Adjustable Dead-Latching Bolt Mechanism for Door Sag Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Exit devices, such as vertical rod exit devices, face challenges in maintaining a secure locked position due to variations in door heights and recess depths, and over time, door sag and wear can alter the latch device's extension, leading to potential unauthorized unlocking.
Innovation Solution
The apparatus includes a displacement rod with a lever member and a latch bolt, where the lever member is pivotally coupled to the displacement rod, and the latch bolt is structured for slideable insertion into an aperture, with a foot portion to prevent unauthorized retraction and an offset latch slot to enhance locking security.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the latch device extension distance is adjusted to accommodate different door heights and recess depths, then the adaptability is improved, but the device complexity increases due to multiple adjustment mechanisms
Solution Approach 1:
The latch device incorporates an adjustable extension mechanism that allows the latch to dynamically change its extension distance. The housing includes multiple holes at different positions, and a pin can be inserted into different holes to adjust the extension distance according to specific door and frame requirements, making the device adaptable without requiring complex electronic controls.
Solution Approach 2:
The invention changes the physical parameter of the latch extension distance by providing multiple predetermined positions through holes in the housing. By selecting different hole positions for pin insertion, the extension distance parameter is adjusted to match different door heights and recess depths, achieving adaptability through discrete parameter variations.
2Ease of operation
If the latch device is allowed to move freely along the same axis as extension, then the ease of operation is improved, but the reliability decreases due to lack of dead-latching capabilities
Solution Approach 1:
The latch device employs asymmetric engagement surfaces where the latch bolt has a shaped engagement surface that interacts with a corresponding surface on the bar. This asymmetric design creates a mechanical interlock that prevents unauthorized displacement while still allowing controlled operation through the push bar mechanism, achieving both ease of operation and reliability.
Solution Approach 2:
The dead-latching mechanism incorporates preliminary anti-action by designing the engagement surfaces to inherently resist forced retraction. The shaped engagement surface and corresponding features create a mechanical barrier that prevents tools, fingers, or cards from engaging the latch through the door gap, providing security before any unauthorized action can occur.
3Ease of manufacture
If the pin positioning is done by feel during installation, then the ease of manufacture is improved, but the manufacturing precision deteriorates
Solution Approach 1:
The installation process utilizes the installer's sense of touch (feel) to guide the pin into the correct hole position. The housing and latch device are designed with clearly distinguishable hole positions that can be identified through tactile feedback during assembly, allowing precise positioning without requiring specialized tools or complex alignment procedures.
Data Source
AI summary
Latch mechanisms adapted to prevent unauthorized displacement of a latch bolt from an extended, locked position to a retracted, unlocked position. The latch mechanisms prevent the failure of a latch bolt of one latch mechanism to return to an extended lock position from interfering with the ability of a latch bolt of an inter-related latch mechanism from being able to return to an extended, locked position. Further embodiments provide a mounting bracket mounted to a door to allow the associated latch mechanism to be indirectly secured to the door. Additionally, the mounting bracket may have a plurality of mounting orifices that allow the mounting bracket to be used with a wide range of latch mechanisms, as well as provide adjustable attachment of the latch mechanism to the mounting bracket.