Dual Hook Arm Coupling for Handheld Tool Attachment

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Solution Overview

Problem

Handheld power tools with single-position hook arrangements face difficulties in attachment to counterholds, leading to unfavorable center of gravity and handling challenges, especially when tools like screw magazines are attached.

Innovation Solution

The implementation of a dual hook arm system with movement coupling allows for attachment at different points on the housing, enabling one hook arm to be positioned for hooking while the other is in a non-use position, reducing interference and improving handling by allowing the tool to be attached at various points on the housing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a single hook arrangement is provided on the housing, then the structure is simple, but the tool can only be attached at one position which may result in unfavorable center of gravity and handling difficulties

Engineering Contradiction:
Improveattachment position flexibilityVSAvoidhook arrangement structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The hook arrangement is segmented into a first hook arm and a second hook arm that are coupled together. This segmentation allows the tool to be attached at different positions (using either the first or second hook arm) while maintaining a unified coupled structure. The segmentation resolves the contradiction by providing multiple attachment positions without requiring completely separate hook structures.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The coupled hook arrangement serves multiple functions: it can be attached at the first position using the first hook arm, or at the second position using the second hook arm. This multi-functionality allows the same hook structure to adapt to different attachment scenarios, resolving the contradiction between versatility and complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If tools like screw magazines are attached to the hand-held machine tool, then the tool functionality is enhanced, but the center of gravity becomes unfavorable and handling becomes difficult

Engineering Contradiction:
Improvetool attachment capabilityVSAvoidhandling ease
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The coupled hook arrangement provides dynamic adaptability by allowing the user to switch between the first and second hook arms depending on what is attached to the tool. When a screw magazine or other accessory is attached, the user can select the hook arm that positions the center of gravity favorably, thus maintaining ease of operation while enhancing tool functionality.

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If one hook arm is moved into a hooking position while the other remains in non-use position, then interference is reduced, but the coupling mechanism becomes more complex

Engineering Contradiction:
Improvehooking operation smoothnessVSAvoidcoupling device structure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The coupling device merges the first and second hook arms into a single coupled assembly. This merging allows the hook arms to move in a coordinated manner, where one hook arm can be positioned for hooking while the other is in non-use position, reducing interference. The unified coupling structure achieves this coordination without requiring overly complex independent control mechanisms for each hook arm.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP2308652B1Manually operated machine tool with a hook assembly
Publication Date: 2012.09.19 FESTOOL GMBH
  • EP2308652B1 patent drawingFigure 1
  • EP2308652B1 patent drawingFigure 2~4
  • EP2308652B1 patent drawingFigure 5~6

AI summary

The hand-held machine tool (10) has a hook arrangement (28) with two hook arms (29a), which are movably supported on the housing (18) and which are assigned opposing housing walls (27a) of the housing. The hook arms are movably coupled such that the hook arm is moved away from its assigned housing wall by the movement of the other hook arm to its assigned housing wall.