Combination Drawstring Lock for Secure Bag Closure

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Solution Overview

Problem

Drawstring bags lack effective security mechanisms, as existing toggle systems and knots can be easily operated or undone, compromising the closure of the bag opening.

Innovation Solution

A drawstring lock system comprising a housing with a stop mechanism and a lock mechanism that allows the drawstring to be locked in a drawn-in state, requiring a correct combination code to unlock and release, ensuring only authorized users can open the bag.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a toggle is used to secure the drawstring, then the drawstring can be easily operated to open and close the bag, but the security is compromised as anyone can easily slide the toggle to open the bag

Engineering Contradiction:

Improveease of operationVSAvoidsecurity

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The locking mechanism is segmented into multiple independent components: a housing, a stop mechanism with twist portion, and a lock mechanism with lock block and locking recesses. This segmentation allows the security function to be separated from the operation function, enabling easy opening/closing while maintaining security through the locked state

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The lock block is preliminarily positioned to engage with the locking recesses before the drawstring is fully drawn. When the twist portion is rotated to the locked position, the lock block automatically engages with the locking recesses in advance, preventing unauthorized opening before the user intends to open the bag

Inventive Principle:

Principle #10Preliminary action

2Device complexity

If basic knots are used instead of toggles to secure the drawstring, then the structure is simpler, but the security is still compromised as the knots can be easily undone

Engineering Contradiction:

Improvestructure simplicityVSAvoidsecurity

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The traditional mechanical knot-tying system is replaced with a mechanical locking system consisting of the lock mechanism and lock block. This substitution maintains structural simplicity while providing superior security, as the lock block engages with locking recesses through rotational movement rather than requiring complex knot manipulation

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If a lock mechanism is added to secure the drawstring, then security is improved, but the device complexity increases

Engineering Contradiction:

ImprovesecurityVSAvoiddevice complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The housing serves multiple functions: it contains the lock mechanism, provides structural support, and guides the drawstring through its opening. The lock block serves both as a locking element and as a indicator of the locked state. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in device complexity while maintaining improved security

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS11339851B2Drawstring lock

Publication Date: 2022.05.24 YU CHUN TE

AI summary

A drawstring lock includes a housing that allows the two ends of a drawstring to pass through, a stop mechanism disposed on the housing, and a lock mechanism connected to the stop mechanism. The housing is able to shift freely along the drawstring and once reaching its desired position, it is able to operate the stop mechanism so that the housing is stopped and cannot be shifted. Subsequently, the lock mechanism is used to lock the stop mechanism, keeping it secured until the lock mechanism is unlocked.