Drive coupler for power scrubber

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Solution Overview

Problem

Existing drive adapters for power tools, such as scrubbers, face challenges in accommodating various sizes and types of tool heads, particularly brushes with different sizes, shapes, and stiffnesses, requiring adaptable connection mechanisms that can securely engage and transmit power across different configurations.

Innovation Solution

A power tool and scrubber design featuring a drive with a connector that includes an internal bore for engaging tool shanks and external lobes with bayonet couplings, allowing for adjustable engagement and secure locking of working tools in both axial and rotational directions, enabling compatibility with diverse scrubber heads and facilitating telescoping shaft adjustments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single connection mechanism is used for all tool heads, then device complexity is reduced, but adaptability to different tool head sizes and types deteriorates

Engineering Contradiction:
Improveconnection mechanismVSAvoidtool head compatibility
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The drive adapter incorporates a universal connector design with an internal bore and multiple lobes that can accommodate different tool head types (brushes, bits, fasteners) through a single connection interface. The connector's internal bore receives various shank sizes while the lobes provide standardized engagement, allowing one adapter to serve multiple tool head configurations without requiring separate connection mechanisms for each tool type.

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

2Adaptability or versatility

If different connection mechanisms are used for various tool heads, then adaptability to different tool heads is improved, but device complexity increases

Engineering Contradiction:
Improvetool head compatibilityVSAvoidconnection mechanism
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The connection mechanism is segmented into distinct functional components: an internal bore for receiving tool shanks, multiple lobes for engagement, and a locking mechanism. This segmentation allows each component to be optimized for its specific function while working together as an integrated system, reducing overall complexity compared to having entirely separate connection mechanisms for different tool types.

Inventive Principle:
Principle #1Segmentation

3Reliability

If a locking mechanism is added to secure tool heads, then connection reliability is improved, but device complexity increases

Engineering Contradiction:
Improvetool head connectionVSAvoidconnector structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The locking mechanism is merged with the lobe structure itself, where the lobe's geometry and movement path inherently provide the locking action. As the connector engages with the tool head shank, the lobe's radial movement and angular orientation create a self-locking effect that secures the connection without requiring a separate, independent locking component, thus maintaining reliability while minimizing added complexity.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3995258A1Drive coupler for power scrubber
Publication Date: 2022.05.11 TECHTRONIC CORDLESS GP
  • EP3995258A1 patent drawingFigure 1
  • EP3995258A1 patent drawingFigure 2~3
  • EP3995258A1 patent drawingFigure 4~5

AI summary

A power tool (10) includes a power head receiving power from a power source (22). A drive (86) coupled to the power head extends along a longitudinal axis (86), and the drive is engaged with a connector (94). Various aspects relate to the connector. The connector includes an internal bore (114) configured to couple to the drive to a shank (122) of a working tool. The connector further includes an external lobe (98) protruding radially outward from the longitudinal axis, the lobe having a locking mechanism configured to secure the second working tool (200) in response to relative movement between the lobe and the second working tool in both an axial direction and a rotational direction.