Abstract:
A log feeding apparatus for feeding a log to first and second cutting spindles is provided, in which a log is fed to a second receiving position when centering spindles have reached a second delivery position that is away from the second receiving position downstream in the direction of log transport by a distance equal to or greater than an assumed maximum diameter of the log. That is, a new log is transported to the second receiving position by placing sections when the log held between the centering spindles reaches a position that will avoid contact with the new log. As a result, the time can be reduced for transporting the log to the cutting spindles.
Abstract:
The invention concerns a method for recovering partial sized veneer sheets in the veneer production. A veneer sheeting peeled from a log is monitored with a machine vision device for detecting and localizing defects and defining corresponding partial sized sheet sections in the veneer sheeting. The partial sized sections of the veneer sheeting are evaluated for sound veneer in veneer lengths of a multiple of 2′+n′. The partial sized veneer sheets are cut as sound veneer sections in the longitudinal and transversal direction of the veneer sheeting controlled on the evaluation of value factors of the sections.
Abstract:
A veneer-slicing apparatus includes a flitch table movable relative to a carriage which carries a cutting blade for slicing veneer sheets from the flitch. The cutting blade is mounted on a blade carrier that is rotatable relative to the carriage. The apparatus further includes a remotely operable mechanism for adjusting the angle of attack of the cutting blade relative to the flitch by rotating the blade carrier relative to the carriage. The adjusting mechanism includes an electrohydraulic cylinder and piston coupled to the carriage and the cutting blade, a hydraulic fluid flow control valve, a piston position sensor, a computer, and an operator console. All of the components of the adjusting mechanism are electrically coupled to each other. The computer receives operator commands indicating a desired blade angle from the operator console, compares the actual blade angle with the desired blade angle, and actuates the electrohydraulic piston and cylinder, through the hydraulic flow control valve, to change the actual blade angle to the desired blade angle.
Abstract:
A veneer lathe apparatus and method are described in which the height of the nose bar roller relative to the knife is automatically adjusted during peeling by a computer control system. In addition, the two veneer exit gaps between the nose bar and the knife and between the nose bar and the knife backing member are automatically maintained substantially the same as or slightly greater than the veneer path width which is equal to the thickness of the veneer plus a clearance space of a predetermined amount. As a result the automatic control positions the nose bar as close as possible to the knife during peeling thereby greatly improving the quality of the veneer. The height of the nose bar is adjusted by moving a moveable wedge along a fixed wedge with a control cylinder in response to a computer generated control signal. A resilient hold-down device is employed for mounting the nose bar carriage to enable its horizontal movement and vertical movement with respect to the main carriages during peeling due to height adjustment and horizontal gap adjustment of the nose bar relative to the knife.
Abstract:
A method of controlling the feed of the backup rolls of a log backup apparatus for use in a veneer lathe for preventing a log from bowing while veneer is peeled from the log. The method comprises the step of centripetally feeding the backup rolls from a control-start diameter .PHI. at a provisional feed rate f which is higher than a predetermined feed rate F by a feed rate of a pre-selected correction value .alpha. per log rotation. The aforementioned control-start diameter .PHI. is slightly larger than the diameter of the log at which the backup rolls are brought into contact with the log. The method further comprises the steps of stopping the centripetal feeding of the backup rolls at the provisional feed rate f when the bowing is eliminated from the log and thereafter centripetally feeding the backup rolls at the predetermined feed rate F, thereby eliminating the bowing that occurs during the veneer peeling from the log.
Abstract:
A method of controlling the clearance angle of a veneer lathe knife in a veneer lathe having a knife holder beam rotatably mounted on a knife carrier. The beam's vibration frequency is continuously measured and compared with a stored representation of a vibration frequency range (about 50-200 Hz.) characteristic of disruption of the veneer peeling operation. If the comparison reveals that the measured vibration frequency is within the characteristic disruptive range, the beam is rotatably adjusted until the comparison reveals that the measured vibration frequency no longer lies within the disruptive range. Usually, the adjustment accelerates lowering of the beam in order to make the knife clearance angle less positive.
Abstract:
An improved apparatus and method for use in the rotary cutting of wood veneer is disclosed. The improved apparatus and method are preferably employed in connection with a conventional lathe having a pressure bar. Such a lathe is of the type that is used to produce wood veneer from a workpiece of wood, such as a log. The improvement is characterized as maintaining a preselected pressure of the pressure bar against the wood, and subsequently adjusting the preselected pressure bar position by using means for doing so, thereby producing wood veneer of uniform thickness and surface quality, independent of variations in wood density and wood hardness, such variations resulting from natural growth conditions and temperature of the wood.
Abstract:
Glass fiber evaporative cooler media are provided having melamine-formadehyde resin binders coated on the glass fiber. These melamine-formaldehyde coated glass fibers provide evaporative cooler pads with increased capallarity or surface sheeting characteristics while simulataneously demonstrating increased water resistance or hydrophobicity. The melamine-formaldehyde resins of the present invention furthermore provide coatings having greater resistance to thermomigration of binder during drawing. The melamine-formaldehyde binders of the present invention are of three types based upon the resins used: 1) melamine-formaldehyde/urea-formaldehyde; 2) melamine-formaldehyde only; and 3) melamine-formaldehyde/polyurethane.
Abstract:
A method and apparatus for positioning a log in a lathe charger for transfer to a veneer lathe for peeling in which the geometrical centerline of the log is first determined by sensing the log in an at-rest position with light sensors or mechanical sensors and then two geocenters where such centerline intersects the ends of the log are determined. The log is then scanned with light scanners while it is rotated on charger spindles about such centerline to determine the optimum yield axis of the log by computer processing of the scan data. Two computed centers where the optimum yield axis intersects the opposite ends of the log are computed and the vectors of such computed centers relative to the geocenters are computed. A common line extending between the computed centers is determined and the displacement angle between such common line and a reference line is computed. The reference line may be a vertical axis or the charger pendulum arm radius. Then the log is rotated through the displacement angle to position the common line parallel to the reference line. Next the charger spindles are adjusted laterally along the reference line until the computed centers of the log are both positioned at the point of intersection of the common line and an arc line of travel of the pendulum arm. Then the pendulum arms clamp the log with chucks engaging the ends of the log and the log is transferred from the charger to the veneer lathe spindles by pivoting the pendulum arms to move their chucks and the log along the arc line to the lathe.
Abstract:
The method of the present invention realizes accurate control of the feed rate in a veneer lathe under a centerless condition and improves the productivity of the veneer lathe. After spindles (8a) are moved away and disengaged from the axial ends of a log (11), that is, under the centerless condition, the method of the invention controls the feed rate of a knife carriage (9) based on the current rotating speed of the log (11), which is measured by a speed measuring device (7) engaged with the periphery of the log (11). When a difference between the current rotating speed of the log (11) measured by the speed measuring device (7) and a theoretical rotating speed of the log (11) driven by a peripheral drive system (2) exceeds a preset level, the method of the present invention stops the feeding operation of knife carriage (9) and thereby the veneer peeling operation of the veneer lathe. This structure effectively prevents the lowered productivity of veneers and keeps the veneers free from obvious or conspicuous traces of engagement with the peripheral drive system or cracks due to the insufficient synchronism of the veneer lathe with a subsequent veneer processing apparatus.