Paper-sheet punching device switchback delivery alignment

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Solution Overview

Problem

Conventional paper-sheet punching devices require a wide clearance between the punch and die to accommodate varying paper thicknesses, leading to irregular hole punching due to longer strokes, which increases the likelihood of punching errors.

Innovation Solution

A paper-sheet punching device with a switchback delivery system that corrects skew and punches holes in the paper sheet before folding, allowing the paper to be delivered in a consistent manner through the punching units, eliminating the need for a wide clearance between the punch and die.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a wide clearance is secured between the punch and die to accommodate varying paper thickness, then the device can handle different paper types, but the stroke becomes longer which increases the likelihood of punching irregularities

Engineering Contradiction:

Improveability to handle varying paper thicknessVSAvoidpunching accuracy

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The paper sheet is conveyed in a reversed direction (switchback delivery) to position it precisely before punching occurs. This preliminary positioning action ensures the paper is correctly aligned and stable before the punching stroke begins, eliminating the need for excessive clearance and preventing punching irregularities

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The delivery direction of the paper sheet is reversed (switchback delivery) so that the paper is fed back through the punching unit in the opposite direction. This inversion allows for better positioning control and ensures the paper is properly aligned before punching, resolving the contradiction between adaptability and precision

Inventive Principle:

Principle #13The other way round (Inversion)

2Length of moving object

If a longer stroke is used to accommodate the wide clearance, then the device can process thicker papers, but the punching accuracy decreases due to increased chance of irregular holes

Engineering Contradiction:

Improvepunch stroke lengthVSAvoidhole punching accuracy

Core Design Contradiction:

Length of moving objectVSManufacturing precision

Solution Approach 1:

The switchback delivery mechanism performs preliminary positioning of the paper sheet before the punching stroke. By conveying the paper in reverse direction and positioning it precisely, the system ensures accurate hole placement even with shorter strokes, eliminating the need to increase stroke length for accuracy

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system replaces the mechanical approach of increasing stroke length for better positioning with a controlled delivery mechanism. The switchback delivery system uses controlled paper conveyance to achieve precise positioning, substituting the need for long strokes with a controlled feeding system

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS7783244B2Paper-sheet punching device, paper-sheet folding device, and image forming device

Publication Date: 2010.08.24 RICOH CO LTD

AI summary

A paper-sheet punching device punches a hole in a paper sheet. The paper sheet punching device includes a punching unit that receives a paper sheet via an inlet, and punches a hole in the paper sheet; and a return roller that delivers the paper sheet with the hole via an outlet.