Sheet Conveying Device Cam Mechanism for Solenoid-Free Pressure Control
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Solution Overview
Problem
Existing sheet conveying devices require solenoids to increase contact pressure between the feed roller and the sheet, which can be cumbersome and inefficient.
Innovation Solution
A sheet conveying apparatus that includes a pivotable support tray, a cam mechanism, and a drive mechanism using a sector gear and drive gear to increase contact pressure between the feed roller and the sheet without the need for a solenoid, utilizing a selector lever and hook to control the rotation of the cam and sector gear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a solenoid is used to increase contact pressure between the feed roller and the sheet, then the contact pressure can be increased, but the device complexity and noise increase
Solution Approach 1:
The patent replaces the solenoid (electromagnetic actuator) with a purely mechanical cam mechanism. The cam, driven by a motor through a gear system, mechanically pushes the feed roller against the sheet to increase contact pressure during the feed operation. This substitution eliminates the need for electromagnetic components while achieving the same force application function.
Solution Approach 2:
The patent implements dynamic contact pressure control where the feed roller is pressed against the sheet only during the feed operation, then released. The cam mechanism provides temporary, dynamic pressure increase rather than continuous pressure, allowing the feed roller to return to its original position after feeding. This dynamic approach reduces overall device complexity while maintaining effective contact pressure when needed.
2Force
If a solenoid is used to increase contact pressure between the feed roller and the sheet, then the contact pressure can be increased, but noise increases
Solution Approach 1:
The patent replaces the solenoid (electromagnetic actuator) with a purely mechanical cam mechanism. The cam, driven by a motor through a gear system, mechanically pushes the feed roller against the sheet to increase contact pressure during the feed operation. This substitution eliminates the need for electromagnetic components while achieving the same force application function.
3Device complexity
If a cam mechanism with sector gear and drive gear is used instead of a solenoid, then device complexity is reduced, but the reliability of contact pressure control may be affected
Solution Approach 1:
The patent implements dynamic contact pressure control where the feed roller is pressed against the sheet only during the feed operation, then released. The cam mechanism provides temporary, dynamic pressure increase rather than continuous pressure, allowing the feed roller to return to its original position after feeding. This dynamic approach reduces overall device complexity while maintaining effective contact pressure when needed.
Solution Approach 2:
The patent incorporates a sheet presence detection mechanism that controls the cam activation. When a sheet is detected on the support tray, the cam mechanism is activated to press the feed roller against the sheet. This feedback control ensures the mechanical system operates only when needed, maintaining reliability by preventing unnecessary operations and ensuring proper timing of the contact pressure application.
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
Enables reliable and efficient contact between the feed roller and sheet, allowing for increased contact pressure and flexible control of the sheet conveying process without the use of solenoids, improving the stability and noise reduction of the device.
Implementation Method 1
a spring, a sector gear, a drive gear, a feed roller, and a drive mechanism. The first cam is configured to, when engaging the hook, stop rotating in a rotation direction of the first cam. The spring is configured to urge the first cam in the rotation direction.
Implementation Method 2
a first cam rotatable and engageable with the hook. The first cam is configured to, when engaging the hook, stop rotating in a rotation direction of the first cam.
Implementation Method 3
a sector gear, a drive gear, a feed roller, and a drive mechanism. The sector gear is rotatable together with the first cam. The rive gear is engageable with the sector gear. The drive gear is configured to, when engaging the sector gear, transmit a drive force to the sector gear.
Data Source
AI summary
A sheet conveying device includes a sheet supporting portion, a first lever pivotable by contact with a sheet supported by the sheet supporting portion, a hook movable together with the first lever, a first cam configured to, when engaging the hook, stop rotating in a rotation direction of the first cam, a spring configured to urge the first cam in a rotation direction, a sector gear rotatable together with the first cam, a drive gear configured to, when engaging the sector gear, transmit a drive force to the sector gear, a feed roller rotatable in contact with the sheet, and a drive mechanism configured to receive a drive force from the sector gear and move one of the feed roller and the sheet supporting portion toward the other of the feed roller and the sheet supporting portion, to increase contact pressure between the feed roller and the sheet.