Shaft Tester Using Multi-Point Deflection for Circumferential Fatigue Profiling
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Solution Overview
Problem
Current methods for testing the durability of golf club shafts, such as air cannon tests, are time-consuming, noisy, potentially dangerous, and focus on a single point, leading to false positive results due to variations in shaft wall thickness and poor design, which can result in incomplete assessment of structural integrity across the shaft's circumference.
Innovation Solution
A shaft testing device that supports the shaft at multiple fixed positions, uses an actuator to cause deflection, and a sensor to measure load force, allowing for controlled rotation and data collection to generate a fatigue profile, providing a comprehensive assessment of the shaft's structural integrity across its entire circumference without the need for human supervision or ballistic testing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If air cannon testing is used to test shaft durability, then structural integrity can be assessed, but the testing process becomes time-consuming and dangerous
Solution Approach 1:
The patent replaces the air cannon mechanical testing system with a controlled mechanical testing apparatus that applies precise forces to the shaft. The system uses a motorized actuator to apply controlled displacement and force to the shaft while it rotates, eliminating the need for repeated high-velocity ball impacts. This substitution maintains reliability in assessing structural integrity while dramatically reducing testing time and eliminating safety hazards associated with projectile launch.
2Device complexity
If single-point testing is performed on the shaft, then testing simplicity is maintained, but measurement accuracy decreases due to false positive results
Solution Approach 1:
The patent divides the shaft testing process into multiple measurement points by implementing circumferential rotation of the shaft during testing. The testing apparatus applies force at one location while the shaft rotates to present different circumferential positions to the measurement point, effectively segmenting the testing across the entire shaft circumference. This segmentation eliminates false positives by identifying the weakest point around the circumference rather than assuming uniform strength, thereby improving measurement precision without significantly increasing device complexity.
3Reliability
If multiple iterations of air cannon hits are applied, then durability testing thoroughness is improved, but productivity decreases
Solution Approach 1:
The patent implements continuous rotation of the shaft during the testing process, allowing the testing apparatus to continuously apply force and measure response across the entire circumference in a single continuous operation. This eliminates the need for multiple discrete iterations of loading and unloading the shaft, as the continuous rotation ensures all circumferential positions are tested during one continuous measurement cycle. This continuity maintains thoroughness in durability assessment while significantly improving productivity by reducing the number of separate test cycles required.
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 enables quick, safe, and accurate testing of golf club shafts, providing a comprehensive fatigue profile that assesses structural integrity across the entire circumference, reducing the risk of false positives and improving the efficiency and safety of the testing process.
Implementation Method 1
an actuator coupled to the third shaft support and adapted to displace the third portion relative to the first portion and the second portion to cause a deflection in the shaft
Implementation Method 2
a sensor coupled to one of the first support, the second support and the third support and adapted to output a signal corresponding to a load force exerted by the shaft due to the deflection
Implementation Method 3
a motor adapted to rotate the shaft when the shaft experiences the lateral deflection
Data Source
AI summary
Methods and apparatus are provided for testing shafts, such as golf club shafts. In one embodiment, the invention can be characterized as a shaft tester comprising: a frame; a first shaft support supporting a first portion of a shaft at a first fixed position; a second shaft support supporting a second portion of the shaft at a second fixed position; and a third shaft support supporting a third portion of the shaft at a third fixed position. An actuator couples to the third shaft support to displace the third portion relative to the first and second portions to deflect the shaft. A sensor couples to one of the first, second and third supports outputting a signal corresponding to a force exerted by the shaft due. A controller controls displacement of the shaft. In some embodiments, the shaft is rotated while being deflected.