Carrying device

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Solution Overview

Problem

Existing carrying devices face challenges in efficiently moving handles between storage and carrying positions, particularly when a large amount of folding is required, leading to space constraints and potential overstretching of elastic elements, which affects usability and lifespan.

Innovation Solution

The integration of pulley-shaped elements connected to both the non-elastic strap and elastic element allows for a longer distance of strap movement with reduced force, preventing overstretching and providing a stable carrying experience by distributing the weight solely on the non-elastic strap, while maintaining a compact retracted position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a relatively long extension of the elastic element is used to achieve a relatively large amount of folding of the flexible non-elastic strap, then the folding amount is improved, but the space required in or around the carrying device increases

Engineering Contradiction:
Improvefolding amount of strapVSAvoidspace required
Core Design Contradiction:
Ease of operationVSVolume of moving object

Solution Approach 1:

A pulley system is introduced as an intermediary mechanical element between the elastic band and the non-elastic strap. The pulley converts the linear motion of the elastic band into a mechanical advantage system, allowing a shorter elastic band extension to achieve the same strap folding distance through rotational leverage and mechanical multiplication of force.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system transitions from a static elastic band-strap connection to a dynamic pulley-based mechanism. The pulley allows the elastic band to exert force through rotational motion, enabling the same folding effect with reduced linear extension distance. The dynamic interaction between the pulley wheel and the elastic band creates a more space-efficient retraction system.

Inventive Principle:
Principle #15Dynamics

2Force

If the elastic element is extended over a long distance to retract the handle, then the retraction force is improved, but the elastic element may be overstretched which reduces its lifespan

Engineering Contradiction:
Improveretraction forceVSAvoidlifespan of elastic element
Core Design Contradiction:
ForceVSReliability

Solution Approach 1:

The pulley acts as a mechanical intermediary that distributes and multiplies the retraction force. Instead of the elastic band directly pulling the strap over a long distance, the pulley system divides the retraction action into rotational segments, reducing peak stress on the elastic material while maintaining effective retraction force.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The pulley system provides mechanical advantage, allowing the elastic band to exert sufficient retraction force with a shorter, less extreme extension. This partial action approach achieves the necessary retraction effect without over-extending the elastic element, thereby preserving its lifespan and preventing material fatigue.

Inventive Principle:
Principle #16Partial or excessive action

3Ease of operation

If the handle is moved easily between retracted and carrying positions over long distances, then the ease of operation is improved, but the force required to control the movement increases

Engineering Contradiction:
Improveease of handle movementVSAvoidforce required to control movement
Core Design Contradiction:
Ease of operationVSForce

Solution Approach 1:

The pulley mechanism transforms the linear pulling motion into a rotational system with mechanical advantage. As the user pulls the handle, the pulley rotates, distributing the control force across a larger arc and reducing the instantaneous force required. This dynamic conversion makes long-distance handle movement easier to control.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The pulley's circular geometry provides a curved path for the elastic band and strap interaction. This curvature allows the system to convert linear pulling force into rotational motion, creating a more gradual and controllable movement experience over long distances, reducing the peak force needed by the user.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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

This design enables easy and efficient movement of handles over any predetermined length, prevents overstretching of the elastic element, and provides a safe and stable carrying experience similar to non-elastic straps, with improved usability and extended lifespan of the elastic component.

Implementation Method 1

at least one elastic element coupled to the flexible, non-elastic strap and configured to bias the flexible, non-elastic strap toward the retracted position

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the elastic element will retract under influence of the spring force of the elastic element to an unloaded position

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 3

Both pulley shaped elements act as pulleys. This has the advantage that if the second pulley shaped element moves under a certain force over a certain distance towards the first pulley shaped element that an end of the non-elastic strap guided along the first and second pulley shaped elements will be moved over twice said distance at half said force

Methodology Applied
Scientific EffectMechanical advantage: Mechanical Advantage

Data Source

PatentEP3721745B1Carrying device
Publication Date: 2021.09.08 MAXI MILIAAN BV
  • EP3721745B1 patent drawingFigure 1
  • EP3721745B1 patent drawingFigure 2
  • EP3721745B1 patent drawingFigure 3A~3B

AI summary

A carrying device comprises at least one object to be carried and at least one handle connected with at least one end to the object. The handle is movable between a retracted position and a carrying position. The retractable handle comprises a flexible, non-elastic strap adapted to be held by a user and at least one elastic element coupled to the flexible, non-elastic strap and configured to bias the flexible, non-elastic strap toward the retracted position.