Rotational Wedge Locking Mechanism for Folding Knife Blade Security
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Solution Overview
Problem
Existing folding knives lack a simple, inexpensive, and reliable locking mechanism that securely maintains the blade in an extended position without the risk of inadvertent closure, and often require complex components or are prone to failure.
Innovation Solution
A rotational wedge locking mechanism using a pin to engage both the blade tang and back spacer, providing superior strength, durability, and ease of use, with a minimal number of components and a biasing means to prevent accidental closure, allowing quick release via a thumb-operated mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional locking mechanisms (liner lock, backlock) are used, then the blade can be secured in extended position, but the mechanism becomes complex and expensive to manufacture
Solution Approach 1:
The locking mechanism is divided into two separate functional components: a lock bar that engages the blade tang to prevent closure, and a stop pin that limits blade extension. This segmentation allows each component to perform its specific function simply and effectively, reducing overall mechanism complexity while maintaining reliability.
Solution Approach 2:
A compression spring is introduced as an intermediary element between the lock bar and the handle. The spring provides continuous compression force to maintain engagement between the lock bar and blade tang, ensuring reliable locking without requiring complex mechanical linkages or adjustment mechanisms.
2Reliability
If traditional locking mechanisms are used, then the blade can be secured, but the mechanism is prone to failure after excessive use
Solution Approach 1:
The compression spring continuously applies force to maintain engagement between the lock bar and blade tang, creating a self-sustaining locking action that does not degrade with use. The spring's elastic properties allow it to compensate for wear and dimensional variations, ensuring consistent performance over extended continuous use periods.
3Ease of manufacture
If a simple locking mechanism is used, then manufacturing cost is reduced, but the mechanism lacks sufficient strength to prevent inadvertent closure
Solution Approach 1:
The blade tang is designed with a predetermined engagement surface that automatically aligns with the lock bar's engagement surface when the blade is inserted. This preliminary positioning ensures that the simple locking mechanism engages at the optimal location, maximizing locking strength without requiring complex adjustment or alignment features.
4Reliability
If a secure locking mechanism is used, then blade security is improved, but the release mechanism becomes difficult to manipulate
Solution Approach 1:
The release function is extracted from the main lock bar structure and implemented through a separate, easily accessible feature on the handle. This could be a thumb stud, notch, or protrusion that allows the user to apply direct force to disengage the lock bar from the blade tang, maintaining secure locking during normal use while enabling quick release when needed.
Data Source
AI summary
A locking mechanism for a folding knife is provided. More specifically, the locking mechanism is a rotational wedge locking mechanism that maintains the folding knife's blade in an extended position and prevents the blade from inadvertently closing when the knife is in use in the extended position. The rotational wedge locking mechanism also impedes the folding knife from inadvertently opening when the blade is in a closed position of storage. The rotational wedge locking mechanism generally comprises a lock pin, a means for moving the lock pin, and a biasing member, which work in conjunction with the tang of the blade and the back spacer to securely retain the folding knife in an open or closed position.