Handheld Power Tool Gearbox Fixing Device

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Hand-held power tools experience instability due to unintentional shifting of locking devices in their transmission systems, leading to unpredictable torque transmission and direction changes.

Innovation Solution

A fixing device is introduced to securely lock the locking devices in their respective switching positions, preventing unintentional shifts and ensuring stable operation by using mechanisms like latching devices, clamping devices, magnet arrangements, or spring-loaded elements to maintain the blocking direction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If locking devices are made switchable to change blocking direction, then adaptability is improved, but stability deteriorates due to unintentional shifting

Engineering Contradiction:
Improveswitching capabilityVSAvoidlocking position stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The fixing device is activated before the locking device can unintentionally shift, preventing the instability from occurring. The fixing mechanism engages in advance to secure the locking device in its current position, ensuring that any subsequent movements or vibrations cannot cause unintended switching of the blocking direction.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The fixing device acts as an intermediary between the locking device and the external environment, isolating the locking device from forces that could cause unintentional shifting. This intermediate fixing mechanism ensures that the locking device remains stable while still allowing controlled switching when needed.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stability of the object's composition

If fixing device is added to prevent unintentional shifting, then stability is improved, but device complexity increases

Engineering Contradiction:
Improvelocking position stabilityVSAvoidtransmission structure complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The fixing device is merged with the existing locking device structure, sharing common components such as the housing, actuating mechanism, and mounting points. This integration ensures that the fixing function is added without requiring a completely separate system, thereby minimizing the increase in device complexity while still providing the necessary stability.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of operation

If locking devices are made manually actuable, then ease of operation is improved, but reliability deteriorates due to human error

Engineering Contradiction:
Improvemanual switching capabilityVSAvoidoperational consistency
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The manual actuation mechanism is designed with mechanical features such as detents, springs, and positive engagement elements that eliminate the need for precise human control. The mechanical system automatically ensures proper engagement and locking, replacing the need for skilled manual operation and reducing human error while maintaining ease of use.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP3335839B1Handheld machine tool
Publication Date: 2019.05.01 FESTOOL GMBH
  • EP3335839B1 patent drawingFigure 1~7
  • EP3335839B1 patent drawingFigure 2~4
  • EP3335839B1 patent drawingFigure 5~6

AI summary

The invention relates to a hand-held power tool (10), in particular a screwdriver and/or drill, with a drive motor (16) for driving a gear drive (25) of a gearbox (30), which has a gear output (26) for driving a tool holder (18) of the hand-held power tool (10) and a first gear stage (41) and a second gear stage (42), wherein the gearbox has a first locking device (61) for locking a gear element forming a locking gear element (43) of the first gear stage (41) and a second locking device (62) for locking a gear element forming a locking gear element of the second gear stage (42), wherein the gear stage with the respective locked locking gear element transmits a torque from the gear drive (25) to the gear output (26).wherein the direction of rotation of the drive motor (16) is switchable and, depending on the direction of rotation of the drive motor (16), the first gear stage (41) or the second gear stage (42) transmits a torque from the gear input (25) to the gear output (26), wherein the locking devices (61, 62) lock the respective locking gear element (43, 46) in a locking direction (S1, S2) and release it in a free-running direction, and wherein it has a switching device for switching the locking direction (S1, S2) and the free-running direction of at least one locking device (61, 62), in particular both locking devices (61, 62). It is provided that it has a locking device for fixing the locking devices in the respective switching position (T1, T2).