Separation Pad Mechanism for Low-Height Document Feeders
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The use of a compression coil spring to press the separation pad against the sheet feed roller in document conveying devices increases the device height and requires a strong force to remove jammed sheets, potentially damaging them.
Innovation Solution
A document conveying device with a pad holder that can turn upward and downward, biased by a tension spring, and a separation pad support mechanism that allows the pad to be separated from the feed roller against the tension spring's bias, reducing the need for a separate drive source and minimizing device height.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a compression coil spring is used to press the separation pad against the sheet feed roller, then the separation pad can be pressed with sufficient force, but the device height increases and strong force is required to remove jammed sheets
Solution Approach 1:
The patent inverts the conventional compression spring mechanism by using a tension spring instead. The tension spring pulls the pad holder upward to press the separation pad against the feed roller, eliminating the need for a compression spring disposed below the roller and reducing device height while maintaining sufficient pressing force.
Solution Approach 2:
The pad holder is designed to be movable around a turning shaft, allowing dynamic adjustment of the separation pad position. This enables the separation pad to be pressed against the feed roller during normal operation and separated when sheets are jammed, providing adaptive force application.
2Reliability
If a compression coil spring is used to press the separation pad, then reliable separation is achieved, but the device height increases by the height of the spring
Solution Approach 1:
The patent replaces the compression spring arrangement with a tension spring arrangement, inverting the force application direction. This eliminates the need for vertical space below the feed roller, reducing device height while maintaining reliable separation through the pad holder mechanism.
Solution Approach 2:
The separation pad pressing mechanism transitions from a vertical compression approach to a rotational movement around a turning shaft. This dimensional change allows the tension spring to apply force horizontally through the pad holder, eliminating the need for vertical spring space.
3Reliability
If the separation pad is pressed with predetermined pressure by an elastic member, then the uppermost sheet can be reliably separated, but strong force is required to pull out jammed sheets
Solution Approach 1:
The pad holder's rotational capability around the turning shaft creates a dynamic system where the separation pad can be easily separated from the feed roller when sheets are jammed. This reduces the force required to remove jammed sheets while maintaining reliable separation during normal operation through the tension spring bias.
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
The solution enables easy removal of jammed sheets with minimal force, reduces device height by about 8%, and eliminates the need for a compression coil spring below the sheet feed roller.
Implementation Method 1
The tension spring 55 biases the pad holder 51 upward to press the separation pad 35 against the feed roller 33
Data Source
AI summary
A document conveying device includes a feed roller, a separation pad, a pad holder, a tension spring, and a separation pad support mechanism. The feed roller and the separation pad form a separation nip at which a sheet is separated and conveyed. The pad holder holds the separation pad and can be turned upward and downward around a turning shaft. The tension spring biases the pad holder upward to press the separation pad against the feed roller. The separation pad support mechanism turns the pad holder in a direction to separate the separation pad from the feed roller against a biasing force of the tension spring.