Magnetic Morticed Bolt Keep for Narrow Tubular Closures

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Solution Overview

Problem

Existing morticed bolt keeps require manual user intervention for unlatching and are not suitable for narrow tubular members with square or rectangular cross-sections, and they face issues with force requirements and mechanical catch malfunctions in outdoor applications.

Innovation Solution

A morticed bolt keep with a magnetic actuator comprising a longitudinally extending core and coil assembly, using multiple permanent magnets and coils to generate a Lorentz force for unlatching, and an electromagnet to maintain the actuated state without mechanical means, suitable for narrow tubular members and outdoor conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If a fixed coil surrounding an iron core is used to actuate the latch bolt, then the latch bolt can be pushed outwards, but the bolt keep becomes too large to fit into narrow hollow tubular members

Engineering Contradiction:

Improvelatch bolt pushing forceVSAvoidbolt keep volume

Core Design Contradiction:

ForceVSVolume of moving object

Solution Approach 1:

The patent replaces the traditional mechanical fixed coil and iron core actuator with a magnetic actuator system comprising a permanent magnet and a movable armature. This substitution reduces the overall size of the actuator while maintaining the force required to push the latch bolt, enabling the bolt keep to fit into narrow hollow tubular members with external dimensions of 4 cm, 5 cm or 6 cm.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the operational parameters of the actuator by using a permanent magnet instead of an electromagnet. This parameter change allows the actuator to achieve the necessary force output in a more compact configuration, reducing the volume of the bolt keep while maintaining outdoor application capability with higher latch bolt forces.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If a mechanical catch is used to keep the iron core in its withdrawn position, then the core can be retained, but dirt, insects and misalignment can hamper operation and increase the force required to pull the core

Engineering Contradiction:

Improvecore retention reliabilityVSAvoidcore retrieval ease

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent replaces the mechanical catch system with a magnetic retention mechanism. The movable armature is held in its retracted position by magnetic attraction to the permanent magnet, eliminating mechanical contact points that could accumulate dirt or insects. This magnetic retention system maintains reliability while significantly improving ease of operation, as the armature can be released by simply de-energizing the coil without overcoming mechanical friction.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If the latch bolt is designed for outdoor applications with longer throw to compensate for misalignment, then alignment tolerance is improved, but the force required to push the latch bolt increases

Engineering Contradiction:

Improvemisalignment compensationVSAvoidlatch bolt pushing force

Core Design Contradiction:

Adaptability or versatilityVSForce

Solution Approach 1:

The patent uses the magnetic actuator system with permanent magnet and movable armature to efficiently transmit force over the extended throw distance required for outdoor applications. The magnetic field provides continuous force throughout the movement, enabling the latch bolt to travel longer distances (exceeding 10 mm, e.g. 15 mm) to compensate for misalignment while maintaining adequate pushing force despite the increased travel distance.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 enables automatic unlatching, fits into narrow tubular members, withstands higher forces required for outdoor locks, and prevents mechanical catch malfunctions, ensuring reliable operation with reduced power consumption.

Implementation Method 1

a magnetic actuator comprising: a core which extends in the longitudinal direction and comprises at least one permanent magnet; and a coil assembly which extends in the longitudinal direction and comprises at least one coil

Methodology Applied

Scientific EffectElectromagnetic interaction: Electromagnetic Induction

Data Source

PatentEP4567232B1A morticed bolt keep and a closure system comprising the same

Publication Date: 2026.05.13 LOCINOX NV

Figure 1A~1B
Figure 2A~2B
Figure 3A~3B

AI summary

A morticed bolt keep to cooperate with a lock having a latch bolt which is slidable between a retracted position and an extended position. The morticed bolt keep comprises: an elongated body to be positioned inside a hollow tubular member (7); a cavity (14) to receive the latch bolt in its extended position; a latch bolt engager (25) which is displaceable between a rest state and an actuated state; and a magnetic actuator (30) to displace the latch bolt engager from its rest state to its actuated state upon activation. The magnetic actuator comprises: a core (32) which extends in a longitudinal direction (10) and comprises at least one permanent magnet (36, 38, 40); and a coil assembly (31) which extends in the longitudinal direction and comprises at least one coil (41, 42), wherein one of the core and the coil assembly is slidable in the longitudinal direction and is operatively connected to the latch bolt engager.