processing logs having a diameter which generally increases toward their root end and which are fed with their narrower, top end through a timber processing installation having a flat reducing section including a pair of reducing disks which are independently adjustable toward or away from a center line, and a sawing section including at least two laterally adjustable saw blades positioned on opposite sides of said center line, said saw blades being adapted to form at least one plank on each side of said logs after they have been processed by said reducing section, said method comprising:

measuring the profile of said log with respect to a reference line;
determining a minimum acceptable plank thickness, length and width;
calculating from said profile measurements the available plank thickness, length and width corresponding to the thickness, length and width, respectively, of the portions of said log which would be removed by said reducing disk in their current positions;
comparing said available plank thickness, length and width with said minimum acceptable thickness, length and width, respectively, for each side of said log;
generating an actuating signal for removing a disk away from said center line by at least said minimum acceptable plank thickness when said available plank thickness, length and width on the same side of said log as the reducing disk to be moved is larger than said minimum acceptable plank thickness, length and width, respectively;
and
releasing said signal when the respective log passes through said flat reducing section, thereby maximizing the yield from said log and minimizing the saw mill waste.

4 more elements

A timber processing system, comprising:

a flat reducing section having a pair of reducing disks on opposite sides of a center line, said reducing section further including respective positioning devices for moving said reducing disks toward and away from said center line;
a sawing section positioned on said center line downstream from said reducing section, said sawing section having at least two laterally adjustable saw blades;
a conveyor moving logs longitudinally along said center line through said reducing section and said sawing section;
a profile measuring device for determining the contour of said logs relative to a reference line before being processed by said reducing section;
calculator means programmed with a minimum acceptable plank thickness, width and length, said calculator means receiving the output of said profile measuring device and determining from the contour of said logs the available plank thickness, width and length corresponding to the thickness, width and length of the portions of said log which would be removed by said reducing disks in their current positions, said calculator means further comparing said available plank thickness, width and length to said minimum acceptable plank thickness, width and length, respectively, and generating an actuating signal for the positioning device of at least one of said reducing disks to move said disk away from said center line by at least said minimum acceptable thickness in the event that said available plank thickness, width and length are all greater than said minimum acceptable plank thickness, width and length, respectively;
memory means for receiving and storing said signal;
and
trigger means actuatable by said logs one by one for feeding said signal to said positioning device.

5 more elements

Dependencies are inferred from the claim text.