Sheet Supplying Roller Pivot Mechanism for Friction Control
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Solution Overview
Problem
Existing sheet supplying devices for ink-jet recording apparatuses face issues with excessive wear and potential locking of sheet-supply rollers due to high friction forces when few thin recording sheets remain, leading to sheet flexing, wrinkling, or jamming.
Innovation Solution
A sheet supplying apparatus with a moving device that includes a detecting portion and a detection-movement converting device, which pivots the sheet supplying arm to lift the roller away from the support surface when no sheets are present, preventing excessive friction and wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the sheet-supply roller is pressed against the recording sheets with high friction force to prevent underlying sheets from being supplied, then the separation reliability is improved, but the roller may be locked and the driving system may be broken when no sheets remain
Solution Approach 1:
The patent applies preliminary action by providing a relief hole in the sheet supporting portion before the roller makes contact. This relief hole prevents excessive friction force from being generated when no sheets are present, thereby preventing roller locking and driving system damage while maintaining reliable sheet separation when sheets are available
Solution Approach 2:
The patent uses a relief hole (a form of porous structure) in the sheet supporting portion to allow the roller to contact the supporting portion only at specific locations. This reduces the contact area and prevents excessive friction force from being applied to the roller when no sheets are present, thereby preventing roller locking while maintaining sheet separation reliability
2Ease of operation
If the sheet-supply roller is pressed against thin recording sheets with high friction force, then the sheet supply control is improved, but the thin sheets may be flexed, wrinkled, or jammed
Solution Approach 1:
The patent applies local quality by creating a relief hole at a specific location in the sheet supporting portion. This allows the roller to press against thin sheets with controlled friction force only at locations where sheets are present, preventing excessive friction from causing sheet flexing or wrinkling while maintaining adequate sheet supply control
Solution Approach 2:
The relief hole is pre-formed in the sheet supporting portion to control the friction force application. When thin sheets are present, the roller contacts the sheets through the relief hole opening, providing sufficient friction for supply control without excessive force that would cause sheet deformation
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 excessive wear and locking of the sheet-supplying rollers, ensuring smooth operation and preventing motor seizure by eliminating friction forces when no sheets are left, thus maintaining efficient sheet supply.
Implementation Method 1
The arm member is biased downward by a biasing force of a spring
Implementation Method 2
an outer circumferential surface of the sheet-supply roller is formed of a material having a high friction coefficient, such as rubber
Data Source
AI summary
A sheet supplying apparatus, comprising a sheet accommodating portion which accommodates stacked recording sheets such that the recording sheets are supported by a support surface thereof; a sheet supplying arm which is supported by a frame such that the sheet supplying arm is pivotable about a first axis line, and which is biased toward the support surface of the sheet accommodating portion; a sheet supplying roller which is supported by an end portion of the sheet supplying arm such that the sheet supplying roller is rotatable about a second axis line parallel to the first axis line, and which is pressed on the uppermost recording sheet, so that when the sheet-supply roller is rotated, the uppermost recording sheet is supplied from the sheet accommodating portion; a receiving portion which is provided in the support surface and which is covered by the recording sheets and is opened when a trailing end of the last recording sheet passes over the receiving portion; and a moving device including a detecting portion which is supported by the recording sheets and which moves, when the trailing end of the last recording sheet passes over the receiving portion, into the receiving portion, and further including a detection-movement converting device which converts the movement of the detecting portion into the receiving portion, into the pivotal movement of the sheet supplying arm about the first axis line in a direction to move the sheet supplying roller away from the support surface of the sheet accommodating portion.