Key Control Element for Rotary Lock Cylinder Security

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Solution Overview

Problem

Existing rotary lock cylinders and keys, while tamper-proof, face limitations in security against copying and permutation possibilities, necessitating enhanced security measures.

Innovation Solution

A key design featuring a key shank with control recesses and a movably arranged control element, assisted by a spring-loaded bolt, which interacts with tumblers to increase security by allowing the control element to move from a locked to a release position, enhancing safety and permutation possibilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a control element is added to increase security against copying, then security is improved, but device complexity increases

Engineering Contradiction:
Improvesecurity against copyingVSAvoidkey structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The control element is nested within the key shaft, with the recess opening into the bore to allow the engagement element to project into the bore through the recess. This nested configuration integrates the control mechanism within the existing key structure rather than adding external components, thereby improving security against copying while minimizing increases in device complexity

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The recess acts as an intermediary structure that allows the engagement element of the rotary lock cylinder to interact with the control element through the key shaft. This mediator approach enables the control function without requiring direct exposure or complex external mechanisms, balancing security enhancement with structural simplicity

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a recess is created for the engagement element, then security is improved, but the key cross-section is weakened

Engineering Contradiction:
Improvesecurity against manipulationVSAvoidkey cross-section strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The recess is localized to specific regions of the key shaft where control elements are positioned, rather than creating a continuous opening. This localized approach provides the necessary access for engagement elements while maintaining the structural integrity and strength of the key cross-section in critical areas

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The recess opens into the bore in a direction that minimizes cross-sectional weakening. By utilizing the bore space and creating a recess that projects into the bore rather than opening externally, the design maintains key strength while providing access for the engagement element to act on the control element

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

3Adaptability or versatility

If control elements are positioned forward in the key shaft, then permutation possibilities are increased, but manufacturing precision requirements increase

Engineering Contradiction:
Improvepermutation possibilitiesVSAvoidcontrol element positioning precision
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The control elements are pre-positioned within the key shaft at predetermined locations along the longitudinal axis. The recess and bore structures are designed in advance to accommodate these control elements at specific positions, allowing for increased permutation possibilities while managing manufacturing precision requirements through pre-planned positioning features

Inventive Principle:
Principle #10Preliminary action

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

The key design significantly increases security against manipulation and copying, while minimizing the weakening of the key cross-section, allowing for a larger area for control bores and increased permutation possibilities.

Implementation Method 1

a bolt and spring element, in particular a compression spring, arranged in a bore in the key, which spring element exerts a force on the bolt that pushes the control element inwards from the key shaft

Methodology Applied
Scientific EffectSpring force: Spring

Data Source

PatentEP3280855B1Key and rotary lock cylinder
Publication Date: 2020.05.20 ASSA ABLOY (SCHWEIZ) AG
  • EP3280855B1 patent drawingFigure 1
  • EP3280855B1 patent drawingFigure 2
  • EP3280855B1 patent drawingFigure 3a~3c

AI summary

The invention relates to a key (1) for a rotary lock cylinder (2), comprising a key grip (3) and a key shaft (4) which adjoins the key grip (3) and extends along a longitudinal axis (L), wherein the key shaft (4) has control recesses (6), in particular control bores, on its outside (5) for properly positioning tumblers on the rotary lock cylinder (2) and also has at least one control element (7) which is movably arranged in the key shaft (4), said control element (7) having a control surface (9) which interacts with a tumbler (8) of the rotary lock cylinder (2). The key shaft (4) has a recess (10) which is designed in such a way that a manipulation element (11) of the rotary lock cylinder (2) can act on the control element (7) via the recess (10) when the key (1) is inserted into the rotary lock cylinder, such that the control element (7) is movable with respect to the key shaft (4) and the tumbler (8) can be brought into the release position.