Retractable Knife Spring-Assisted Blade Extension Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional retractable blade knives require manual effort to fully open or close the blade, making the process slow and inconvenient, while switchblade knives are restricted by laws and not commonly used due to their automatic opening mechanism.
Innovation Solution
A retractable blade knife with an opening assisted mechanism featuring a positioning frame, slider, and spring assembly, where the blade is manually pushed to engage the resilient rod, allowing the spring to extend the blade quickly and prevent accidental retraction or extension, using a detent and lock protrusion to control the movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the blade is manually pushed to fully open or close to activate the locking mechanism, then the locking mechanism can lock the blade in open and closed positions, but the blade extension and retraction process becomes slow and inconvenient
Solution Approach 1:
The spring mechanism is pre-loaded in the extended position, ready to automatically propel the blade forward once the locking mechanism releases it. This preliminary preparation eliminates the need for manual pushing during operation, making the blade extension quick and convenient while maintaining reliable locking when closed
Solution Approach 2:
The system transitions from a static manual pushing requirement to a dynamic automatic extension mechanism. The spring provides dynamic force to propel the blade, while the locking mechanism dynamically switches between locked and unlocked states, enabling quick transition from manual to automatic operation
2Speed
If a spring mechanism is used to automatically open the blade like a switchblade knife, then the blade can be fully opened very quickly, but the knife is restricted by laws and restricted to some people only
Solution Approach 1:
The spring mechanism provides more force than needed for simple opening, enabling the blade to not only open quickly but also to perform utility functions like cutting packaging or box openings. This partial automatic action with manual initiation satisfies legal requirements while achieving rapid blade deployment
Solution Approach 2:
The locking mechanism serves as an intermediary between the manual user input and the automatic spring-driven blade extension. By pressing the release button, the user triggers the intermediary to disengage the lock, allowing the spring to automatically propel the blade forward, thus combining manual control with automatic speed
3Ease of operation
If the blade can be quickly extended with minimal manual effort, then the convenience is improved, but the risk of accidental opening or closing increases
Solution Approach 1:
The resilient rod and detent mechanism create preliminary resistance against unintended blade movement. The detent engages with the resilient rod to lock the blade in place, requiring deliberate user action (pressing the release button) to overcome this preliminary anti-action and prevent accidental opening
Solution Approach 2:
The spring mechanism serves itself by automatically propelling the blade forward when released, without requiring continuous manual force. The locking mechanism also serves itself by automatically engaging and disengaging based on blade position, providing self-regulating safety that prevents accidental operation while enabling quick extension
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
Enables quick and safe extension of the blade with minimal manual effort, preventing accidental opening or closing, thus enhancing convenience and safety.
Implementation Method 1
a spring being attached to the positioning frame and the slider. When the detent of the blade and a lock protrusion of the slider both depart from the resilient rod of the positioning frame, the spring may further pull the slider to move together with the blade to stretch out the blade
Implementation Method 2
The positioning frame has a resilient rod selectively abutting the spine edge of the blade and the proximal end of the blade
Data Source
AI summary
A retractable blade knife with an opening assisted mechanism has a handle, a blade mounted in the handle, an extending assembly mounted between the blade and the handle. At least one detent formed at a spine edge of the blade. The extending assembly has a positioning frame, a slider mounted beside the positioning frame and attached to the blade and a spring attached to the positioning frame and the slider. The positioning frame has a resilient rod selectively abutting the spine edge and a proximal end of the blade. The blade should be pushed manually a certain distance to allow the spine edge of the blade to push a rear end of the resilient rod outwardly. When the detent of the blade and a lock protrusion of the slider both depart from the resilient rod of the positioning frame, the spring may further pull the slider to move together with the blade to stretch out the blade. Thus, the spring helps the blade to be extended quickly and the extending assembly also prevents the blade from being retracted or extended accidentally. Therefore, the retractable blade knife with an opening assisted mechanism is used safely and conveniently.