Anti-Detection Combination Lock with Split Gear Mechanism

Solution Overview

Problem

Combination locks are susceptible to unauthorized password deduction through observation and manipulation, producing distinct sounds when the correct password is reached, compromising security.

Innovation Solution

Incorporation of an anti-detection piece that prevents lower gears from rotating by abutting against upper gears when the knob is rotated, obstructing number detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the knob is rotated to manipulate the numeral wheels, then the lock can be unlocked with the correct password, but unauthorized individuals can deduce the password through observation and analysis of the click sounds

Engineering Contradiction:

Improvepassword securityVSAvoidnormal unlocking operation

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The numeral wheel is divided into two independent gears: an upper gear that rotates with the knob and a lower gear that displays the numbers. This segmentation allows the upper gear to rotate without causing the lower gear to rotate, eliminating the click sounds that reveal the correct password while maintaining normal unlocking functionality.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A non-circular transmission element with a cam profile is introduced as an intermediary between the upper gear and the lower gear. This cam mechanism transfers rotational motion from the upper gear to the locking bolt without causing the lower gear to rotate, thereby preventing password detection through sound while enabling lock actuation.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Device complexity

If traditional single-gear numeral wheels are used, then the structure is simple, but the lower gears rotate when the knob is turned, producing detectable click sounds

Engineering Contradiction:

Improvenumeral wheel structureVSAvoidpassword detection through sound

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The numeral wheel is divided into two independent gears: an upper gear that rotates with the knob and a lower gear that displays the numbers. This segmentation allows the upper gear to rotate without causing the lower gear to rotate, eliminating the click sounds that reveal the correct password while maintaining normal unlocking functionality.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A non-circular transmission element with a cam profile is introduced as an intermediary between the upper gear and the lower gear. This cam mechanism transfers rotational motion from the upper gear to the locking bolt without causing the lower gear to rotate, thereby preventing password detection through sound while enabling lock actuation.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS20250223836A1Anti-detection combination lock

Publication Date: 2025.07.10 REAL LOCKS & SECURITY CO LTD

AI summary

A combination lock is disclosed. A lock seat includes a base and a lock core, and numeral wheels are arranged spacedly on the base. Each numeral wheel includes a lower gear and an upper gear, and part of each lower gear protrudes from the base. An anti-detection piece includes a main rod and branch rods. Each branch rod is located on one side of each upper gear. A panel covers the base, and numeral holes and an opening are defined on the panel. A knob is arranged on one side of the anti-detection piece. The knob is connected to the lock core and protrudes from the opening.