Lock Release Lever Prevents Premature Bolt Retraction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing locks with spring-loaded bolts and lever systems often release prematurely when the latch strikes a strike plate or door jamb, leading to security issues and increased manufacturing complexity due to numerous moving parts.

Innovation Solution

A lock design where the release lever is actuated only when the latch securely engages with the strike plate, utilizing a push rod for easy control and incorporating a minimal number of moving parts to prevent premature bolt release and enhance locking security.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a lever system with connecting links is used to control the bolt, then the locking mechanism can be actuated, but the device complexity increases and manufacturing costs increase

Engineering Contradiction:
Improvelocking mechanism actuationVSAvoidnumber of moving parts
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the complex lever system with connecting links from the locking mechanism. Instead, it uses a simple release lever (5) with only two arms that pivots on a single axis (6), directly actuating the bolt (4) without intermediate connecting links. This extraction of unnecessary components resolves the contradiction by maintaining operational functionality while dramatically reducing device complexity and manufacturing costs.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the functions of multiple components into a single integrated release lever (5). The first arm (9) engages with the latch head (8) while the second arm (13) directly actuates the bolt (4), combining what would traditionally require separate levers and connecting links into one unified component. This merging eliminates numerous moving parts and pivot points while preserving the locking mechanism's operational capability.

Inventive Principle:
Principle #5Merging (Combining)

2Speed

If the bolt is released when the latch strikes the strike plate, then the locking mechanism responds quickly, but the reliability decreases due to premature bolt release

Engineering Contradiction:
Improvebolt release speedVSAvoidlocking security
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent implements preliminary action by requiring the latch (3) to fully penetrate into the corresponding opening of the strike plate before the release lever (5) can pivot and release the bolt (4). The geometry of the release lever ensures that its first arm (9) is only pushed back against spring (12) force after the latch has securely engaged, preventing premature bolt release while maintaining rapid response once engagement is confirmed. This preliminary engagement requirement resolves the contradiction by ensuring reliability before speed of release.

Inventive Principle:
Principle #10Preliminary 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

Ensures the bolt is only released when the latch is fully engaged, improving security and reducing manufacturing costs by minimizing parts, thus preventing easy opening and enhancing locking reliability.

Implementation Method 1

a bolt (4) which is pretensioned against its pushed-out position

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a spring-loaded, operable latch (3)

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2927400B1Lock
Publication Date: 2019.05.01 ROTO FRANK FENSTER UND TUERTECH GMBH
  • EP2927400B1 patent drawingFigure 1
  • EP2927400B1 patent drawingFigure 2
  • EP2927400B1 patent drawingFigure 3

AI summary

The invention relates to a lock with a bolt (4) pre-tensioned against its extended position and a spring-loaded, actuated latch (3), the strike plate (8) of which can be engaged with a strike plate, wherein the strike plate (8) has a ramp (11) and a rear stop surface (10), and wherein a locking mechanism is provided which blocks the bolt (4) in its retracted position and can be released via a two-armed release lever (5) arranged in the latch (3) and pivotable about a pivot axis (6) perpendicular to the direction of movement of the latch (3), the first arm (9) of which projects from the strike plate (8) in its rest position over a surface of the strike plate (8) which is substantially parallel to the pivot axis (6) of the release lever (5), and the second arm (13) of the release lever (5) acts on the locking mechanism.The first arm (9) of the release lever (5) protrudes from the rear stop surface (10) of the strike plate (8) and can be actuated by a corresponding complementary surface in the strike plate.