Lock Drive Assemblies with Worm-Driver Catch Actuation
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Solution Overview
Problem
Existing electromechanical lock assemblies fail to reliably transition to a locked state when the handle is rotated, necessitating improvements in systems and methods for lock assemblies with electromechanical actuators.
Innovation Solution
A motor drive assembly featuring a longitudinally movable link, a catch that moves between locking and unlocking positions, and a worm drive mechanism with a spring and driver system that translates rotary motion into longitudinal movement to control the catch's position, ensuring reliable locking and unlocking states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional electromechanical actuator is used in the lock assembly, then the lock can transition between locked and unlocked states, but the system fails to reliably transition to a locked state when the handle is rotated
Solution Approach 1:
The patent introduces a worm drive mechanism as an intermediary between the handle rotation and the catch movement. The worm gear engages with the driver to convert rotational motion into linear motion, providing reliable actuation of the catch to ensure consistent locking state transitions regardless of handle rotation variations
Solution Approach 2:
The patent replaces a conventional direct electromechanical actuator with a worm drive mechanism. This mechanical substitution provides self-locking characteristics and more reliable force transmission, ensuring the catch reliably transitions to the locked state when the handle is rotated, addressing the reliability issue
2Device complexity
If the spring is directly engaged with the worm, then the structure is simplified, but the longitudinal movement control is compromised
Solution Approach 1:
The patent introduces a driver as an intermediary component between the spring and the worm. The driver translates the spring's force into precise longitudinal movement through its engagement with the worm gear, maintaining control precision while allowing the spring to be engaged with the driver rather than directly with the worm
Solution Approach 2:
The patent segments the force transmission path into distinct functional components: the spring provides force, the driver translates and controls the movement, and the worm converts rotational to linear motion. This segmentation allows each component to be optimized for its specific function, maintaining precision while simplifying the overall assembly
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 system provides reliable transitions between locked and unlocked states, enhancing the functionality and reliability of electromechanical locks by ensuring the catch engages or disengages with the hub effectively, preventing unauthorized access.
Implementation Method 1
a longitudinally extending shaft comprising a worm, a motor operable to rotate the shaft, a driver engaged with the worm. Engagement between the worm and driver is configured to longitudinally move the driver in response to rotation of the shaft
Data Source
AI summary
An illustrative motor drive assembly is configured for use in a lockset comprising a case, a longitudinally movable link, and a catch configured to move among a locking position and an unlocking position in response to longitudinal movement of the link. The illustrative motor drive assembly includes a longitudinally extending shaft comprising a worm, a motor operable to rotate the shaft, a driver engaged with the worm, and a longitudinally extending spring. The spring is not directly engaged with the worm, and includes a first end coupled with the driver and a second end connectable with the link. Engagement between the worm and driver is configured to longitudinally move the driver in response to rotation of the shaft.