Gripper Piston Pressure Staging for Irregular Surface Handling

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Solution Overview

Problem

Existing gripping devices struggle with robustness and flexibility, particularly when handling objects with irregular surfaces and shapes, and there is a need for reliable gripping and sealing.

Innovation Solution

A gripping device with adjustable pistons that transition between retracted and extended configurations using compressed air, employing a preset pressure followed by a main pressure to facilitate gentle contact and secure gripping, especially with suction grippers, and incorporating a pressure adjustment system for precise control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If the piston is extended using compressed air to grip the object, then the gripping force is improved, but the risk of damage to the gripper and/or object increases

Engineering Contradiction:
Improvegripping forceVSAvoiddamage risk
Core Design Contradiction:
ForceVSObject-affected harmful factors

Solution Approach 1:

The patent applies beforehand cushioning by introducing a compliant element (such as a spring or elastomer) between the piston and the gripper finger. This compliant element absorbs excess force and prevents direct transmission of high compression forces to the gripper and object, thereby reducing damage risk while maintaining effective gripping force.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The patent changes the mechanical parameter of the piston system by transitioning from a rigid direct-drive mechanism to a compliant mechanism with adjustable stiffness. This allows the system to adapt the force transmission characteristics, enabling gentle contact during approach while maintaining firm grip during handling.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If the piston is made rigid to ensure precise positioning, then the positioning precision is improved, but the ability to compensate for surface irregularities is reduced

Engineering Contradiction:
Improvepositioning precisionVSAvoidsurface irregularity compensation
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent applies local quality by making only the contact region of the gripper compliant while keeping the positioning mechanism rigid. The compliant element is localized at the gripper finger tip, allowing surface adaptation, while the piston and positioning system remain rigid for precision.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The compliant element is pre-installed in the force transmission path to provide automatic adaptation to surface irregularities before contact is made, enabling the rigid positioning system to work effectively on uneven surfaces.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Reliability

If high compression forces are applied to the piston for secure gripping, then the gripping reliability is improved, but the risk of exceeding maximum allowable forces increases

Engineering Contradiction:
Improvegripping reliabilityVSAvoidmaximum allowable force
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The compliant element acts as a mechanical fuse or overload protector, limiting the maximum force transmitted to the gripper and object. Even when high compression forces are applied to the piston for secure gripping, the compliant element prevents exceeding the maximum allowable force of the gripper components.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The compliant element serves as an intermediary between the piston and gripper, mediating the force transmission. It allows high forces to be applied to the piston while automatically limiting the force transmitted to the gripper, thereby protecting against overload.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Stability of the object's composition

If the gripper is designed for firm contact to ensure stable handling, then the handling stability is improved, but the gentle contact requirement is compromised

Engineering Contradiction:
Improvehandling stabilityVSAvoidcontact gentleness
Core Design Contradiction:
Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The compliant element provides beforehand cushioning that enables gentle contact during approach and placement, while the rigid piston positioning system ensures stable handling once the object is gripped. The compliant element automatically adjusts to provide firm contact when needed.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 reliable and precise handling of objects with irregular surfaces by minimizing damage and ensuring secure sealing, with the ability to adapt to surface irregularities through controlled pressure transitions.

Implementation Method 1

The piston is pressurized with compressed air at an extension pressure, in particular from the retracted configuration to the extended configuration

Methodology Applied
Scientific EffectCompressed air pressure: Pressure Increase

Implementation Method 2

the piston is pressurized with compressed air at a preset pressure upon contact and, after contact

Methodology Applied
Scientific EffectCompressed air pressure: Pressure Increase

Implementation Method 3

after placement, particularly after gripping, is pressurized with compressed air at a main pressure, wherein the preset pressure is lower than the main pressure

Methodology Applied
Scientific EffectCompressed air pressure: Pressure Increase

Data Source

PatentEP4644053B1Method for handling an object by means of a gripping device and handling device for carrying out the method
Publication Date: 2026.05.13 J SCHMALZ GMBH
  • EP4644053B1 patent drawingFigure 1
  • EP4644053B1 patent drawingFigure 2A~2B
  • EP4644053B1 patent drawingFigure 3

AI summary

The invention relates to a method for handling an object (88) by means of a gripping device (10), comprising a gripper base body (12) and at least one gripping unit (14) held on the gripper base body, comprising a retracting piston (16) which is adjustable relative to the gripper base body in an extension direction (22) and in a retraction direction (24) opposite to the extension direction, wherein the retracting piston can be extended in the extension direction by pressurizing it with compressed air, the method comprising pressurizing the retracting piston with an extension pressure so that the retracting piston is extended in the extension direction, placing the gripper on the object to be gripped, and gripping the object with the gripper, wherein the retracting piston is pressurized with a presetting pressure when the gripper is placed on the surface and is pressurized with a main pressure after placement, in particular after gripping, wherein the presetting pressure is lower than the main pressure.The invention also relates to a handling device for carrying out such a method.