Disc Cartridge Shutter Attachment via Mechanical Insertion
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Solution Overview
Problem
Conventional disc cartridges face issues with uniform thermal deformation of support shafts during crimping, leading to detachment and poor rotation of shutter members due to temperature control challenges, resulting in inconsistent expanded-diameter head parts.
Innovation Solution
The disc cartridge employs a support shaft with an oblong detachment restricting head part and a slot-like bearing hole, allowing for secure attachment without crimping, ensuring consistent size and thickness, and preventing unintentional detachment by integrating the support shaft during injection molding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If thermal crimping is used to form expanded-diameter head parts on support shafts, then attachment strength of shutter members to inner shell is improved, but manufacturing precision deteriorates due to difficulty in maintaining constant head molding tip temperature during continuous mass production
Solution Approach 1:
The patent extracts the thermal crimping process from the manufacturing flow and replaces it with a mechanical insertion process. The support shafts are inserted through bearing holes without thermal deformation, eliminating the temperature control problem while maintaining secure attachment through the expanded-diameter head parts formed by simple insertion and engagement with the bearing hole structure.
Solution Approach 2:
The patent replaces the thermal field (heat-based crimping) with a mechanical field (mechanical insertion). Instead of using a head molding tip that applies thermal and mechanical pressure to deform the support shaft ends, the invention uses a straightforward mechanical insertion where the support shafts pass through bearing holes and are retained by the hole structure itself, eliminating temperature control issues.
2Reliability
If head molding tip temperature is increased to ensure sufficient thermal deformation, then attachment reliability is improved, but the thickness of expanded-diameter head parts becomes too thin causing breakage
Solution Approach 1:
The patent removes the thermal deformation step entirely from the process. The expanded-diameter head parts are formed not by heating and pressing, but by mechanical insertion where the support shaft structure itself creates the expanded form as it passes through the bearing hole, eliminating the trade-off between temperature and head part thickness.
Solution Approach 2:
The support shafts are designed with pre-formed expanded-diameter head parts at their ends before insertion. This preliminary formation of the head parts eliminates the need for thermal deformation during assembly, ensuring consistent thickness and strength without relying on temperature control.
3Use of energy by moving object
If head molding tip temperature is too low during crimping, then energy consumption is reduced, but the diameter of expanded-diameter head parts becomes reduced causing easy detachment
Solution Approach 1:
The patent replaces the thermal-mechanical crimping system with a pure mechanical insertion system. The support shafts are inserted through bearing holes and retained by the hole structure without any thermal deformation, eliminating the need to balance temperature and energy consumption while ensuring reliable attachment through the mechanical engagement geometry.
4Strength
If crimping process is used to attach shutter members to inner shell, then attachment strength is improved, but device complexity increases due to need for thermal crimping device and temperature control system
Solution Approach 1:
The patent extracts the thermal crimping device and temperature control system from the manufacturing equipment. The attachment process is simplified to mechanical insertion where support shafts with expanded-diameter head parts are inserted through bearing holes and retained by the hole structure, eliminating complex thermal processing equipment while maintaining secure attachment.
Solution Approach 2:
The patent replaces the complex thermal-mechanical crimping system with a simple mechanical insertion system. The head molding tip, temperature control apparatus, and thermal deformation process are replaced by a straightforward insertion process where the support shaft geometry and bearing hole structure work together to secure the shutter members without any thermal processing equipment.
Data Source
AI summary
A disc cartridge is constructed so that disc access to a recording medium enclosed within the disc cartridge via an opening in the cartridge case is restricted by a disc tray and a shutter member disposed inside the cartridge case. The shutter member is rotatably attached to one of the disc tray and the cartridge case, and detachment of the shutter member is restricted at least in a range of rotation of the shutter member between a position where the shutter member covers part of the opening and a position where the shutter member has been withdrawn from the opening. Attachment of the shutter member is carried out without crimping.