Veneer stacking system
AssigneeU.S. Natural Resources, Inc.
InventorJohn C. Holbert
Life of this patent
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Abstract
In a veneer stacking system, a sensing device for sensing the incoming veneer sheets and computer determining from the information of the sensing device the stack on which the sheets are to be deposited. Knock-off shoes are positioned above the path of incoming veneer sheets. Multiple hydraulic cylinders connected into a hydraulic control system controls movement of the shoes. The multiple cylinders are simultaneously actuated by master cylinders which in turn are simultaneously actuated by a computer controlled mover piston. Air leaked into the hydraulic system is bled off by bleed orifices in the master cylinders communicating with a hydraulic fluid reservoir whereby air rises in the system up through the orifices and into the reservoir.
Claims9
In a veneer stacking system wherein sheets of veneer are conveyed on an overhead conveyor and selectively deposited on stacks, apparatus for transferring the veneer sheets from the overhead conveyor to the stacks comprising;
- a pair of knock-off shoes extendably supported over the sheets being conveyed by the overhead conveyor and over a stack onto which selected ones of the sheets are to be deposited,
- a plurality of hydraulic motor means each including a piston and defining a substantially non-restricted conduit for a hydraulic fluid moved by the piston in the conduit, said hydraulic motor means cooperatively extending the pair of shoes to engage the selected sheets and transfer the sheets from the conveyor to the stacks;
- return means operating to retract the shoes to the non-extended position upon release thereof by the hydraulic motor means;
- a single pneumatic control means simultaneously activating the plurality of hydraulic control means for simultaneous extension of the pair of shoes and to permit retraction thereof by the return means;
- and
- computer means controlling actuation of the pneumatic control means in response to computation of information determining the required instant of actuation of the shoes for depositing the selected sheets onto the stack.
A method of stacking veneer sheets into stacks positioned below an overhead conveyor conveying veneer sheets in sequence, said stacks segregating the veneer sheets into categories of common physical characteristics, which method comprises;
- scanning the sheets for the physical characteristics that determine stack designation,
- computing the requirements for orienting the sheets relative to the conveyor,
- orienting the sheets being conveyed with a leading edge thereof perpendicular to the path of travel,
- monitoring the position of the sheets as they are conveyed along said conveyor,
- positioning pairs of extendable knock-off shoes above the conveyor and above the stack position, each pair of knock-off shoes extended simultaneously by actuation of a plurality of hydraulic motor means which forces hydraulic fluid through a non-restricted conduit, and wherein said plurality of hydraulic motor means is actuated by a common computer controlled pneumatic motor means,
- urging the knock-off shoes to a non-extended position, and computing from the information of the monitoring and scanning steps the precise point of actuation for simultaneous extension of the pair of knock-off shoes so as to deposit the sheets onto the designated stacks while maintaining the orientation established in the orienting step and returning the knock-off shoes to the non-extended position following conclusion of the actuation step.
Dependencies are inferred from the claim text.