Pickup Roller Arm Angle Control for Sheet Conveyance Oscillation
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Solution Overview
Problem
Conventional sheet conveying apparatuses in image forming devices experience self-oscillation and reduced frictional force when the number of sheets decreases, leading to delayed conveyance, as the pickup roller slips on the sheet due to reduced contact pressure and friction.
Innovation Solution
The sheet conveying apparatus is designed such that the arm angle, rigidity of the oscillation system, and arm length are set to satisfy a specific relationship, preventing self-oscillation by ensuring the arm angle is less than a calculated value, which maintains effective contact pressure and frictional force even with fewer sheets, thereby preventing the pickup roller from oscillating and ensuring consistent conveyance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the number of sheets is reduced, then the sheet conveying apparatus can handle fewer sheets, but the pickup roller oscillates and contact pressure decreases causing conveyance delay
Solution Approach 1:
The invention changes the geometric parameters of the oscillation system by defining a specific relationship between arm angle θ, arm length L, and rigidity K. By ensuring θ ≤ (Pse × K^0.5) × (1/L), the system prevents self-oscillation across different sheet quantities, maintaining reliable conveyance whether handling many or few sheets.
2Force
If the pickup roller contact pressure is reduced, then the frictional force decreases, but the pickup roller slips on the sheet causing conveyance delay
Solution Approach 1:
The invention establishes a parameter relationship θ ≤ (Pse × K^0.5) × (1/L) that prevents self-oscillation, thereby maintaining stable contact pressure between the pickup roller and sheet. This ensures sufficient frictional force for conveyance without slipping, even when sheet quantity varies.
3Force
If the arm angle is increased, then the pickup roller can apply more pressure to the sheet, but self-oscillation occurs when sheet number decreases
Solution Approach 1:
The invention defines a maximum arm angle threshold θ ≤ (Pse × K^0.5) × (1/L) based on the oscillation system's rigidity and length. By keeping the arm angle within this calculated limit, the system maintains both sufficient contact pressure and stability, preventing self-oscillation while ensuring reliable sheet conveyance.
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 configuration prevents self-oscillation and maintains consistent sheet conveyance distance, even when the number of sheets is reduced below twenty, thereby eliminating delays in the sheet conveyance process.
Implementation Method 1
a spring attached to the other end of the arm. The pickup roller is capable of oscillating in a top-to-bottom direction. Furthermore, the pickup roller is brought into contact with a sheet by the spring at a predetermined pressure.
Implementation Method 2
the sheet is conveyed in a paper feed direction by frictional force between the pickup roller and the sheet
Data Source
AI summary
A sheet conveying apparatus, an automatic draft conveying apparatus, a paper feeding apparatus, and an image forming apparatus capable of preventing self-oscillation of a conveying roller. When rigidity of an oscillation system of the conveying roller is K [N/m], the distance between a supporting point of an arm and a section of the arm to which an axis of the conveying roller is attached is L [mm], and arm angle, which is formed between a sheet and a line segment connecting the supporting point of the arm to the section of the arm to which the axis of the conveying roller is attached on an assumed plane perpendicular to a direction of the axis of the conveying roller, is θ [deg], θ≦(Pse×K−0.5)×(1/L) is satisfied, where Pse=37500.