Foam-Filled Graphite Racquet Frame for Vibration Damping
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Solution Overview
Problem
Conventional graphite composite sports racquet frames, such as tennis racquets, suffer from hollow designs that increase vibration and shock transmission to the player's arm and shoulder due to air injection manufacturing methods, leading to higher injury rates and limitations in frame thickness for strength and swing speed.
Innovation Solution
A carbon composite frame structure with an inner core of foam plastic and a closed end at the base of the handle, utilizing micro encapsulated foaming plastic materials to eliminate the need for air injection, allowing for a solid and thinner racquet frame that reduces shock and vibration while maintaining strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If air injection method is used to manufacture graphite composite racquet frames, then the manufacturing process is simple and efficient, but the frame becomes hollow which increases vibration and shock transmission to the player
Solution Approach 1:
The patent uses a composite structure combining graphite fiber layers with foam plastic material. The foam plastic is injected into the graphite fiber layup and cured together, creating a composite frame that is both lightweight and capable of dampening vibrations. This composite approach allows the frame to maintain structural integrity while reducing harmful vibrations transmitted to the player.
Solution Approach 2:
The patent applies different materials to different parts of the frame structure. The outer shell and structural components use graphite fiber for strength and lightweight properties, while the inner core uses foam plastic for vibration dampening. This local differentiation of material properties allows the frame to simultaneously achieve structural performance and vibration reduction.
2Weight of moving object
If the frame is made hollow for weight reduction, then the racquet is lighter for faster swing speed, but the frame thickness must be increased to maintain strength
Solution Approach 1:
The composite structure of graphite fiber reinforced with foam plastic allows the frame to achieve high strength-to-weight ratio. The graphite fiber provides structural strength while the foam plastic adds damping and structural support, enabling thinner walls that maintain strength while reducing overall weight.
Solution Approach 2:
The patent changes the physical and mechanical parameters of the frame by incorporating foam plastic material with specific density and damping properties. This allows optimization of the frame's strength characteristics without increasing weight, as the foam plastic provides structural support and vibration dampening in a lightweight form.
3Object-affected harmful factors
If foam plastic material is used to fill the frame, then vibration and shock are reduced, but the manufacturing process becomes more complex
Solution Approach 1:
The patent combines the molding and foam injection processes into a single integrated operation. The foam plastic is injected into the graphite fiber layup already positioned in the mold, and both materials are cured simultaneously in one heating cycle. This merging of processes adds minimal complexity while achieving vibration reduction.
Solution Approach 2:
The foam plastic material serves multiple functions simultaneously: it acts as a structural core, a vibration dampener, and a bonding agent between graphite fiber layers. The material's expansion during curing automatically fills the frame cavity and conforms to the mold shape, eliminating the need for separate shaping operations.
4Object-affected harmful factors
If the frame is made solid and thinner, then shock absorption is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The patent utilizes the foam plastic's physical properties, particularly its expansion ratio and curing characteristics, to achieve precise dimensional control. The foam expands to fill the mold cavity completely, ensuring uniform wall thickness and accurate reproduction of the frame geometry. The curing process locks in these dimensions with high precision.
Solution Approach 2:
The foam plastic material provides a porous yet structurally sound core that absorbs shock while maintaining dimensional stability. The cellular structure of the foam allows for energy absorption through cell collapse and deformation, while the overall frame dimensions remain precisely controlled by the mold and curing process.
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 results in a racquet with improved shock absorption, increased 'sweet spot' size, and enhanced playing characteristics, including reduced injury risk and customizable weight distribution, enabling more efficient manufacturing and wider range of player preferences.
Implementation Method 1
placing a foam plastic forming material inside the wrapped flat members, closing the ends of the wrapped flat members to define a substantially closed bladder, introducing the closed bladder into a mold, causing the foam plastic forming material to form a foam plastic
Implementation Method 2
causing the foam plastic forming material to form a foam plastic
Implementation Method 3
The resinous material is then cured, for example by heat
Implementation Method 4
The cured layup is removed from the mold
Data Source
AI summary
The inventive fiber manufacturing process is particularly adapted for demanding applications such as sports racquets, including tennis racquets, badminton racquets and other sports applications. Because of the improved strength to weight ratio of components formed using the inventive method, a wide range of flexibility is achieved, allowing use of the inventive process to manufacture, for example, a fiber reinforced (for example, graphite) modular sports racquet, optionally provided with user-selectable weights and/or handle replacements. From the standpoint of the player, this allows a racquet frame featuring self customization. From the standpoint of a retailer, the benefit provided is reduction of inventory. The inventive fiber, for example graphite fiber) racquet frame is filled with a plastic foam and is formed using, for example, microencapsulation technology to time, generate and apply the pressure used to form the graphite composite material of which the racquet is comprised. Advantageously, inner and outer tubular members may be used to form the racquet frame, with the inner tubular member extending around the head of the racquet frame. This compares to the standard industry technique of air injection. The racquet is thus not hollow like conventional graphite racquets, and the walls therefore can be made thinner than those of existing graphite racquets still being of the same strength or being stronger, which gives the racquet exceptional performance. In addition, the overall dimensions of, for example the cross-section, of the racquet can also be reduced while still maintaining performance characteristics.