Safe Locking Bolt with Worm Drive Mechanism

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Solution Overview

Problem

Existing locking mechanisms for valuables containers, such as safes, are complex and bulky due to the need for a linear displacement of bolts between locked and unlocked positions, which requires a significant amount of space and effort to operate.

Innovation Solution

A compact locking device utilizing a plate-shaped bolt with radial hooks and an adjusting worm that converts rotational movement into linear displacement through a helical adjusting web and inclined guide groove, allowing for efficient and space-saving operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a traditional linear displacement mechanism is used for the bolt, then the locking function is achieved, but the device becomes complex and bulky

Engineering Contradiction:
Improvelocking mechanism complexityVSAvoidlocking function
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent replaces the traditional complex linear displacement mechanism with a worm gear mechanism. The rotating worm (adjusting element) engages with the bolt to directly produce linear displacement, substituting multiple mechanical components with a single integrated worm gear system that is both simpler and more reliable.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The worm serving as the adjusting element performs multiple functions: it converts rotational motion to linear motion, provides self-locking capability, and directly actuates the bolt. This multi-functionality reduces the number of separate components needed, simplifying the overall locking mechanism while maintaining reliability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Volume of moving object

If a traditional locking mechanism is used, then security is provided, but significant space is required

Engineering Contradiction:
Improvelocking device spaceVSAvoidsecurity
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The worm is integrated within the housing structure, with the adjusting element nested inside the bolt assembly. The helical adjusting web is contained within the housing, allowing the entire locking mechanism to be compact and space-efficient while maintaining full security functionality.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The worm extends in the axial direction of the bolt displacement, utilizing the third dimension (depth) rather than requiring lateral space. The helical adjusting web wraps around the worm axis, efficiently packing the mechanism within a compact volume while providing the necessary mechanical advantage for secure locking.

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

3Ease of operation

If a complex actuating mechanism is used, then precise bolt control is achieved, but user effort increases

Engineering Contradiction:
Improveuser effortVSAvoidactuating mechanism
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The worm gear mechanism provides inherent mechanical advantage, allowing the user to apply small rotational force at the lock to generate large linear force on the bolt. This substitution of a simple rotary actuation for complex linear actuation significantly reduces user effort while maintaining precise control.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The helical adjusting web provides a curved, continuous engagement surface that smoothly converts rotational motion to linear motion. This helical geometry distributes the mechanical advantage throughout the rotation, providing consistent and easy operation throughout the entire locking cycle.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 solution provides a robust, space-saving, and user-friendly locking mechanism that enables easy conversion between locked and unlocked positions with minimal effort, ensuring secure and efficient operation.

Implementation Method 1

an adjusting element which is designed as an adjusting worm which is non-rotatably connected to the lock and can be rotated about a worm axis

Methodology Applied
Scientific EffectWorm drive: Worm Drive

Implementation Method 2

the adjusting element of the adjusting worm being designed as an adjusting web which extends helically in an acute or obtuse circumferential angle area around the axis of the worm

Methodology Applied
Scientific EffectHelical mechanism: Helix

Implementation Method 3

the guide element of the bolt is designed as a straight guide groove, which extends on a side of the bolt facing the adjusting web, forming an acute angle of inclination to a displacement direction of the bolt

Methodology Applied
Scientific EffectMechanical advantage through inclined plane: Inclined Plane

Data Source

PatentEP2177698B1Locking device for a safe
Publication Date: 2012.05.23 WINCOR NIXDORF INT GMBH
  • EP2177698B1 patent drawingFigure 1~2
  • EP2177698B1 patent drawingFigure 3~4
  • EP2177698B1 patent drawingFigure 5~6

AI summary

The device has a locking bar, which is linearly slid between an unlocking position and locking position. An actuator for adjusting the locking bar, is actuated by a lock (8). The actuator forms a servo screw rotated around the screw axis, which projects radially from the screw axis. A positioning element runs in direction with an axial direction- and circumferential direction component, which stays in contact with the guiding element of the locking bar.