Switchable Blocking Mechanism for Lock Bolt Security

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Solution Overview

Problem

Existing lock devices with switchable thumb turn latches face difficulties in meeting stringent security requirements, as they can be easily manipulated by unauthorized individuals, especially those who have gained entry through windows, allowing them to unlock and exit through the main door.

Innovation Solution

A lock device with a switchable blocking mechanism that prevents the second follower from being used to influence the lock bolt unless the lock is first unlocked by the first follower, ensuring the lock bolt is in its unlocked position, thereby enhancing security and making manipulation by insertion of objects or external forces more difficult.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a thumb turn is provided for easy unlocking from inside, then ease of operation is improved, but security deteriorates as unauthorized persons can easily unlock and exit

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

Solution Approach 1:

The blocking mechanism is made switchable between blocking and non-blocking states, allowing the system to dynamically adapt its security level based on whether the lock bolt is locked or unlocked, resolving the contradiction between easy operation and security

Inventive Principle:
Principle #15Dynamics

2Reliability

If a switchable blocking mechanism is added to prevent unauthorized use, then security is improved, but device complexity increases

Engineering Contradiction:
ImprovesecurityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The blocking mechanism is merged with the existing driver and lock bolt structure, sharing common components and spatial arrangement, which minimizes the increase in device complexity while achieving the security function

Inventive Principle:
Principle #5Merging (Combining)

3Ease of operation

If the blocking mechanism is made switchable, then ease of operation is improved for authorized users, but vulnerability to manipulation increases

Engineering Contradiction:
Improveease of operationVSAvoidmanipulation vulnerability
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The blocking mechanism proactively prevents manipulation attempts by blocking the driver's movement path before unauthorized actions can occur, especially when the lock bolt is in the locked position, thus countering harmful factors before they can affect the system

Inventive Principle:
Principle #9Preliminary anti-action

Data Source

PatentEP2397628B1Lock device with switchable blocking mechanism
Publication Date: 2018.04.04 ASSA OEM AB
  • EP2397628B1 patent drawingFigure 1a
  • EP2397628B1 patent drawingFigure 1b
  • EP2397628B1 patent drawingFigure 2

AI summary

Lock device comprising a lock housing (10, 210), in which there is arranged: a lock bolt (30, 230), which is movable between an unlocked position and a locked position, and a first follower (50, 250). A driver (60, 260) is coupled to the first follower and is arranged to, by means of the first follower, manoeuvre the lock bolt between its unlocked and locked position, as well as, in the locked position of the lock bolt, to dead lock the lock bolt by contact against the lock bolt. A second follower (70, 270) is arranged to, by rotation, influence the functioning of the lock device. A blocking mechanism (100, 300) is switchable between a blocking state, in which rotation of the second follower is barred, and a non-blocking state, in which rotation of the second follower is allowed. The blocking mechanism (100, 300) is arranged to, when the lock bolt (30, 230) is in its locked, dead locked position and the blocking mechanism has assumed its blocking state, by mechanical interaction with the driver (60, 269), bar the blocking mechanism from being switched from its blocking state to its non-blocking state.