Stapler Clincher Unit Downward Rotation Mechanism

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Solution Overview

Problem

Conventional staplers face issues with bending staple legs inward when binding multiple sheets, leading to leg collision with clincher surfaces, requiring longer staples and wider staple crowns, which increases the stapler's size and complexity, and results in poor usability and increased costs due to the need for different staple types and potential leg overlap.

Innovation Solution

A stapler design that uses a clincher unit with offset clinchers and a partition plate to guide the staple legs inward, allowing for secure bending without leg overlap, and maintains the clincher direction through a return spring mechanism to prevent sheet deviation and improve appearance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the legs of the staple are bent inward by rotating the clinchers, then the binding strength is improved, but when there are many sheets to be bound, the legs collide with the clincher surfaces at upper sides of rotating fulcrum points, preventing proper bending

Engineering Contradiction:
Improvebinding strengthVSAvoidleg bending operation
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

Instead of rotating the clinchers upward to bend the legs inward (conventional method), this invention rotates the clinchers downward. The clincher holder is configured to rotate the clinchers in a downward direction about the rotating fulcrum points, allowing the legs to be bent inward without colliding with upper clincher surfaces. This inversion of the rotation direction resolves the collision problem while maintaining binding strength.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

A clincher holder is introduced as an intermediary component that mediates between the driving mechanism and the clinchers. The clincher holder rotatably supports the clinchers and transmits the driving force, enabling controlled downward rotation about rotating fulcrum points. This intermediary structure facilitates the inverted rotation method and ensures reliable leg bending.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If staples with longer legs are used to enable proper protrusion from the backside of the sheet, then the binding capability for many sheets is improved, but the width of the staple crown must be widened, increasing the magazine width and overall apparatus size

Engineering Contradiction:
Improvebinding capability for many sheetsVSAvoidstaple crown width and magazine width
Core Design Contradiction:
Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

By inverting the clincher rotation direction to downward rotation, the invention enables proper leg bending without requiring excessively long legs. The downward rotation allows the legs to be bent inward effectively even with moderate leg lengths, thereby reducing the required staple crown width and magazine width while maintaining adaptability for binding many sheets.

Inventive Principle:
Principle #13The other way round (Inversion)

3Stability of the object's composition

If the clincher holder is pushed up by the return spring at the front side, then the clincher direction is maintained, but the position of the sheets deviates, causing the legs to be deviated in the front-rear direction during penetration

Engineering Contradiction:
Improveclincher direction stabilityVSAvoidsheet and leg positioning precision
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The invention addresses the positioning problem by changing the dimension of support. Instead of supporting only the front side (single-point support in the front-rear dimension), the clincher holder supports both the front side and the rear side (dual-point support across two dimensions). This distributed support prevents sheet deviation while maintaining clincher direction stability.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Shape

If the clinchers are offset in the front-rear direction to prevent leg overlap, then the appearance is improved, but the device complexity increases

Engineering Contradiction:
Improveleg arrangement and appearanceVSAvoidclincher configuration complexity
Core Design Contradiction:
ShapeVSDevice complexity

Solution Approach 1:

By inverting the clincher rotation to downward direction, the invention prevents leg overlap through the rotation mechanism itself rather than through spatial offset. The downward rotation naturally guides the legs inward without requiring front-rear offset, thereby achieving improved appearance while reducing device complexity.

Inventive Principle:
Principle #13The other way round (Inversion)

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 secure bending of staple legs inward, preventing leg overlap and maintaining the clincher direction, thus improving usability and reducing the need for multiple staple types, while maintaining a compact design and enhancing the stapler's operational efficiency.

Implementation Method 1

the clincher holder is applied with the force of pushing up the same by a return spring

Methodology Applied
Scientific EffectElastic force: Elasticity

Data Source

PatentEP2540447B1Stapler
Publication Date: 2018.08.08 MAX CO LTD
  • EP2540447B1 patent drawingFigure 1
  • EP2540447B1 patent drawingFigure 2
  • EP2540447B1 patent drawingFigure 3

AI summary

A clincher unit (2A) is provided with a pair of clinchers (20L, 20R) for bending two legs (10b) of a staple; and a clincher driving mechanism (21, 22L, 22R, 23) for rotating and moving the clinchers (20L, 20R) in separating/contacting directions. The clincher driving mechanism (21, 22L, 22R, 23) moves the pair of clinchers (20L, 20R) in an approaching direction each other, as a movement of starting to bend the legs (10b) of the staple having penetrated the sheets.