Robot Impact Protection with Guided Springs and Position Sensing

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Solution Overview

Problem

Existing impact protection safety devices for robots are not adequately manufacturable, compact, and robust, lacking a design that balances functionality with ease of production and stability under varying loads.

Innovation Solution

A shock protection safety device for robots featuring a first and second connecting part with guides of different types and compression springs, integrated with a position sensor and actuator-sensor box, allowing precise movement and detection of relative positioning, and utilizing 3D-printed components for enhanced stability and manufacturability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a buffer mechanism with sliding pins and pistons is used to absorb impact forces, then collision protection is improved, but the device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improvecollision protectionVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The buffer mechanism is divided into modular components: connecting parts with integrated guides, separate spring elements, and distinct sensor units. This segmentation allows each component to be optimized independently and simplifies assembly and manufacturing processes while maintaining the overall collision protection function.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The connecting parts are designed to perform multiple functions simultaneously: they provide structural connection, incorporate guide functions through integrated guides, support spring elements for shock absorption, and enable sensor mounting. This multi-functionality reduces the total number of separate components needed in the system.

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

2Manufacturing precision

If multiple guide elements and spring elements are integrated into connecting parts, then movement control precision is improved, but the volume and weight of the device increase

Engineering Contradiction:
Improvemovement control precisionVSAvoiddevice volume
Core Design Contradiction:
Manufacturing precisionVSVolume of moving object

Solution Approach 1:

Spring elements are positioned within or alongside the guide structures in the connecting parts, allowing the spring support function and guide function to occupy overlapping or adjacent spatial volumes. This nesting arrangement provides precise movement control through integrated guides while minimizing the overall device volume by eliminating wasted space between separate components.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Reliability

If compression springs are used to pre-tension connecting parts, then impact absorption is improved, but the device becomes less compact due to spring extension requirements

Engineering Contradiction:
Improveimpact absorptionVSAvoiddevice length
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

Spring elements are arranged in multiple spatial dimensions and orientations within the connecting parts rather than extending in a single linear direction. This multi-dimensional arrangement allows the springs to provide effective pre-tension and impact absorption while fitting within a more compact three-dimensional envelope, reducing the overall device length.

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

4Ease of manufacture

If 3D-printed components are used for connecting parts, then ease of manufacture is improved, but manufacturing precision may be compromised

Engineering Contradiction:
Improveease of manufactureVSAvoidmanufacturing precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The design of 3D-printed connecting parts incorporates specific geometric parameters and tolerances optimized for additive manufacturing processes. Features such as guide geometries, spring mounting interfaces, and sensor mounting provisions are designed with parameters that leverage the strengths of 3D printing while maintaining the required functional precision through careful parameter selection and post-processing considerations.

Inventive Principle:
Principle #35Parameter changes

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 device provides a compact, robust, and stable impact protection with precise movement control, ensuring effective response to collisions while maintaining ease of manufacturing and minimizing tilting moments, suitable for industrial robots.

Implementation Method 1

several spring elements, which are designed as compression springs and are stretched between the connecting parts

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

spring elements designed as compression springs... which in normal robot operation, a fixed geometric relationship exists between the connection parts

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 3

A position sensor is provided, which is integrated into an actuator-sensor box... The position sensor detects whether the second connecting part... has returned to its initial position

Methodology Applied
Scientific EffectPosition detection:

Implementation Method 4

spring elements designed as compression springs... When high impact forces act upon it, the second connection part can be displaced against spring force

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 5

shock protection safety device... provides a compact, robust, and stable impact protection

Methodology Applied
Scientific EffectShock absorption: Damping

Data Source

PatentEP4259389B1Impactprotection safety device for a robot
Publication Date: 2026.02.18 SCHAEFFLER TECHNOLOGIES AG & CO KG
  • EP4259389B1 patent drawingFigure 1~3

AI summary

An impact-protection safety device for a robot comprises a first connection part (2), which is intended to be connected to a robot arm, and a second connection part (3), which is intended to be connected to an actuator, wherein the connection parts (2, 3) cooperate with one another by means of guides (8, 9) of a first and second type, and a plurality of spring elements (11) in the form of compression springs are tensioned between the connection parts (2, 3). The different guides (8, 9) each comprise a plurality of pegs (14, 15) connected to the second connection part (3), wherein the pegs (14) to be assigned to the guide (8) of the first type each have a stop contour (18) that acts in the pull-out direction and engages behind a contour (19) of the first connection part (2), and the pegs (15) to be assigned to the guide (9) of the second type are each surrounded by one of the spring elements (11).