Abstract: The pressure of a carrier gas entering a gas chromatography (GC) column is controlled by increasing or decreasing the gas pressure over a pressure change cycle by which a desired gas pressure is obtained while avoiding pressure pulses in the column. The pressure change cycle may follow a function that dictates the rate of pressure change. A gas flow controller that controls the gas pressure at the inlet or head of the column may be operated to implement the pressure change cycle. The gas flow controller may be controlled by an electronic controller.

Abstract: The pressure of a carrier gas entering a gas chromatography (GC) column is controlled by increasing or decreasing the gas pressure over a pressure change cycle by which a desired gas pressure is obtained while avoiding pressure pulses in the column. The pressure change cycle may follow a function that dictates the rate of pressure change. A gas flow controller that controls the gas pressure at the inlet or head of the column may be operated to implement the pressure change cycle. The gas flow controller may be controlled by an electronic controller.

Abstract: A circular saw shaft for cutting wood comprises a motor-driven shaft and a ircular saw blade mounted on the shaft. A support disk is mounted on the shaft in spaced relationship to the saw blade to apply to the wood a supporting force in a direction extending parallel to the axis of rotation of the shaft. The support disk can be fixed to the shaft, or biased along the shaft axis by springs. In lieu of springs, the support disk could be elastically flexible.

Abstract: A circular saw head (1) for the cutting of side boards (3) from a log (2), as a circular saw blade (4) mounted on a saw shaft (10) by a support flange (5). Within a rim of saw teeth (13) and radially spaced apart from it a frontal annular support surface (12) is provided, extending axially over the frontal surface (8) of the saw blade (4) and located in the plane of the frontally outer edges (14) of the saw teeth (13). The support surface (12) supports the surface cut on the wood by the saw teeth (13), thereby guiding the wood.

Abstract: A circular cross-cut sawing apparatus comprises two transversely adjustable lides each carrying a plurality of saw blades. The saw blades on each slide can be selectively lowered into the path of oncoming boards. The slides are independently adjustable so that any given board can be cut by blades on both slides.

Abstract: A tree trunk is fed to a cutting station along a centerline line by a pluity of groups of centering rolls spaced along the centering line. Some rolls are driven to advance the trunks. The groups of rolls are adjustable from a centering mode to a non-centering mode by either retracting the rolls or unloading the rolls. During the advancement of a trunk successively through the roll groups, the groups are successively adjusted between their centering and non-centering modes such that roll groups located to support front and rear ends of the trunk are in their centering modes, while at least one roll group disposed therebetween is in its non-centering mode.

Abstract: In a method for profile chipping, the necessary chipping out of wany-edged corners laterally defining a side board (4) to be separated is carried out in such a manner that firstly in a direction perpendicular to the trunk axis saw incisions (6) are made to the full depth of the corner but that material adjacent the saw incision (6) is simultaneously chipped out by chipping blades only to a lesser depth, and in a second working step in a second direction perpendicular to the first direction (17) remaining corner material (20) is chipped out by means of chipping blades and simultaneously a second saw incision (18) is made. The side board (4) exposed in this manner is separated by a saw severance cut. This provides throughout corner faces worked by saw cut which do not have any material splits due to chipping blades.

Abstract: Two circular saws are arranged with their rotary axes parallel to each other and driven in opposite rotational directions. The flight circles of the two saws overlap each other. The cutting edges each extend, without touching, into the gaps of the respective other saw. The saws are driven in forced synchronism.

Abstract: A log sawing and cutting apparatus has a knife head which serves as a cutting tool for the production of wood chips and a coaxial circular sawblade which serves to saw off at least one side board. The knife head is connected with a hollow shaft. The saw shaft is connected to a saw shaft and is pivoted and axially displaceably supported in the hollow shaft. The saw shaft is connected with a drive apparatus which provides a higher spped than the hollow shaft.

Abstract: A method and an apparatus for cutting boards from tree trunks in which transverse cuts are made in a tree trunk which extend into the trunk a predetermined depth and thereafter longitudinal cuts are made into said trunk, which cuts pass through a plane passing through the inner ends of the transversal cuts, whereby the boards are separated from the trunk. The apparatus for cutting boards from tree trunks comprises guide rollers for advancing a trunk in a longitudinal direction, saw units adapted to move in a vertical and in a longitudinal directions to produce the transverse cuts and saw blades movable in the longitudinal direction to produce the longitudinal cuts after the transversal cuts have been made.

Abstract: An improved method and apparatus for efficiently producing machined lumber products such as boards and squared timber is described wherein, after initial four-sided planing of a log, the remaining wany edge regions are milled using saw/chipper units which present, at each milled region, a relatively smooth and a relatively rough surface. The final step in log processing involves sawing the log along the plane of the rough milled surfaces so as to yield a pair of substantially smooth, severed boards, as well as a smooth central timber or cant. The apparatus includes respective, carriage-mounted, shiftably adjustable heads (each having a chopping tooth member and an adjacent saw blade of substantially the same diameter) along with cooperating second saw blades.

Abstract: An improved method and apparatus for processing elongated logs to give maximum production of lumber is described wherein the log is initially cut to present four flattened faces thereon with wany edge regions between adjacent faces, followed by first partially milling the wany edge regions with severance of boards from opposed log faces, and thereafter completing the milling of the wany edge regions with subsequent removal of additional finished boards. Such stepwise partial milling of the wany edge regions materially increases the amount of lumber obtainable from a given log, as compared with prior practices. In preferred forms, the log is processed in an improved apparatus including log turning stations having a pair of pivotally mounted, opposed log-gripping arms; the respective arms are supported on a circular frame which is itself rotatable about the longitudinal axis of the log.