Hinged Door Finger Injury Prevention Bumper

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Solution Overview

Problem

Existing door safety devices fail to prevent finger injuries from closing doors while allowing easy closure, are often expensive, and require skilled installation, and may not be suitable for temporary use or standard door sizes.

Innovation Solution

A flexible member with a resilient bumper and a deformable handle is attached to the door jamb or stile, allowing the bumper to settle into the hinge space and resist full closure, while the handle can be manually operated to move the bumper out of the way for complete closure, ensuring the door can be closed from either side without damaging the door.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a bumper is introduced into the hinge space to prevent full door closure, then finger injury is prevented, but the door cannot be closed from the hinge side

Engineering Contradiction:
Improvefinger injury preventionVSAvoiddoor closure accessibility
Core Design Contradiction:
Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The bumper is made movable rather than fixed, allowing it to be dynamically repositioned. The resilient handle enables the bumper to move between a first position (blocking the hinge space to prevent injury) and a second position (clearing the hinge space to allow door closure), resolving the contradiction between safety and operability

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The resilient handle acts as an intermediary mechanism that mediates between the safety function (bumper blocking) and the closure function (door moving). By pulling the handle, the bumper is temporarily displaced to allow closure, then automatically returns to its blocking position, enabling both safety and ease of operation

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If a complex bumper mechanism is installed to prevent finger trapping, then safety is improved, but installation cost and complexity increase

Engineering Contradiction:
Improvefinger injury preventionVSAvoidinstallation complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The safety device is segmented into simple, separate components: a bumper element and a resilient handle attached to the door frame. This segmentation allows for easy installation and removal without requiring complex assembly procedures or specialized skills, while still providing effective finger injury prevention

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The bumper and handle are designed as simple, inexpensive components that can be easily manufactured and installed. The resilient handle can be made from common materials like rubber or plastic, making the overall device affordable and suitable for widespread installation on all doors

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Object-affected harmful factors

If a permanent door modification is made to prevent closure, then safety is ensured, but door appearance and value are compromised

Engineering Contradiction:
Improvefinger injury preventionVSAvoiddoor appearance
Core Design Contradiction:
Object-affected harmful factorsVSShape

Solution Approach 1:

The resilient handle is attached to the door frame in a way that utilizes existing door frame structures, requiring no modification to the door itself. The bumper and handle system is designed to be installed on the frame rather than the door, preserving the door's appearance and allowing easy removal when no longer needed

Inventive Principle:
Principle #25Self-service

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 solution effectively prevents finger injuries by allowing full door closure without damaging the door and is inexpensive, easy to install, and suitable for temporary use, addressing the limitations of prior art devices.

Implementation Method 1

said bumper being resiliently deformable to facilitate drawing the bumper through the hinge gap by means of the handle

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

said handle is fabricated to be resiliently deformable in a first horizontal direction and substantially rigid in a second direction corresponding to a vertical direction

Methodology Applied
Scientific EffectResilient deformation: Elasticity

Data Source

PatentEP3315703B1Apparatus to minimise injury caused by an extremity trapped by a closing hinged door
Publication Date: 2019.06.19 WELCH ANDREW
  • EP3315703B1 patent drawingFigure 1.1
  • EP3315703B1 patent drawingFigure 1.2
  • EP3315703B1 patent drawingFigure 1.3~1.4

AI summary

An apparatus is provided having a foam cushion (9) attached to an elongate elastic member (8). Adhesive pads (10) are attached one to each end of the elastic member (8). A "U" shaped resiliently deformable handle is attached to the uppermost and lowest cushion (9) and adapted to project through the hinge gap formed between the hinge stile (6) and the door jamb (7) when the door is swung open. The apparatus can be secured to the hinge stile (6) of a hinge mounted door leaf (3) by means of the adhesive pads (10) and with the elastic member (8) under sufficient tension to keep the cushions resting against the hinge stile and the handle projecting through the hinge gap. If an attempt is made to close the door without displacing the cushions 9 from the hinge gap the cushions prevent full closure. To fully close the door the handle is pulled from the hinge side of the door, until the cushions (9) are displaced through the hinge gap and the door can then be closed. The cushions are too wide to pass through the reduced hinge gap when the door is closed. When the door is opened the spring force of the elastic member causes the cushions (9) to pull back through the widening hinge gap.