Lock Key System Radial Segment Disc Anti-Picking Mechanism

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Solution Overview

Problem

Existing lock-key systems are vulnerable to picking and tampering, particularly pin cylinders, which lack effective security features against unauthorized access and mechanical stress.

Innovation Solution

Integration of a disc cylinder safety feature into a pin cylinder, utilizing radially movable segment discs and a locking bar mechanism that scans key incisions only after a specific angle of rotation, providing enhanced security and anti-snap protection by ensuring segment discs do not protrude into the keyway when the key is removed, and incorporating a circumferential breaking point in the cylinder housing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If segment discs are used to scan key coding, then security against picking is improved, but the device complexity increases

Engineering Contradiction:
Improvesecurity against pickingVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The locking mechanism is divided into multiple independent segment discs (first and second segment discs) that can move radially relative to each other. Each segment disc scans different portions of the key coding, creating multiple security checkpoints that must all be satisfied simultaneously, thereby enhancing security against picking while maintaining manageable complexity through modular design

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The segment discs are arranged radially and can move in the radial dimension, allowing them to scan key coding at different radii. This dimensional arrangement enables multiple scanning positions without increasing axial complexity, as the segment discs engage with the key at different radial depths rather than requiring additional axial layers

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

2Stability of the object's composition

If segment discs are pressed against the cylinder housing wall, then stability during operation is improved, but friction and wear increase

Engineering Contradiction:
Improvestability of segment discsVSAvoidfriction and wear
Core Design Contradiction:
Stability of the object's compositionVSStress or pressure

Solution Approach 1:

The segment discs are designed to be radially movable rather than fixed, allowing them to dynamically adjust their position. During normal operation, they are pressed against the cylinder housing wall for stability, but when the key is inserted and rotated, they can move radially inward to reduce friction and wear, creating a dynamic system that adapts to operational conditions

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The segment discs engage in periodic contact with the cylinder housing wall during the locking cycle. They are pressed against the wall during stable positioning phases, then move away during rotation phases to minimize friction, creating a periodic pattern of engagement and disengagement that balances stability with reduced wear

Inventive Principle:
Principle #19Periodic action

3Reliability

If the locking bar is moved radially inward during rotation, then security against core pulling is improved, but the mechanism complexity increases

Engineering Contradiction:
Improvesecurity against core pullingVSAvoidmechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The locking bar's radial movement is merged with the rotational motion of the cylinder core. As the core rotates, the locking bar is automatically moved radially inward through the interaction between the ball and the inclined surfaces, combining two security actions (rotation and radial movement) into a single integrated mechanism rather than requiring separate actuation systems

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The ball acts as an intermediary element between the cylinder core and the locking bar. It transmits the rotational motion and converts it into radial movement of the locking bar through the inclined surfaces, serving as a mechanical mediator that simplifies the overall mechanism by eliminating the need for complex direct coupling between the core and locking bar

Inventive Principle:
Principle #24Intermediary (Mediator)

4Ease of operation

If a ball is used to move segment halves radially, then ease of operation is improved, but the manufacturing precision requirements increase

Engineering Contradiction:
Improveease of segment movementVSAvoidalignment precision
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The ball mechanism is designed to be self-aligning and self-adjusting during operation. As the cylinder core rotates, the ball automatically finds its correct position and applies the appropriate radial force to move the segment halves, eliminating the need for precise pre-alignment during manufacturing. The system self-corrects for minor manufacturing tolerances through the inherent mechanics of the ball-and-inclined-surface interaction

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3530845B1Lock and key system
Publication Date: 2020.09.16 ASSA ABLOY SICHERHEITSTECHNIK GMBH
  • EP3530845B1 patent drawingFigure 1~5

AI summary

1. Lock-key system. 2.1. The invention relates to a lock-key system comprising a cylinder with a cylinder housing and a cylinder core rotatably mounted therein, the cylinder core having a keyway for inserting a key. The key's face has a code by means of notches that can be read by cylinder pins interacting with cylinder housing pins. 2.2. The key has at least one further code on its back, which can be read by at least one radially divided segment disc mounted in a radial groove in the cylinder core, surrounding the keyway in an annular manner, movable in the groove, and pressed against the cylinder housing by springs.