Rotation Limiting Arrangement for Window Sash Wind Load Stability
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Solution Overview
Problem
Existing rotary opening limiting arrangements for windows and doors are not stable enough to maintain a limited rotary opening position under high wind loads, causing the sash to slam shut.
Innovation Solution
A rotary opening limiting arrangement featuring a rotation-limiting element on the fixed frame side, interacting with a blocking element that can be controlled by a connecting rod, ensuring the sash is fixed in a limited rotary opening position, using materials like stainless steel and aluminum for stability, and incorporating a pin and guide system for secure locking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a rotary opening limiting arrangement is used to prevent full opening, then ventilation control is improved, but the sash cannot withstand high wind loads and slams shut
Solution Approach 1:
The locking system is segmented into multiple independent components: a rotation limiting element with guide, a separate locking element with receptacle, and a connecting rod mechanism. This segmentation allows each component to perform its specific function optimally - the guide ensures precise positioning, the receptacle provides secure engagement, and the connecting rod enables controlled operation, collectively achieving both ventilation control and wind load resistance.
Solution Approach 2:
The locking element is preliminarily positioned in a release position that allows the rotation limiting element to be inserted into the guide. When the connecting rod is actuated, the locking element is moved into the locked position before wind loads can cause slamming. This preliminary positioning and pre-engagement mechanism ensures the sash is secured in the limited opening position before adverse wind conditions can affect it.
2Reliability
If a locking mechanism is added to prevent slamming, then stability under wind loads is improved, but the device complexity increases
Solution Approach 1:
The locking element serves multiple functions: it acts as a stop to limit rotation opening movement, a locking mechanism to prevent slamming, and a releasable engagement component for controlled operation. The rotation limiting element simultaneously provides guidance for the locking element and defines the limited opening position. This multi-functionality reduces the need for separate components, maintaining simplicity while achieving reliability.
Solution Approach 2:
The guide on the rotation limiting element acts as an intermediary between the rotation limiting element and the locking element. It facilitates the movement and positioning of the locking element during the locking and releasing operations, enabling smooth transitions between locked and release positions without requiring complex mechanisms. The guide mediates the interaction, simplifying the overall system while ensuring reliable locking.
3Strength
If the locking element is made robust (e.g., stainless steel), then strength and reliability are improved, but the manufacturing cost and weight increase
Solution Approach 1:
Only the locking element, which is directly subjected to wind loads and requires high strength, is made of robust material such as stainless steel. The rotation limiting element and guide, which have different functional requirements, can be made of lighter materials like aluminum or plastic. This local application of high-strength material optimizes the strength-to-weight ratio, providing necessary robustness where needed while minimizing overall weight and cost.
Data Source
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AI summary
In a rotation opening limiting arrangement (4) for a window (1) or a door for limiting the rotation opening movement of a sash (3) of a window (1) or a door, a rotation movement limiter (5) that can be mounted on a sash (3) of the door or window (1) has a rotation limiting element guide (7) for a fixed frame-side rotation limiting element (8) and a locking element (12) for fixing the rotation limiting element (8) in a limited rotation opening position.