Spherical Connecting System for Uniform Resistance Training
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Solution Overview
Problem
Existing resistance training methods for stick sports, such as baseball and lacrosse, often restrict the use of personal sticks and provide uneven resistance due to non-swiveling attachment mechanisms, and lack universal motion capabilities and field-assemblability.
Innovation Solution
A connecting system featuring a spherical outer surface with a bore and a retaining collar allowing universal motion, enabling attachment of a tensioning member to a free-space shaft with axial and lateral deviation, and capable of field assembly and repair without additional components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a clamp or U-bracket is used to attach the resistance band to the shaft, then the attachment is secure, but the resistance becomes uneven when the shaft rotates or deviates angularly
Solution Approach 1:
The patent employs a spherical bearing interface where the shaft end is spherical and fits into a spherical bearing within the retaining collar. This spherical geometry allows the shaft to rotate and angularly deviate freely while maintaining continuous contact, ensuring uniform resistance throughout the range of motion. The curved spherical surfaces enable smooth rotation without the binding that occurs with rigid clamp attachments.
Solution Approach 2:
The patent transitions from a static rigid attachment (clamp or U-bracket) to a dynamic spherical bearing attachment. The spherical bearing allows the connection point to move and adapt its orientation as the shaft rotates and deviates, maintaining optimal alignment and uniform resistance characteristics throughout the dynamic range of motion rather than being fixed in a single orientation.
2Adaptability or versatility
If a universal joint is used to provide realistic resistance dynamics, then the range of motion improves, but the device complexity and cost increase due to steel bearings and co-forming processes
Solution Approach 1:
The patent divides the universal joint into two separate, simpler components: a spherical shaft end and a spherical bearing housed in the retaining collar. This segmentation allows each component to be manufactured independently using simpler processes, eliminating the need for expensive co-forming of integrated bearing structures while maintaining the universal motion capability.
Solution Approach 2:
The patent replaces expensive, precision-machined steel bearings with a simpler spherical bearing design that can be manufactured more economically. The design accepts that the bearing is a consumable component that may wear over time but is replaced rather than repaired, reducing initial complexity and cost while maintaining performance during the service life.
3Reliability
If existing universal joints are used, then the shaft restraint is adequate, but the universal range of motion over several feet of distance is not achieved
Solution Approach 1:
The patent extends the range of motion by allowing movement in multiple dimensions through the spherical bearing interface. The spherical geometry permits rotation about the shaft axis and angular deviation in multiple directions, enabling the shaft to move through a wide three-dimensional arc over several feet of distance while maintaining adequate restraint and control.
4Speed
If steel bearings optimized for high speed rotation are used, then the rotational speed performance is adequate, but the field repair and field assembly becomes impossible
Solution Approach 1:
The patent segments the bearing system into removable components (spherical shaft end and spherical bearing in retaining collar) that can be assembled and disassembled in the field. This allows the shaft to be detached from the bearing for field repair or replacement without requiring specialized equipment or complex procedures, unlike integrated steel bearing systems.
Solution Approach 2:
The spherical bearing design allows the shaft to be easily inserted into and removed from the bearing by the user without requiring specialized tools or technical expertise. The simple spherical interface enables field assembly and disassembly by the end user for maintenance or replacement purposes.
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 system provides a universal, evenly distributed resistance over a wide range of motion, allowing for realistic training with personal sticks and enabling field assembly and repair, enhancing proprioceptive awareness and training effectiveness.
Implementation Method 1
an inner element having an element spherical outer surface truncated at opposite truncated ends... a collar spherical inner surface complementary to and configured to receive the element spherical outer surface... the retaining collar may allow universal motion of the bore axis relative to the collar axis
Data Source
AI summary
A connecting system for connecting a tensioning member to a free-space shaft may comprise an inner element having an element spherical outer surface truncated at opposite truncated ends and may include an element bore extending through the inner element and coaxial with the element spherical outer surface. The element bore may have a bore axis and a bore cross section sized and configured complementary to a shaft cross section of the free-space shaft. A retaining collar may include a collar spherical inner surface complementary to and configured to receive the element spherical outer surface, and may have opposing collar ends. The collar spherical inner surface may define a collar axis. The retaining collar may allow universal motion of the bore axis relative to the collar axis. The retaining collar may include an arching portion for connecting the tensioning member to the shaft.