Combination Lock Tool-Free Code Change Mechanism

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing combination locks require a tool to change the code, and there is a risk of accidental recoding due to incorrect alignment of clutch wheels and dials, which can lead to locking issues.

Innovation Solution

A combination locking device that allows code changes without a tool, featuring an interference-free interface between clutch wheels and dials, with second locking members providing precise alignment and preventing accidental recoding, and a spindle with multiple positions for locked, code change, and unlocked conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an interference fit between clutch wheel and dial is used to prevent accidental recoding, then the lock security is improved, but a tool is required to change the code which reduces ease of operation

Engineering Contradiction:
Improvelock securityVSAvoidease of code change
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent removes the interference fit between the clutch wheel and dial, extracting the problematic mechanical constraint that required tools for code changes. Instead, it uses a separate alignment mechanism with ridges and grooves to ensure proper positioning during recoding, allowing the dial to rotate freely without excessive force while maintaining alignment precision.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces an intermediary alignment mechanism consisting of ridges on the clutch wheel and corresponding grooves on the dial. This intermediary structure mediates between the need for precise alignment and the need for easy code changes, ensuring correct positioning without requiring tool-assisted forceful rotation.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If ridges and grooves are provided for alignment between clutch wheel and dial, then alignment precision is improved, but the complexity of the device increases

Engineering Contradiction:
Improvealignment precisionVSAvoiddevice complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent segments the alignment function into distinct ridges on the clutch wheel and corresponding grooves on the dial. Each ridge-groove pair corresponds to a specific numerical position, dividing the alignment task into discrete, manageable segments that are simple in individual design but collectively provide precise multi-position alignment capability.

Inventive Principle:
Principle #1Segmentation

3Ease of operation

If the dial can freely rotate relative to the gate wheel during code change, then ease of operation is improved, but the risk of incorrect alignment increases

Engineering Contradiction:
Improveease of dial rotationVSAvoidalignment accuracy
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent implements a self-aligning mechanism where the ridges on the clutch wheel automatically guide the dial into correct alignment positions through their geometric interaction. As the dial rotates during code changes, the ridges and grooves self-correct any misalignment, ensuring that the dial settles into the precise numerical positions without requiring operator intervention or external alignment tools.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3168395B1A combination locking device
Publication Date: 2019.06.26 HENRY SQUIRE & SONS
  • EP3168395B1 patent drawingFigure 1~2
  • EP3168395B1 patent drawingFigure 3
  • EP3168395B1 patent drawingFigure 4~5

AI summary

A combination locking device is disclosed. The device includes a spindle which is axially movable, has recesses in it and locking protrusion on it. Around the spindle are annular dials with markers on the outside and associated recesses on the inside. Between each dial and the spindle are gate wheels which have apertures extending radially from the spindle to the dial. The gate wheels also have recesses matching the locking protrusions and when the protrusions and recesses are aligned and the spindle moved axially the gate wheels are rotatably fixed to the spindle. A plurality of locking balls are located within the apertures. Axial movement of the spindle selects device conditions including a code change condition where the locking balls are able to enter the spindle recesses freeing them from the dial recesses and allowing the dials to move around the gate wheels.