Two-Part Key With Segmented Safety Openings

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Solution Overview

Problem

Existing key designs fail to effectively prevent undesired loosening of the connection between the first and second parts, making them susceptible to manipulation.

Innovation Solution

The key features a first part with a through-hole safety opening and a second part with a blind-hole or stepped-groove safety opening, or both parts with stepped grooves, forming a secure connection that is difficult to manipulate without causing visible damage, and includes a locking bit and bearing part with a fastening shaft for enhanced security.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If standard fastening technology is used to connect the first and second parts, then the connection can be easily loosened with standard tools, but the ease of manufacture and assembly is improved

Engineering Contradiction:
Improveease of manufactureVSAvoidconnection security
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The safety opening is segmented into two distinct parts: a through-hole in the first part and a blind-hole in the second part. This segmentation prevents standard fastening tools from accessing the complete opening, thereby securing the connection while maintaining manufacturing simplicity through standard drilling processes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The safety opening acts as an intermediary element between the first and second parts. By designing it as a through-hole in one part and a blind-hole in the other, it mediates the connection security requirement without compromising ease of manufacture, as both hole types can be created using conventional drilling equipment.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the safety openings are designed as through-holes in both parts, then the assembly is simple, but undesired manipulation and loosening can occur

Engineering Contradiction:
Improveassembly simplicityVSAvoidanti-manipulation security
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The safety opening design employs asymmetry by making one opening a through-hole and the other a blind-hole. This asymmetric configuration maintains relative assembly simplicity while effectively preventing manipulation, as the blind-hole prevents tool insertion from the opposite side, blocking disassembly attempts.

Inventive Principle:
Principle #4Asymmetry

3Reliability

If blind-holes or stepped grooves are used for safety openings, then manipulation is prevented, but the manufacturing complexity increases

Engineering Contradiction:
Improveanti-manipulation securityVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The blind-hole is created only in the second part where it is locally required for security, while the first part maintains a simple through-hole. This local application of the more complex blind-hole design achieves anti-manipulation security without unnecessarily increasing the overall manufacturing complexity of the entire assembly.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2169152B1Key with a first and second piece
Publication Date: 2015.10.21 HELLA GMBH & CO KGAA
  • EP2169152B1 patent drawingFigure 1
  • EP2169152B1 patent drawingFigure 2~3
  • EP2169152B1 patent drawingFigure 4

AI summary

The key (1) has two elements (2,4), which have a safety opening (6), and the former element has a safety recess formed as a through hole and the latter element has another safety recess formed as a blind hole. The elements have a safety opening formed as offset groove, where both the grooves form a blind hole together in the mounting condition of the key.