Rotatable Knob Handle with Dual-Element Snap Locking Mechanism

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing cleaning device handles with rotatable knobs lack secure attachment, leading to potential detachment during use and complex captive connections that are difficult to disassemble for repair or disposal, while also being challenging to manufacture and assemble efficiently.

Innovation Solution

A handle design featuring a dual knob element system with a snap closure and locking mechanism that secures the knob axially and radially, allowing for easy detachment and reattachment without tools, using a combination of plastic and rubber-elastic materials for ergonomic comfort and durability, and incorporating spring tongues for resilient assembly and disassembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the knob is easily attached to the handle, then the manufacturing and assembly process is simplified, but the knob becomes insecure and may detach during use

Engineering Contradiction:
Improveease of attachmentVSAvoidsecurity of attachment
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The knob is divided into two separate elements: a first knob element with locking means that engages with the handle, and a second knob element with a locking element. This segmentation allows the locking mechanism to be integrated into the knob structure itself, providing secure attachment while maintaining ease of assembly through the snap-in closure design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The locking element of the second knob element automatically blocks the locking means of the first knob element when the elements are connected, creating a self-securing mechanism. The knob secures itself to the handle without requiring additional fastening operations or tools, resolving the contradiction between easy attachment and secure fixation.

Inventive Principle:
Principle #25Self-service

2Reliability

If the knob is securely attached to the handle, then the knob remains fixed during use, but the connection becomes complex and difficult to remove for repair or disposal

Engineering Contradiction:
Improvesecurity of attachmentVSAvoidcomplexity of connection
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The traditional complex mechanical fastening systems (screws, bolts, captive connections) are replaced with a snap-in closure mechanism combined with elastic locking means. This substitution maintains secure attachment through the blocking action of the locking element while dramatically simplifying the connection structure, allowing tool-free assembly and disassembly.

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

Solution Approach 2:

The locking mechanism utilizes elastic deformation of the locking means (spring tongues) to achieve secure engagement. By changing the physical state of the locking means from rigid to elastic, the system provides both secure attachment during use and easy release when force is applied, reducing structural complexity while maintaining reliability.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If a simple connection method is used, then the assembly is easy and inexpensive, but the connection lacks sufficient strength to prevent detachment

Engineering Contradiction:
Improvesimplicity of connectionVSAvoidstrength of connection
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The locking mechanism combines plastic material for the knob elements with elastic material for the locking means (spring tongues). This composite approach integrates the simplicity of plastic injection molding with the strength and resilience of elastic materials, achieving both easy manufacture and strong, secure connection that resists detachment during use.

Inventive Principle:
Principle #40Composite materials

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The design provides a secure, ergonomic, and fatigue-free cleaning experience with reduced manufacturing complexity, enabling easy adaptation and maintenance by preventing unintentional detachment and allowing quick assembly and disassembly, while also enhancing user comfort and handle stability.

Implementation Method 1

The first knob element (3) is equipped with locking means (6) by means of which the first knob element (3) is rotatably locked to the handle (1)... The locking means can be designed as elastic spring tongues

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

The first knob element and the second knob element can be positively connected to each other, with the positive connection between the first knob element and the second knob element being a snap-in closure

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4269035B1Handle with a rotatable knob
Publication Date: 2024.10.23 CARL FREUDENBERG KG
  • EP4269035B1 patent drawingFigure 1
  • EP4269035B1 patent drawingFigure 2
  • EP4269035B1 patent drawingFigure 3

AI summary

Handle (1) for a cleaning device, comprising a knob (2) rotatably arranged at one end of the handle (1), the knob (2) comprising a first knob element (3) and a second knob element (4), the first knob element (3) being connected to the second knob element (4), the second knob element (4) having a recess (5) in which the handle (1) is rotatably arranged, the first knob element (3) being equipped with locking means (6) by means of which the first knob element (3) is rotatably locked to the handle (1), the second knob element (4) having a locking element (7), the locking element (7) blocking the locking means (6) of the first knob element (3) relative to the handle (1) when the first knob element (3) and the second knob element (4) are connected to each other.