Adjustable Backset Door Latch with Sliding Inner Casing
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Solution Overview
Problem
Existing adjustable backset door latches require multiple components to be adjusted, making them time-consuming and difficult to adjust, and once installed, they cannot be readjusted without removal.
Innovation Solution
A latch assembly with an inner casing slidably received within an outer casing, featuring a transverse void and a cam mechanism that allows adjustment between two backset dimensions with minimal components, enabling in-place adjustment and re-adjustment without removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple components are adjusted to change backset dimension, then the latch can accommodate different backset dimensions, but the adjustment process becomes time-consuming and complex
Solution Approach 1:
The latch mechanism is divided into modular components including a latch body, bolt assembly, and cam mechanism that can independently adjust. The bolt assembly separates the backset adjustment function from the latching function, allowing the backset to be modified without affecting the core latching mechanism.
Solution Approach 2:
The cam mechanism provides dynamic adjustment capability where rotating the cam changes the effective backset dimension. This allows the latch to adapt between different backset positions (typically 2-3/8 inches and 2-3/4 inches) through a simple rotational motion rather than disassembling and reconfiguring multiple components.
2Reliability
If the latch is installed in a door, then it provides security and latching function, but it cannot be readjusted without complete removal
Solution Approach 1:
The cam mechanism is pre-configured with adjustment slots or positions that allow backset modification before final installation. The design anticipates future adjustment needs by incorporating accessible adjustment features that remain operational even after the latch is mounted in the door frame.
Solution Approach 2:
The adjustable components are nested within the latch body structure, with the cam and bolt assembly contained within the latch housing. This nested arrangement allows adjustment mechanisms to be accessed and operated through openings in the latch body without requiring complete removal of the installed latch.
3Ease of manufacture
If a simple adjustment mechanism is used, then manufacturing cost is reduced, but the mechanism may lack durability for longtime use
Solution Approach 1:
The cam mechanism is designed to be self-adjusting within defined parameters, where the cam profile automatically maintains proper bolt alignment and engagement force throughout the adjustment range. This self-service capability eliminates the need for complex adjustment procedures or specialized tools, reducing manufacturing costs while ensuring reliable operation over time.
Solution Approach 2:
The adjustment mechanism is merged with the existing latch structure rather than being a separate additive component. The cam is integrated into the bolt assembly, and adjustment features are incorporated into the latch body itself, combining multiple functions into unified components that reduce part count and manufacturing complexity while maintaining durability.
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 mechanism allows for easy adjustment between 2⅜ inches and 2¾ inches backset dimensions with minimal effort, maintaining reliability and durability, and can be readjusted after initial installation, reducing manufacturing costs and complexity.
Implementation Method 1
A spring biases the bolt to an extended position extend out from the casing and returns the slide to a home position of release of the knob
Implementation Method 2
A cam is rotatably mounted within the casing and engaged to the slide and to a bolt also slideably received within the casing. The bolt is slideably retractable into the casing by rotation of the cam
Data Source
AI summary
A latch assembly for insertion into an edge of a door and adjustable for actuation by a half-round spindle at either a first backset or a second backset. The latch has an inner casing non-rotatably received within an outer casing and slideable along an axis. The inner casing is provided with a transverse void substantially perpendicular to the sliding axis and is slideable between a first position in which the transverse void is aligned at the first backset and a second position is which the transverse void is aligned at the second backset. A slide within the casing is, without adjustment, engageable by the half-round spindle at either backset. A cam is rotatably mounted within the casing and engaged to the slide and to a bolt also within the casing. The bolt is slideably retractable into the casing by rotation of the cam in response to sliding of the slide. A spring biases the bolt to an extended position extend out from the casing.