Method and means for stacking veneer sheets
OwnerHarry B. Calvertinventor
Life of this patent
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Abstract
A veneer stacker for receiving sheets of veneer at a relatively high rate of speed and assembling them into a uniform stack. The stacker utilizes the velocity of the veneer sheet, acting against a series of curved guide shoes, for supporting the sheet by means of centrifugal force, while guiding it to a stacking position. As the sheet approaches the stacking position, it initiates a momentary vacuum braking action adapted to draw the sheet into intimate engagement with the guide shoes, stopping the sheet, thereby removing its supporting force. Continuously rotating vacuum drums engage the lead edge of the falling sheet for positioning it against an aligning forward stop, and correcting skew of the sheet as an incident to such positioning.
Claims23
In a veneer stacker for accepting moving veneer sheets and assembling said sheets on a stack, the combination comprising stationary guide means for guiding a moving veneer sheet into position over the stack, said guide means including an inverted concave surface to divert the sheet to follow a curved path adapted to support said sheet, means for stopping the sheet while said sheet is in contact with the guide means thereby to remove its source of support, and means for aligning the sheet with the stack as the sheet falls to the stack.
A stacker for veneer sheets comprising, in combination, means for imparting a predetermined velocity to the veneer sheet, guide means utilizing the velocity of the sheet to support said sheet while guiding the sheet into position over a stack, braking means for stopping the sheet while said sheet is in contact with the guide means thereby to allow the sheet to fall to the stack, and means for aligning the sheet while the stack as the sheet falls to the stack.
A veneer stacker for receiving sheets of veneer and stacking said sheets on a stack comprising in combination an infeed conveyor for inparting a predetermined velocity to the sheet, overhead guide means for receiving the sheet from the conveyor on the underside of the guide means and guiding the sheet to a position generally over the stack, the guide means having a concave curvature adapted to impose an accelerating force on the sheet of at least 1 g. thereby to centrifugally support the sheet, means responsive to the position of the sheet for applying a braking force adapted to stop said sheet, and aligning means arranged for motion in a continuous path engaging the leading edge of the stopped sheet for aligning said leading edge with the stack as the sheet falls to the stack.
A stacker for veneer sheets comprising in combination a support structure, an upwardly directed infeed conveyor, means for driving the conveyor at a predetermined speed, means for supplying a sheet of veneer to the infeed conveyor whereby the conveyor causes the sheet to travel at a predetermined velocity, a plurality of laterally spaced guide shoes carried by the supporting structure, the upstream end of the guide shoes arranged substantially adjacent the output end of the conveyor to smoothly intercept the moving veneer sheet, each guide shoe including a pair of coplanar inverted guide tracks forming an internal chamber therebetween, said chamber having an inlet throat, the guide tracks being curved with a rate of curvature adapted to divert the veneer sheet to follow an arcuate path defined by the underside of the guide tracks, a vacuum plenum carried by the support structure, an exhaust fan coupled to the plenum for creating a vacuum within the plenum, apertures in the plenum coupled to the guide shoe throats, a valve within each aperture for applying vacuum to the guide shoes, a switch having an actuator in the path of sheet travel, means responsive to the actuation of the switch for opening the valves, the switch being positioned so that the vacuum applied to the guide shoes serves to draw the veneer sheet to the guide shoes stopping the sheet substantially in stacking position, means for closing the valves to release the veneer sheet for falling, an elevating table below the guide shoes in the stacking position, a plurality of laterally spaced shell-like drums substantially contained within the vacuum plenum, the vacuum plenum including drum apertures at the downstream end of the guide shoes for exposing a portion of the periphery of the drums to the leading edge of the stopped veneer sheet, the drums including a patterned array of peripheral ports for attracting the leading edge of the stopped sheet, an aligning forward stop, and means for rotating the drums to carry the leading edge of the veneer sheet to the aligning stop when said sheet is released from the guide shoes.
A method of stacking veneer sheets including the steps of imparting a predetermined velocity to the veneer sheet, acting on the upper surface of the moving veneer sheet to divert the sheet and guide it to a stacking position in a curved path adapted to support the sheet, stopping the sheet when said sheet is guided substantially to a stacking position thereby allowing the sheet to fall, attracting the leading edge of the stopped sheet, and carrying said leading edge to an aligned stacking position as said sheet falls to the stack.
A method of stacking veneer sheets comprising the steps of imparting a predetermined velocity having an upward component to the veneer sheet, diverting the sheet to guide it in a curved path into substantially a stacking position, the curvature of the path being sufficient to support the sheet by means of centrifugal force, stopping the sheet when said sheet is substantially in stacking position and in contact with the guide means thereby to remove its source of support, and carrying the leading edge of the falling sheet into an aligned position on the stack.
Dependencies are inferred from the claim text.