Oscillating Tool Sanding Disc With Gradient Support

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Solution Overview

Problem

Existing sanding pads for oscillating power tools face challenges in maintaining efficient large-area sanding while preventing abrasive burning, especially in corner areas where increased pressure leads to heat generation and adhesion issues.

Innovation Solution

A sanding disc design featuring a carrier element made of flexible material with a support element that provides varying degrees of stiffness, allowing for efficient core area sanding while maintaining flexibility at the edges, using a ratio of radii between the carrier and support elements to optimize contact pressure and heat management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the sanding pad is stiffened to maintain constant contact with the material being removed, then large-area sanding efficiency is improved, but corner maneuverability deteriorates and abrasive burning occurs due to increased pressure

Engineering Contradiction:
Improvelarge-area sanding efficiencyVSAvoidcorner maneuverability
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The support element is designed with non-uniform thickness, being thicker in the central core area and thinner toward the periphery. This creates a gradient structure where the central area provides stiffness for efficient large-area sanding, while the peripheral areas remain flexible for corner maneuverability, resolving the contradiction between productivity and ease of operation

Inventive Principle:
Principle #3Local quality

2Ease of operation

If increased contact pressure is applied in corner areas to maintain sanding contact, then corner sanding capability is improved, but heat generation increases causing abrasive adhesion

Engineering Contradiction:
Improvecorner sanding capabilityVSAvoidheat generation
Core Design Contradiction:
Ease of operationVSTemperature

Solution Approach 1:

The varying thickness of the support element creates localized flexibility at the periphery, allowing the corners to conform to workpiece geometry without requiring excessive contact pressure. This reduces friction and heat generation in corner areas while maintaining adequate sanding contact

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The flexible peripheral areas of the support element act as a cushion that absorbs excess pressure before it reaches the abrasive. This preemptive pressure distribution prevents the conditions that lead to abrasive burning and adhesion before they occur

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 effective large-area sanding with good corner mobility, reducing heat generation and abrasive adhesion, thus extending the usable life of the sanding pad.

Implementation Method 1

The mounting element is designed to provide a rotationally fixed connection between the grinding disc and the drive shaft

Methodology Applied
Scientific EffectPositive engagement: Mechanical Fastener

Implementation Method 2

The support element is made of a flexible material for attaching an abrasive to the grinding disc

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 3

a rotary oscillation drive, which sets a tool shaft of the grinding tool into a rotary oscillation motion

Methodology Applied
Scientific EffectOscillating motion: Harmonic Oscillator

Data Source

PatentEP3135432B1Grind plate for a hand-held electric tool, and electric tool system
Publication Date: 2019.12.11 ROBERT BOSCH GMBH
  • EP3135432B1 patent drawingFigure 1~2
  • EP3135432B1 patent drawingFigure 3~4
  • EP3135432B1 patent drawingFigure 5~6

AI summary

The invention relates to a grinding disc (10) for a hand-held power tool (100), in particular for a grinding device with an oscillating drive shaft (110), comprising a receiving element (12) for attaching the grinding disc (10) to a drive shaft (110) of the power tool, wherein the receiving element (12) is designed to provide a rotationally fixed connection between the grinding disc and the drive shaft (110), and a support element (14) made of at least one flexible material (16). It is proposed that the support element (14) be at least partially supported by a support element (22) connected to the receiving element (12), wherein the ratio (R) of the radii of a circumcircle (24) circumscribing the support element (14) to at least one circumcircle (26) circumscribing the support element (26) is in the range of 1.3 to 2, in particular in the range of 1.4 to 1.5.Furthermore, the invention relates to an electric tool system (210) comprising at least one electric tool (110), in particular a grinding device with an oscillating drive shaft, and such a grinding disc (10).