Telescopic Scissor Arm for Window Fitting Alignment

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Solution Overview

Problem

Existing window and door fitting arrangements face challenges in maintaining correct alignment due to misadjustments, leading to increased wear and noise from repeated misalignment issues, especially when the sash settles over time.

Innovation Solution

The scissor arm is designed in two parts with a support member and a pivot member that can be displaced relative to each other, allowing for variable length adjustment to maintain correct alignment, and the scissor link is articulated with a fixed pivot point to ensure stable mounting, with locking mechanisms to automatically adjust the scissor arm length based on the sash's orientation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the scissor arm is designed with fixed length, then the structure is simple and stable, but misalignment occurs over time due to sash settling, leading to increased wear and noise

Engineering Contradiction:
Improvealignment stabilityVSAvoidscissor arm structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The scissor arm is designed with a telescopic mechanism that allows it to change length dynamically. The support member can slide relative to the pivot member along the longitudinal axis, enabling the scissor arm to automatically adjust its length to compensate for misalignments caused by sash settling, thereby maintaining reliable operation without requiring complex manual adjustment mechanisms

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The scissor arm is divided into two functional segments: a support member and a pivot member. These segments can move relative to each other along the longitudinal axis of the scissor arm, allowing independent adjustment of the support position while maintaining the overall structural integrity and function of the scissor arm assembly

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If the scissor arm length is variable, then misalignment compensation is possible, but the device complexity increases due to additional adjustment mechanisms

Engineering Contradiction:
Improvealignment adjustment capabilityVSAvoidlength adjustment mechanism
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The telescopic scissor arm mechanism is designed to automatically adjust its length in response to misalignment conditions. The support member can slide along the longitudinal axis under the influence of operational forces, enabling the system to self-correct alignment issues without requiring external intervention or complex control systems

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The length parameter of the scissor arm is made variable through the telescopic design. By allowing the support member to change its position relative to the pivot member along the longitudinal axis, the system can adapt the scissor arm length to match the actual spacing requirements, thereby compensating for misalignments and maintaining proper geometric relationships

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If the scissor arm supports the sash weight during rotation, then the sash can be opened completely, but the scissor arm experiences increased stress and wear

Engineering Contradiction:
Improverotary opening capabilityVSAvoidscissor arm load bearing
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The telescopic mechanism allows the scissor arm to dynamically adjust its length based on the operational state. During rotary opening when the sash weight creates maximum leverage, the support member can slide to optimize the moment arm, thereby reducing the stress on the scissor arm while still supporting the full weight necessary to enable complete opening

Inventive Principle:
Principle #15Dynamics

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 allows for automatic compensation of misalignments, reducing wear and noise by ensuring the sash remains correctly aligned during rotation and tilting, with the scissor arm lengthening or shortening as needed to support the sash's weight and maintain stability.

Implementation Method 1

the support member and the pivot member are relative to one another displaceable, in particular along a longitudinal axis of the scissor arm

Methodology Applied
Scientific EffectMechanical displacement: Displacement

Implementation Method 2

the scissor arm supports the wing in its rotationally open condition against the force of gravity acting on the wing

Methodology Applied
Scientific EffectGravitational force: Gravitation

Implementation Method 3

The scissor link is articulated with an arm-side end to a fork portion of the scissor arm and is articulated with a wing-side end to the cover rail

Methodology Applied
Scientific EffectArticulated connection: Hinge

Data Source

PatentEP3516143B1Fitting assembly
Publication Date: 2021.02.17 MACO TECHNOLOGIE GMBH
  • EP3516143B1 patent drawingFigure 1a~1b
  • EP3516143B1 patent drawingFigure 2~4
  • EP3516143B1 patent drawingFigure 5a~5b

AI summary

The invention relates to a fitting assembly for a window, a door or the like, for mounting a sash on a frame such that said sash can be opened by rotation about a rotation axis and opened by tilting about a tilting axis. Said fitting assembly comprises a cover rail, a scissor arm and a scissor link. The cover rail is designed to be fastened to a side of the sash which is remote from the tilting axis. The scissor arm is designed to be mounted on the frame such that it can rotate about the rotation axis, in particular via a scissor bearing, at the frame-side end, and is articulated to the cover rail at the sash-side end. The scissor link is articulated at an arm-side end to a forked section of the scissor arm and is articulated at a sash-side end to the cover rail. The distance between the forked section and the sash-side end of the scissor arm is variable. Furthermore, the scissor arm is in at least two parts and comprises a carrying member, on which the frame-side end of the scissor arm is formed, and a separate pivot member, on which the sash-side end of the scissor arm is formed. The carrying member and the pivot member can be moved relative to each other, in particular along a longitudinal axis of the scissor arm.