Folding Knife Toggle Lock Prevents Accidental Closure
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Solution Overview
Problem
Conventional folding knives lack an additional safety mechanism to prevent accidental closure of the blade, which can lead to injuries or unintended operation.
Innovation Solution
The integration of a secondary lock zone and a toggle mechanism that requires additional motion to close the blade, ensuring it remains open until a specific forward pressure is applied, and engages a secondary lock face to prevent accidental closure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional single lock mechanism is used, then the device complexity is low, but the reliability is insufficient due to lack of accidental closure prevention
Solution Approach 1:
The lock mechanism is divided into two distinct zones: a primary lock zone with a first lock face and a secondary lock zone with a second lock face. This segmentation allows the blade to be locked at different stages of closure, preventing accidental closure while maintaining structural organization. The toggle mechanism interacts with different lock faces at different positions, creating a staged locking system.
Solution Approach 2:
The secondary lock zone is positioned to engage before the blade fully closes, requiring the user to complete a specific rotational motion to disengage it. This preliminary action ensures that even if the primary lock fails or is accidentally triggered, the secondary lock provides an additional layer of protection against unintended blade closure.
2Reliability
If a toggle mechanism with secondary lock zone is added, then the reliability improves through additional safety, but the ease of operation decreases due to required additional motion
Solution Approach 1:
The toggle mechanism is designed to dynamically interact with both the primary and secondary lock zones during the blade closing motion. The toggle rotates through a defined arc that naturally sequences the disengagement of the secondary lock face followed by the primary lock face, creating a smooth, integrated operation rather than two separate actions.
Solution Approach 2:
The secondary lock zone and primary lock zone are merged into a single continuous locking system that operates through one rotational motion of the toggle. The lock faces are positioned and angled so that disengaging the secondary lock transitions seamlessly into disengaging the primary lock, combining safety functions without requiring separate user actions.
3Reliability
If the lock mechanism is made more secure with additional zones, then the reliability improves, but the device complexity increases
Solution Approach 1:
The toggle mechanism serves multiple functions: it locks the blade in the open position by engaging the primary lock face, provides secondary safety by engaging the secondary lock face, and unlocks the blade through a single rotational motion that disengages both lock faces. This multi-functionality achieves enhanced reliability without proportionally increasing complexity.
Solution Approach 2:
The secondary lock zone is nested within the overall lock mechanism structure, with the second lock face positioned along the blade tang adjacent to the first lock face. The toggle mechanism is designed to interact with both lock faces in sequence, creating a nested arrangement where the secondary safety feature is integrated into the primary locking system rather than added as a separate external mechanism.
Data Source
AI summary
A folding knife has a handle and a blade with a working end and a tang, the blade being coupled to the handle and pivotable relative to the handle about a fold axis between an open position and a closed position. A toggle is coupled to the handle and pivotable relative to the handle about a toggle axis, the toggle axis being located a radial distance from the fold axis. A free end of the toggle has an open lock face located a radial distance from the toggle axis. A primary lock face on the tang is located on the opposite side of the fold axis from the working end. When the blade is in the open position, the open lock face engages the primary lock face to prevent rotation of the blade toward the closed position.