Self-Closing Device With Overlapping Retracting Modules
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Solution Overview
Problem
Existing self-closing devices for image forming apparatuses face challenges in balancing user workability and positioning precision of sheet feeding cassettes, as they either require high force for sheet replenishment or compromise on cassette positioning due to varying spring biasing forces, and alternative weight-based systems increase device size and weight.
Innovation Solution
A self-closing device with multiple retracting modules that partially overlap in their strokes and have different start positions, utilizing coil springs and oil dampers to maintain consistent retracting forces and reduce the required pulling force, allowing for precise cassette positioning without increasing device size or weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a spring is used as a biasing member with increased size to maintain biasing force at completion of retracting, then positioning precision of the sheet feeding cassette is improved, but the size of the self-closing device is increased and design freedom is reduced
Solution Approach 1:
The self-closing device is divided into multiple retracting modules (first retracting module and second retracting module), each with its own spring biasing member. This segmentation allows the total retracting force to be distributed across multiple smaller springs, achieving the required positioning precision without increasing the size of individual spring components.
Solution Approach 2:
Multiple retracting modules with spring biasing members are combined to work together, providing cumulative biasing force. The first and second retracting modules operate simultaneously, merging their individual forces to achieve the required positioning precision without requiring a single large spring.
2Manufacturing precision
If the biasing force at completion of retracting is increased to improve positioning precision, then positioning precision of the sheet feeding cassette is improved, but a large force is required to pull out the sheet feeding cassette during sheet replenishment, impairing user workability
Solution Approach 1:
The biasing force is made dynamic through the engagement mechanism. When the sheet feeding cassette is inserted, the engagement part engages with the engaging part to activate the spring biasing members, providing strong positioning force. When the cassette needs to be removed, the engagement can be disengaged, allowing easy pull-out without fighting the spring force.
Solution Approach 2:
The retracting function is divided into multiple modules with different engagement characteristics. The first retracting module engages at a different position than the second retracting module, allowing staged engagement and disengagement that provides strong positioning during operation but easy removal when needed.
3Force
If a weight-based self-closing device is used to retract the sheet feeding cassette, then the biasing force is provided by self-weight, but a space housing the weight is required and the device becomes heavy, increasing the size of the self-closing device
Solution Approach 1:
The weight-based gravitational system is replaced with spring-based elastic systems. Instead of using a weight that relies on gravity to provide biasing force, compact spring biasing members are used that can generate the required force in a much smaller volume, eliminating the need for large weight housing spaces.
Solution Approach 2:
The physical principle generating the biasing force is changed from gravitational force (weight) to elastic force (springs). This parameter change allows the same function to be achieved with significantly reduced size and weight, as springs can be made compact while still providing adequate biasing force.
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
The solution enhances user workability by reducing the maximum pulling force required and maintains precise cassette positioning, while minimizing the device's size and weight, thus improving overall operational efficiency and design flexibility.
Implementation Method 1
If a spring is used as a biasing member for retracting the sheet feeding cassette
Implementation Method 2
the self-closing device is provided with a buffering member to buffer a biasing force
Data Source
AI summary
A self-closing device is configured to retract a unit capable of being pulled out with respect to an apparatus main body, to the apparatus main body. The self-closing device includes a plurality of retracting modules configured to retract the unit from a retracting start position towards a retracting end position. The plurality of retracting modules are provided such that retracting strokes from the retracting start position to the retracting end position partially overlap each other and the retracting start positions are different from each other in the retracting direction.