Utility Knife Auto-Ejecting Blade Carrier Mechanism

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Solution Overview

Problem

Existing utility knives with blade storing carriers face difficulties in easy grip and secure blade storage, as the carriers can disengage from the housing over time, making them inconvenient to use.

Innovation Solution

An auto-ejecting mechanism is introduced, comprising a housing with compartments, a blade holder, an elastic unit, and a locking mechanism that includes a movable member and engaging members, allowing for easy insertion and automatic release of the blade storing carrier, enabling convenient blade replacement and storage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the blade storing carrier is pivotally connected to and received within the housing in tight fitting, then the blade storing carrier can be securely held, but it becomes hard to be gripped to be open and can disengage after long use

Engineering Contradiction:
Improvesecure holding of blade storing carrierVSAvoidease of opening and gripping
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The blade storing carrier is designed to be movable between a stored position (received within the housing) and a protruding position (extending outward). The elastic unit provides dynamic engagement and disengagement capability, allowing the carrier to be easily opened by pressing while maintaining secure holding during normal use. This dynamic design resolves the contradiction between secure holding and ease of opening.

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If the blade storing carrier is detachably inserted in the housing, then easy removal is achieved, but secure blade storage may be compromised

Engineering Contradiction:
Improveeasy removal of blade storing carrierVSAvoidsecure blade storage
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The elastic unit acts as an intermediary between the blade storing carrier and the housing. It provides a resilient connection that allows easy removal when needed while maintaining secure engagement during normal operation. The elastic unit's engagement and disengagement features create a reliable yet easily removable connection, resolving the contradiction between easy removal and secure storage.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 auto-ejecting mechanism ensures secure blade storage and easy access, enhancing user convenience by allowing effortless ejection and retraction of the blade storing carrier, preventing disengagement issues and improving practical usability.

Implementation Method 1

an elastic unit, disposed between the housing and the blade storing carrier, biasing the receiving portion in a direction opposite to the assembling direction

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4032666B1Utility knife
Publication Date: 2024.06.19 MING SHIN TOOLS CO LTD
  • EP4032666B1 patent drawingFigure 1
  • EP4032666B1 patent drawingFigure 2
  • EP4032666B1 patent drawingFigure 3

AI summary

A utility knife is provided, including: a housing (1), including first and second compartments (11, 12); a blade holder (2), movably received within the first compartment (11); a blade storing carrier (3), detachably inserted in the second compartment (12), including a receiving portion (31) for receiving at least one spare blade (8); an elastic unit (4), disposed between the housing (1) and the blade storing carrier (3); and a locking mechanism (5), including a base body (51) disposed to the housing (1), a movable member (52) attached to the base body (51) and movable between locking and release positions, a first engaging member (53) disposed on the movable member (52) and a second engaging member (54) disposed on the receiving portion (31) and releasably engageable with the first engaging member (53), when the first engaging member (53) is disengaged from the second engaging member (54), the elastic unit (4) biases the receiving portion (31) to eject the blade storing carrier (3).