Door Lock Access Control Mounting with Thermal Release

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Solution Overview

Problem

Fire resistive door assemblies face challenges in passing fire tests due to combustible materials in access control components, which are not effectively removed from the door surface during fires, with wires acting as tethers even when plastics melt, posing a risk of igniting.

Innovation Solution

A wire disconnection apparatus and method that automatically releases combustible components from the door by using a spring or expandable material to disconnect wires at elevated temperatures below the ignition point, ensuring safe separation of access control components from the door.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If access control components are mounted to the door using combustible materials, then the components can be securely attached and function normally, but the combustible materials may ignite during fire conditions and sustain the fire

Engineering Contradiction:
Improvefire safetyVSAvoidcomponent mounting
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent implements a temperature-responsive release mechanism that is pre-configured to automatically disconnect wire connectors when a predetermined temperature is reached. This preliminary action ensures that before ignition can occur, the combustible materials are automatically separated from the door assembly, eliminating the fire sustainment risk while maintaining normal mounting functionality during operational conditions.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If wires are used to connect access control components to the door, then electrical connectivity is maintained, but the wires act as tethers that prevent combustible components from separating during fire conditions

Engineering Contradiction:
Improvefire safetyVSAvoidwire connection system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The wire connector system is designed with a temperature-responsive release feature that is pre-configured to automatically disconnect the wires when the predetermined temperature is reached. This preliminary disconnection action eliminates the tethering effect during fire conditions, allowing combustible components to separate freely while maintaining reliable electrical connectivity during normal operation.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If combustible materials are used to mount access control components, then the components can be installed on the door, but the combustible materials remain on the door surface and may ignite, requiring automatic removal mechanisms

Engineering Contradiction:
Improvefire safetyVSAvoidcomponent removal
Core Design Contradiction:
ReliabilityVSExtent of automation

Solution Approach 1:

The mounting system incorporates a temperature-responsive release mechanism that enables the access control components to automatically remove themselves from the door assembly when fire conditions are detected. The system self-activates based on temperature sensing, eliminating the need for external intervention or complex automated removal mechanisms, while ensuring combustible materials are cleared from the door surface before ignition can occur.

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

Effectively prevents the access control components from igniting by automatically disconnecting wires and removing combustible materials from the door surface at temperatures below the ignition point, enhancing fire safety ratings.

Implementation Method 1

the retainer will lose strength causing the retainer to release the spring from the loaded state above a predetermined temperature that is lower than the temperature at which the combustible material will ignite

Methodology Applied
Scientific EffectThermal softening: Melting

Implementation Method 2

the spring is adapted to bias the retainer in a direction away from the door

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 3

expandable material may expand, to apply force to cause the wires to separate at connectors

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP2971419B1Door lock access control component mounting
Publication Date: 2020.11.04 SARGENT MANUFACTURING COMPANY
  • EP2971419B1 patent drawingFigure 1
  • EP2971419B1 patent drawingFigure 2
  • EP2971419B1 patent drawingFigure 3

AI summary

An apparatus and method for releasably mounting access control components for a door lock to a door. A base element is adapted to be mounted to the door. A first wire connector element is mounted to the base element. A mounting element with combustible material attached is provided. A second wire connector element is mounted to the mounting element, and the second wire connector element is releasably connected to the first wire connector element to mount the mounting element to the base element. A spring is provided, and a retainer holds the spring in a loaded state, but in a fire event the retainer may melt, allowing the spring to apply force to the mounting element. Alternatively, an expanding material may apply the force. The force causes the wire connector elements to disconnect and allow the mounting element to separate from the base element.