Self-Closing Hinge with Arcuate Roll Pin for Automatic Closure
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Solution Overview
Problem
Traditional mechanical hinges require manual operation and use of torsion springs that have a limited lifetime, preventing the screen or lid from remaining open at a fixed angle.
Innovation Solution
A self-closing hinge structure with a housing, roll pin, and shaft members that utilize an interference fit and crimping mechanism to allow automatic closure at small angles while allowing the hinge to remain open at discrete angles, using a roll pin with an arcuate and non-arcuate profile to create friction and torque for snapping closure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If torsion springs are used to force automatic closing, then automatic closing function is achieved, but the hinge cannot remain open at a fixed angle and the spring has limited lifetime
Solution Approach 1:
The patent removes the torsion spring from the hinge mechanism entirely, replacing it with a spring-less design that uses a cam and follower system to achieve automatic closing at small angles while allowing the hinge to remain open at fixed positions, thereby eliminating the reliability issues associated with spring degradation
Solution Approach 2:
The invention changes the operational parameters by providing two distinct modes: automatic closing mode when the hinge is within a small angle range (e.g., less than 15 degrees) and manual positioning mode when opened beyond that range, allowing the hinge to stay open at chosen angles without requiring a spring mechanism
2Device complexity
If traditional mechanical hinges are used, then the structure is simple, but manual operation is required for the full range of motion
Solution Approach 1:
The hinge performs self-service by automatically closing itself when the angle between the door and main body becomes small (within the predetermined angle range), eliminating the need for manual closing operations while maintaining a relatively simple overall structure
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
Enables automatic closure of the screen or lid at small angles while allowing it to be held open at chosen angles, maintaining the closed position until manually opened, eliminating the need for torsion springs and extending the hinge's operational life.
Implementation Method 1
The roll pin has a roll-pin cross-sectional profile in the plane orthogonal to the longitudinal axis. The roll-pin cross-sectional profile has at least one arcuate roll-pin portion and at least one non-arcuate roll-pin portion
Implementation Method 2
The shaft member pin of one shaft member of the pair of shaft members is inserted in an interference fit in a first end of the roll-pin bore and the shaft member pin of the other shaft member of the pair of shaft members is inserted in an interference fit in a second end of the roll-pin bore
Data Source
AI summary
A self-closing hinge has a housing shaft section with a bore extending therethrough in a direction substantially parallel to a longitudinal axis is attachable to a first rotatable member. A bore extends through the housing shaft section. The cross-sectional profile of the bore in a plane orthogonal to the longitudinal axis has at least one arcuate portion and at least one non-arcuate portion. A roll pin rotatably disposed in the bore has substantially the same cross-sectional profile as the bore. A pair of shaft members, each having a shaft-member body attachable to a second rotatable member, has a pin inserted in an interference fit in the opposed ends of the roll-pin bore. The pins have a cross-sectional profile corresponding to the roll-pin cross-sectional profile.