Espagnolette Lock Bolt Passage Step Blocking

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Solution Overview

Problem

Existing espagnolette locks are complex to manufacture and require intricate mechanisms for transitioning between locked and released positions, with insufficient simplicity in design.

Innovation Solution

The espagnolette lock design features a bolt passage window with a step-formed blocking section, where the locking cam of the fully closed bolt aligns with the drive rod's projections, allowing for a simple pre-locking mechanism that blocks both lateral and rearward displacement, enabling the drive rod to transition between locked and released positions based on the bolt's closure state.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the blocking section of the bolt passage window is formed by two sections of window wall converging in a V-shape, then the bolt can be restrained in a form-fitting manner against transverse displacement, but the manufacturing complexity increases

Engineering Contradiction:
Improveform-fitting restraint of boltVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The blocking section is divided into two separate projections that can be independently formed and assembled. Each projection is a discrete element that can be manufactured separately and then combined to form the complete blocking section, simplifying the manufacturing process while maintaining the form-fitting restraint function.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The blocking section is reconfigured from a V-shaped converging structure to a step-formed structure with projections extending in different dimensional orientations. This dimensional reconfiguration allows for simpler manufacturing processes while achieving the same functional restraint of the bolt against transverse displacement.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If the locking cam is positioned to block the drive rod from moving in the locked position, then the locking reliability is improved, but the device complexity increases

Engineering Contradiction:
Improvelocking reliabilityVSAvoidmechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The locking cam function is merged with the existing step structure of the bolt passage window. The locking cam is formed as an integral part of the step configuration, combining the blocking function with the structural element already present in the design, thereby avoiding additional complexity from separate locking components.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The locking cam automatically engages with the drive rod to prevent movement when the bolt is in the locked position. The mechanism self-regulates the locking function through the geometric relationship between the locking cam and drive rod, eliminating the need for external control systems or additional actuation mechanisms.

Inventive Principle:
Principle #25Self-service

3Ease of operation

If the bolt passage window has a narrowing formed by two opposite projections, then the latch can be pulled back by actuating a pusher, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvelatch actuation capabilityVSAvoidprojection alignment precision
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The narrowing of the bolt passage window is formed by two separate projections that can be independently manufactured and assembled. This segmentation allows for more tolerant manufacturing processes compared to forming a single continuous narrowing, as each projection can be produced with standard tolerances and the assembly process accommodates minor variations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The projections are pre-formed with predetermined dimensions and positions during the manufacturing process. This preliminary formation of the narrowing structure ensures proper alignment and geometry before assembly, reducing the need for high-precision final assembly operations while maintaining the latch actuation functionality.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP1867817B1Connecting rod fastener
Publication Date: 2009.01.21 CARL FUHR GMBH & CO
  • EP1867817B1 patent drawingFigure 1~2
  • EP1867817B1 patent drawingFigure 3
  • EP1867817B1 patent drawingFigure 4~5

AI summary

The lock has a front closing of the catch is blocked in the release position of the connecting rod, and a profile mesh is blocked in the amplitude of inclined blocking section of a catch downward window of the connecting rod into the broadside recess (24) of the catch (4) is blocked. The front closable catch with a locking cam (25) is blocked in a reverse path of connecting rod from their locked position. The blocking section of the catch downward window trains a stage, before which the locking cam of the completely unlocked catch lies.