Convertible Backpack Wheel Cover and Strap Retraction Mechanism

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Convertible backpacks face issues with shoulder straps getting dirty and frayed when used as trolley cases, and wheels can transfer dirt and moisture to garments when used as backpacks, leading to aesthetic and hygienic problems.

Innovation Solution

A convertible backpack with a rotatable wheels cover mechanism and a shoulder straps retraction mechanism, where the telescopic handle operates the wheels covers to uncover them when in trolley mode and cover them when in backpack mode, and the straps are retracted upwards when in trolley mode to prevent contact with the ground.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the backpack is used as a trolley case with wheels on the ground, then rolling functionality is achieved, but the wheels transfer dirt and moisture to garments when carried on the back

Engineering Contradiction:
Improverolling functionalityVSAvoiddirt and moisture transfer to garments
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The wheel assembly is segmented from the main backpack body through a detachable connection mechanism. The wheels can be separated into an independent rolling unit that can be used independently or attached to the backpack body when needed, preventing dirt transfer to garments when the backpack is carried on the back.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The wheels are extracted as a separate functional module from the backpack body. This extracted wheel module can be detached and used independently as a rolling device, or attached to provide rolling functionality, while keeping the main backpack body clean and suitable for carrying on the back.

Inventive Principle:
Principle #2Taking out (Extraction)

2Adaptability or versatility

If the backpack is used as a trolley case, then rolling capability is provided, but the shoulder straps get dragged on the ground and become dirty and frayed

Engineering Contradiction:
Improvetrolley case functionalityVSAvoidshoulder straps condition
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The shoulder straps are designed with dynamic adjustability, allowing them to be repositioned or detached based on usage mode. When used as a trolley case, the straps can be adjusted to a higher position or detached to prevent ground contact, while maintaining proper positioning when carried on the back.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Before using the backpack as a trolley case, the shoulder straps are preliminarily adjusted or detached to prevent them from being dragged on the ground. This preliminary action protects the straps from dirt and fraying before the harmful effect can occur.

Inventive Principle:
Principle #10Preliminary action

3Object-affected harmful factors

If wheel covers are added to protect garments from dirt, then hygiene is improved, but the mechanism becomes cumbersome and expensive

Engineering Contradiction:
Improvegarment protection from dirtVSAvoidwheel cover mechanism complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The wheel cover function is merged with the wheel detachment mechanism. The same structural elements that enable wheel detachment also provide protective coverage, eliminating the need for separate complex wheel cover mechanisms and reducing overall device complexity and cost.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The wheel assembly structure serves multiple functions: it provides rolling capability when attached, protects garments from dirt through its design, and can be easily detached for independent use. This multi-functionality eliminates the need for separate protective covers, simplifying the overall mechanism.

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

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 solution keeps the straps clean and undamaged, prevents dirt and moisture transfer to garments, and maintains the backpack's appearance and hygiene by effectively covering the wheels when used as a backpack and exposing them when used as a trolley case.

Implementation Method 1

at least two retraction springs mounted on said wheel shaft; wherein, upon insertion of the telescopic trolley handle downward, each of said wheel covers is rotated by said wheel shaft outward by pressure produced by said crankshaft top pressure slider on said crank so as to cover said outer sides of the wheels, and upon extraction of the telescopic trolley handle upward, said crankshaft top pressure slider is pulled up, releasing the pressure on said crank, thereby allowing the wheel shaft to rotate inward with the aid of the force applied by said at least two retraction springs

Methodology Applied
Scientific EffectSpring: Spring

Data Source

PatentEP3357372B1A convertible backpack
Publication Date: 2020.01.29 STARRY LTD
  • EP3357372B1 patent drawingFigure 1A~1C
  • EP3357372B1 patent drawingFigure 2A~2B
  • EP3357372B1 patent drawingFigure 2C~2D

AI summary

This invention is related to a convertible backpack (100) capable of being converted from a regular backpack into a trolley case and vice versa according to a user preference. The convertible backpack of the invention comprises at least a rotatable wheels cover mechanism (60), for covering the outer side of each one of the wheels (40) upon usage of the convertible backpack (100) as a backpack and for uncovering the outer side of each one of the wheels upon usage of the convertible backpack as a trolley case.