Retractable Knife Cam Lever Actuation Safety
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Solution Overview
Problem
Existing craft knives often have poor ergonomics, are difficult to handle, especially for children, and have complex blade replacement mechanisms, which can lead to safety issues and blade dullness.
Innovation Solution
A retractable knife design featuring a handle with a removable portion, a blade mounted to a cartridge that can be easily replaced, and an actuator mechanism that allows the blade to move between retracted and extended positions using a cam and lever system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the blade is exposed for easy access, then the knife is easier to use, but safety risks increase and the blade dulls faster
Solution Approach 1:
The blade is designed to be movable rather than fixed, allowing it to transition between exposed and retracted positions. The spring mechanism provides automatic retraction when not in use, while the user can easily extend it when needed. This dynamic configuration resolves the contradiction by providing easy access when required while maintaining safety when the blade is not actively being used.
2Object-affected harmful factors
If the blade is made frangible and retractable for safety, then safety improves, but ergonomics deteriorate and handling becomes difficult
Solution Approach 1:
The spring-loaded mechanism automatically returns the blade to a retracted position after use, eliminating the need for manual retraction operations. This dynamic system maintains safety while preserving ease of operation through automatic operation.
Solution Approach 2:
The spring mechanism performs the retraction function automatically without requiring user intervention. The system serves itself by automatically returning to a safe state after the blade is extended, improving both safety and ease of operation.
3Object-affected harmful factors
If the blade shape is limited to frangible form, then safety is improved, but cutting versatility deteriorates
Solution Approach 1:
The retractable mechanism serves multiple functions: it provides safety by retracting the blade, maintains ease of use through automatic operation, and can accommodate various blade shapes and sizes. The universal design of the housing and mechanism allows different blade configurations while maintaining the safety benefits of retraction.
4Manufacturing precision
If blade replacement is made complex for precision, then manufacturing precision improves, but ease of replacement deteriorates
Solution Approach 1:
The blade is designed as a separate, replaceable component that can be independently removed and replaced. This segmentation allows for simple replacement procedures while maintaining precise manufacturing tolerances for the interface between blade and housing.
Solution Approach 2:
The blade is designed as a disposable or easily replaceable component with a simple insertion and removal process. This approach prioritizes ease of replacement over complex retention mechanisms, allowing users to quickly replace blades without requiring precision tools or complex procedures.
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 design enhances safety and ease of use by allowing the blade to be safely retracted, improving ergonomics, and simplifying blade replacement, making it suitable for children and less-abled individuals.
Implementation Method 1
The blade may biased toward the retracted position by biasing means (e.g. a spring)
Implementation Method 2
an actuator operatively engages a cam or lever, the cam/lever rotatable into abutment with a linkage operatively engaged with the blade
Implementation Method 3
an actuator operatively engages a cam or lever, the cam/lever rotatable into abutment with a linkage operatively engaged with the blade
Data Source
AI summary
The present invention relates to a retractable knife (2) comprising a handle (4) and a blade (6) movably mounted to the handle (4). An actuator (14) is movably mounted to the handle (4), and the actuator (14) operatively engages a cam (42) or lever, the cam/lever (42) rotatable into abutment with a linkage (34) operatively with the blade (6), such that movement of the actuator (14) effects movement of the blade (6) between a retracted position where the blade (6) is partially contained within the handle (4), and an extended position where the blade (6) extends from the handle (4).