Utility Knife Blade Retention Mechanism
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Solution Overview
Problem
Existing utility knives with replaceable blades pose a safety hazard due to the risk of accidental detachment of blades, especially when the locking device is unintentionally switched to an unlocked state, potentially causing harm to the user.
Innovation Solution
Incorporating a restriction means, such as a projection or protective cover, that prevents the blade from detaching from the blade holder even when the locking device is in an unlocked state, ensuring the blade remains securely housed within the knife handle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a locking device is used to retain the blade in the blade holder, then the blade can be securely held during use, but the blade may accidentally detach when the locking device is unintentionally switched to unlocked state
Solution Approach 1:
The patent applies preliminary anti-action by introducing a restriction means that prevents blade detachment before the harmful effect can occur. The restriction means includes a first restriction that blocks the blade from detaching when the locking device is unlocked, and a second restriction that prevents the locking member from moving to the unlocked position when the blade holder is retracted. This preemptive measure eliminates the safety hazard of accidental blade exposure during blade replacement operations.
2Productivity
If the blade holder is designed to be extendable for blade replacement, then swift blade replacement is enabled, but the blade holder may be unintentionally extended causing safety hazards
Solution Approach 1:
The patent applies preliminary anti-action by introducing a restriction means that prevents blade detachment before the harmful effect can occur. The restriction means includes a first restriction that blocks the blade from detaching when the locking device is unlocked, and a second restriction that prevents the locking member from moving to the unlocked position when the blade holder is retracted. This preemptive measure eliminates the safety hazard of accidental blade exposure during blade replacement operations.
Solution Approach 2:
The patent applies dynamics by making the restriction means movable between different positions. The first restriction moves between a first position where it blocks blade detachment and a second position where it allows blade detachment for intentional replacement. The second restriction moves between a first position where it prevents locking member movement and a second position where it allows locking member movement. This dynamic design enables swift blade replacement when needed while preventing unintentional exposure during normal use.
3Ease of operation
If a switching member is provided for operating the locking device, then easy operation is achieved, but the switching member may be unintentionally operated causing the locking device to switch to unlocked state
Solution Approach 1:
The patent applies preliminary anti-action by introducing a restriction means that prevents blade detachment before the harmful effect can occur. The restriction means includes a first restriction that blocks the blade from detaching when the locking device is unlocked, and a second restriction that prevents the locking member from moving to the unlocked position when the blade holder is retracted. This preemptive measure eliminates the safety hazard of accidental blade exposure during blade replacement operations.
Data Source
AI summary
The present invention first provides a utility knife with a replaceable blade, comprising a knife handle, a blade holder, a blade and a locking device that locks the blade in the blade holder. The blade holder and the blade are enabled to switch between a first position and a second position. When the blade holder and the blade are in the first position, the blade is used for cutting operation, and when the blade holder and the blade are in the second position, both the blade holder and the blade are received in the knife handle. The utility knife further includes a restriction means which is thus arranged as, when the blade holder is in the second position and the locking device is in unlocked state, the restriction means is used for preventing the detachment of the blade from the blade holder by confining the movement of the blade relative to the blade holder. The present invention also provides a folding utility knife with a replaceable blade and a retractable utility knife with a replaceable blade, and a utility knife with multiple tools and replaceable blades.