Sensor-Integrated Gripper for Reliable Thin-Walled Object Inspection

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Solution Overview

Problem

Existing grippers used in the production of identification, valuable, or security documents lack process reliability, necessitating improved methods to ensure flawless operation and early detection of errors during production.

Innovation Solution

A gripper equipped with a sensor system that integrates a transmitter and receiver to emit and detect electromagnetic or sound waves, allowing for the presence and properties of objects to be determined before, during, or after gripping, with features like anti-slip layers and light guides to enhance precision and protection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional grippers are used without integrated sensors, then the device complexity is low, but the process reliability deteriorates due to inability to detect objects and errors early

Engineering Contradiction:
Improveprocess reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the gripping function with sensor detection functions by integrating transmitters, receivers, and evaluation units directly into the gripper structure. This merging allows the gripper to simultaneously perform mechanical gripping and optical/acoustic detection, enabling early error detection and improved process reliability without requiring separate external sensing systems

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The gripper is designed as a multi-functional device that can both mechanically grip objects and perform non-contact detection using electromagnetic or sound waves. The same gripper structure serves dual purposes: mechanical manipulation and quality inspection, reducing the need for additional separate devices and improving overall process reliability

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If sensors are integrated into gripper fingers, then measurement precision improves for detecting object presence and properties, but the device complexity increases

Engineering Contradiction:
Improvemeasurement precisionVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical sensing mechanisms with non-contact electromagnetic or acoustic wave-based detection systems. Instead of using mechanical contacts or complex mechanical sensors, the gripper uses transmitters and receivers that emit and detect waves, providing precise measurement of object presence and properties through optical or acoustic properties

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

Solution Approach 2:

The patent introduces electromagnetic waves or sound waves as intermediaries between the gripper and the object being detected. These waves serve as mediators that carry information about the object's presence, position, and properties back to the receiver, enabling precise measurement without direct mechanical contact or complex sensor integration

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If the transmitter is arranged on the gripping surface side, then the detection precision improves, but the transmitter is more susceptible to pressure stress and contamination

Engineering Contradiction:
Improvedetection precisionVSAvoidpressure stress and contamination
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent positions the transmitter on the gripping surface side (one dimension) while arranging the receiver on the opposite side or at a different location (another dimension). This spatial separation in different dimensions allows the transmitter to maintain close proximity to the object for precise detection while the receiver is positioned to avoid direct pressure stress and contamination, with wave guidance structures bridging the spatial gap

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

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 gripper provides enhanced process reliability by accurately detecting and inspecting objects, ensuring defect-free gripping and positioning, thereby improving production quality and efficiency.

Implementation Method 1

The first gripper finger (302) comprises a transmitter (310) for emitting electromagnetic waves or sound waves into a space (308) spanned by the two gripper fingers (302, 304). A receiver (312) is also assigned to the first gripper finger (302) or the second gripper finger (304), which is configured to detect at least some of the waves emitted by the transmitter (310).

Methodology Applied
Scientific EffectElectromagnetic wave emission and detection: Electromagnetic Induction

Implementation Method 2

The first gripper finger (302) comprises a transmitter (310) for emitting electromagnetic waves or sound waves into a space (308) spanned by the two gripper fingers (302, 304)

Methodology Applied
Scientific EffectSound wave propagation: Sound

Implementation Method 3

The passage (314) is filled with a material or gas to facilitate sound transmission. When emitting electromagnetic waves, this passage may also be empty of air (gas), so that electromagnetic waves can still be conducted to the intermediate space (308). It has proven advantageous if the passage is irradiated with a uniform intensity, conclusions can be drawn about the position of the object or material between the gripper fingers.

Methodology Applied
Scientific EffectLight guidance through optical material: Optical Fibre

Data Source

PatentEP4074476B1Gripper and method for gripping and testing an item
Publication Date: 2025.08.06 BUNDESDRUCKEREI GMBH
  • EP4074476B1 patent drawingFigure 1~2b
  • EP4074476B1 patent drawingFigure 2c~2f
  • EP4074476B1 patent drawingFigure 3

AI summary

The invention relates to a gripper (300), in particular for use in the manufacture of identification, valuable or security documents (100), comprising a first gripper finger (302) and a second gripper finger (304) which are arranged to grasp an object (120), in particular a thin-walled object, with their gripping surfaces (306), which is placed in a space (308) opened by the two gripper fingers (302, 304), for which purpose at least one of the two gripper fingers (302, 304) is mounted adjustably relative to the other of the two gripper fingers (302, 304). The first gripper finger (302) comprises a transmitter (310) for emitting electromagnetic waves or sound waves into the space (308), and the first gripper finger (302) or the second gripper finger (304) comprises a receiver (312) configured to detect at least some of the waves emitted by the transmitter (310).The invention also relates to a method for gripping and inspecting an object (120) with such a gripper (300).