Mortise Lock Door Position Sensor Using Auxiliary Latch Alignment
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Solution Overview
Problem
Conventional door position sensing in mortise locks is inaccurate due to interference from significant metal content, which prevents the magnetic field sensor from detecting the magnetic field generated by the magnet when the door is closed, leading to incorrect positioning indications and the removal of the auxiliary latch feature.
Innovation Solution
Positioning a magnetic field sensing device on the auxiliary latch assembly or main latch assembly within the mortise lock, aligned with a magnetic field generating device on the door strike, to accurately detect the magnetic field when the door is closed, while maintaining the auxiliary latch feature and minimizing additional installation requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the magnetometer is positioned on the PCBA inside the mortise lock assembly, then the door position sensor is closer to the magnet on the strike, but the significant metal content between the magnetometer and magnet prevents detection of the magnetic field
Solution Approach 1:
The patent introduces a magnetic field generating device (magnet) mounted on the door strike as an intermediary element. This magnet creates a magnetic field that extends through the metal-containing mortise lock assembly to the magnetic field sensing device, enabling detection despite the metal interference. The magnet acts as a mediator that bridges the gap between the door position and the sensor while overcoming the shielding effect of the metal components.
2Measurement precision
If the magnetometer is repositioned to the deadbolt location to increase detection capability, then the sensor is closer to the magnet, but the deadbolt is removed and is no longer available to the user
Solution Approach 1:
The patent applies multi-functionality by utilizing the deadbolt cavity space for a dual purpose: housing the magnetic field sensing device while preserving deadbolt functionality. The sensor is positioned in the deadbolt location but configured to work alongside the deadbolt mechanism, allowing the same spatial region to serve both security (deadbolt) and sensing (door position detection) functions simultaneously.
Solution Approach 2:
The magnetic field sensing device is nested within or alongside the deadbolt assembly structure. The sensor is integrated into the existing deadbolt cavity or mounting area, allowing it to occupy the same space without interfering with deadbolt operation. This nesting approach enables the sensor to be positioned optimally for magnetic field detection while the deadbolt maintains its full functionality.
3Measurement precision
If the magnetometer is positioned on the auxiliary latch assembly, then the door position sensor can accurately detect the magnetic field, but additional door preparation may be required
Solution Approach 1:
The patent segments the sensing function from the main lock body by positioning the magnetic field sensing device on the auxiliary latch assembly rather than integrating it into the primary lock mechanism. This segmentation allows the sensor to be mounted on a separate, movable component that naturally positions itself close to the magnet on the strike when the door is closed, improving detection accuracy without requiring complex modifications to the door structure.
Solution Approach 2:
The auxiliary latch assembly's natural movement and positioning serve the dual purpose of its original function (latching) and the new sensing function. When the door closes, the auxiliary latch assembly automatically moves into position, bringing the magnetic field sensing device into optimal alignment with the magnet on the strike without requiring additional adjustment or door preparation by the installer.
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
Ensures accurate door position detection without additional door preparation, maintains the auxiliary latch functionality, and eliminates interference from the metal content in mortise locks, providing reliable closed-position detection.
Implementation Method 1
A magnetic field sensing device that is positioned on the auxiliary latch assembly and is configured to detect a magnetic field generated by a magnetic field generating device positioned on a door strike
Data Source
AI summary
A mortise lock assembly is disclosed that enables a position of a door associated with the mortise lock assembly to be determined despite whether a deadbolt is in a retracted state or an engaged state. An auxiliary latch assembly transitions between an engaged state and a retracted state. A main latch assembly may also transition between an engaged state and a retracted state. A magnetic field sensing device that is positioned on the auxiliary latch assembly detects a magnetic field generated by a magnetic field generating device positioned on a door strike. The magnetic field sensing device is positioned on the auxiliary latch assembly such that the magnetic field sensing device is aligned with the magnetic field generating device positioned on the door strike when the door is in a closed position. The magnetic field sensing device may also be positioned on the main latch assembly in a similar manner.