Anti-Copy Key With Offset Elevation And Inclined Clamping

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Solution Overview

Problem

Conventional key copying devices can easily replicate keys, making it difficult to secure locks, and existing designs do not effectively prevent unauthorized copying or deformation during the process.

Innovation Solution

The key design features an offset elevation on the shank and bow that protrudes beyond the broad sides, with a recess in the locking channel to accommodate the elevation, ensuring that the key is held in an inclined position and making it difficult to clamp and copy, while the recess prevents the key from being used if the elevation is removed or deformed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional key design with a flat bow and shaft is used, then the key can be easily clamped and copied in standard copying devices, but this makes key duplication too easy and compromises security

Engineering Contradiction:
ImprovesecurityVSAvoidcopying difficulty
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent applies asymmetry by providing an elevation on only one of the two broad sides of the shaft, creating an asymmetric key profile. This asymmetric design prevents the key from being properly clamped in conventional copying devices that expect symmetric flat surfaces, thereby making unauthorized copying difficult while maintaining the key's functional operation in the lock cylinder.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent transitions from a two-dimensional flat key surface to a three-dimensional structure by adding an elevation that protrudes from the broad side of the shaft. This dimensional change creates an uneven surface that interferes with the clamping mechanism of conventional copying devices, which rely on flat contact surfaces, thus preventing easy duplication.

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

2Reliability

If the elevation is made narrow in relation to the broad side of the shaft, then copying with conventional devices becomes more difficult, but tension forces on the elevation become low causing possible deformation

Engineering Contradiction:
Improvecopying preventionVSAvoidelevation stability
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent specifies that the elevation has a width of between 0.5 mm and 2.0 mm, optimizing the balance between copying prevention and structural stability. This parameter range is narrow enough to interfere with conventional copying device clamping surfaces but wide enough to provide sufficient structural strength and resist deformation under tension forces during key operation.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the elevation extends to directly in front of the edge of the bow, then clamping on the bow becomes much more difficult, but this requires precise positioning during manufacturing

Engineering Contradiction:
Improvecopying preventionVSAvoidelevation positioning
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The elevation is designed to extend to directly in front of the edge of the bow, proactively preventing clamping attempts on the bow by conventional copying devices. This preliminary geometric arrangement ensures that even if a copying device attempts to clamp the bow, the elevation will interfere with the clamping action, making the precise positioning a deliberate security feature rather than a manufacturing constraint.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP1975350B1Key for a locking cylinder and key with a locking cylinder
Publication Date: 2011.12.28 WINKHAUS
  • EP1975350B1 patent drawingFigure 1~4
  • EP1975350B1 patent drawingFigure 5~8

AI summary

The key has a shaft (4) and a key bow (3) is connected to the shaft. The shaft has narrow sides and broad sides (15) opposite to each other forming rectangular cross section. A closing groove (6) is arranged in the shaft for controlling pin positions of the locking cylinder. An elevation (17), extending from the shaft till the key bow, is narrow in relation to the dimensions of the broad sides of the shaft. The elevation is arranged on the broad sides and spaced from the closing grooves.