Document Stacker Load Cell Capacity Assessment

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Solution Overview

Problem

Document stackers face challenges in accurately assessing remaining capacity due to manual document removal and handling, leading to incorrect capacity signals and reduced production efficiency in high-speed document processing devices.

Innovation Solution

A document stacker with a linearly movable document support attached to a frame via a non-horizontal guide, equipped with a load cell to measure weight independently of the center of mass, and a controller to emit signals when the load approaches maximum capacity, ensuring accurate capacity assessment and controlled operation of document processing devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a counting mechanism is used to track documents fed onto the stacker, then the number of documents can be monitored, but the remaining capacity cannot be accurately assessed when operators manually remove documents

Engineering Contradiction:
Improveremaining capacity assessmentVSAvoidmanual document removal
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent replaces the mechanical counting mechanism with a load cell-based weighing system. Instead of counting individual documents mechanically or electronically, the system measures the total weight on the document support and calculates remaining capacity based on weight differences, eliminating the need to track individual document additions and removals

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The load cell acts as an intermediary that indirectly measures document quantity through weight. Rather than directly counting documents, the system uses weight as a proxy measurement, which naturally accounts for any manual removals without requiring separate detection mechanisms

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If the stacker emits a capacity signal based on document count, then the document processing device can be controlled, but unnecessary halts occur when the signal is premature

Engineering Contradiction:
Improveproduction efficiencyVSAvoidcapacity signal accuracy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system implements continuous weight-based feedback to the document processing device. The load cell provides real-time weight measurements that are converted to capacity information, allowing the processing device to adjust its operation based on actual remaining capacity rather than predetermined counts, preventing premature halts while ensuring timely spin-down

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The mechanical counting system is replaced with a weight-based measurement system using a load cell. This substitution provides more reliable capacity assessment because weight measurement is not affected by manual document removals and provides a continuous, accurate indication of actual remaining capacity

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If a non-horizontal linear guide means is used, then a single load cell can measure weight independently of center of mass, but the structure becomes more complex

Engineering Contradiction:
Improveload measurement accuracyVSAvoidlinear guide structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces asymmetry by using a non-horizontal (inclined) linear guide means instead of a horizontal one. This asymmetric orientation allows the load cell to measure the component of gravitational force along the incline, enabling accurate weight measurement independent of the center of mass position of documents on the support

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The system changes the orientation parameter of the linear guide from horizontal to inclined. This parameter change transforms the measurement geometry so that the load cell measures force along the incline direction, which correlates to the total weight of documents regardless of their distribution or center of mass position

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables precise tracking of remaining capacity, preventing unnecessary halts and optimizing production efficiency by accurately predicting when the stacker will be full, even with manual document removals.

Implementation Method 1

a load cell configured to resist relative movement between the frame and the document support along said predetermined path and to emit an output signal representative of the load applied to the load cell by the document support

Methodology Applied
Scientific EffectGravitation: Gravitation

Data Source

PatentEP3976517B1A document stacker comprising a load cell
Publication Date: 2024.11.13 PLOCKMATIC INT
  • EP3976517B1 patent drawingFigure 1~2

AI summary

A document stacker (1) for receiving documents from a document processing device (3), wherein the document stacker comprises: a document support (4), and a frame (5), wherein the document support is attached to the frame by a linear guide means configured such that the document support is linearly movable with respect to the frame along a predetermined path of movement (7) inclined to a horizontal plane, and wherein the document stacker further comprises a load cell (14) configured to resist relative movement between the frame and the document support along said predetermined path and to emit an output signal representative of the load applied to the load cell by the document support.