Tilt-before-turn Espagnolette Fitting with Segmented Limiting Arm

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Solution Overview

Problem

Existing tilt-in-front drift fittings for windows struggle to maintain the wing in a tilting position under high-acting forces and often experience instability and unwanted friction, particularly in applications like high-rise buildings and schools where windows are not fully openable and must withstand forced opening attempts.

Innovation Solution

The design features a boundary arm with two sections connected via storage, allowing the sections to fold or extend between locking and tilting positions, ensuring the wing remains in the tilting position and incorporating adjustable storage axles, safety elements, and a blocking device to prevent accidental opening, with a fixing device for enhanced stability and security.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a single-section limiting arm is used, then the structure is simple, but the stability under high forces is insufficient

Engineering Contradiction:
Improvestability under high forcesVSAvoidstructure complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The limiting arm is divided into two separate sections that can pivot relative to each other. This segmentation allows the arm to extend into a stable triangular configuration when forces are applied, providing structural strength while maintaining operational simplicity through the pivot connection between sections.

Inventive Principle:
Principle #1Segmentation

2Reliability

If the limiting arm sections are extended to hold the sash in tilt position, then the stability under high forces is improved, but the device complexity increases

Engineering Contradiction:
Improveholding capability in tilt positionVSAvoidlimiting arm structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The limiting arm sections are designed to pivot dynamically between a retracted position (when not in use) and an extended position (when holding the sash in tilt). This dynamic configuration allows the system to maintain reliability when needed while minimizing structural complexity during normal operation.

Inventive Principle:
Principle #15Dynamics

3Stability of the object's composition

If the bearing axes are made immovable in the holders, then the stability is improved, but the adaptability for adjusting tilt range is reduced

Engineering Contradiction:
Improvestability of tilt limiting devicesVSAvoidadjustability of tilt range
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The holder assembly is segmented into a fixed portion and an adjustable portion. The bearing axes are made immovable relative to the fixed holder to ensure stability, while the adjustable portion allows for modifying the tilt range by repositioning the bearing axes, thus achieving both stability and adaptability.

Inventive Principle:
Principle #1Segmentation

4Ease of operation

If coupling means are made manually releasable, then the ease of operation is improved, but the reliability against accidental decoupling is reduced

Engineering Contradiction:
Improveease of disconnecting limiting armVSAvoidsecurity against accidental opening
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The coupling means incorporate a preliminary locking mechanism that prevents accidental decoupling before it can occur. The manually releasable feature allows intentional disconnection through a deliberate action, while the preliminary anti-action (locking element) blocks unintended separation, thus achieving both ease of operation and reliability.

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

This design effectively keeps the wing in the tilting position under high forces, allows easy operation, and provides enhanced stability and security against accidental opening, ensuring the window remains securely locked in the intended position.

Implementation Method 1

Cam guides regularly lead to an impairment of the stability of the interconnected components and to undesirable friction.

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4119755A1Tilt-before-turn espagnolette fitting for a sash pivoting against a frame
Publication Date: 2023.01.18 AUG WINKHAUS SE
  • EP4119755A1 patent drawingFigure 1~2
  • EP4119755A1 patent drawingFigure 3~4
  • EP4119755A1 patent drawing

AI summary

A tilt-before-rotate connecting rod fitting (3) has a tilt limiting device (10) arranged on a vertical post (9) with a limiting arm (15) connecting two brackets (13, 14). The limiting arm (15) has two sections (16, 17) pivotally connected to each other via a bearing (18) and pivotable bearings (19, 20) on the brackets (13, 14). This allows the tilting position of the connecting rod fitting (3) to withstand high forces.