Exit Device Damper Assembly for Quieter Door Hardware Operation

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Solution Overview

Problem

Conventional door hardware, particularly exit devices, generate excessive noise that exceeds industry guidelines, and there is a lack of a standardized metric for evaluating and quantifying sound output performance, hindering effective comparison and development of noise-reducing solutions.

Innovation Solution

A noise-reducing mechanism for door hardware comprising a housing, damper, and stop that slows operational movement to reduce noise, utilizing components like a drive rod damper assembly and connector link damper assembly to minimize noise generation during actuation and deactuation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If conventional exit devices are used to ensure quick egress operation, then operational speed is improved, but noise generation increases beyond industry guidelines

Engineering Contradiction:
Improveoperational speedVSAvoidnoise generation
Core Design Contradiction:
SpeedVSObject-generated harmful factors

Solution Approach 1:

The patent applies beforehand cushioning by incorporating dampers that are pre-positioned to cushion the movement of door hardware components during operation. The dampers are installed in advance to reduce noise before the harmful noise effect occurs, allowing the exit device to operate quickly while maintaining acceptable noise levels through pre-configured vibration damping.

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

2Object-generated harmful factors

If damping elements are added to reduce noise, then noise generation is reduced, but device complexity increases

Engineering Contradiction:
Improvenoise generationVSAvoiddevice complexity
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The patent applies universality by designing dampers that serve multiple functions: they reduce noise from door hardware operation while also providing structural support and guidance for moving components. The dampers are integrated into existing door hardware assemblies, allowing a single component to address noise reduction without proportionally increasing overall device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Measurement precision

If industry-wide noise evaluation standards are established, then measurement precision is improved, but implementation difficulty increases due to lack of existing frameworks

Engineering Contradiction:
Improvenoise evaluation precisionVSAvoidimplementation ease
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent applies copying by adopting and adapting noise measurement methodologies from existing acoustic evaluation standards to door hardware testing. Rather than creating entirely new measurement protocols, the invention utilizes established acoustic measurement techniques and adapts them for door hardware noise evaluation, making implementation more straightforward while achieving precise noise measurements.

Inventive Principle:
Principle #26Copying

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 mechanism effectively reduces noise generated by door hardware operations, ensuring compliance with industry noise standards and improving user experience in environments sensitive to acoustic disturbances.

Implementation Method 1

The damper is configured to slow the operational movement, thereby reducing noise generated by operation of the door hardware

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3665345B1Door hardware noise reduction and evaluation
Publication Date: 2026.01.21 SCHLAGE LOCK CO LLC
  • EP3665345B1 patent drawingFigure 1
  • EP3665345B1 patent drawingFigure 2
  • EP3665345B1 patent drawingFigure 3~4

AI summary

An exemplary noise-reducing mechanism for door hardware includes a housing, a damper, and a stop. The door hardware includes a first component and a second component, and an operational movement of the door hardware causes relative movement of the first and second components. The housing is mounted to the first component, and the damper is mounted to the housing. The stop is mounted to the second component such that the stop engages the damper during the operational movement. The damper is configured to slow the operational movement, thereby reducing noise generated by operation of the door hardware.