Sheet Feeder Friction Member with Slanted Guide Surface
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Solution Overview
Problem
Existing sheet feeders face issues with multi-feed, empty feed, and wrinkled or folded sheets due to dimensional variations in the friction member and recessed section, leading to inadequate frictional force and contact pressure.
Innovation Solution
A sheet feeder design with a friction member having a contact pressure surface closer to the feed roller than the supporting member's upper surface, and a slanted guide surface to guide sheets effectively, preventing intersection with the supporting member, ensuring consistent frictional resistance and proper sheet alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the friction member is disposed on the upper surface of the supporting member without a recessed section, then the structure is simpler, but the upper surface of the friction member must be higher than the supporting member, creating a step-shaped boundary that causes empty feed and wrinkled or folded sheets
Solution Approach 1:
The friction member is nested within a recessed section of the supporting member, allowing the friction member's upper surface to be at the same level as the supporting member's upper surface, eliminating the step-shaped boundary that causes feeding problems while maintaining structural simplicity
2Device complexity
If the upper surface of the friction member protrudes from the upper surface of the supporting member, then the friction member can be simpler in structure, but the leading end of the sheet collides against the upstream end of the friction member, causing empty feed and wrinkled or folded sheets
Solution Approach 1:
The friction member is positioned within the recessed section such that its upper surface is at the same level as the supporting member's upper surface, preventing sheet collision while maintaining structural simplicity
3Device complexity
If the upper surface of the friction member is recessed from the upper surface of the supporting member, then the friction member can be simpler in structure, but the contact pressure between the sheet and friction member is low, resulting in insufficient frictional force and multi feed
Solution Approach 1:
The friction member is nested within the recessed section with its upper surface at the same level as the supporting member, ensuring sufficient contact pressure and frictional force to prevent multi-feed while maintaining structural simplicity
4Manufacturing precision
If a recessed section is formed with depth equal to the friction member thickness, then the upper surfaces align perfectly, but dimensional variations within tolerances cause the friction member upper surface to protrude or be recessed, leading to feeding failures
Solution Approach 1:
The recessed section is designed with specific dimensional characteristics that compensate for manufacturing tolerances, ensuring that the friction member's upper surface maintains appropriate alignment with the supporting member's upper surface under varying manufacturing conditions
Solution Approach 2:
The recessed section design anticipates and compensates for dimensional variations within tolerances, preventing feeding failures before they occur by ensuring proper alignment even when manufacturing precision varies
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
Prevents multi-feed and ensures smooth sheet feeding by maintaining consistent frictional force and alignment, reducing the likelihood of empty feed and wrinkled or folded sheets.
Implementation Method 1
a friction member configured to contact a bottom one of stacked sheets in a sheet staking direction, so as to prevent such a failure that two or more sheets are fed together
Implementation Method 2
a feed roller configured to apply a feeding force to the stacked sheets by rotating in contact with an upward-facing side of a top one of the stacked sheets
Data Source
AI summary
A sheet feeder is provided that includes a friction member that includes a contact pressure surface that is configured to contact a feed roller when there is no sheet between the friction member and the feed roller and disposed closer to the feed roller than an upper surface of a supporting member supporting the friction member such that a virtual tangential plane, which is such a virtual plane as if the contact pressure surface were extended toward an upstream side and a downstream side in a sheet feeding direction, does not intersect with the supporting member, and a slanted guide surface that is disposed upstream relative to the contact pressure surface in the sheet feeding direction and slanted with respect to the virtual tangential plane so as to be farther away down from the virtual tangential plane toward the upstream side in the sheet feeding direction.