Rotary Protrusion Connector for Tool-Free High-Force Assembly
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing connectors require tools for assembly and disassembly due to the need for increased axial-direction engagement force, which complicates the process and limits frequent attachment/detachment operations.
Innovation Solution
A connector design featuring a male joint member with radial outer protrusions and a female joint member with inner protrusions, allowing direct axial engagement without additional members, enabling easy assembly and high engagement force through relative rotation of the protrusions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the stiffness of the locking element is increased to increase the engagement force in the axial direction, then the engagement force is improved, but fitting between protrusions and recesses becomes difficult and assembly requires tools
Solution Approach 1:
The locking element is divided into multiple segments that can elastically deform independently. This segmentation allows the locking element to flex during assembly to accommodate the protrusions and recesses, eliminating the need for tools while maintaining sufficient engagement force through the combined effect of multiple segments
Solution Approach 2:
The stiffness parameter of the locking element is optimized to achieve a balance between engagement force and assembly ease. By carefully selecting the stiffness value and the elastic deformation characteristics, the locking element provides strong axial engagement force while remaining flexible enough to be assembled without tools
2Ease of operation
If a stopper is used to connect male and female joint members, then assembly is simplified, but a tool and screwing operation are needed to move the stopper in the circumferential direction
Solution Approach 1:
The screwing operation and tool-based circumferential movement mechanism are completely removed from the assembly process. The locking element achieves both axial engagement and circumferential positioning through pure elastic deformation and geometric interlocking, eliminating unnecessary complexity while maintaining ease of operation
Solution Approach 2:
The locking element automatically performs both axial locking and circumferential positioning functions through its own elastic deformation capabilities, without requiring external tools or separate stopping mechanisms. The single component serves multiple functions that previously required separate elements
3Force
If screws are used to tighten the connection between male and female joint members, then engagement force is improved, but a tool for tightening is required
Solution Approach 1:
Screws and tightening tools are completely removed from the connection mechanism. The locking element provides both engagement force and positional control through elastic deformation and geometric interlocking alone, eliminating the need for threaded fasteners and associated tools
Solution Approach 2:
The screw-based mechanical tightening system is replaced with an elastic deformation-based locking system. The locking element uses elastic theory to generate engagement force, substituting the screw-mechanism with a more simple elastic interlocking mechanism that achieves the same force without requiring tools
Data Source
AI summary
To provide a connector that facilitates assembly while having a great axial-direction engagement force, a male joint member to be connected to a first member has a plurality of outer protrusions, and a female joint member to be connected to a second member has a plurality of inner protrusions. A circumferential-direction gap between adjacent two inner protrusions allows the outer protrusion to pass therethrough. The female joint member has, in an area opposed to inner protrusion back surfaces, a circular space that allows the plurality of outer protrusions to relatively rotate therein. The inner protrusion back surfaces of the plurality of inner protrusions are engaged in the axial direction with outer protrusion back surfaces of the plurality of outer protrusions that have passed through the circumferential-direction gaps between the plurality of inner protrusions.