Sheet Feeding Apparatus Opening Unit Creep Deformation
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Solution Overview
Problem
The manual tray type sheet feeding apparatus in image forming devices is prone to deformation due to the high pressurizing force from the spring mechanism, especially in high temperature environments, which can lead to creep deformation over time.
Innovation Solution
A sheet feeding apparatus design that includes an opening/closing unit with a moving member and a transmitting portion to manage the urging force, allowing the moving unit to be pressed against the urging force while closing, thereby reducing the force received by the opening/closing unit at the closed position, and incorporating a restrict member to control the movement and force transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pressurizing spring is used to urge the lift member downward to bring the pickup roller into contact with the sheet, then the sheet feeding reliability is improved, but the opening/closing unit may undergo creep deformation under high temperature environment
Solution Approach 1:
A cam mechanism is introduced as an intermediary between the pressurizing spring and the lift member. The cam mechanism converts the continuous urging force of the spring into intermittent contact force, allowing the pickup roller to press against the sheet during sheet feeding while releasing the force when not in use, thereby preventing creep deformation of the opening/closing unit.
Solution Approach 2:
The lift member is designed to perform periodic swing operations, contacting the sheet only when needed for sheet feeding. The cam mechanism controls this periodic action, ensuring the pressurizing force is applied intermittently rather than continuously, which reduces cumulative stress and prevents creep deformation of the opening/closing unit under high temperature conditions.
2Reliability
If the lift member has a certain length to stably bring the pickup roller into contact with and separate from the sheet, then the sheet feeding stability is improved, but the device complexity increases due to storage requirements
Solution Approach 1:
The lift member is merged with the opening/closing unit, forming an integrated structure where the lift member is supported by the opening/closing unit. This integration eliminates the need for separate storage mechanisms, as the lift member naturally returns to its initial position through the swing operation linkage with the opening/closing unit, simplifying the overall device structure while maintaining sheet feeding stability.
Solution Approach 2:
The lift member is designed as a dynamic component that swings between contact and separation positions rather than a static component requiring storage. The swing operation linkage with the opening/closing unit enables the lift member to dynamically adjust its position based on operational needs, eliminating the complexity of fixed storage mechanisms while ensuring stable sheet feeding.
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 design effectively suppresses deformation of the opening unit and reduces the risk of creep deformation, maintaining the structural integrity of the apparatus even in high temperature conditions, while ensuring efficient sheet feeding operations.
Implementation Method 1
a pressurizing spring configured to urge the swing arm in the first direction
Data Source
AI summary
A sheet feeding apparatus includes an opening/closing unit including a stacking portion, a moving unit including a feed roller and a moving member supporting the feed roller, an urging portion, and a transmitting portion to transmit urging force of the urging portion to the moving member. The opening/closing unit presses and moves the moving unit in the second direction against the urging force while the opening/closing unit moves from the open position to the closed position. A force that the opening/closing unit receives from the moving unit in a state where the opening/closing unit is at the closed position is smaller than a maximum force that the opening/closing unit receives from the moving unit that is urged in the first direction by the urging portion while the opening/closing unit moves from the open position to the closed position.