Variable Speed Stapler for Small Sheet Bundles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional sheet processing apparatuses in image forming devices face productivity losses due to prolonged stapling times when handling small sheet bundles, as the motor speed decreases with increased sheet bundle weight, requiring larger motors and increased costs or apparatus size to maintain efficiency.
Innovation Solution
The apparatus adjusts the moving speed of the sheet bundle based on its weight or number of sheets, allowing for faster movement when stapling smaller bundles by moving the stapler and sheet bundle in opposite directions, thereby reducing stapling process time without enlarging the apparatus or increasing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the sheet bundle moving speed is kept constant regardless of bundle size, then the motor design is simplified, but the productivity decreases significantly for small sheet bundles
Solution Approach 1:
The patent applies dynamics by making the sheet bundle moving speed variable rather than constant. The control unit dynamically adjusts the moving speed based on the detected number of sheets in the bundle, allowing faster movement for small bundles and slower movement for large bundles, thereby optimizing productivity across different bundle sizes without requiring an oversized motor.
Solution Approach 2:
The patent changes the speed parameter of the sheet bundle based on the bundle size. The control unit modifies the moving speed parameter according to the number of sheets detected, implementing a variable speed regime that adapts to different workload conditions, thus improving overall system efficiency and productivity.
2Speed
If a motor with large output is used to maintain constant speed for heavy bundles, then the speed stability is improved, but the apparatus size and cost increase
Solution Approach 1:
The system uses dynamic speed adjustment to match the motor's operating conditions to the actual load requirements. By reducing the speed for heavier bundles and increasing it for lighter bundles, the motor operates within an optimal range throughout, eliminating the need for an oversized motor that would be required to maintain constant high speed under all conditions.
Solution Approach 2:
The patent changes the speed parameter dynamically based on bundle weight (inferred from sheet count), allowing the motor to operate efficiently across different load conditions. This parameter adaptation enables the use of a smaller, more cost-effective motor while maintaining appropriate speed control for productivity.
3Productivity
If the sheet bundle moving speed is increased for small bundles, then the productivity is improved, but the moving accuracy may deteriorate
Solution Approach 1:
The patent applies local quality by implementing different speed characteristics for different phases of the moving cycle. High speed is used during the majority of the travel distance to maximize productivity, while controlled deceleration and positioning phases ensure accurate placement at the destination, thus achieving both high productivity and positioning accuracy.
Solution Approach 2:
The moving operation follows a periodic pattern of acceleration, constant high-speed travel, deceleration, and positioning. This cyclic speed variation allows the system to achieve high average speeds for productivity while ensuring precise positioning at each stapling location, balancing speed and accuracy requirements.
Data Source
AI summary
A sheet processing apparatus includes a stack tray, a stapler, a stapler moving device, and an aligning member. When a stapling process is performed at least two staple positions of the sheet bundle stacked on the stack tray using the stapler, the stapler is moved to the next staple position by relative movement in which the stapler and the sheet bundle are moved in the opposite directions by the stapler moving device and the aligning member respectively. When the number of sheets in the sheet bundle or a weight of the sheet bundle is lower than a predetermined value, a moving speed of the sheet bundle is set faster than a moving speed of the sheet bundle at which the number of sheets in the sheet bundle is not lower than the predetermined value or the weight of the sheet bundle is not lower than the predetermined value.