Torsion Coil Spring Retention Mechanism for Rotation
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Solution Overview
Problem
Conventional rotation mechanisms using torsion coil springs face issues with disengagement due to high spring torque, and existing solutions either compromise on part count or weight.
Innovation Solution
The rotation mechanism incorporates protrusions with spring holding portions and inclined surfaces to securely compress and hold the torsion coil spring, preventing disengagement, while maintaining a simple and lightweight design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the spring torque of the torsion coil spring is increased, then the urging force for rotation is improved, but the spring deformation becomes large causing end portions of the coil shape to be disengaged from the protrusions
Solution Approach 1:
The invention transitions from a single-point engagement system to a distributed multi-point engagement system. Multiple protrusions are arranged circumferentially around the pivot axis, and the coil shape engages with multiple corresponding protrusions simultaneously. This dimensional distribution prevents disengagement by requiring simultaneous disengagement of multiple engagement points, thereby maintaining reliability even with high spring torque and large deformation.
Solution Approach 2:
The invention combines multiple engagement elements (protrusions and corresponding engagement features on the coil shape) into a unified engagement system. By integrating multiple protrusions that work together to hold the coil shape, the system achieves enhanced engagement reliability without requiring additional separate components or increasing overall complexity.
2Reliability
If protrusions are lengthened to prevent disengagement, then engagement reliability is improved, but the torsion coil spring cannot be held around the axes of the protrusions
Solution Approach 1:
The invention applies local quality by creating circumferential variations in the engagement structure. Protrusions are distributed around the pivot axis with specific radial and axial positions, creating localized engagement zones. This allows the coil shape to be properly positioned and held around the pivot axis through distributed local engagement points, preventing disengagement without requiring excessive protrusion length that would hinder assembly.
3Reliability
If a shaft is used to hold the torsion coil spring instead of protrusions, then detachment is prevented, but the number of parts is increased and weight is increased
Solution Approach 1:
The invention merges the functions of multiple separate components into a unified structure. Instead of using a shaft plus multiple protrusions or separate retention mechanisms, the design integrates multiple protrusions directly into the existing structure, allowing the coil shape to be held securely without requiring additional shaft components. This reduces part count while maintaining detachment prevention.
Solution Approach 2:
The protrusions serve multiple functions simultaneously: they guide the coil shape into proper position during assembly, provide engagement points to prevent disengagement under high spring torque, and maintain the coil shape around the pivot axis. This multi-functionality eliminates the need for separate dedicated retention components, reducing overall device complexity.
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
This configuration effectively prevents unintentional detachment of the torsion coil spring, even with high spring torque, enhancing the mechanism's reliability and assembly ease.
Implementation Method 1
a torsion coil spring (5) which urges one of the first member (1, 1A) and the second member (2) so as to rotate relative to the other
Data Source
Figure 1A~1B
Figure 2A~2C
Figure 3A~3B
AI summary
This rotation mechanism is provided with: a first member (1, 1A); a second member (2) which is rotatably coupled to the first member (1, 1A) by a pivot (36); and a torsion coil spring (5) which applies force such that one from among the first member and the second member is rotated relative to the other. Any one of the first member and the second member is provided with a torsion coil spring-accommodating part (35) in which a pair of protrusions (37, 38) facing each other in the axial direction of the pivot (36) is provided. The pair of protrusions (37, 38) are configured so as to hold, around the axes of the protrusions (37, 38), the two end portions (5a) of the coil shape of the torsion coil spring (5), and so as to protrude while being displaced in the radial direction of the coil shapes forming the two ends (5a), with respect to the axial direction of the pivot (36).