Rotatable Power Tool Switch Layout for Slim Dust-Resistant Handles

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Solution Overview

Problem

Conventional power tools face challenges with limited space in the handle for switching devices, leading to ergonomic and safety issues, especially for users with small hands, and are sensitive to dust due to linear movement actuation.

Innovation Solution

A switching system with a rotatable switching element and guide elements connected via a spacer, positioned inside the power tool's housing, reducing dust sensitivity and allowing a slim, ergonomic handle design with a lock mechanism preventing unintentional actuation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the switching device is installed within the handle area of the power tool, then the switching function is integrated, but the available space is limited resulting in a large gripping distance

Engineering Contradiction:
Improvegripping distanceVSAvoidhandle area
Core Design Contradiction:
Ease of operationVSArea of stationary object

Solution Approach 1:

The switching element is moved from the traditional linear position within the handle to a rotatable arrangement where the switching element can be positioned at different angular positions around the handle axis. This dimensional change from linear to rotational space allows the switching device to be integrated without increasing the linear gripping distance, as the switching action occurs in the angular dimension rather than extending the handle length.

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

2Reliability

If the switching device uses linear movement for actuation, then the switching function is simple, but the device is sensitive to dust

Engineering Contradiction:
Improvedust sensitivityVSAvoidswitching mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Instead of using linear movement to actuate the switching device, the patent inverts the approach by using rotational movement of the handle assembly to actuate the switching element. The switching element rotates together with the handle, and the switching action is triggered by the angular position rather than linear displacement. This inversion from linear to rotational actuation reduces dust sensitivity as rotational seals and contacts are less prone to dust contamination.

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

3Ease of operation

If the switching element is movably arranged in the handle, then the switching function is integrated, but space for electrical components is reduced

Engineering Contradiction:
Improvehandle ergonomicsVSAvoidhandle interior space
Core Design Contradiction:
Ease of operationVSVolume of stationary object

Solution Approach 1:

The patent extracts the switching device from the handle interior and positions it in the housing, separating the switching function from the handle structure. The switching element remains integrated in the handle for ergonomic actuation, but the actual switching mechanism is relocated to the housing where electrical components have more space. This extraction resolves the space conflict by distributing components to their optimal locations.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP3808509B1Electric tool with a switching device
Publication Date: 2024.06.19 HILTI AG
  • EP3808509B1 patent drawingFigure 1
  • EP3808509B1 patent drawingFigure 2
  • EP3808509B1 patent drawingFigure 3

AI summary

The present invention relates to a switching system for a power tool, wherein the switching system comprises a switching element (1) as an actuating element, wherein the switching element (1) is movably arranged in a handle (2) of the power tool, wherein the switching system comprises a first guide element (3) and a second guide element (4), wherein the guide elements (3, 4) are connected to each other via a spacer element (5), wherein the guide elements (3, 4) are rotatably mounted in the handle (2) of the power tool, and wherein the guide elements (3, 4) are connected to the switching element (1), wherein the switching element (1) is connected to a connecting element (7) via a first connecting means (6), such that the connecting element (7) actuates a switching device (8) when the switching element (1) is actuated, wherein the switching device (8) is arrangable in a housing (9) of the power tool