Flat Key Lock Assembly Rotational Blocking Member

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing flat key security lock assemblies are vulnerable to break-ins, particularly due to the ease with which movable blocking members can be driven in rotation using hooks.

Innovation Solution

A ball locking member that is movable in rotation but not in translation, housed between the passageway and a ball, is implemented, which is kept in an active position by a torsion spring, allowing the ball to retract when the rotor is rotated and providing additional locking mechanism to prevent external rotation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a movable blocking member is implemented to lock the ball, then the locking security is improved, but the vulnerability to hook-based attacks increases

Engineering Contradiction:
Improvelocking securityVSAvoidvulnerability to hook attacks
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The blocking member is designed to be movable in rotation rather than in translation, inverting the conventional approach. This rotational movement cannot be easily actuated by hooks from the outside, as hooks are effective only at linear pulling motions. The key bit translates linearly but converts this motion into rotational movement of the blocking member through a cam or lever mechanism, achieving the desired inversion of motion type to resist external attacks.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The blocking member operates in a different dimensional space by rotating around an axis perpendicular to the key insertion direction, rather than moving linearly along the key path. This adds a rotational dimension to the locking mechanism that is not accessible from the external keyway, making hook attacks ineffective while maintaining internal controllability through the key's linear motion.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If additional locking mechanisms are added to prevent break-in, then the security against forcing is improved, but the device complexity increases

Engineering Contradiction:
Improvesecurity against forcingVSAvoidlocking mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The blocking member combines multiple functions into a single component: it locks the ball in the blind hole, prevents rotational movement of the rotor, and is controlled by the key's linear translation. This merging of functions reduces the need for separate locking components while maintaining high security against forcing attempts.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The blocking member serves multiple purposes: it acts as a lock for the ball, a barrier against rotor rotation, and a mechanism that converts linear key motion into rotational locking action. This multi-functionality reduces overall device complexity while enhancing security features.

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

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 configuration significantly enhances the security of the lock assembly by making it more difficult to drive the movable member in rotation from the outside and allows for a more compact design while maintaining effective locking functionality.

Implementation Method 1

a blocking member movable in rotation to be able to hold said ball projecting from said rotor, which blocking member is kept in an active position by a torsion spring

Methodology Applied
Scientific EffectTorsion spring: Torsion Spring

Data Source

PatentEP3658724B1Security lock and flat key assembly
Publication Date: 2021.05.26 DOM SECURITY
  • EP3658724B1 patent drawingFigure 1~2
  • EP3658724B1 patent drawingFigure 3A~4B
  • EP3658724B1 patent drawingFigure 5A~5B

AI summary

The invention concerns a flat-key lock assembly comprising: a stator (12) having a cylindrical recess and a blind hole (28), said stator (12) comprising a plurality of locking pins (62); a rotor (18) mounted to rotate inside said cylindrical recess, said rotor (18) comprising a plurality of radial recesses (66) opening to the outside in order to allow said locking pins (62) to extend into said radial recesses (66), the rotor (18) further comprising a ball (58) and an immobilisation member (42) that can move in rotation in order to hold the ball (58) protruding from the rotor (18); and, a flat key (80) for pushing back said locking pins (62) to the outside of the rotor (18) and, simultaneously, controlling said movable immobilisation member (42) in order to allow said ball (58) to retract inside the rotor (18).