Latch Module Guard Bolt Blocking Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing latch modules for doors are not cost-effective and lack reliable mechanisms to prevent unauthorized retraction of the latch bolt, particularly vulnerable to 'credit card attacks'.
Innovation Solution
A latch module design featuring a housing with a latch bolt and guard bolt, where the guard bolt acts as a sensor to detect the door's position, controlling a blocking mechanism to prevent unauthorized retraction and incorporating a stem with selective coupling to manage the latch bolt's position, ensuring secure operation at reduced manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional latch module design is used, then the door can be operated, but it is vulnerable to credit card attacks and unauthorized retraction
Solution Approach 1:
The patent combines the guard bolt and blocking mechanism into a single integrated assembly. The guard bolt serves dual functions: it physically blocks credit card insertion and simultaneously activates the blocking mechanism through its movement. This merging reduces the number of separate components while maintaining security functionality.
Solution Approach 2:
The guard bolt automatically activates the blocking mechanism through its own movement during normal door operation. When the guard bolt retracts, it directly triggers the blocking mechanism to engage, eliminating the need for separate actuators or control systems. This self-service approach simplifies the overall device complexity.
2Reliability
If a blocking mechanism is added to prevent credit card attacks, then security is improved, but manufacturing cost increases
Solution Approach 1:
The blocking mechanism is merged with the existing guard bolt structure, eliminating the need for separate blocking components. The guard bolt's movement directly controls the blocking function, reducing part count and assembly complexity, which lowers manufacturing costs.
Solution Approach 2:
The blocking mechanism is activated automatically by the guard bolt's own movement during normal operation. This eliminates the need for additional actuators, motors, or control systems, reducing both manufacturing cost and device complexity while maintaining security functionality.
3Ease of operation
If the stem is always coupled to the latch bolt, then the latch bolt can be controlled, but the door cannot be slammed closed easily
Solution Approach 1:
The coupling between the stem and latch bolt is made dynamic rather than static. The stem is selectively coupled to the latch bolt only when needed for controlled operation, while allowing free movement during slamming. This dynamic coupling adapts to different operational requirements, providing both ease of slamming and reliable control when necessary.
Solution Approach 2:
The stem's coupling to the latch bolt is segmented into distinct operational states: coupled for controlled operation and uncoupled for free slamming. This segmentation allows the system to provide different levels of control based on the operational context, balancing ease of operation with reliability.
Data Source
AI summary
A latch module for selectively engaging into a striking plate of door jamb, including at least a housing, a latch bolt, a guard bolt, and a stem for retracting the latch bolt is particularly versatile, safe and has low manufacturing costs, if the stem is movably supported relative to the latch bolt and if the stem has a block for entraining the latch bolt, if the stem reaches a first intermediate position while being moved from the stem's closed position towards the stem's open position.