Bag Gripper Excess Movement for Misaligned Sack Alignment

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Solution Overview

Problem

Existing devices for aligning and gripping valve sacks often fail to ensure optimal contact with positioning stops due to misalignment or angled side edges, leading to faulty gripping and transfer issues.

Innovation Solution

A device with a movable gripper and positioning stop system that allows for a predetermined excess movement to ensure the gripper can grip the sack even when the side edge is not directly aligned, using a controller and position sensor to adjust the excess based on detected distances, and optionally employing a light barrier device for precise positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a positioning stop is used to position the side edge of the sack, then the sack alignment is improved, but faulty gripping occurs when the side edge is not in direct contact with the positioning stop

Engineering Contradiction:
Improvesack alignment precisionVSAvoidgripping reliability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The gripper is moved by a predetermined excess beyond the positioning stop before gripping the sack. This preliminary movement ensures that even if the sack side edge is not perfectly aligned with the positioning stop, the gripper will still make contact with the sack edge and achieve reliable gripping.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

A position sensor detects the actual position of the sack side edge relative to the positioning stop, and a controller adjusts the excess movement of the gripper accordingly. This feedback mechanism ensures optimal gripping by adapting the gripper position to the actual sack alignment status.

Inventive Principle:
Principle #23Feedback

2Device complexity

If the gripper is positioned exactly at the positioning stop, then the device complexity is reduced, but the gripping accuracy deteriorates when sack alignment varies

Engineering Contradiction:
Improvegripper positioning system complexityVSAvoidgripping accuracy
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

Instead of positioning the gripper exactly at the positioning stop, the system preliminarily moves the gripper by a predetermined excess beyond the positioning stop. This simple adjustment maintains device complexity while significantly improving gripping accuracy for misaligned sacks.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The gripper performs an excessive movement beyond what would be theoretically needed (positioning stop location) to ensure contact with the sack edge. This excessive action compensates for alignment variations without requiring complex adaptive mechanisms.

Inventive Principle:
Principle #16Partial or excessive action

3Reliability

If a predetermined excess movement is applied to the gripper, then gripping reliability is improved, but the device complexity increases due to controller and position sensor requirements

Engineering Contradiction:
Improvegripping reliabilityVSAvoidcontrol system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system uses a predetermined excess movement value that can be set in advance without requiring complex real-time calculations. This approach maintains gripping reliability while minimizing control system complexity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The position sensor and controller work together to automatically adjust the excess movement based on actual sack position, making the system self-adjusting without requiring external intervention or complex programming.

Inventive Principle:
Principle #25Self-service

4Reliability

If the excess is set to a large value to compensate for misalignment, then gripping reliability is improved, but the positioning precision deteriorates due to excessive movement

Engineering Contradiction:
Improvegripping reliabilityVSAvoidsack positioning precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The system applies just enough excessive movement to ensure reliable gripping without over-compensating. The predetermined excess is optimized to be sufficient for alignment variations but not so large as to compromise positioning precision.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The position sensor provides feedback on the actual sack position, allowing the controller to adjust the excess movement dynamically. This ensures that the excess is only as large as needed to compensate for actual misalignment, maintaining positioning precision while ensuring gripping reliability.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3088310B1Apparatus and method for aligning and gripping of a bag
Publication Date: 2017.12.13 BEUMER GROUP GMBH & CO KG
  • EP3088310B1 patent drawingFigure 1
  • EP3088310B1 patent drawingFigure 2~3
  • EP3088310B1 patent drawingFigure 4~5

AI summary

Device for aligning and gripping a sack (12), comprising a positioning stop (28) for positioning a side edge of the sack, a movable gripper for gripping the side edge of the sack adjacent to the positioning stop while it is in a provision position, wherein the gripper has a gripper stop (34) and is movable for gripping the sack from a starting position in which the gripper stop is located behind the positioning stop (28) as seen from the provision position, to a gripping position in which the gripper stop (34) is located in front of the positioning stop by a predetermined excess (a) as seen from the provision position, and method.