Cylinder Lock Clutch Axial Biasing for Tamper Resistance

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Solution Overview

Problem

Conventional euro-profile lock cylinders can be easily broken into and tampered with, allowing unauthorized access due to their design, where the clutch can be forced to move and the cam components can be removed or pivoted to expose the lock assembly.

Innovation Solution

The lock cylinder incorporates a resiliently biased clutch mechanism that locks axially, with a mechanical locking mechanism rendering it immobile, and an anti-drill component to prevent tampering, along with a weakened area to absorb forced entry attempts, ensuring the cam remains in place and secure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the clutch is designed to be axially slidable to selectively connect interior and exterior locking mechanisms, then the ease of operation is improved, but the reliability deteriorates as the clutch can be forced to move and components can be removed or pivoted

Engineering Contradiction:
Improveease of operationVSAvoidreliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The clutch is designed with dynamic axial mobility to selectively engage either the interior or exterior locking mechanism based on operational needs. This allows the clutch to slide axially within defined limits, enabling flexible connection to the cam from either side while maintaining structural integrity through controlled movement rather than fixed positioning.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

A resilient member is pre-installed to bias the clutch toward a neutral or default position, creating preliminary resistance against unauthorized axial movement. This resilient biasing mechanism prevents the clutch from being easily forced into unintended positions or allowing components to be inadvertently removed, thereby counteracting potential tampering before it occurs.

Inventive Principle:
Principle #9Preliminary anti-action

2Ease of operation

If the clutch is biased into a default position by a spring, then the ease of operation is improved, but the object-generated harmful factors worsen as forced deformation can break components and expose the lock assembly

Engineering Contradiction:
Improveease of operationVSAvoidobject-generated harmful factors
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The resilient member acts as a cushioning element that absorbs and dissipates forced deformation energy before it can transmit to critical components like the cam and locking mechanisms. This preliminary cushioning prevents catastrophic failure by allowing controlled deformation of the resilient member itself, thereby protecting the overall lock assembly from breakage and component exposure during forced entry attempts.

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

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

This design significantly enhances the security of the lock cylinder by making it more difficult to tamper with and remove, preventing unauthorized access while allowing authorized users to open the closure with a key.

Implementation Method 1

a resilient member arranged to bias the clutch towards the third condition

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2300673B1Lock mechanism
Publication Date: 2018.07.18 AVOCET HARDWARE UK
  • EP2300673B1 patent drawingFigure 1a~1c
  • EP2300673B1 patent drawingFigure 2~4
  • EP2300673B1 patent drawingFigure 5a~5c

AI summary

A cylinder lock (100) having a first actuator assembly (102) and a second actuator assembly (106) positioned either side of a cam (132), in which the first and second actuator assemblies (102, 106) can selectively actuate the cam (132) by means of a clutch (142, 150) movable between two conditions and in which removal of the first actuator assembly (102) causes the clutch to move into a third, locked condition in which it is constrained. A cylinder lock (100) having a predetermined weakened area on the first actuator side of a cam.