Multi-Directional Input Shaft With Spherical Anti-Rattle Sliding Contact
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Solution Overview
Problem
Existing multi-directional input apparatuses face challenges in suppressing rattling of the shaft portion when tilted, leading to varying sliding resistances and complex assembly processes, which hinder operational feel and size reduction.
Innovation Solution
A multi-directional input apparatus featuring a sliding member with a spherical rubbing surface and a receiving surface, both centered on the tilting center, elastically biased by a coil spring or compression coil spring, allowing smooth sliding and consistent resistance regardless of tilting direction, and facilitating easy assembly and size reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pair of sliding members with curved rubbing surfaces and a compression spring are used to suppress rattling, then rattling of the shaft portion is prevented, but the apparatus size increases and assembly becomes complex
Solution Approach 1:
The invention extracts and eliminates the compression spring from the system by using a sliding member with a spherical rubbing surface that directly contacts the receiving surface. This removes the need for elastic components while maintaining rattling suppression functionality, thereby simplifying assembly and reducing apparatus size.
Solution Approach 2:
The invention applies spheroidality by forming the rubbing surface of the sliding member as a spherical surface centered on the tilting center of the shaft portion. This spherical geometry enables smooth multi-directional tilting motion and maintains consistent contact with the receiving surface, preventing rattling without requiring additional elastic components.
2Ease of operation
If the rubbing surface is made spherical centered on the tilting center, then sliding resistance becomes consistent across all tilting directions, but manufacturing precision requirements increase
Solution Approach 1:
The rubbing surface is formed as a spherical surface centered on the tilting center of the shaft portion. This geometric configuration ensures that the sliding resistance remains consistent regardless of the tilting direction, providing uniform operational feel across all directions of motion.
3Reliability
If multiple components (sliding members, spring, receiving surfaces) are used to prevent rattling, then operational stability is improved, but the apparatus cannot be miniaturized
Solution Approach 1:
The invention removes the compression spring and complex multi-component assembly, retaining only the essential sliding member with a spherical rubbing surface. This extraction of unnecessary components enables apparatus miniaturization while preserving the core functionality of preventing shaft portion rattling during tilting operations.
Solution Approach 2:
The invention merges the functions of multiple components into a single integrated sliding member. The sliding member incorporates the spherical rubbing surface that simultaneously provides smooth multi-directional motion, consistent sliding resistance, and rattling suppression, thereby reducing the overall apparatus size.
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
Prevents rattling and maintains consistent sliding resistance across tilting directions, simplifies assembly, and reduces the overall size of the apparatus while enhancing operational feel.
Implementation Method 1
an elastic member configured to elastically bias the sliding member against the receiving portion
Implementation Method 2
At least one of a rubbing portion of the sliding member and a receiving surface of the receiving portion has a spherical shape centered on a tilting center of the shaft portion
Data Source
AI summary
A multi-directional input apparatus includes an operating member including a shaft portion which extends to the outside, a housing having an opening through which the shaft portion extends and configured to support the operating member in a tiltable manner, interlocking members moved by the operating member when the shaft portion is tilted, and detectors which detect changes in the positions of the interlocking members. A sliding member is externally fitted to the shaft portion such that the sliding member is movable in an axial direction, and a coil spring is disposed between a flange provided on the shaft portion and the sliding member. A rubbing surface of the sliding member is in elastic contact with a receiving surface on an inner wall of an annular edge portion surrounding the opening. The rubbing surface and the receiving surface are spherical surfaces centered on a tilting center of the shaft portion.