Timber Stacker Zig-Zag Transporter for High-Capacity Alignment

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Solution Overview

Problem

Current stacker arrangements for timber have limited capacity, particularly due to time-consuming separation and individual feeding of timber pieces during end alignment, resulting in inefficient sorting and formation of stacks, with capacities typically around 200 units per minute, which is not sufficient for increased demand.

Innovation Solution

The method involves using a combination of transporters, including a layer-formation transporter, end-alignment transporter, and layer-transfer arrangement, where timber pieces are transported in a zig-zag pattern using alternating low and high sections on a chain transporter to achieve synchronized speed adjustments and controlled separation, allowing for higher capacity stacking by forming subsets that are uniformly aligned in alternating directions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If individual pieces of timber are separated and fed one by one during end alignment, then the stacking precision and uniformity are improved, but the handling capacity and productivity are reduced

Engineering Contradiction:
Improvestacking precisionVSAvoidhandling capacity
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The timber layer is segmented into multiple subsets that are processed in parallel through the end-alignment transporter. Each subset is handled independently but simultaneously, allowing the system to maintain individual piece precision while processing multiple pieces at once, thereby increasing overall capacity from 200 to 400 units per minute

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a new dimension of processing by arranging timber pieces in multiple parallel rows (subsets) rather than a single file. This multi-row arrangement allows simultaneous end-alignment of multiple pieces across different spatial positions, increasing throughput without sacrificing the individual alignment precision required for proper stacking

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If timber pieces are sorted and aligned in a single direction, then the handling capacity is improved, but the uniformity and correctness of the stack are compromised

Engineering Contradiction:
Improvehandling capacityVSAvoidstack uniformity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The end-alignment transporter employs asymmetric stop contacts positioned at different locations for different subsets of timber pieces. This asymmetric arrangement allows each subset to be aligned in its optimal direction (some left-aligned, some right-aligned) while maintaining overall stack uniformity, achieving both high capacity and precision

Inventive Principle:
Principle #4Asymmetry

Data Source

PatentEP2780265B1Method and arrangement for forming stacks of timber, and stack obtained through said method
Publication Date: 2016.08.17 RENHOLMEN
  • EP2780265B1 patent drawingFigure 1
  • EP2780265B1 patent drawingFigure 2~3
  • EP2780265B1 patent drawingFigure 4~5

AI summary

The invention concerns a method and arrangement for forming stacks of timber where the pieces of timber are end-aligned through interaction with transverse rollers, and are formed into stacks through layers being stacked one of top of each other with, in some cases, the insertion of intermediate laths. In order to achieve higher capacity, the method includes the following operational steps: - that in a first step pieces of timber (3) form a contiguous layer (20), - that in a second step the pieces of timber in the layer (20) are separated from each other - that in a third step the separated layer (20) is divided into a number (n) of pre-determined sublayers (20:1-20:n) of pieces of timber, - that in a fourth step the sublayers (20:1-20:n) are end-aligned against a first end stop (37), - that in a fifth step any one of the sublayers (20:1-20:n) is end-aligned against a second end stop (38), - that in a sixth step the relevant sublayers (20:1-20:n) are collected to form a contiguous layer (20), - that in a seventh step the contiguous layers (20) are stacked one on top of each other to form a stack of timber.