Dunnage Discharge Chute Safety Interlock Mechanism

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Solution Overview

Problem

Paper dunnage producing machines pose safety hazards to operators due to exposed cutting blades and counter-rotating gears, particularly during paper jams or when reaching into the discharge chute, which can lead to injury.

Innovation Solution

A dunnage discharge chute with a movable door and sensors that detect its position, disabling the machine if the door is not in a safe configuration, preventing operator access to the chute and ensuring the machine does not operate when the door is open, thereby preventing injuries.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the discharge chute is left open for operator access, then ease of operation is improved, but safety is worsened due to exposure to cutting blades and gears

Engineering Contradiction:
Improveoperator access to discharge chuteVSAvoidinjury risk from cutting blades and gears
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

A door is introduced as an intermediary element between the operator and the hazardous internal components (cutting blades and gears). The door can be opened to allow operator access for loading/unloading dunnage products, but when closed, it physically blocks access to the hazardous areas, thus mediating between the need for access and the need for safety.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

Optical sensors detect the position of the door and provide feedback signals to the controller. The controller monitors these signals and automatically disables the cutting blades and gears when the door is open, creating a feedback loop that ensures safety measures are activated based on the actual state of the discharge chute.

Inventive Principle:
Principle #23Feedback

2Object-affected harmful factors

If sensors and control systems are added to monitor door position, then safety is improved, but device complexity increases

Engineering Contradiction:
Improveinjury preventionVSAvoidsensor and control system components
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical interlocking safety systems with an optical sensing and electronic control system. Instead of using mechanical linkages and switches that would require physical contact and complex assembly, optical sensors use light fields to detect door position, and the controller uses electronic logic to manage safety, simplifying the overall system architecture.

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

Solution Approach 2:

The system automatically monitors door position and controls the hazardous components without requiring manual intervention from the operator. The sensors continuously detect door status and the controller automatically disables or enables the cutting blades and gears based on detected conditions, making the safety system self-regulating and reducing the need for complex manual safety procedures.

Inventive Principle:
Principle #25Self-service

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

The solution effectively prevents operator injuries by ensuring the machine is only operational when the door is in a safe position, reducing the risk of accidents related to reaching into the discharge chute or paper jams.

Implementation Method 1

One or more sensors, which may comprise optical flag sensors, are configured to detect the position of the door and each output a position signal

Methodology Applied
Scientific EffectOptical detection: Absorption (EM radiation)

Data Source

PatentEP2459367B1Dunnage discharge safety chute
Publication Date: 2013.07.17 SEALED AIR U S
  • EP2459367B1 patent drawingFigure 1
  • EP2459367B1 patent drawingFigure 2
  • EP2459367B1 patent drawingFigure 3

AI summary

A dunnage discharge chute includes features designed to prevent injury to an operator of a dunnage producing machine. The dunnage discharge chute includes at least one door with sensors that monitor the position of the door and output position signals. The position signals are received by a controller which outputs a control signal that disables operation of the dunnage producing machine based at least in part on a change in the position signals over a predetermined period of time. Additional sensors may detect whether the door is open beyond an upper open position, and a relay may disable operation of the dunnage producing machine immediately if the door is opened beyond the upper open position. Thus, if the operator reaches in through the door, the dunnage discharge chute will disable operation of the dunnage producing machine.