Elastomeric Shaft Lock for Lacrosse Handle Connection Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The conventional screw connection between the handle and head of lacrosse sticks is prone to loosening and dislodgement due to stress, vibration, and thread stripping, especially with lighter and thinner-walled handles, leading to instability and potential disconnection during competitive play.
Innovation Solution
A dual-material shaft lock mechanism featuring a hard plastic screw-anchor embedded in an elastomeric body, which is compression-fitted inside the handle, providing constant tension and resistance to loosening and thread stripping through a combination of threaded engagement and elastomeric compression.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional screw connection is used to attach the head to the handle, then the assembly is simple and easy to manufacture, but the connection is prone to loosening, dislodgement, and thread stripping under stress and vibration
Solution Approach 1:
The shaft lock mechanism employs a nested structure where the screw-anchor is embedded within the elastomeric body, which in turn is compression-fitted inside the handle. This nested arrangement (screw-anchor inside elastomeric body inside handle) provides a robust connection system that maintains reliability while organizing components efficiently within the available space
Solution Approach 2:
The shaft lock utilizes composite construction by combining a rigid screw-anchor (hard plastic) with a compliant elastomeric body. This composite approach allows the hard anchor to provide threaded engagement strength while the elastomeric material provides compression fit and constant tension, resolving the contradiction between connection reliability and structural complexity
2Weight of moving object
If lighter and thinner-walled handles are used to reduce weight, then the overall stick weight decreases, but the handle becomes more susceptible to thread stripping and connection failure
Solution Approach 1:
The connection system is segmented into distinct functional components: the screw-anchor for threaded engagement, the elastomeric body for compression fitting, and the handle wall. This segmentation allows each component to be optimized independently - the screw-anchor provides concentrated anchoring points that distribute stress, preventing thread stripping in thin-walled handles while maintaining lightweight construction
Solution Approach 2:
The elastomeric body undergoes parameter change through compression, transforming from an uncompressed state to a compressed state that exerts constant tension on the screw-anchor. This parameter change allows the system to adapt to thinner handle walls while maintaining connection strength, as the compression fit compensates for reduced material thickness
3Ease of repair
If repeated removal and reassembly of the screw connection is performed, then maintenance and adjustment become possible, but the threads become stripped and the connection becomes unstable
Solution Approach 1:
The elastomeric body serves as a cushioning element that protects the screw-anchor threads from damage during repeated assembly and disassembly operations. The compliant elastomeric material absorbs mechanical shocks and reduces stress concentrations on the threads, preventing thread stripping even after multiple reassembly cycles, thereby maintaining both ease of repair and thread integrity
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 shaft lock ensures a robust and secure connection between the handle and head, resisting impact and vibration, preventing loosening and dislodgement, and maintaining thread integrity, thus enhancing the durability and stability of the lacrosse stick.
Implementation Method 1
The elastomeric body portion is deformable and, when compressed, exerts a constant tension on the screw-anchor
Implementation Method 2
at least one screw threaded through the handle into the screw-anchor from top-to-bottom, the screw(s) engaging the screw anchor
Implementation Method 3
The insert is anchored inside the handle by at least one screw threaded through the handle into the screw-anchor from top-to-bottom
Data Source
AI summary
A shaft lock for interconnection of an elongate tubular lacrosse handle and a plastic lacrosse head. The shaft lock comprises an elastomeric insert compression-fitted inside the handle. The insert has a compressible body portion which, in an uncompressed form generally conforms to the interior walls of the handle and is defined by a plurality of co-planar ribs that span the interior walls of the handle. A hard screw-anchor is embedded within the elastomer insert, and the insert is anchored inside the handle by at least one screw threaded through the handle into the screw-anchor from top-to-bottom, the screw(s) engaging the screw anchor and compressing it against the elastomeric insert. The threaded engagement of the screw(s) through the wall of the handle and into the screw-anchor compresses the elastomeric insert, maintaining a constant tension against the screw(s) and against the interior walls of the handle. This avoids loosening and/or dislodgement as a result of impact or vibration, and resists the threads of the screw from stripping either the handle wall(s) or the insert as a result of torque or other stress.