Retractable Strap Friction Clamping for Safe Spring Recoil

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Solution Overview

Problem

Existing spring loaded retractable devices pose a risk of injury due to high recoil speeds of the strap when retracting, as the powerful spring can cause the attachment means to swing back with significant force, potentially causing injuries.

Innovation Solution

A spring loaded retractable device with a dynamic clamping mechanism that adjusts frictional resistance to control the recoil speed of the strap, ensuring safe retraction without compromising the strength of the spring or durability of the device.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a powerful spring is used to retract the strap fully, then the retraction capability is improved, but the risk of injury from swinging attachment means increases

Engineering Contradiction:
Improveretraction capabilityVSAvoidinjury risk from swinging attachment means
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

A damper is introduced as an intermediary component between the spring and the strap. The damper controls the release of spring energy, allowing the strap to retract fully while limiting the swinging motion of the attachment means. This mediator absorbs excess energy and regulates the force transmission to the strap.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The damper is pre-configured to provide cushioning during the retraction process. By anticipating the potential harmful swinging motion, the damper is designed to absorb and dissipate energy before the attachment means can swing back with injurious force, thus protecting the user in advance.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Object-affected harmful factors

If a weaker spring is used to reduce injury risk, then the safety is improved, but the ability to retract the full length of the strap deteriorates

Engineering Contradiction:
Improveinjury riskVSAvoidretractable strap length
Core Design Contradiction:
Object-affected harmful factorsVSLength of moving object

Solution Approach 1:

The damper serves as a mediator that allows the use of a weaker spring while still achieving full retraction. It regulates the force application over time, enabling the strap to be pulled in completely despite the reduced spring strength, thus resolving the contradiction between safety and retraction capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If the recoil speed is increased for faster retraction, then the productivity is improved, but the harmful effects from high-speed recoil increase

Engineering Contradiction:
Improveretraction speedVSAvoidharmful effects from high-speed recoil
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The damper introduces a controlled periodic action to the retraction process. Instead of a single high-speed recoil, the strap retraction occurs in a controlled sequence with the damper regulating energy release in stages, reducing peak speeds while maintaining overall productivity through efficient energy management.

Inventive Principle:
Principle #19Periodic action

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

The device reduces the risk of injury by controlling the recoil speed of the strap, making it as safe to use as traditional non-retractable securing devices while allowing for a more powerful spring to maintain functionality over time.

Implementation Method 1

The movable part is configured to move from a first position into a second position by rotating around an axis of rotation due to friction between the movable part and the moving strap

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3853067B1Spring loaded retractable device
Publication Date: 2023.10.18 JEIKO INNOVATIONS
  • EP3853067B1 patent drawingFigure 1~2
  • EP3853067B1 patent drawingFigure 3A~3E
  • EP3853067B1 patent drawingFigure 4A~4B

AI summary

According to an example aspect of the present invention, there is provided a spring loaded retractable device (1) comprising a frame (9), a movable part (14) hinged to a first pin (10)and comprising an opening (6) radially aligned to the first pin (10), wherein a strap (3) is movable through the opening (6), and wherein the movable part (14) is configured to move from a first position into a second position by rotating around an axis of rotation due to friction between the movable part (14) and the moving strap (3).