Magnetic Single-Bolt Locking for Quiet Low-Wear Door Closure

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Solution Overview

Problem

Existing lock devices often require complex designs with multiple parts, high friction, loud operation, and high wear, leading to issues with door closure and increased production complexity.

Innovation Solution

A lock device with a single bolt mechanism that uses magnetic repulsion to automatically engage with a strike plate upon alignment, minimizing moving parts and requiring no mechanical contact, thus reducing friction and wear, and allowing for silent operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional latch and deadbolt system is used, then the lock device can provide secure locking, but the design becomes complex with multiple parts and configurations

Engineering Contradiction:

Improvesecure lockingVSAvoidmultiple parts and configurations

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the functions of a latch and deadbolt into a single integrated bolt mechanism. The bolt can operate in multiple modes (latched position, locked position, and intermediate positions) without requiring separate physical components, thereby simplifying the overall device structure while maintaining secure locking capability.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The single bolt is designed to perform multiple functions: it can latch automatically when the door closes, be manually retracted by a handle, and be locked in the extended position by a deadbolt mechanism. This multi-functional design eliminates the need for separate latch and deadbolt components.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If a conventional mechanical latch system is used, then the locking function is achieved, but friction losses and wear increase

Engineering Contradiction:

Improvelocking functionVSAvoidfriction losses

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent introduces a magnetic interaction system that works in conjunction with the mechanical bolt. The magnetic force assists in holding the bolt in the extended locked position, reducing the reliance on purely mechanical friction-based latching mechanisms and thereby reducing friction losses and wear.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If a conventional latch system is used, then the door can be secured, but noise is generated during operation

Engineering Contradiction:

Improvedoor securityVSAvoidnoise

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The magnetic interaction system provides a non-contact force that assists in the locking operation. The magnetic attraction/repulsion between the lock device magnet and strike plate magnet reduces the need for high-velocity mechanical impacts, thereby reducing noise during latching and locking operations.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Reliability

If separate deadbolt and latch setups are used, then comprehensive locking is achieved, but the number of configurations and production complexities increase

Engineering Contradiction:

Improvecomprehensive lockingVSAvoidproduction complexities

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent integrates the deadbolt and latch functions into a single bolt assembly, eliminating the need for separate components. This integration simplifies the manufacturing process, reduces the number of parts to be produced and assembled, and decreases production complexities while maintaining comprehensive locking capability.

Inventive Principle:

Principle #5Merging (Combining)

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 reliable, energy-efficient, and cost-effective lock system with reduced tolerances and simplified production, ensuring smooth and quiet door closure without the need for separate deadbolts or latches.

Implementation Method 1

a lock device magnet movable between a passive position and an active position in response to a repulsive magnetic force acting on the lock device magnet

Methodology Applied

Scientific EffectRepulsive magnetic force: Magnetism

Implementation Method 2

triggered by a magnetic interaction between the lock device and strike plate magnets

Methodology Applied

Scientific EffectMagnetic interaction: Magnetism

Data Source

PatentUS12612804B2Lock device and system

Publication Date: 2026.04.28 ASSA ABLOY AB

AI summary

A lock device (12) comprising a bolt (22) movable between a retracted position (24) and an extended position (90); a bolt force device (26) arranged to force the bolt (22) from the retracted position (24) towards the extended position (90); a blocking member (28) movable between a blocking position (32) and an unblocking position (96); a lock device magnet (46) movable between a passive position (48) and an active position (94) in response to a repulsive magnetic force acting on the lock device magnet (46); and a release transmission (52) arranged to mechanically transmit a movement of the lock device magnet (46) from the passive position (48) to the active position (94), to a movement of the blocking member (28) from the blocking position (32) to the unblocking position (96). A system (10) comprising a lock device (12) and a strike plate (14) is also provided.