Robotic Tool Changer Coupling for Stable Compact Tool Exchange

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Solution Overview

Problem

Existing robotic tool changer systems face issues with limited freedom of movement, accidental tool dropping due to unstable grip, and require large space for tool changes, lacking effective locking mechanisms and precise alignment during tool exchange.

Innovation Solution

A robotic tool changer system with a first coupling unit and multiple second coupling units, utilizing a combination of acting forces to securely engage and disengage tools, including a first acting force, a second acting force, and a third force-applying member to maintain stability and alignment, employing magnetic or elastic forces for secure tool holding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a tool locking arm rotates on a plane with an elastic force-applying member, then the tool can be engaged or disengaged horizontally, but the freedom of movement of the tool locking arm is relatively low

Engineering Contradiction:
Improvefreedom of movementVSAvoidmovement constraint
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent transforms the static plane rotation into dynamic three-dimensional movement. The coupling unit can move not only horizontally but also vertically and angularly, allowing the tool locking arm to adapt its movement path dynamically. This dynamic capability increases freedom of movement while maintaining controlled engagement through the elastic force-applying member.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention adds vertical and angular dimensions to the traditional horizontal plane rotation. The coupling unit can now move in multiple spatial dimensions, transforming a two-dimensional rotation problem into a three-dimensional engagement process. This dimensional expansion resolves the movement constraint while preserving the elastic engagement mechanism.

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

2Productivity

If the robot arm moves the coupling unit horizontally to couple with or decouple from the tool change gripper, then the tool change can be performed, but a larger space is required for the tool change

Engineering Contradiction:
Improvetool change capabilityVSAvoidspace required
Core Design Contradiction:
ProductivityVSArea of stationary object

Solution Approach 1:

The patent utilizes vertical movement and angular adjustment in addition to horizontal movement. By engaging the coupling unit from above or at an angle rather than purely horizontally, the system performs tool changes in a compact three-dimensional space, reducing the horizontal area required while maintaining full tool change functionality.

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

Solution Approach 2:

The coupling unit is designed to nest within or closely approach the tool change gripper structure. The compact design allows the coupling unit to be positioned within the vertical and angular envelope of the gripper, minimizing the external space required for the tool change operation while maintaining effective coupling capability.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Reliability

If no additional force acts on the second tool changer part during entry or exit, then the structure remains simple, but the second tool changer part may accidentally drop due to vibration or unstable grip

Engineering Contradiction:
Improvetool holding stabilityVSAvoidforce-applying mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The elastic force-applying member is pre-loaded to provide continuous engagement force on the coupling unit throughout the tool change process. This preliminary action ensures that the tool changer part remains securely held during entry, exit, and intermediate positions, preventing accidental drops due to vibration or unstable grip without requiring complex active force control mechanisms.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The elastic force-applying member automatically adjusts and maintains engagement force through its inherent elastic properties. The system uses the elastic deformation and recovery of the member to self-regulate the holding force, providing reliable tool retention without requiring external active control or complex mechanical force-applying mechanisms.

Inventive Principle:
Principle #25Self-service

4Manufacturing precision

If the protruding portion and recess are used for coupling, then precise alignment can be achieved, but the coupling unit requires stable positioning during the tool change process

Engineering Contradiction:
Improvealignment precisionVSAvoidpositioning stability
Core Design Contradiction:
Manufacturing precisionVSStability of the object's composition

Solution Approach 1:

The coupling unit incorporates localized positioning features such as guide surfaces, alignment pins, or tapered interfaces at specific locations to ensure precise alignment of the protruding portion and recess. These localized quality enhancements provide stable positioning during tool change while maintaining overall structural simplicity and not requiring the entire coupling unit to be precisely positioned.

Inventive Principle:
Principle #3Local quality

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

Ensures precise and stable tool changes by preventing accidental dropping and reducing the space required, with improved alignment and secure tool engagement through interactive forces.

Implementation Method 1

The first force-applying member is configured to apply the first acting force to the first ejector pin. The first acting force, the second acting force and the third acting force are an elastic force or a magnetic force.

Methodology Applied
Scientific EffectElastic force: Elasticity

Implementation Method 2

The first force-applying member is configured to apply the first acting force to the first ejector pin. The first acting force, the second acting force and the third acting force are an elastic force or a magnetic force.

Methodology Applied
Scientific EffectMagnetic force: Magnetism

Implementation Method 3

The second force-applying member is configured to apply the second acting force to drive the guide lock. The first acting force, the second acting force and the third acting force are an elastic force or a magnetic force.

Methodology Applied
Scientific EffectElastic force: Elasticity

Implementation Method 4

The second force-applying member is configured to apply the second acting force to drive the guide lock. The first acting force, the second acting force and the third acting force are an elastic force or a magnetic force.

Methodology Applied
Scientific EffectMagnetic force: Magnetism

Implementation Method 5

The third force-applying member is configured to apply the third acting force to hold the second coupling unit. The first acting force, the second acting force and the third acting force are an elastic force or a magnetic force.

Methodology Applied
Scientific EffectElastic force: Elasticity

Implementation Method 6

The third force-applying member is configured to apply the third acting force to hold the second coupling unit. The first acting force, the second acting force and the third acting force are an elastic force or a magnetic force.

Methodology Applied
Scientific EffectMagnetic force: Magnetism

Data Source

PatentEP4190515B1Robotic tool changer system and method for performing tool change with robotic tool changer system
Publication Date: 2025.07.23 CHIEFTECH PRECISION
  • EP4190515B1 patent drawingFigure 1
  • EP4190515B1 patent drawingFigure 2
  • EP4190515B1 patent drawingFigure 2A

AI summary

A robotic tool changer system and a method for performing a tool change with the robotic tool changer system are disclosed. Providing a plurality of second coupling units (3, 3A, 3B, 3C) each connected with a tool, wherein the second coupling units (3, 3A, 3B, 3C) are detachably connected to a respective tool changer grippers (2, 2B); driving a first coupling unit (1, 1A, 1B, 1C) along a second direction (D2) with a robot arm end shaft (A) to be coupled with a selected second coupling unit (3, 3A, 3B, 3C); driving the first coupling unit (1, 1A, 1B, 1C) coupled with the selected second coupling unit (3, 3A, 3B, 3C) away from the corresponding tool changer gripper (2, 2B) in a first direction (D1), defining an angle between the first direction (D1) and the second direction (D2); wherein when the selected second coupling unit (3, 3A, 3B, 3C) is moved to the corresponding tool changer gripper (2, 2B) and before the first coupling unit (1, 1A, 1B, 1C) to separate from the selected second coupling unit (3, 3A, 3B, 3C), a third acting force (F3) is applied to the selected second coupling unit (3, 3A, 3B, 3C) for restricting movement.