Double-Gripper Optical Workpiece Transfer for Faster Changeovers

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Solution Overview

Problem

Existing machining devices for optical workpieces, such as lenses, face challenges in achieving high throughput, high precision, and short changeover times while maintaining a simple or compact design.

Innovation Solution

A machining device with a milling station and a rotary station, featuring workpiece spindles facing each other, a tool changer positioned between them, and a double gripper that rotates and moves linearly for fast workpiece exchange, along with a minimal number of stacked motion axes and a compact design, allowing for efficient transfer and machining of the same side of the workpiece.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a tool changer is arranged between two workpiece spindles facing each other, then workpiece exchange time is reduced and throughput is increased, but the device complexity increases due to the need for precise positioning and pivoting mechanisms

Engineering Contradiction:
ImprovethroughputVSAvoiddevice complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The tool changer is positioned between two workpiece spindles that face each other, utilizing spatial arrangement in multiple dimensions to enable direct workpiece transfer. This dimensional optimization reduces transfer distance and time, improving throughput while managing complexity through clever spatial design

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

Solution Approach 2:

The tool changer employs a pivoting mechanism that allows dynamic repositioning between the two workpiece spindles. This dynamic capability enables rapid workpiece exchange by rotating the tool changer to align with either spindle, reducing changeover time while maintaining operational flexibility

Inventive Principle:
Principle #15Dynamics

2Loss of time

If a double gripper with rotating and linearly movable elements is used for workpiece transfer, then changeover time is reduced, but the ease of operation increases due to the complexity of controlling multiple motion axes

Engineering Contradiction:
Improvechangeover timeVSAvoidease of operation
Core Design Contradiction:
Loss of timeVSEase of operation

Solution Approach 1:

The double gripper is divided into separate functional elements: a rotating component for angular positioning and linearly movable components for radial adjustment. This segmentation allows each element to be controlled independently, reducing changeover time by enabling simultaneous multi-axis motion while simplifying control through modular actuation

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The double gripper elements are pre-positioned and pre-oriented during idle periods or between machining operations. The rotating and linearly movable components are advanced to anticipated positions, so that when workpiece transfer is required, the gripper is already optimally configured, minimizing actual changeover time

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If the minimum number of stacked motion axes is used in each station, then manufacturing precision is improved, but the adaptability of the machining device is reduced

Engineering Contradiction:
Improvemachining precisionVSAvoidadaptability
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

Each machining station is designed with a minimal number of stacked motion axes to maximize precision, while the tool changer provides multi-functionality by serving both workpiece transfer and tool change operations. The double gripper mechanism can perform multiple functions including gripping, rotating, and linear positioning, compensating for the reduced number of dedicated motion axes at each station

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

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 high throughput, high precision machining with short changeover times and a simple design by optimizing the arrangement of the tool changer and using a double gripper for rapid workpiece transfer between stations.

Implementation Method 1

The double gripper (31) has two gripping elements or suction cups (32), which point in the same direction and/or are held by a common carrier (33)

Methodology Applied
Scientific EffectSuction: Suction

Data Source

PatentEP4180177B1Machining device for optical workpieces
Publication Date: 2026.03.11 SCHNEIDER GMBH & CO KG
  • EP4180177B1 patent drawingFigure 1
  • EP4180177B1 patent drawingFigure 2
  • EP4180177B1 patent drawingFigure 3

AI summary

A machining device for optical workpieces and the use of a double gripper are proposed, wherein a swiveling changeover device with a double gripper is arranged between a milling station and a rotary station. This allows parallel machining in the milling station and the rotary station and minimizes the workpiece changeover time.