Rotary Tool Grip Switching Lever for Seamless Mode Selection

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Solution Overview

Problem

Existing rotary tools require users to release their grip to operate mode switches with the non-grip hand, causing interruptions in work.

Innovation Solution

A rotary tool design featuring a switching lever around the grip that allows mode switching by thumb or index finger while holding the grip, with a neutral state preventing trigger pull beyond a predetermined position to avoid motor activation during mode changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a mode switch is provided on a circuit board in a lower portion of a body grip, then the rotation mode can be selected depending on the kind of screw or member to be screwed, but the switch cannot be operated by a hand holding the grip, requiring another hand which interrupts work

Engineering Contradiction:
Improverotation mode selectionVSAvoidswitch operation convenience
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The mode switch is repositioned from the lower portion of the body grip to the grip portion, specifically arranged alongside the trigger. This spatial relocation allows the operator to access the mode switch with the thumb or index finger of the same hand holding the grip, eliminating the need to use the other hand and thus resolving the contradiction between mode selection capability and operational convenience

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

2Adaptability or versatility

If the switch is operated with the non-grip hand, then mode switching is possible, but the user must release the holding member, causing interruption of work

Engineering Contradiction:
Improvemode switching capabilityVSAvoidwork continuity
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The mode switch is relocated to the grip portion where it is accessible to the thumb or index finger of the hand holding the grip. This allows mode switching to be performed without releasing the holding member, maintaining continuous control and eliminating work interruptions, thus resolving the contradiction between mode switching capability and work continuity

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

3Ease of operation

If the trigger can be pulled freely during mode switching, then operation is simple, but the motor may activate unintentionally during mode changes

Engineering Contradiction:
Improvetrigger operation simplicityVSAvoidunintentional motor activation prevention
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

A trigger lock mechanism is introduced that automatically locks the trigger in a predetermined state during mode switching. This preliminary protective action prevents unintentional motor activation by restricting trigger movement at the critical moment when mode changes occur, while still allowing simple trigger operation during normal use when the lock is disengaged

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The trigger lock acts as an intermediary mechanism between the trigger and the motor activation system. During mode switching, the trigger lock mediates by physically preventing the trigger from being pulled, thereby blocking the signal path that would otherwise cause unintentional motor activation, while maintaining the simplicity of trigger operation during normal drilling or driving tasks

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP2589465B1Rotary tool
Publication Date: 2018.06.20 MAX CO LTD
  • EP2589465B1 patent drawingFigure 1
  • EP2589465B1 patent drawingFigure 2
  • EP2589465B1 patent drawingFigure 3

AI summary

A rotary tool (10) having a plurality of switchable modes is provide with a trigger (19) and a switching lever (20) disposed around a grip (13) for selecting a rotational direction of a motor (31). The switching lever (20) is operated between a forward rotation state, a reverse rotation state, and a neutral state. A switching of the modes is executed when the switching lever (20) is positioned in the neutral state and the trigger (19) is pulled.