Retractable Quill Coat Mechanism for Concealed Self-Defense

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Solution Overview

Problem

There is a need for a self-defense coat device that allows users to protect themselves with embedded metal quills that can be easily activated to cause injury to an assailant during an assault or abduction, while also functioning as a standard coat for comfort and warmth, and being conveniently retractable to avoid detection.

Innovation Solution

A self-defense coat device with retractable quills that can be extended or retracted via a button mechanism, featuring a thick material to conceal the quills when not in use, and powered by a battery-operated linear actuator for quick deployment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If metal quills are embedded in the coat for self-defense, then the protective capability is improved, but the detectability and comfort are worsened

Engineering Contradiction:

Improveself-defense capabilityVSAvoiddetectability of quills

Core Design Contradiction:

ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

The quills are designed to be retractable rather than fixed, allowing them to dynamically change position between extended (defensive) and retracted (concealed) states. This dynamic mechanism resolves the contradiction by providing protection only when needed while maintaining a normal coat appearance during normal wear.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The quills are nested within channels or compartments in the coat structure, allowing them to be hidden inside the coat body when not in use. This nesting approach enables the quills to be present for defense but invisible during normal wear, resolving the detectability issue.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Difficulty of detecting and measuring

If quills are made retractable for concealment, then the detectability is improved, but the device complexity increases

Engineering Contradiction:

Improveconcealment of quillsVSAvoidretraction mechanism complexity

Core Design Contradiction:

Difficulty of detecting and measuringVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical retraction systems with simpler actuation mechanisms such as buttons, zippers, or magnetic fields. This substitution maintains the retractable functionality for concealment while significantly reducing the overall device complexity and improving reliability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The quills are extracted as separate movable components from the coat structure, allowing them to be independently controlled for retraction and extension. This extraction enables simplified control mechanisms while maintaining effective concealment capability.

Inventive Principle:

Principle #2Taking out (Extraction)

3Reliability

If quills are extended for self-defense, then the protective capability is improved, but the comfort and normal coat function are worsened

Engineering Contradiction:

Improveprotection during assaultVSAvoidcomfort during normal wear

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The coat system dynamically adapts its configuration based on the situation - maintaining a normal, comfortable appearance during everyday wear and transitioning to a protective configuration only when threat is detected or manually activated. This dynamic behavior resolves the contradiction between comfort and protection.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The quills are pre-positioned in a retracted state that allows normal coat function and comfort. When needed, they are rapidly deployed to counter the threat. This preliminary positioning in a non-intrusive state ensures comfort during normal wear while maintaining readiness for defense.

Inventive Principle:

Principle #9Preliminary anti-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

Provides users with a safe and convenient means of self-defense by allowing quick activation of quills without additional tools, while maintaining comfort and warmth, and ensuring the quills are hidden when not needed.

Implementation Method 1

Methodology Applied

Scientific EffectLinear actuator: Linear Motor

Data Source

PatentUS20260022911A1Self-Defense Coat Device

Publication Date: 2026.01.22 WETZEL MARIAN

AI summary

A self-defense coat device is disclosed which comprises a coat component that is configured in the shape of a traditional coat or jacket. With the push of a button, the user may expand or retract the quills from the coat component. Further, the retractable quills are comprised of sharp, pointed ends that injure and ward off an assailant to keep the user safe. Thus, the coat component is especially useful for vulnerable people. The retractable quills can also be retracted and hidden to allow the coat component to simply function as a traditional jacket. Further, the coat component comprises multiple sizes and colors to fit the user's preference. The fabric of the coat component is very thick in width in order to successfully hide the quills when retracted.