Folder Fastener Slider Mechanism for Safe Clamping

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Solution Overview

Problem

Existing fasteners for document folders require manual effort to open and close, posing risks of hand injury and inconvenience in document sorting, as they often require one hand to hold the fastener and another to manage documents or assist in closing, which can lead to accidental pinching.

Innovation Solution

A fastener design featuring a base plate, hook bracket, and torsion springs with a sliding mechanism that allows independent opening and closing, where the hook bracket is secured by torsional force, eliminating the need for manual hand control during opening and preventing hand injury during closure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If the torsional force of torsion springs is increased to increase the clamping force of the fastener, then the clamping force is improved, but the fastener requires manual holding during opening and may cause hand injury during closing

Engineering Contradiction:
Improveclamping forceVSAvoidease of operation
Core Design Contradiction:
ForceVSEase of operation

Solution Approach 1:

The fastener is divided into independent functional components: the hook bracket for clamping, the slider for control, and the retaining sections for positioning. This segmentation allows the high-force clamping function to be separated from the user interaction function, enabling strong clamping force without requiring manual holding during operation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The fastener design enables self-servicing through the slider mechanism that automatically controls the hook bracket's movement. The slider engages with the retaining sections to initiate opening/closing actions, and the torsion springs provide the necessary force automatically, eliminating the need for continuous manual intervention while maintaining safety.

Inventive Principle:
Principle #25Self-service

2Force

If the torsional force of torsion springs is increased to increase the clamping force of the fastener, then the clamping force is improved, but the risk of hand pinching during closing increases

Engineering Contradiction:
Improveclamping forceVSAvoidhand pinching risk
Core Design Contradiction:
ForceVSObject-affected harmful factors

Solution Approach 1:

The slider acts as an intermediary between the user's manual input and the high-force hook bracket movement. When the user presses the slider, it engages with the retaining sections to control the opening/closing sequence, mediating the interaction to prevent direct hand exposure to the high-force moving parts while still enabling effective operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The retaining sections are pre-positioned on the rotating shafts, and the slider is designed to engage with these sections before the hook bracket moves into the closing position. This preliminary positioning ensures that the high-force closing action is controlled and guided, preventing accidental hand pinching during the closing operation.

Inventive Principle:
Principle #10Preliminary action

3Force

If manual effort is required to hold the fastener during opening, then the clamping force can be maintained, but document sorting becomes inconvenient

Engineering Contradiction:
Improveclamping forceVSAvoiddocument sorting efficiency
Core Design Contradiction:
ForceVSProductivity

Solution Approach 1:

The fastener design enables self-servicing through the slider mechanism that automatically controls the hook bracket's movement. The slider engages with the retaining sections to initiate opening/closing actions, and the torsion springs provide the necessary force automatically, eliminating the need for continuous manual intervention while maintaining safety.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The fastener is divided into independent functional components: the hook bracket for clamping, the slider for control, and the retaining sections for positioning. This segmentation allows the high-force clamping function to be separated from the user interaction function, enabling strong clamping force without requiring manual holding during operation.

Inventive Principle:
Principle #1Segmentation

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 convenient document sorting without manual effort during opening and ensures safe closure by preventing accidental hand pinching, as the torsional force secures the hook bracket, making the fastener safer and easier to use.

Implementation Method 1

torsion springs are respectively sleeved on the rotating shafts on two sides of the front end of the hook bracket; one ends of the torsion springs are fixed on the rotating shafts and the other ends of the torsion springs are fixed on the base plate

Methodology Applied
Scientific EffectTorsion spring: Torsion Spring

Data Source

PatentEP2752306B1Clamp body applied to folder
Publication Date: 2016.05.11 LEUNG MING FUK
  • EP2752306B1 patent drawingFigure 1
  • EP2752306B1 patent drawingFigure 2
  • EP2752306B1 patent drawingFigure 3

AI summary

A fastener for a document folder, comprising a base plate (1), a hook bracket (2) and torsion springs (5), wherein the front end of the base plate (1) is extended upwards and curled to form a bending section (12); a slot is formed by the surrounding of the bending section (12); rotating shafts (21) on two sides of the front end of the hook bracket (2) are respectively arranged at two ends of the inside of the slot; the torsion springs (5) are respectively sleeved on the rotating shafts (21) on two sides of the front end of the hook bracket (2); one ends of the torsion springs (5) are fixed on the rotating shafts (21) and the other ends of the torsion springs (5) are fixed on the base plate; end sections of the rotating shafts (21) are bent upwards to form retaining sections (211); clamp holes engaged with the retaining sections (211) and used for fastener opening formed on the front of the bending section (12).