Adjustable Finger-Push Safety Knife Blade Extension
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing safety knives have fixed maximum blade extension distances, making them inconvenient to use and limiting their application, as users cannot adjust the push stroke to control the blade extension length effectively.
Innovation Solution
A finger-push safety knife design featuring a shifter, blade ejection gear, and locking gear mechanism that allows the blade holder to be locked at preset positions within the knife housing, enabling adjustable blade extension lengths and secure retraction, using a rotating shifter and spring reset assembly for efficient and safe operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the blade extension distance is fixed at maximum, then safety is improved, but usability and adaptability deteriorate due to inability to adjust push stroke
Solution Approach 1:
The patent applies the dynamics principle by making the blade extension distance adjustable rather than fixed. The shifter mechanism allows the knife holder to be positioned at different locations along the guiding groove, enabling dynamic adjustment of the blade extension length according to different usage requirements, thus resolving the contradiction between safety (fixed maximum extension) and adaptability (variable extension lengths).
Solution Approach 2:
The patent changes the parameter of blade extension distance from a fixed value to an adjustable range. By allowing the shifter to be positioned at different locations and locked in place, the system enables users to select appropriate blade extension lengths for different tasks, improving both safety and versatility simultaneously.
2Length of moving object
If the blade extension distance is reduced by controlling push distance consciously, then blade exposure is controlled, but ease of operation deteriorates due to inability to directly adjust push stroke
Solution Approach 1:
The patent applies preliminary action by providing a mechanism that pre-establishes multiple fixed positions for the knife holder along the guiding groove. Instead of requiring users to consciously control push distance during operation, the system allows users to pre-select the desired blade extension length by positioning and locking the shifter at the appropriate location before use, significantly improving ease of operation.
Solution Approach 2:
The shifter acts as an intermediary mechanism between the user's intent and the blade extension control. Rather than directly pushing the blade to a desired position, the user operates the shifter to select from pre-defined extension lengths, and the shifter mediates this selection to automatically position the knife holder at the correct location, making the operation simpler and more intuitive.
3Adaptability or versatility
If multiple push distances are used in different pushes, then adaptability is improved, but reliability deteriorates due to inconsistent blade extension lengths
Solution Approach 1:
The patent applies segmentation by dividing the continuous blade extension range into discrete, pre-defined positions along the guiding groove. The shifter can be locked at specific locations corresponding to different extension lengths, allowing users to select appropriate segments for different tasks. This segmentation ensures that each push produces a consistent, predetermined blade extension length, maintaining reliability while preserving adaptability through multi-position selection.
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 consistent blade extension by a fixed length, improving cutting efficiency and safety performance by allowing users to set and maintain precise blade exposure, enhancing the usability and versatility of safety knives.
Implementation Method 1
when the knife holder is pushed by an external force, the reset assembly is deformed, so that the knife holder can be moved to the preset position in the cavity to enable the blade to extend from the knife housing; and when the knife holder is not pushed by an external force, the reset assembly can be restored from the deformation
Data Source
AI summary
A finger-push safety knife, including a knife housing, a knife holder, a blade, and a shifter. The blade is installed onto the knife holder. The knife holder is disposed in a cavity of the knife housing. A restricting groove is disposed on the knife holder. A gear adjustment slot is disposed on the knife housing. When the shifter rotates to the blade ejection gear, the shifter fits with the restricting groove to enable the knife holder to move and move to a preset position in the cavity, and the shifter is clamped at a blade ejection position in the restricting groove, so that the displacement of the knife holder can be restricted and the knife holder can be fastened at the preset position in the cavity under the action of an external force, to restrict an extension length of the blade from the knife housing.