Folding Knife Locking Spring Recess Bias

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Solution Overview

Problem

Folding knives often lack effective mechanisms to prevent accidental opening of the blade, which can lead to injuries.

Innovation Solution

A folding knife design that incorporates a sliding lock and a locking spring, where the locking spring interfaces with a recess on the blade and biases the sliding lock away from the blade tip when the blade is retracted, thereby preventing accidental opening.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a folding knife is designed without a locking mechanism, then the device complexity is reduced, but the reliability of preventing accidental opening deteriorates

Engineering Contradiction:

Improveprevention of accidental openingVSAvoidlocking mechanism complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The locking mechanism is divided into separate functional components: a locking arm with a locking surface, a spring providing biasing force, and a blade tang with a notch. This segmentation allows each component to perform its specific function efficiently while keeping the overall mechanism simple and reliable.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The spring-loaded locking mechanism automatically engages when the blade is inserted into the handle, requiring no manual intervention. The spring provides continuous biasing force to maintain the locked position, and the geometry of the locking surfaces ensures automatic disengagement when the blade is intentionally opened, making the system self-regulating and reliable.

Inventive Principle:

Principle #25Self-service

2Reliability

If a sliding lock mechanism is added to prevent accidental opening, then the reliability improves, but the ease of operation deteriorates

Engineering Contradiction:

Improveblade security in closed positionVSAvoidblade opening and closing

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The locking arm extends across the opening of the handle cavity, creating a preliminary barrier that prevents accidental blade opening. The locking surface on the locking arm is positioned to engage with the blade tang before the blade can accidentally open, providing proactive protection while allowing intentional opening through deliberate user action.

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

The locking mechanism transitions between static locked and dynamic unlocked states. The spring provides continuous biasing force to maintain the locked position, while the geometry of the locking surfaces allows smooth transition to the unlocked state when sufficient force is applied to the blade, balancing security with ease of operation.

Inventive Principle:

Principle #15Dynamics

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 mechanism effectively secures the blade in the closed position, minimizing the risk of accidental opening and ensuring safe handling.

Implementation Method 1

The locking spring interfaces against the sliding lock and biases the sliding lock away from a tip of the blade when the blade is in the retracted position

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS12304092B2Folding knife safety mechanism

Publication Date: 2025.05.20 MILWAUKEE ELECTRIC TOOL CORP

AI summary

A folding knife with a locking mechanism is provided. The folding knife includes a locking spring that interfaces with a recess in the blade to bias the blade from being pivoted out of the handle. A button interfaces with the locking spring to actuate the locking spring interfacing with the blade.