Security Grille Chain Mechanism for Sag Prevention

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Solution Overview

Problem

Existing security grille systems face issues such as space inefficiency, aesthetic concerns, tampering risks, and safety hazards due to heavy rolling shafts and limited width, which can lead to sagging and require costly maintenance.

Innovation Solution

A security grille system with a design that allows bars to be stacked in a retracted state, using elongated connecting elements and a chain mechanism to prevent lifting and reduce the need for a heavy rolling shaft, along with a chain engaging with a sprocket wheel for secure operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a traditional rolling shaft system is used to support the security grille, then the grille can be rolled up and down, but the rolling shaft becomes very heavy (150-200 kg for 6-7 meters) and requires a powerful motor, creating safety hazards during installation and maintenance

Engineering Contradiction:
Improvegrille support capabilityVSAvoidrolling shaft weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The patent divides the traditional single rolling shaft into multiple smaller shaft segments (first shaft, second shaft, third shaft) that are distributed along the grille structure. Each shaft segment is supported by multiple bars rather than one heavy shaft, distributing the load and reducing individual component weights while maintaining overall structural strength

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent replaces the traditional heavy rolling shaft mechanism with a bar-based support system where multiple horizontal bars provide structural support. The chain and sprocket mechanism is used to move individual bars or groups of bars rather than rotating a heavy shaft, substituting the mechanical rolling action with a lifting/dragging action on lighter components

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Length of moving object

If the security grille is designed to be wide to cover large openings, then better coverage is achieved, but the rolling shaft becomes longer and heavier, increasing the risk of sagging and requiring more powerful motors

Engineering Contradiction:
Improvegrille widthVSAvoidrolling shaft weight
Core Design Contradiction:
Length of moving objectVSWeight of stationary object

Solution Approach 1:

The patent segments the grille into multiple bar sections that can be independently supported and moved. Instead of one long rolling shaft, multiple shorter shaft segments are used, each supporting a portion of the wide grille, allowing wide coverage without proportionally increasing shaft weight

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from a single-dimension rolling shaft approach to a multi-dimensional bar network structure. The grille is supported in multiple directions by interconnected bars, distributing the load across a three-dimensional framework rather than relying on the strength of a single long shaft

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Adaptability or versatility

If the grille housing is designed with plenty of empty space to accommodate the rolled-up grille, then the grille can be retracted, but this empty space allows villains to lift the unrolled grille by hand

Engineering Contradiction:
Improvegrille retraction capabilityVSAvoidtampering risk
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent removes the traditional large housing that accommodates rolled-up grilles. Instead, the grille bars are supported directly by the distributed shaft system and can be moved along the bars without requiring a enclosing housing, eliminating the empty space that enables tampering while preserving retraction functionality

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces chain and sprocket mechanisms as intermediaries between the motor and the grille bars. These mechanisms provide controlled movement and locking capabilities, preventing unauthorized manual lifting while enabling authorized retraction, acting as a mediator between security requirements and operational flexibility

Inventive Principle:
Principle #24Intermediary (Mediator)

4Object-affected harmful factors

If a lock is installed to prevent manual lifting of the grille, then security is improved, but the system becomes more complex and may jam during motor operation, requiring service intervention

Engineering Contradiction:
Improvetampering preventionVSAvoidlocking mechanism complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent designs the chain and sprocket system to provide automatic engagement and disengagement based on motor operation. The chain mechanism naturally locks the grille in position during motor-driven movement and allows free movement when the motor is not operating, eliminating the need for separate locks and avoiding jamming issues

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system incorporates feedback through the chain tension and sprocket engagement that automatically responds to motor operation. When the motor drives the grille, the chain engages the sprockets and provides controlled movement; when the motor stops, the system naturally returns to a locked state, providing automatic security without complex additional mechanisms

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3102767B1Security grille and security grille system
Publication Date: 2019.09.25 STACKDOOR BV
  • EP3102767B1 patent drawingFigure 1a~1b
  • EP3102767B1 patent drawingFigure 2a~2b
  • EP3102767B1 patent drawingFigure 3a~3b

AI summary

Security grille and security grille system The invention relates to a security grille system (1) for securing a passage at least partly. The security grille (2) is arranged to be brought from an extended state, in which the grille (2) can block the passage at least partly, into a retracted state, in which at least a part of the previously blocked part of the passage is unblocked. The security grille (2) comprises a multiplicity of bars (4), preferably substantially horizontally extending bars (4), connected by means of multiple elongated connecting elements for interconnecting respective bars (4). The security grille system (1) further comprises a chainconnected to the grille (2), preferably a chainbeing flexible in only one dimension and/or being roller chain, and at least one chain limiting (28) member for at least locally limiting movement of the chain (19), e.g. in a direction in which it is flexible, such as to counteract that one or more links of the chain can be substantially moved away from a regular route along which the links move when the grille (2) is moved from its extended state to its retracted state or vice versa.