Adjustable Light Barrier for Bending Machine Working Gap Safety

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Solution Overview

Problem

Existing protective devices for bending machines do not provide an adequate level of safety to prevent operator injury from the risk of being squeezed in the working gap during the forming process.

Innovation Solution

A protective device that includes a radiation source and a receiver, along with a safety-style light barrier control, to secure a variable working gap by providing a bundle of radiation that interrupts the work movement if an operator's hand or fingers are detected in the gap.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a light barrier is positioned between the upper tool and lower tool to detect operator intrusion, then safety detection capability is improved, but the working gap cannot be fully utilized and machine productivity deteriorates

Engineering Contradiction:
Improvesafety detection capabilityVSAvoidmachine productivity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The light barrier is made dynamically adjustable in position along the movement path of the upper tool. The control device automatically adjusts the light barrier's position to maintain an optimal safety distance from the lower tool, allowing the safety monitoring zone to adapt as the upper tool approaches or retreats, thus maximizing both safety coverage and working gap utilization

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

A control device receives position signals from the upper tool's drive mechanism and automatically adjusts the light barrier's position accordingly. This feedback loop ensures the light barrier maintains a predetermined safety distance from the lower tool while tracking the upper tool's movement, enabling continuous safety monitoring without fixed positional constraints

Inventive Principle:
Principle #23Feedback

2Reliability

If the light barrier is positioned close to the lower tool to maximize safety coverage, then safety monitoring effectiveness is improved, but the working gap is reduced and productivity deteriorates

Engineering Contradiction:
Improvesafety monitoring effectivenessVSAvoidworking gap size
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The light barrier's position is dynamically adjusted based on the upper tool's real-time position. When the upper tool is retracted, the light barrier moves closer to the lower tool to maximize safety coverage. When the upper tool approaches, the light barrier automatically retreats to maintain the predetermined safety distance, preserving the working gap size and enabling full productivity

Inventive Principle:
Principle #15Dynamics

3Device complexity

If a fixed light barrier position is used to simplify device structure, then device complexity is reduced, but the ability to adapt to different working conditions deteriorates

Engineering Contradiction:
Improvedevice structure simplicityVSAvoidadaptability to working conditions
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The control device automatically manages the light barrier's position adjustment without requiring manual intervention. The system self-adjusts based on position signals from the upper tool's drive mechanism, maintaining optimal safety distance automatically. This self-service capability provides adaptability to different working conditions while keeping the control mechanism relatively simple

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 interrupts the work movement when an operator's hand or fingers are detected in the working gap, thereby preventing injury and ensuring a higher level of safety during the bending process.

Implementation Method 1

a radiation source (52) which is designed to provide a beam of radiation (56) into the working gap (15)

Methodology Applied
Scientific EffectLight emission: Light

Implementation Method 2

a radiation receiver (54) which is arranged opposite the radiation source (52) and which is designed to receive beams (56) from the radiation beam (56)

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentEP4541471A1Protective device, bending machine and method for operating a bending machine
Publication Date: 2025.04.23 FIESSLER ELEKTRONIK GMBH & CO KG
  • EP4541471A1 patent drawingFigure 1
  • EP4541471A1 patent drawingFigure 2
  • EP4541471A1 patent drawing

AI summary

The invention relates to a protective device (51) for safeguarding a working gap (14) of a forming device (1), comprising a radiation source (52) for providing a beam of radiation (56) into the working gap (14) and a radiation receiver (54) arranged opposite the radiation source (52) for receiving beams from the beam of radiation (56), as well as a safety-oriented light barrier control (71) for redundant processing of sensor signals from the radiation receiver (54), an adjustment device (28) for mounting on a machine frame or on an upper tool (21) of a forming device (1) and for providing linear movement for the radiation source (52) and the radiation receiver (54), wherein the adjustment device (28) comprises a drive (26, 27) and a safety-oriented displacement measuring system (58, 59, 60) with a displacement sensor and a control arrangement for the displacement sensor.as well as with a safety-oriented adjustment control (83) which is connected to the adjustment device (28) for an evaluation of sensor signals from the displacement sensor and signals from the control arrangement and for a controlled control of the drive (26, 27).