Rotary Clothes Dryer Rope Retraction for Low-Force Opening

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Solution Overview

Problem

Existing rotary clothes dryers require excessive force to open and have a complex design, leading to issues like noise from the hanging elevator rope, tangling, and instability during the spreading process.

Innovation Solution

A rotary clothes dryer with a retraction device featuring a displaceably mounted weight body for smoothly drawing in the elevator rope, combined with a pre-spreading mechanism and block and tackle system for reduced effort and improved stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a block and tackle system is used to help overcome the dead center, then the difficulty of overcoming dead center is reduced, but the force required for complete transfer into the expanded position remains high

Engineering Contradiction:
Improvedifficulty of overcoming dead centerVSAvoidforce required for complete transfer
Core Design Contradiction:
Ease of operationVSForce

Solution Approach 1:

A weight body is introduced as a counterweight system to assist the block and tackle mechanism. The weight body, when displaceably mounted, creates a gravitational counterforce that reduces the net force the user must apply to the elevator cable during the complete transfer process, not just for overcoming dead center.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

Solution Approach 2:

The weight body acts as an intermediary element between the user's input force and the spreading mechanism. It mediates the force transmission by providing gravitational assistance, thereby reducing the direct force requirement on the elevator cable while working in conjunction with the block and tackle system.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If the elevator cable is allowed to hang freely after spreading, then the mechanism is simple, but the cable causes noise and may become tangled

Engineering Contradiction:
Improvesimplicity of mechanismVSAvoidnoise and tangling
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The harmful aspect (freely hanging cable) is extracted and addressed by introducing a retraction device. This device actively retrieves the elevator cable after the spreading operation is complete, removing the source of noise and tangling while maintaining the simplicity of the core spreading mechanism.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The retraction device automatically retrieves the elevator cable using the existing block and tackle system and weight body mechanics. The system serves itself by utilizing its own components to solve the problem of cable management without requiring additional complex mechanisms or manual intervention.

Inventive Principle:
Principle #25Self-service

3Stability of the object's composition

If the mast end is closed with a protruding cover cap and guide members, then the spreader body stability is improved, but the design complexity increases

Engineering Contradiction:
Improvespreader body stabilityVSAvoidmast end construction
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The cover cap and guide members are merged into a single integrated component at the mast end. This combination provides both the stabilizing function (preventing tipping and canting) and the protective function (covering the spreader body) without requiring separate complex assemblies, thereby reducing overall design complexity while maintaining stability.

Inventive Principle:
Principle #5Merging (Combining)

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

Enables easy operation with reduced force required for opening and prevents noise and tangling, simplifying the design and enhancing handling by retracting the elevator rope into the dryer components.

Implementation Method 1

a pull-in device for pulling the elevator rope (8) into a component of the rotary clothes dryer (1; 4; 6), with the spreader body (3) forming a displaceably mounted weight body for pulling in the elevator rope

Methodology Applied
Scientific EffectGravity: Gravitation

Implementation Method 2

A pre-spreading mechanism is provided for moving the support arms from the rest position with a block and tackle (2) for actuating the pre-spreading mechanism

Methodology Applied
Scientific EffectMechanical advantage: Mechanical Advantage

Data Source

PatentEP2354297B1Rotary clothes drier
Publication Date: 2012.05.09 LEIFHEIT
  • EP2354297B1 patent drawingFigure 1

AI summary

The clothes dryer is provided with lifting arms (1) in the resting position, and a lift cable (8). A retraction device is provided for retracting the lift cable into a component of the clothes dryer, particular in the lifting arm or in a pole (4) provided in a support arm (6).