Reversible Cylinder Lock Key with Angled Recess Coding

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Solution Overview

Problem

Existing flat-bladed keys have limited coding permutations and are prone to being copied due to easily measurable geometric properties of the recesses, which compromises security.

Innovation Solution

The key features angled lateral flanks of coding recesses, allowing for increased coding flexibility and precision by varying the position and depth of the recesses along an inclined coding axis, making it more difficult to decode and copy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If traditional flat-bladed keys with simple recess coding are used, then manufacturing is easy and geometry is understandable, but security is compromised due to easily measurable geometric properties

Engineering Contradiction:
Improvecoding precisionVSAvoidkey copying difficulty
Core Design Contradiction:
Manufacturing precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The patent transitions from traditional depth-coded recesses to angled lateral flanks where coding is achieved through the position along an inclined coding axis. This dimensional change from vertical depth to angular lateral positioning increases measurement complexity and security while maintaining manufacturing precision through controlled angular machining.

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

Solution Approach 2:

The invention introduces asymmetric angled lateral flanks with specific inclination angles rather than symmetric vertical recesses. This asymmetry makes the key geometry more complex to measure and copy, as the angled surfaces require precise angular measurement and reproduction, thereby enhancing security.

Inventive Principle:
Principle #4Asymmetry

2Adaptability or versatility

If more coding permutations are implemented to increase security, then key blade area must increase, but compact key design is compromised

Engineering Contradiction:
Improvecoding permutationsVSAvoidkey blade area
Core Design Contradiction:
Adaptability or versatilityVSArea of moving object

Solution Approach 1:

By utilizing the angled lateral flank geometry with an inclined coding axis, the patent effectively adds a dimensional aspect to the coding scheme. This allows multiple coding positions to be accommodated along the inclined axis within the existing key blade footprint, increasing coding permutations without proportionally increasing key area.

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

Solution Approach 2:

The angled lateral flanks create a dynamic coding scheme where the effective coding position is determined by the intersection of the flank angle with the pin contact point. This dynamic geometric relationship allows for increased coding density within the same physical space, as the angled surfaces provide multiple potential coding positions along their length.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3822433B1Key, cylinder lock, system and method
Publication Date: 2025.01.29 SEA SCHLIESS SYST
  • EP3822433B1 patent drawingFigure 1a~1c
  • EP3822433B1 patent drawingFigure 2a~2f
  • EP3822433B1 patent drawingFigure 3~5

AI summary

A reversible key blade 1 is described for use with a cylinder lock having radial pins 24. Pins 24 may be biased towards the key blade by springs 26 and pin drive elements 25. The blade 1 is provided with rows of coding recesses 2, 2', each with a pin-contact point 6 on an inclined lateral flank 10 of the recess 2, 2'. The recesses of a row have similar cross-sectional profile shapes and orientations, and may be formed by machining perpendicular to the face 7 of the key blade. Coding of the recesses 2, 2' is provided by varying the positions of the inner lateral flanks 10 but not the position of the opposite, outer, flanks 11 of the recesses 2, 2'. The coding of a recess at a particular pin location can be defined by a single number, representing the distance or position of the recess along the coding axis C. The coding axis C is preferably coaxial with the displacement axis of the pin 24, and the coding recess flanks 10 are preferably orthogonal to the coding axis C.