Swing Bar Door Guard Bumper Impact Distribution

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Solution Overview

Problem

Existing door latch systems for swing bar door guards do not effectively prevent noise and damage from door impacts, as they often result in the door slamming against the latch, causing wear and noise due to direct contact with metal edges.

Innovation Solution

A door latch system with a latch bar and bumpers that include a jamb bumper portion and a door bumper portion, designed to contact the door jamb and door respectively, distributing impact force and reducing noise and wear by angling protrusions to direct contact with the bumpers rather than metal edges.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the door latch uses direct metal-to-metal contact between the door and latch bar, then the latch provides effective door blocking function, but the door and latch experience wear and noise from direct impact

Engineering Contradiction:
Improvedoor blocking functionVSAvoidnoise and wear from impact
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces bumpers as intermediary components between the door and latch bar. These bumpers absorb the impact force when the door closes, preventing direct metal-to-metal contact. The bumpers are positioned to make contact with the door edge, thereby reducing noise and wear while maintaining the door blocking function through the latch mechanism.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the latch bar is positioned to block door closure effectively, then door security is improved, but the door impacts the latch causing damage and noise

Engineering Contradiction:
Improvedoor securityVSAvoiddamage resistance of door and latch
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The bumpers are installed in advance on the latch bar at positions that will contact the door edge during closure. This beforehand cushioning absorbs the impact force before it reaches the latch bar and door, preventing damage to both components while maintaining effective door blocking and security functions.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Ease of manufacture

If the latch system uses simple metal components for durability, then manufacturing cost is reduced, but noise and wear increase due to direct contact

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidnoise generation
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The bumpers are designed as separate, easily replaceable components that can be manufactured from various materials. If wear or damage occurs, they can be replaced without replacing the entire latch assembly. This approach balances manufacturing simplicity with noise reduction, as the bumpers provide the necessary cushioning while remaining cost-effective and serviceable.

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

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 system effectively prevents door damage and noise by distributing impact force through bumpers, reducing wear on the door guard and protecting both the door and door jamb, while maintaining functionality to prevent door closure.

Implementation Method 1

a bumper configured to contact the door and door jamb, distributing impact force

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

the door impacting the door latch as it closes

Methodology Applied
Scientific EffectImpact force: Impact Force

Data Source

PatentEP3676469B1Swing bar door guard
Publication Date: 2023.01.25 QUIET LOCK CORP
  • EP3676469B1 patent drawingFigure 1~2
  • EP3676469B1 patent drawingFigure 3~4
  • EP3676469B1 patent drawingFigure 5~6

AI summary

A swing bar door guard includes a door latch having a latch base configured to be connected to a door jamb, a latch bar configured to be connected to the latch base, and first and second bumpers configured to extend through openings in the latch bar. The first and second bumpers each include a jamb bumper portion for contacting the door jamb when in a blocking position and a door bumper portion for contacting the door in the blocking position.