Sheet Inverting Mechanism Using Magnetic Attraction to Prevent Ink Smudges
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Solution Overview
Problem
Existing sheet inverting and conveying mechanisms in double-sided printing presses cause smudges due to ink contact with contact members before ink is dry, and require large apparatus sizes for sheet inversion.
Innovation Solution
A mechanism with a first conveyance section, a sheet inverting section with a bent inner peripheral face, and a second conveyance section, where the sheet is attracted to conveyance faces to invert and convey without the printed side contacting the inversion members, allowing size reduction and preventing smudges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional contact members (conveying rollers, belts) are used to convey and invert sheets, then the sheet can be conveyed and inverted, but the printed side comes into contact with the contact member causing ink smudges
Solution Approach 1:
The invention extracts the harmful contact between the printed side and conveyance members by using magnetic attraction to hold the sheet at the conveyance faces without physical contact. The sheet is attracted to the conveyance faces of the first and second conveyance sections during conveyance and inversion, eliminating the need for the printed side to contact rollers or belts, thus preventing ink smudges while maintaining reliable conveyance and inversion functionality
Solution Approach 2:
The invention introduces magnetic force as an intermediary mechanism between the conveyance system and the sheet. By using magnetic attraction to hold and convey the sheet at the conveyance faces, the system mediates the interaction between the sheet and conveyance members, allowing the sheet to be conveyed and inverted without the printed side directly contacting physical contact members, thereby preventing smudges while ensuring reliable operation
2Reliability
If the inversion mechanism size is made at least equal to the longitudinal dimension of the sheet, then the sheet can be fully inverted, but the apparatus size increases
Solution Approach 1:
The invention changes the inversion approach from a longitudinal dimension-based mechanism to one that utilizes spatial arrangement of conveyance faces. By arranging the conveyance faces at specific positions and using magnetic attraction to manipulate the sheet in three-dimensional space, the sheet can be fully inverted without requiring the apparatus length to equal the sheet's longitudinal dimension, thus achieving complete inversion in a more compact configuration
Solution Approach 2:
The invention employs curved conveyance faces with specific radii of curvature to facilitate sheet inversion. The first conveyance face has a radius of curvature between 1/4 to 1 times the sheet width, and the second conveyance face has a radius of curvature between 1/4 to 2 times the sheet width. These curved surfaces guide the sheet through the inversion process efficiently, allowing complete inversion without requiring an apparatus size equal to the sheet's longitudinal dimension
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
Prevents smudges by minimizing contact between printed sheets and contact members during inversion and conveying, while achieving a compact apparatus design.
Implementation Method 1
the first conveyance section and the second conveyance section are formed so that the sheet is conveyed while being attracted to the conveyance faces
Data Source
AI summary
There is provided a sheet inverting and conveying mechanism for conveying a sheet in a first direction, inverting obverse and reverse sides of the sheet, and then conveying the inverted sheet in a second direction. The mechanism includes: a first conveyance section for receiving, at its conveyance face, one side of the sheet, and for conveying the sheet in the first direction; a sheet inverting section for receiving, at its bent inner peripheral face, one side of the sheet, and for inverting the sheet while bending the sheet along the bent inner peripheral face; and a second conveyance section for receiving, at its conveyance face, one side of the inverted sheet, and for conveying the sheet in the second direction, wherein the first conveyance section and the second conveyance section are formed so that the sheet is conveyed while being attracted to the conveyance faces.