Flat Key Control Rib for Cylinder Lock Jamming

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Solution Overview

Problem

Conventional cylinder lock and flat key systems face a conflict between operability and security due to limited key variations, leading to uneven key catches or removals and reduced locking accuracy from increased play to accommodate oblique control webs.

Innovation Solution

The design incorporates a control rib on the key shank with scanning sections and connecting sections that deviate from the insertion direction, featuring a thinner thickness in connecting sections to create lateral constrictions, providing greater play for locking slides and maintaining security by reducing the width in these areas.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the control web runs obliquely to the direction of insertion, then the key can accommodate complex key variations, but the control web must be made thinner to avoid tilting or jamming, which reduces manufacturing precision and increases play

Engineering Contradiction:
Improvekey variationsVSAvoidlocking accuracy
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The control rib is designed with varying thickness along its length, with thinner sections in oblique connecting areas and thicker sections in scanning areas. This local variation in geometry allows the control rib to accommodate oblique paths for key variations while maintaining sufficient thickness in scanning sections to ensure precise engagement with locking slides, thereby resolving the conflict between adaptability and manufacturing precision

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The control rib is segmented into different functional sections: scanning sections with greater thickness for precise locking engagement, and connecting sections with reduced thickness to accommodate oblique paths. This segmentation allows each section to be optimized for its specific function, enabling complex key variations without compromising overall locking accuracy

Inventive Principle:
Principle #1Segmentation

2Ease of operation

If the thickness of the control web is reduced in oblique sections, then tilting or jamming is avoided, but the play between the control web and scanning components increases, reducing security

Engineering Contradiction:
Improvesmooth insertionVSAvoidlocking security
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The control rib features localized thickness variations where thinner sections are positioned specifically in oblique connecting areas to facilitate smooth key insertion and prevent jamming, while thicker sections are maintained in scanning areas to ensure tight engagement with locking slides. This local differentiation resolves the contradiction by providing ease of operation where needed while maintaining reliability where critical

Inventive Principle:
Principle #3Local quality

3Ease of operation

If the clearance between the control land and scanning components is increased, then operability is improved, but locking accuracy is reduced and illegal opening is facilitated

Engineering Contradiction:
ImproveoperabilityVSAvoidlocking accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The design implements differential clearance through varying control rib thickness: larger clearances are provided in oblique connecting sections to improve operability and prevent jamming, while minimal clearances are maintained in scanning sections to preserve locking accuracy and prevent illegal opening. This localized approach to clearance management resolves the technical contradiction

Inventive Principle:
Principle #3Local quality

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 design enhances the operability and security of the cylinder lock by allowing smooth key insertion and rotation while maintaining precise locking mechanisms, reducing the risk of tilting or jamming and illegal openings.

Implementation Method 1

permanent magnets are provided on the flat key and/or on the cylinder lock, with the permanent magnets of the cylinder lock being rotatably mounted in the cylinder lock, so that they are brought into a position by a predetermined polarity of the magnets of the flat key

Methodology Applied
Scientific EffectMagnetic attraction: Magnetism

Data Source

PatentEP3221536B1Flat key and cylinder lock
Publication Date: 2018.09.12 EVVA SICHERHEITSTECHNOLOGIE GMBH
  • EP3221536B1 patent drawingFigure 1
  • EP3221536B1 patent drawingFigure 2~3
  • EP3221536B1 patent drawingFigure 4

AI summary

The invention relates to a flat key (1) for a cylinder lock (2), comprising a key shank (4) which extends along the direction of insertion (3) of the flat key (1), said key shank (4) having a lateral face (5) on which first key variation elements (6) are provided, in particular in the form of permanent magnetic pills, lateral control grooves and/or lateral control elevations. The key shank (4) has a key back (7) on which a control rib (8) is provided, said control rib comprising feeler portions (10), which form second key variation elements (9) along the direction of insertion (3), a connecting portion (11) between two adjacent feeler portions (10), and two lateral control curves (14).