Rotary Lock Key Recessed Control Element Against Wear and Tampering

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Solution Overview

Problem

Existing rotary locking cylinders and keys are vulnerable to mechanical wear, tampering, and key duplication due to the protruding and poorly protected spring-loaded control elements, necessitating precise manufacturing and increased security against copying.

Innovation Solution

A key design with a control element positioned within a recess in the key shaft, surrounded by a side wall, and a locking mechanism involving conical structures for the stator and rotor pins, which requires simultaneous manipulation of multiple elements for unauthorized access, enhancing security and robustness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the control element is arranged protruding in the key shaft, then the control element is easily accessible for operation, but the control element is vulnerable to mechanical wear and tampering

Engineering Contradiction:
Improveaccessibility of control elementVSAvoidprotection against mechanical wear
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The control element is nested within a recess in the key shaft, with the control surface positioned inside the recess rather than protruding. This nesting configuration protects the control element from mechanical impacts and tampering while maintaining operational accessibility through the recess opening.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Reliability

If the control element is spring-loaded and movable, then the key provides active control for enhanced security, but the control element becomes more visible and vulnerable to key duplication

Engineering Contradiction:
Improvesecurity control capabilityVSAvoidvulnerability to key duplication
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The control element with its control surface is nested within the recess, making it less visible from the outside. The spring-loaded mechanism remains functional for active control, but the recess configuration reduces visibility and accessibility for potential duplicators.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The recess provides a localized protected environment for the control surface, creating a distinction between the protected control area and the rest of the key shaft. This local quality enhancement provides targeted protection where it is most needed.

Inventive Principle:
Principle #3Local quality

3Reliability

If a recess is made in the key shaft for the control element, then the control element is protected, but the key shaft is weakened

Engineering Contradiction:
Improveprotection of control elementVSAvoidstability of key shaft
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The recess is designed with specific dimensional characteristics that provide adequate protection for the control element while minimizing material removal. The recess depth and width are optimized to balance protection needs with structural integrity requirements of the key shaft.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4646519B1Key and rotary lock cylinder with key
Publication Date: 2025.12.31 ASSA ABLOY (SCHWEIZ) AG
  • EP4646519B1 patent drawingFigure 1a~1b
  • EP4646519B1 patent drawingFigure 2a
  • EP4646519B1 patent drawingFigure 2b

AI summary

A key (1) for a rotary lock cylinder (2) comprises a key handle (3) and a key shank (4) which adjoins the key handle (3) and which extends along a longitudinal axis (L), wherein: the key shank (4) comprises control recesses (6), in particular control bores, on its outer side (5) for arranging tumblers on the rotary lock cylinder (2), and at least one control element (7) arranged movably in the key shank (4), which control element (7) has a control surface (9) which interacts with a tumbler (8) of the rotary lock cylinder (2); the control element (7) can be moved from an initial position into an arrangement position during the interaction with the tumbler (8); the key shank (4) has a depression (10) for the control element (7), said depression extending from the outer side (5) into the key shank (4) and being laterally surrounded by a side wall (11) that runs around a central axis (M); and the control surface (9) of the control element (7) is situated in said depression (10).