Low-Profile Keypad Lockset With Clutch Override Alignment
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Solution Overview
Problem
Existing electromechanical door locks face challenges in being compact enough for aesthetic appeal, compatible with storm doors, and requiring no additional holes beyond standard residential door preparation, while maintaining a mechanical override mechanism and ensuring synchronization of clutch components for proper operation.
Innovation Solution
The design incorporates a low-profile electromechanical lock with a clutch mechanism featuring gear trains or four-bar linkages, a cantilever wire spring mechanism, and a torsion spring to ensure precise alignment and engagement, allowing for operation through a single standard door preparation hole, and includes a mechanical override mechanism for electrical failure scenarios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a standard key cylinder is used to provide mechanical override, then reliability is improved, but the lock profile height increases excessively
Solution Approach 1:
The patent implements nesting by placing the key cylinder mechanism inside the escutcheon plate rather than extending it outward. The cylinder is received within a recess in the escutcheon, allowing the mechanical override function to be contained within the low-profile lock body, thus maintaining aesthetic appearance while preserving reliability.
Solution Approach 2:
The patent transitions the key cylinder from a protruding linear arrangement to a recessed configuration within the escutcheon plate. This dimensional repositioning allows the cylinder to be accessed through the face of the escutcheon while being housed within the lock body depth, effectively reducing the external profile height while maintaining full mechanical override functionality.
2Adaptability or versatility
If additional holes are drilled for lock components, then adaptability is improved, but ease of manufacture deteriorates
Solution Approach 1:
The patent makes the escutcheon plate multi-functional by integrating multiple components within it: the key cylinder is received in a recess, the latch bolt is actuated through it, and the keypad is mounted on its face. This consolidation allows the lock to be installed using only the standard two door holes (one for the lock body, one for the latch), eliminating the need for additional drilling while maintaining full functionality.
Solution Approach 2:
The patent merges multiple previously separate components into the single escutcheon plate structure. The key cylinder housing, latch actuation mechanism, and keypad mounting are all integrated into this one component that passes through the door. This merging reduces the number of separate installation holes needed while maintaining adaptability to standard door preparations.
3Length of moving object
If clutch components are closely spaced for low profile, then compactness is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent introduces a clutch piston as an intermediary component that mediates between the motor actuator and the clutch engagement surfaces. The piston provides a controlled, linear motion that precisely positions the clutch components for engagement, reducing the impact of manufacturing tolerances. This intermediary mechanism allows for reliable engagement even with closely spaced components in a low-profile design.
Solution Approach 2:
The clutch mechanism is designed with self-aligning features where the clutch components automatically position themselves for proper engagement through the mechanical interaction of the gear trains and four-bar linkages. The system uses its own operational forces to ensure alignment, reducing dependency on tight manufacturing tolerances while maintaining the low-profile compact design.
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 cosmetically appealing, functionally reliable keypad lock that fits standard door preparations without additional holes, ensuring accurate and reliable engagement of the clutch mechanism and maintaining security and safety by preventing misalignment issues.
Implementation Method 1
A first cantilever wire spring is positioned about a first pivot point of the exterior four-bar linkage and functions to bias the clutch input side into accurate alignment with the clutch output side
Implementation Method 2
A torsion spring is positioned about the clutch bar and functions to bias the clutch components in their home position
Data Source
AI summary
A keypad lockset adapted for deadbolt as well as lever locks, and having as a first embodiment an exterior gear train, an interior gear train, and an electronically controlled clutch for coupling the gear trains when engaged and for uncoupling the gear trains when the clutch is disengaged, so that when the clutch is engaged rotation of an external thumb turn will permit the door latch to be withdrawn and thus to permit opening of the door, and a mechanical override mechanism that can be operated in case of electrical failure, and in which clutch mechanism and the override mechanism both operate through the single, standard 2⅛ inch door preparation hole, or alternatively as a second embodiment, a keypad lockset in which two four-bar mechanical linkages are used in place of gears as means to actuate the clutch, and alternatively to provide for a pass-through override function.