Folding Tool Locking Element for Unintended Closure Prevention

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Solution Overview

Problem

Folding tools, such as pocketknives and multipurpose tools, are prone to unintentional folding during use, compromising safety and functionality.

Innovation Solution

A locking mechanism is integrated into the folding tool, which secures the folding tool in the deployed position using a spring-biased locking element that engages a cam portion's locking surface, preventing unintended folding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If a folding tool is designed to be foldable for compact storage, then the tool size is reduced and portability is improved, but the tool becomes prone to unintentional folding during use which compromises safety and functionality

Engineering Contradiction:
Improvetool sizeVSAvoidsafety
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The locking mechanism is activated in advance by the cam portion before the tool can unintentionally fold. When the tool portion rotates to the deployed position, the cam portion automatically engages the locking element, preventing any subsequent unintentional folding during use.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The locking element is spring-biased to engage the locking surface of the cam portion, creating a counteracting force that prevents the harmful unintentional folding action before it can occur during tool operation.

Inventive Principle:
Principle #9Preliminary anti-action

2Reliability

If a locking mechanism is added to prevent unintentional folding, then safety and reliability are improved, but the device complexity increases

Engineering Contradiction:
ImprovesafetyVSAvoidstructure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The locking mechanism is integrated into the existing folding tool structure. The cam portion is formed as part of the folding tool portion, and the locking element is positioned within the handle portion, merging the locking function with the existing tool components rather than adding separate external locking devices.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The locking mechanism is self-activating through the cam portion's geometric design. As the tool portion rotates to the deployed position, the cam portion automatically engages the locking element without requiring external actuation or complex control systems, making the locking action self-service.

Inventive Principle:
Principle #25Self-service

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 locking mechanism effectively maintains the folding tool in the deployed position, enhancing safety and usability by preventing accidental folding and ensuring secure operation.

Implementation Method 1

the locking element is spring biased by a spring in a direction parallel to the folding tool axis

Methodology Applied
Scientific EffectSpring bias: Spring

Implementation Method 2

the locking element is configured to engage the locking surface of the folding tool portion in response to the folding tool portion moving to the deployed position

Methodology Applied
Scientific EffectMechanical engagement: Mechanical Fastener

Implementation Method 3

the locking element defines at least one of an arcuate surface or a wedge surface for engaging the locking surface of the folding tool portion

Methodology Applied
Scientific EffectWedge geometry: Wedge

Data Source

PatentEP4699748A1Lock for folding tool
Publication Date: 2026.02.25 LEATHERMAN TOOL GROUP INC
  • EP4699748A1 patent drawingFigure 1
  • EP4699748A1 patent drawingFigure 2
  • EP4699748A1 patent drawingFigure 3

AI summary

A lock is provided for a folding tool including a lock that engages a folding tool in an unfolded, deployed position to prevent unintended folding of the tool. By way of example a tool is provided including: a handle portion; a folding tool portion, where the folding tool portion is configured to be rotatable between a folded, stowed position at least partially within the handle portion, and a deployed position substantially outside of the handle portion; and a locking element, where the locking element is configured to engage a locking surface of the folding tool portion in response to the folding tool portion moving to the deployed position, where the locking element includes an arcuate surface for engaging the locking surface of the folding tool portion.