Window Sash Profile Recess for Slip-Free Mullion Attachment

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Solution Overview

Problem

Existing connections for window or door sashes, particularly those involving mullion strips, face issues with difficult tightening due to the mullion strip slipping during fastening, making secure pre-fixation challenging.

Innovation Solution

The sash profile is designed with an additional recess in the profile wall at the stop for retaining an additional element, featuring a locking element that engages with the sash profile's fitting groove, allowing for improved pre-fixation and stability through a snap-fit mechanism.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the additional element is attached using only a locking tab to the hardware groove, then the attachment process is simple, but the additional element slips during fastening making tightening difficult

Engineering Contradiction:
Improveattachment processVSAvoidpre-fixation stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The retention mechanism is divided into two distinct parts: a receiving groove for initial placement and a locking groove for final securing. This segmentation allows the additional element to be first positioned stably in the receiving groove, then locked in place via the locking groove, preventing slippage during fastening while maintaining operational simplicity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The receiving groove provides preliminary retention of the additional element before final fastening. By pre-positioning the element in the receiving groove, the system ensures stable pre-fixation that prevents slippage during the subsequent fastening operation, resolving the reliability issue without complicating the overall attachment process

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the additional element is fully screwed in place, then the connection is secure, but the tightening process becomes difficult due to slippage

Engineering Contradiction:
Improveconnection securityVSAvoidtightening process
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The fastening process is segmented into two stages: first, the additional element is placed in the receiving groove for stable pre-fixation; second, the locking tab engages the locking groove to prevent slippage during screw tightening. This segmentation makes tightening easier by eliminating slippage while maintaining secure connection

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The locking groove acts as an intermediary mechanism between the additional element and the fastening screw. It provides a positive locking action that prevents slippage during tightening, making the fastening process easier while ensuring secure connection

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP4015746B1Connection comprising a wing for a window or door
Publication Date: 2026.03.18 REHAU IND SE & CO KG
  • EP4015746B1 patent drawingFigure 1~2
  • EP4015746B1 patent drawingFigure 3~4

AI summary

A sash (1) for a window or door, comprising a surface element (11), in particular insulating glass; and a sash frame (3) formed from sections of a sash profile (2), which has a glass rebate (8) receiving the surface element (11) and surrounding its end face, wherein the sash profile (2) comprises a stop (16) with a sealing groove (17) for a stop seal (18) on its side opposite the glass rebate (8), wherein the sash is characterized according to the invention in that the sash profile (2) has a further recess (20) in a profile wall (19) at the stop (16) for retaining an additional element (21). Furthermore, the present invention also relates to a sash profile (2) for forming a sash frame (3) for a sash (1) of a window or door according to the invention, and to a connection (22) comprising at least one sash (1) according to the invention and an additional element (21).