Eccentric Anti-Rotation Lock for Window Hinges

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Solution Overview

Problem

Existing stay-open devices for windows and doors with articulated arms face challenges in maintaining precise alignment and preventing unwanted rotation of eccentrics, leading to manufacturing tolerance issues and wear-related distortions, which affect the long-term functionality and adjustment capabilities.

Innovation Solution

The solution involves an anti-rotation lock element that engages with a recess on the end face of a rotatably mounted eccentric, using a bending spring or clip spring to prevent undesired twisting, allowing for simple displacement of the axis of rotation while maintaining a cost-effective and robust design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If an anti-twist device is assigned to the eccentric to prevent unwanted rotation, then the manufacturing precision and alignment stability are improved, but the device complexity increases

Engineering Contradiction:
Improvealignment precisionVSAvoiddevice complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The anti-twist device is segmented into a separate anti-rotation lock element that can be independently designed and manufactured, allowing the eccentric to maintain its primary function while the lock element provides the anti-twist protection. This segmentation enables modular assembly and simplifies the design of each individual component.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The anti-rotation lock element acts as an intermediary component between the eccentric and the housing, providing the anti-twist function without requiring modification of the eccentric itself. This intermediary element mediates between the need for precise alignment and the desire to keep the eccentric design simple.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the position of the axis of rotation is adjusted to compensate for manufacturing tolerances and wear, then the adaptability and long-term functionality are improved, but the ease of operation deteriorates due to required disassembly

Engineering Contradiction:
Improveadjustment capabilityVSAvoidease of adjustment
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The system transitions from a static, fixed-axis configuration to a dynamic, adjustable-axis configuration. The eccentric enables the axis of rotation to be dynamically repositioned within a certain range, allowing the system to adapt to manufacturing tolerances and wear over time while maintaining ease of adjustment through a simple locking mechanism.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The anti-rotation lock element is designed to be engaged or disengaged before making adjustments to the eccentric position. This preliminary action of releasing the lock allows for smooth adjustment of the axis position, and then re-engaging the lock secures the new position, making the adjustment process systematic and easy to perform.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If a symmetrical octagonal outer contour is used for anti-twist protection, then the anti-twist reliability is improved, but the ease of manufacture deteriorates

Engineering Contradiction:
Improveanti-twist reliabilityVSAvoidease of manufacture
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

Instead of using a symmetrical octagonal contour on the eccentric, the invention employs an asymmetric anti-rotation lock element with a specific geometric profile that engages with a corresponding recess. This asymmetric design provides reliable anti-twist protection while allowing the eccentric itself to maintain a simple, easily manufacturable circular or cylindrical shape.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

Rather than modifying the outer contour of the eccentric to provide anti-twist protection, the solution inverts the approach by adding an anti-rotation lock element that engages with a recess in the eccentric. This inversion allows the eccentric to remain simple and easy to manufacture while still achieving the desired anti-twist reliability through the locking mechanism.

Inventive Principle:
Principle #13The other way round (Inversion)

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 ensures that the axis of rotation can be adjusted without disassembly, preventing unwanted rotation and allowing for stepless shifting, thus compensating for manufacturing tolerances and wear, while maintaining a compact and reliable anti-twist mechanism.

Implementation Method 1

an anti-rotation lock element, which engages at least in regions in a recess formed in an end face of the rotatably mounted eccentric

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2304146B1Hinged opening device for a window, a door, or the like
Publication Date: 2014.01.22 ROTO FRANK AG
  • EP2304146B1 patent drawingFigure 1
  • EP2304146B1 patent drawingFigure 2
  • EP2304146B1 patent drawingFigure 3

AI summary

The invention relates to a hinged opening device for a window, a door, or the like, having at least one hinged arm that can be supported so as to be pivotable about a rotation axis, wherein the position of the rotation axis can be shifted by means of a rotatable eccentric, and wherein the eccentric has an anti-rotation locking device. It is provided that the anti-rotation locking device (24; 49) has at least one anti-rotation locking element (46; 51) inserted into at least some areas of a cutout (32; 52) provided in a frontal area (31) of the rotatably supported eccentric (21). The invention further relates to fittings (23) for a window, a door, or the like.