Form Conveyance Power Transfer Unit Ratchet Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Form processing devices face issues with form conveyance when reversing, as stored forms can be accidentally pulled back into the conveyance path, leading to overlapping and feed problems.
Innovation Solution
A form conveyance device with a cylindrical support shaft, a paper feed roller that rotates in both directions, and an in-feed roller that rotates only forward, utilizing a power transfer unit with a ratchet mechanism to interrupt drive power during reverse rotation, preventing the in-feed roller from moving and using an in-feed tab to catch the trailing end of stored forms and prevent them from being pulled back.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the paper feed roller rotates in reverse to convey forms backward, then forms can be reversed for reprocessing, but stored forms may be accidentally pulled back into the conveyance path causing overlapping and feed problems
Solution Approach 1:
The power transmission system is segmented into unidirectional and bidirectional components. The in-feed roller is driven by a unidirectional power transmission mechanism (ratchet and pawl) that allows power transfer only in the forward direction, while the paper feed roller can rotate bidirectionally. This segmentation enables the paper feed roller to reverse forms while the in-feed roller remains stationary, preventing stored forms from being pulled back.
Solution Approach 2:
Instead of allowing the in-feed roller to rotate bidirectionally like the paper feed roller, the invention inverts the approach by making the in-feed roller unidirectional (forward only) while the paper feed roller handles bidirectional rotation. This inversion ensures that during reverse conveyance, the in-feed roller acts as a stationary stop that prevents stored forms from being pulled back into the conveyance path.
2Ease of operation
If the in-feed roller rotates freely in both directions, then it can assist in conveying forms smoothly, but it cannot prevent stored forms from being pulled back during reverse operations
Solution Approach 1:
The ratchet and pawl mechanism serves as an intermediary between the paper feed roller and the in-feed roller. This intermediary component allows power transmission from the paper feed roller to the in-feed roller only in the forward direction, while blocking power transmission in the reverse direction. This enables the in-feed roller to assist in forward conveyance while remaining stationary during reverse operations, preventing stored forms from being pulled back.
3Reliability
If a power transfer unit with ratchet mechanism is introduced, then drive power is interrupted during reverse rotation preventing form pulling back, but device complexity increases
Solution Approach 1:
The ratchet and pawl mechanism is a self-regulating power transmission device that automatically engages and disengages based on the direction of rotation. During forward rotation, the pawl engages the ratchet teeth to transmit power to the in-feed roller. During reverse rotation, the pawl disengages automatically, allowing the in-feed roller to remain stationary. This self-service mechanism provides reliable form conveyance control without requiring external control systems or complex actuation mechanisms.
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
Ensures consistent form conveyance by preventing stored forms from being pulled back into the path during reverse operations, reducing paper jams and maintaining a clear path for subsequent forms.
Implementation Method 1
a ratchet part on the in-feed roller side that transfers and interrupts drive power to the in-feed roller
Implementation Method 2
an elastic part that urges the power transfer unit toward the in-feed roller
Implementation Method 3
an in-feed tab on the in-feed roller catches the trailing end part of any form already stored in the storage unit and stops movement of the stored form in reverse
Data Source
AI summary
A form conveyance device can reverse a form without pulling another form already stored in a storage unit into the conveyance path. A form conveyance device conveys a form on edge in forward and reverse directions and feeds the form into the storage unit. Such device includes a cylindrical support shaft, and a paper feed roller that is axially supported on the support shaft and can rotate in forward and reverse directions. Also included is an in-feed roller that is axially supported on the support shaft, can rotate only in the forward direction, and on the outside surface has in-feed tabs extending in the axial direction. A power transfer unit of the device is disposed between the paper feed roller and in-feed roller, and transfers drive power from the paper feed roller to the in-feed roller only when the paper feed roller rotates in the forward direction.