Reversible Latch Lock with Tool-Operated Stop Arm

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Solution Overview

Problem

Conventional latch locks require pre-orientation during assembly, making them unsuitable for both right-hand and left-hand doors, leading to inefficiencies and additional labor costs due to the need for replacement when incorrectly installed, and existing reversible solutions are either complex or prone to accidental orientation changes.

Innovation Solution

A reversible latch lock design featuring a spring latch and slider assembly with an elastically flexible stop arm that allows for 180° rotation without disassembly, enabling orientation reversal from the outside without removing the lock, using a tool to disengage the stop protrusion from a guide slot, ensuring a simple, safe, and aesthetically pleasing solution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the latch lock is designed with a pre-oriented latch during manufacturing, then the manufacturing process is simple and cost-effective, but the lock cannot be used on both right-hand and left-hand doors, leading to waste of time and additional labor costs when replacement is needed

Engineering Contradiction:
Improvelatch pre-orientation during assemblyVSAvoidsuitability for right-hand and left-hand doors
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The latch is designed with dynamic reconfigurability, allowing it to change its functional state from fixed to reversible. The latch can be rotated 180° within the slider assembly, transforming the static pre-oriented configuration into a dynamic system that adapts to different door orientations (right-hand or left-hand) without requiring manufacturing variations or replacement

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The latch assembly is segmented into separable components (latch body, slider, stop means) that can be independently manipulated. This segmentation allows the latch to be rotated independently within the slider without disassembling the entire lock mechanism, enabling easy reconfiguration while maintaining manufacturing simplicity

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If the latch lock is designed to allow reversal of latch orientation after installation, then versatility for right-hand and left-hand doors is achieved, but the device becomes more complex and costly

Engineering Contradiction:
Improvereversal of latch orientationVSAvoidconstructional complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The reversal mechanism is merged with the existing slider assembly rather than being added as a separate complex mechanism. The stop means are integrated into the slider, and the latch rotation is achieved through the existing sliding and stopping components, combining multiple functions (positioning, stopping, and rotation) into a unified simple structure

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The latch assembly is designed to be self-reconfiguring through simple manual manipulation. The user can rotate the latch 180° within the slider and use the tool-operated stop means to secure it in the new orientation, without requiring complex mechanisms, specialized tools, or professional intervention

Inventive Principle:
Principle #25Self-service

3Ease of operation

If the latch is made reversible by acting from the outside through the front plate, then ease of operation is improved, but the solution becomes mechanically complex requiring additional components

Engineering Contradiction:
Improvereversal operation from outsideVSAvoidmechanical complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The stop means serve multiple functions: they limit the latch's forward movement during normal operation, enable rotation by disengaging to allow 180° turning, and can be re-engaged to secure the latch in the new orientation. This multi-functionality is achieved through a simple tool-operated mechanism that integrates positioning and reversal operations without requiring separate complex systems

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Loss of time

If the latch lock allows easy reversal of orientation, then labor costs and time for replacement are reduced, but the risk of accidental orientation change increases

Engineering Contradiction:
Improvetime for lock replacementVSAvoidaccidental orientation change
Core Design Contradiction:
Loss of timeVSReliability

Solution Approach 1:

The stop means are designed to prevent accidental orientation changes by requiring a specific tool and deliberate action to disengage and rotate the latch. The stop protrusion and guide slot provide mechanical constraint that must be intentionally overridden, creating a preliminary barrier against unintended reversal while still allowing easy reversal when properly operated

Inventive Principle:
Principle #9Preliminary anti-action

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

Enables easy and cost-effective reversal of latch orientation for both right-hand and left-hand doors without removing the lock, reducing labor costs and preventing accidental damage, while maintaining a constructionally simple and aesthetically pleasing design.

Implementation Method 1

an elastically flexible stop arm (31) having a fore end (31a) facing the front plate (12)

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a spring latch (14) and slider (17) assembly operatively connected to an actuating device of the latch lock; wherein the assembly of the latch and slider is elastically biased

Methodology Applied
Scientific EffectSpring force: Spring

Data Source

PatentEP3045625B1Reversible latch lock
Publication Date: 2017.11.22 BONAITI SERRATURE
  • EP3045625B1 patent drawingFigure 1~3
  • EP3045625B1 patent drawingFigure 4~5
  • EP3045625B1 patent drawingFigure 6~8

AI summary

A reversible latch lock suitable for left-hand and right-hand doors; the latch lock comprises a box body (10), a front plate (12) provided with an opening (13) for a spring latch (14), and a latch slider assembly (14, 17) axially guided and elastically biased to slide between a retracted position inside the box body (10), and an advanced position in which the latch (14) partially protrudes from the opening (13) of the front plate (12). Snap engaging means (21, 24) are provided and configured for connecting the spring latch (14) to the slider (17) and for turning the latch (14) of 180. The latch-slider assembly (14, 17) is movable in a more advanced position in respect to the front plate (12) to turn the latch (14) of 180°, by disengaging a protrusion (16) of a stop arm (31) of the slider (17), from a guide slot (15) on a side wall of the box body (10), by flexing the stop arm (31) by a tool insertable from outside, through a side of the opening (13) for the latch (14), or a side hole (33), in a position aligned to the stop arm (31) to turn and reverse the orientation of the latch (14).