Kitchen Tool Coupling Geometry for Play-Free Bidirectional Retention

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Solution Overview

Problem

Existing coupling devices for kitchen appliances fail to securely hold tools in place during operation, leading to potential kickbacks and detachment, especially when processing tough mixes, which can cause injury and complicate cleaning and tool mounting.

Innovation Solution

A coupling device with a peripheral outer surface featuring a first and second engagement area, where the drive edge is angled and the return edge is antiparallel, ensuring a secure, play-free connection in both directions of rotation, preventing tool detachment and facilitating easy mounting and cleaning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single engagement area with nubs or slots is used to connect the tool to the drive shaft, then the tool can be held in a rotationally fixed manner during normal operation, but the tool can detach from the coupling during kickbacks or reverse rotation

Engineering Contradiction:
Improvetool retentionVSAvoidbidirectional rotation capability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The coupling device is divided into two distinct engagement areas: a first engagement area with nubs that engages with corresponding slots in the tool during forward rotation, and a second engagement area with a different geometry that engages with the tool during reverse rotation or kickback conditions. This segmentation allows each area to specialize in holding the tool during specific rotational directions, ensuring reliable tool retention in both directions without requiring a single complex engagement mechanism.

Inventive Principle:
Principle #1Segmentation

2Reliability

If the coupling device uses a complex locking mechanism with multiple slots and nubs to prevent tool detachment, then the tool can be held securely during kickbacks, but the cleaning of the coupling becomes cumbersome due to food getting stuck

Engineering Contradiction:
Improvetool retention during kickbackVSAvoidcleanability
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The invention extracts and removes the problematic complex locking mechanism with multiple interlocking slots and nubs that created cleaning difficulties. Instead, it uses a simplified engagement system where the first engagement area has nubs that fit into corresponding slots, and the second engagement area has a different, simpler geometry. This extraction of the overly complex locking mechanism maintains tool retention reliability while significantly improving cleanability by reducing crevices where food can accumulate.

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of operation

If the coupling device uses a simple design without multiple engagement areas, then the cleaning and mounting is easier, but the tool can jump out of the coupling when processing tough mixes or when speed varies

Engineering Contradiction:
Improvemounting and cleaning easeVSAvoidtool retention under load
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The coupling device employs a dynamic engagement system where the first engagement area is active during forward rotation and normal operation, while the second engagement area becomes active during reverse rotation or kickback conditions. This dynamic switching between engagement areas allows the coupling to adapt to different operational conditions, maintaining reliable tool retention under varying loads and rotation directions while keeping the overall design relatively simple and easy to clean compared to complex static locking mechanisms.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2432356B1Coupling device for a kitchen device
Publication Date: 2014.03.05 BSH HAUSGERATE GMBH
  • EP2432356B1 patent drawingFigure 1
  • EP2432356B1 patent drawingFigure 2~3
  • EP2432356B1 patent drawingFigure 4

AI summary

A coupling device (1) for a kitchen device (13) for coupling to a drive unit of the kitchen device (13) is provided for rotatably driving a tool (10) around a rotation axis (2). The coupling device (1) has a circumferential outer surface (3) comprising at least one receiving region (4) for receiving a tool (10), wherein the at least one receiving region (4) hast a first engagement region (5) and a second engagement region (6), so that the tool (10) can be received along the rotation axis (2) in a manner substantially free of play and independent of the direction of rotation (7).