Composite Backpack Frame with Curved Stay Portions
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Solution Overview
Problem
Existing backpack frames face challenges in achieving a balance between strength and flexibility, with external frames being heavy and internal frames being difficult to manufacture effectively, while also needing to cushion the user against load shifts and properly support the backpack load.
Innovation Solution
A semi-internal backpack frame with a unitary construction, using resin-impregnated materials like carbon fiber, and compression molding techniques to create a frame that dynamically stores and releases energy, providing flexibility and strength through selectively reinforced layers and a curvature matching the human back.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If external backpack frames are made of metal tubes, then the frame is simple to construct, but the frame becomes very heavy
Solution Approach 1:
The patent employs composite materials consisting of carbon fiber layers embedded in a polymer matrix resin. This composite structure provides high strength-to-weight ratio, achieving both lightweight construction and structural integrity. The carbon fiber reinforcement allows the frame to be lighter than traditional metal tubes while maintaining adequate strength through the composite material properties.
2Weight of moving object
If internal backpack frames are made lighter, then the frame weight is reduced, but the frame loses strength and flexibility balance
Solution Approach 1:
The patent implements variable material distribution with different fiber orientations in different regions of the frame. High-strength carbon fiber layers are concentrated in areas requiring maximum strength (such as load-bearing zones), while areas requiring flexibility have different fiber configurations. This local quality variation optimizes the strength-to-weight ratio by placing material only where structurally necessary.
Solution Approach 2:
The composite material system with multiple carbon fiber layers in different orientations within a polymer matrix provides both lightweight properties and controlled strength characteristics. The composite structure allows tuning of mechanical properties to achieve the desired balance between light weight and adequate strength.
3Ease of operation
If the frame is made more flexible to cushion load shifts, then user comfort is improved, but the frame may lose structural support capability
Solution Approach 1:
The frame design incorporates regions with different flexibility characteristics through varied carbon fiber layer configurations. Certain zones are designed with fiber orientations that provide flexibility for load cushioning, while other zones maintain stiffer constructions for structural support. This local differentiation allows simultaneous achievement of comfort and structural integrity.
Solution Approach 2:
The patent designs the frame to be dynamically responsive to load conditions. The composite structure allows controlled deformation under load, absorbing shock and cushioning load shifts through elastic deformation of the polymer matrix and fiber-reinforced structure. This dynamic behavior provides comfort while maintaining structural support capability.
4Strength
If multiple materials are used in different parts of the frame, then flexibility and strength are optimized, but the manufacturing complexity increases
Solution Approach 1:
The patent combines multiple carbon fiber layers with different orientations into a single integrated composite structure embedded in a polymer matrix. This merging approach achieves selective reinforcement in different directions and regions while maintaining a unified manufacturing process. The composite laminate structure allows multiple material functions to be integrated into one component, reducing assembly complexity.
Solution Approach 2:
The use of composite materials with multiple fiber layers in different orientations within a single polymer matrix provides selective reinforcement capabilities while maintaining relative manufacturing simplicity. The composite lamination process allows controlled placement of fibers in specific orientations to optimize strength and flexibility characteristics.
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 effectively decouples the backpack load from the wearer, providing both flexibility and strength, enhancing comfort and load distribution while maintaining a lightweight design.
Implementation Method 1
the stay portions... dynamically store and release energy resiliently so as to decouple the load from the wearer
Implementation Method 2
defined conditions of elevated temperature and pressure are applied to the preform to create the backpack frame
Implementation Method 3
treated with a resin to create a preform, the mold is engaged, and defined conditions of elevated temperature and pressure are applied
Data Source
AI summary
A backpack and frame are disclosed, as are methods of making the frame using composite materials and compression molding. The backpack frame is designed to be at least partially internal and is of unitary construction using a resin-impregnated material, such as resin-impregnated carbon fiber sheets with selective reinforcement by interstitial layers. The frame has a mid-back portion that includes openings for independently positionable shoulder straps and a lower back portion that provides for a rotatable connection to a belt assembly. A pair of curved stay portions is contiguous with the mid-back portion of the frame and curves outwardly as the stay portions extend downwardly. The frame is preferably curved to match the curvature of the human back.