Folding Knife Locking Mechanism With Rotatable Safety Switch
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Solution Overview
Problem
Folding knives often experience lock failure or inadvertent unlocking due to sticky materials and arrangements that require a finger in the path of the closing blade, posing safety risks.
Innovation Solution
A locking mechanism featuring a rotatable safety switch and handle lock with a spring bias, allowing the switch to pivot around the pivot axis, preventing accidental unlocking and providing a tactile feel for user safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a lock mechanism is added to secure the blade in the extended position, then safety is improved, but device complexity increases
Solution Approach 1:
The patent combines the lock bar and safety switch into a single integrated mechanism that rotates about the pivot axis. The lock bar provides the locking function while the safety switch provides the safety function, and both are merged into one component that performs multiple functions simultaneously, reducing overall device complexity while maintaining both safety and reliability.
Solution Approach 2:
The lock bar/safety switch assembly serves multiple functions: it locks the blade in the extended position, prevents inadvertent unlocking through the safety switch mechanism, and provides tactile feedback to the user. This multi-functional design eliminates the need for separate components, resolving the contradiction between safety and device complexity.
2Reliability
If a spring-biased lever lock back structure is used, then the blade can be securely locked, but the lock may fail or be inadvertently released
Solution Approach 1:
The safety switch is positioned to overlap the lock bar in the unlocked position, creating a preliminary barrier that prevents the lock bar from moving into the unlocked position. This anti-action mechanism ensures that even if the spring bias fails or the user inadvertently applies pressure, the blade cannot be accidentally released, thereby improving locking reliability.
Solution Approach 2:
The safety switch acts as an intermediary element between the user's action and the lock bar's movement. It mediates the unlocking process by requiring deliberate action to move the switch out of the way before the lock bar can be released, preventing inadvertent release while maintaining ease of intentional operation.
3Ease of operation
If the release mechanism requires a finger in the path of the closing blade, then the lock can be released, but safety is compromised
Solution Approach 1:
The safety switch and lock bar rotate about the pivot axis in a dimension perpendicular to the blade's closing path. This dimensional change allows the release mechanism to be operated from the side of the handle rather than requiring a finger in the blade's path, maintaining ease of operation while eliminating the safety risk.
Solution Approach 2:
The safety switch serves as an intermediary that redirects the user's action away from the blade's closing path. Instead of pressing directly on the lock bar in the blade's path, the user operates the safety switch which then facilitates lock bar movement, eliminating the harmful factor while preserving operational ease.
4Weight of moving object
If aluminum or titanium handle materials are used, then weight is reduced, but dynamic friction increases causing sticky movement
Solution Approach 1:
The patent changes the surface parameters of the aluminum or titanium handle materials by applying coatings or treatments that reduce the coefficient of friction. This allows the lightweight materials to maintain their weight advantage while eliminating the sticky movement problem, resolving the contradiction between weight reduction and operational smoothness.
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
Enhances safety by preventing accidental closure of the blade, ensuring durability through tactile feedback and redundancy in safety features, reducing wear and risk of lock failure.
Implementation Method 1
A spring, such as a wire form spring, can be arranged within a pocket of the switch, and when the switch is moved between engaged and disengaged positions the spring can be compressed generating a rotational bias on the switch urging the switch toward either the engaged or disengaged position.
Data Source
AI summary
Systems, methods, and apparatus are described for a locking folding knife having a handle lock and a safety switch arranged around and rotatable around a pivot axis of the knife. In an engaged position the switch overlaps at least a portion of the handle lock and prevents it from moving into an unlocked position. A spring, such as a wire form spring, can be arranged within a pocket of the switch, and when the switch is moved between engaged and disengaged positions the spring can be compressed generating a rotational bias on the switch urging the switch toward either the engaged or disengaged position.