Winged Door Finger Guard with Concealed Fastening

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Solution Overview

Problem

Existing finger protection devices for swing doors face challenges with complex and visible fastening mechanisms, which can be tampered with, and lack easy assembly and readjustment capabilities, posing safety risks, especially in public spaces.

Innovation Solution

A finger protection device featuring a roller blind with a housing and fastening means that allows quick assembly and readjustment without tools, using a suspension unit that can be hooked into the fastening means, ensuring concealed fastening and easy detachment without damage, while allowing for adjustable alignment and protection of screws.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If screws are used to fasten the roller blind to the door frame and door leaf, then the fastening is secure, but the screws are visible and freely accessible, disturbing the appearance and encouraging unauthorized manipulation

Engineering Contradiction:
Improvefastening securityVSAvoidunauthorized manipulation
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a cover strip as an intermediary element that conceals the screws while allowing them to remain functional. The cover strip is inserted into a groove and covers the screw heads, preventing direct access for manipulation while maintaining the structural integrity of the fastening system.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The cover strip functions as a thin protective film that overlays the fastening elements. This thin film structure effectively shields the screws from unauthorized access while maintaining visibility of the overall door assembly and not interfering with the mechanical fastening function.

Inventive Principle:
Principle #30Flexible shells and thin films

2Reliability

If the roller blind is fastened securely to prevent manipulation, then safety is improved, but assembly and readjustment become complex and require special tools

Engineering Contradiction:
Improvetamper resistanceVSAvoidassembly simplicity
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The fastening system is segmented into distinct functional elements: screws for structural attachment, cover strips for concealment and protection, and a modular roller blind assembly. This segmentation allows each element to be optimized independently - screws provide secure fastening while cover strips enable easy access and tool-free operation during assembly and maintenance.

Inventive Principle:
Principle #1Segmentation

3Object-affected harmful factors

If the fastening means are concealed to improve appearance and prevent tampering, then safety and aesthetics are improved, but readjustment and repair become difficult

Engineering Contradiction:
Improvetamper preventionVSAvoidreadjustment accessibility
Core Design Contradiction:
Object-affected harmful factorsVSEase of repair

Solution Approach 1:

The cover strip serves as a removable intermediary that provides dual functionality: during normal operation, it conceals and protects the screws to prevent tampering; during maintenance or readjustment, it can be easily removed to expose the screws for tool-based access, thus enabling both security and serviceability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3344843B1Finger guard for a winged door
Publication Date: 2020.04.22 ASSA ABLOY (SCHWEIZ) AG
  • EP3344843B1 patent drawingFigure 1
  • EP3344843B1 patent drawingFigure 2~3
  • EP3344843B1 patent drawingFigure 4~5

AI summary

A finger protection device (S) with a roller blind for a leaf door has a housing (2), a first fastening means (4) and a web (1), wherein the roller blind can be fastened to a door frame (R) and to a door leaf (F) of the leaf door by means of the housing (2) and the first fastening means (4), with the result that, when the device is used as intended, the web (1) covers a gap between the door leaf (F) and the door frame (R). The web (1) has at its free edge an end strip (11) which is held in a second fastening means (3). The second fastening means (3) can be connected to the first fastening means (4) in order to tension the web (1) between the housing (2) and first fastening means (4). The second fastening means (3) is a suspension unit which can be suspended in the first fastening means (4) in order to tension the web (1). The finger protection device according to the invention is of robust design, consists of the simplest means and nevertheless allows optimum protection against manipulation and a maximum degree of readjustability.