Angle Grinder Protective Element With Tool-Free Leaf Spring Clamping

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Solution Overview

Problem

Existing protective elements for angle grinders are mechanically sensitive and complex to manufacture, and they do not meet the requirements for reliable, tool-free attachment and adequate protection during both grinding and cutting operations.

Innovation Solution

A protective element with a leaf spring tensioned between a fastening element and a receiving device, allowing for a simple, reliable, and robust connection to the protective hood without tools, ensuring adequate protection during both grinding and cutting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a clamping element designed as a spring element is used to hold the cover element to the protective hood, then the cover element can be attached without tools, but the arrangement becomes mechanically sensitive and complex to manufacture

Engineering Contradiction:
Improvetool-free attachmentVSAvoidmechanical complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The fastening system is divided into separate functional components: a fastening element with opening attached to the protective hood, and a clamping element with receiving device attached to the cover element. This segmentation allows each component to be optimized independently and simplifies manufacturing while maintaining tool-free attachment capability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of having the spring element directly hold the cover element, the invention inverts the approach by having the fastening element with opening serve as the active component on the protective hood, while the clamping element on the cover element passively engages with it. This inversion simplifies the overall mechanical arrangement

Inventive Principle:
Principle #13The other way round (Inversion)

2Adaptability or versatility

If the protective element is designed to be reversibly connectable to the protective hood, then it can be easily switched between grinding and cutting functions, but the connection may lack reliability and robustness

Engineering Contradiction:
Improvefunction switching capabilityVSAvoidconnection reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The fastening system incorporates a leaf spring that provides dynamic, elastic engagement between the cover element and protective hood. The spring allows for reversible connection while maintaining constant contact force, ensuring both ease of switching and reliable connection throughout the product lifecycle

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The leaf spring's elastic properties enable the connection to accommodate parameter changes such as thermal expansion, vibration, and wear over time. The spring adjusts its deflection to maintain optimal engagement force, ensuring reliable connection while allowing easy removal and reattachment

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 solution provides a secure, reversible, and durable protective element that meets the IEC 62841-2-3 standard, ensuring effective protection from sparks and particles during cutting and grinding without requiring tools for attachment.

Implementation Method 1

a leaf spring (40), wherein the leaf spring (40) is arranged in the receiving device (21) and is tensioned in a mounting position of the protective element (100) on the protective hood (30)

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4596175A1Protective element for an electric machine tool
Publication Date: 2025.08.06 C & E FEIN GMBH & CO KG
  • EP4596175A1 patent drawingFigure 1a~1b
  • EP4596175A1 patent drawingFigure 2~3
  • EP4596175A1 patent drawingFigure 4~6a

AI summary

The invention relates to a protective element, in particular a cover, for the protective hood of a disc-shaped tool of a power tool, in particular an angle grinder, comprising a protective element body that is reversibly fastened to the protective hood in an assembled position by clamping the protective hood between fastening elements and a leaf spring of the protective element body. The invention also relates to a manufacturing method for the protective element and a power tool with this protective element.