Sheet Feeding Apparatus Elevation Control for Reliable Paper Transport
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Solution Overview
Problem
In sheet feeding apparatuses, when the number of sheets stacked decreases, air blown from the air blower may not properly float the sheets, leading to issues with sheet feeding, and existing solutions like constant elevation of the sheet stacker do not effectively address the problem of non-feeding or double feeding.
Innovation Solution
A sheet feeding apparatus with a lifting mechanism, elevation detection sensor, feed detection sensor, and processing circuitry that adjusts the sheet stacker elevation based on sheet thickness and number, ensuring proper sheet feeding by lifting the stacker by varying amounts depending on the remaining sheets and stopping the lift when the threshold is reached.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the sheet stacker is constantly elevated each time a sheet is fed, then the sheet feeding reliability is improved, but the device complexity increases and the manufacturing precision deteriorates due to error accumulation
Solution Approach 1:
The sheet stacker is pre-elevated by a predetermined amount before sheet feeding begins. This preliminary action ensures that the air blower can effectively float the uppermost sheet throughout the feeding process, preventing non-feeding issues without requiring complex real-time adjustments during operation
Solution Approach 2:
A detection sensor monitors whether sheets are present at the sheet stacker, and the processing circuitry adjusts the elevation amount based on this feedback. When sheets are detected, the stacker is elevated by a first amount; when no sheets are detected, it is elevated by a second (smaller) amount, preventing double feeding while maintaining simplicity
2Reliability
If the sheet stacker is constantly elevated, then non-feeding is prevented, but double feeding occurs due to error accumulation
Solution Approach 1:
The sheet stacker is elevated by a predetermined amount before feeding starts, ensuring proper sheet positioning without requiring multiple incremental adjustments. This single preliminary elevation avoids the cumulative errors that would occur with repeated small adjustments
Solution Approach 2:
The detection sensor provides feedback on sheet presence, allowing the processing circuitry to adjust elevation amounts dynamically. This feedback mechanism corrects positioning errors in real-time, preventing both non-feeding and double feeding by adapting the elevation to actual sheet conditions
3Productivity
If the air blower blows air to float sheets, then sheet feeding is enabled, but when the stacker is low the air passes above sheets causing non-feeding
Solution Approach 1:
The sheet stacker is pre-elevated to an optimal position before sheet feeding begins. This ensures that the air flow from the blower directly contacts the sheets to float them effectively, rather than passing above them, thereby enabling reliable feeding from the start
Solution Approach 2:
The elevation position of the sheet stacker is changed as a controllable parameter to optimize sheet floating. By adjusting the stacker height, the system ensures the air blower's flow path intersects with the sheets, transforming a geometric parameter to solve the floating reliability issue
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 solution prevents non-feeding and double feeding by ensuring the uppermost sheet is floated and fed correctly, even when the sheet stacker is low, and temporarily stops the lifting mechanism to reset errors and prevent double feeding.
Implementation Method 1
The air blower blows air from a lateral side of the plurality of sheets stacked on the sheet stacker to the plurality of sheets to float an uppermost sheet of the plurality of sheets
Implementation Method 2
The suction feeder is disposed above the sheet stacker and sucks the uppermost sheet floated by the air blower and feeds the sheet in a feed direction
Data Source
AI summary
A sheet feeding apparatus includes a sheet stacker, an air blower, a suction feeder, a lifting mechanism, an elevation detection sensor, an elevation detection sensor, a feed detection sensor, and processing circuitry. The air blower blows air to float an uppermost sheet of sheets stacked on the sheet stacker. The processing circuitry drives the lifting mechanism such that the sheet stacker is lifted by an elevation amount determined based on a sheet thickness of the sheets stacked on the sheet stacker, each time a sheet is detected when a number of sheets detected is smaller than a threshold number of sheets, and stops lifting of the sheet stacker until a sheet is not detected when the number of sheets reaches the threshold number of sheets, while repeatedly feeding the uppermost sheet and counting the number of sheets.