Reversing Sheet Transport Clutch Timing for Jam Prevention
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Solution Overview
Problem
Existing reversing sheet transport apparatuses face issues with jamming due to thick and rigid sheets being pushed back toward reverse rollers by elastic force when reversing the sheet's side, especially when both registration and reverse rollers are rotated by a single motor, leading to separation from registration rollers before re-transport begins.
Innovation Solution
A reversing sheet transport apparatus with a single motor driving both registration and reverse rollers, utilizing a control section to switch the registration roller clutch to engaged state during normal rotation and the reverse roller clutch to disengaged state after a timed delay from the start of normal rotation, ensuring the reverse rollers are freely rotatable when the sheet is transported by registration rollers, preventing jamming.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single motor is used to drive both registration rollers and reverse rollers, then the device complexity is reduced, but jamming occurs when thick and rigid sheets are pushed back toward reverse rollers by elastic force
Solution Approach 1:
The control section disengages the reverse roller clutch before the registration roller clutch is fully engaged, creating a preliminary period where reverse rollers are freely rotatable. This preliminary action prevents the elastic force of thick sheets from pushing them back toward reverse rollers, thereby preventing jamming while maintaining single motor operation.
Solution Approach 2:
The system dynamically adjusts the engagement state of the reverse roller clutch based on the operational phase. During the transition from reverse rotation to normal rotation, the reverse roller clutch is disengaged to allow free rotation, while during normal transport, it is engaged. This dynamic adjustment resolves the contradiction between using a single motor and preventing jamming.
2Productivity
If the reverse roller clutch is disengaged immediately when the motor switches to normal rotation, then sheets are pulled out rapidly from reverse rollers, but thick and rigid sheets may still be pushed back causing separation from registration rollers
Solution Approach 1:
The control section disengages the reverse roller clutch in advance before the registration roller clutch is fully engaged, creating a safety buffer period. This preliminary disengagement ensures that even thick and rigid sheets cannot be pushed back toward the reverse rollers, preventing jamming while maintaining efficient sheet transport.
Solution Approach 2:
The control section rapidly transitions the reverse roller clutch from engaged to disengaged state, skipping the intermediate period where jamming could occur. This rapid transition ensures sheets are pulled out from reverse rollers before elastic force can cause them to push back, maintaining both productivity and reliability.
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 effectively prevents jamming by ensuring reliable sheet transport without being pushed back toward reverse rollers, allowing even rigid sheets to be pulled out rapidly from the reverse rollers, enhancing operational stability and efficiency.
Implementation Method 1
Such a reversing sheet transport apparatus is provided with an electromagnetic clutch that conveys or shuts off the rotation of a motor to the registration rollers
Implementation Method 2
the sheet is pushed back toward the reverse rollers due to the elastic force of the sheet that has hit against the registration rollers and bent
Data Source
AI summary
When a first elapse time Δt3 from time point t1 of stop of a transport motor reaches a first specified time S1, a registration roller electromagnetic clutch is engaged. At time point t2 at which the first elapse time Δt3 reaches 50 ms, normal rotation of the transport motor is started. At time point t3 at which a second elapse time Δt4 from the time point t2 reaches a second specified time S2 (a given length of time), a reverse roller electromagnetic clutch is switched from an engaged state to a disengaged state, rendering reverse rollers and sheet discharge rollers freely rotatable. At subsequent time point t4, a coil of a solenoid is de-energized, to separate the reverse rollers from each other.