Mirrored Operating Lever Set for Casement Window Leaf Closure
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Solution Overview
Problem
Casement windows with two leaves often have insufficient closure between the primary and secondary leaves, especially when using standard window fittings, and existing solutions for improved closure are complex or limited to specific profiles.
Innovation Solution
A set of operating levers for the secondary leaf of a casement window, designed with mirrored configurations to accommodate both right-hand and left-hand openings, featuring an oblong body with upright ribs and threaded holes for enhanced security and ease of use, and integrated with latches and sliding elements to ensure firm closure and burglar-proofing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If standard window fittings are used for casement windows with two leaves, then the window can be manufactured with standard components, but the closure between the primary and secondary leaves is insufficient
Solution Approach 1:
The operating lever is divided into distinct functional segments: an oblong body for mounting, an operating arm for user interaction, a sliding element for movement along the profile, and a connecting arm for mechanical linkage. This segmentation allows each part to perform its specific function optimally while maintaining overall closure reliability.
Solution Approach 2:
The operating lever features an asymmetric design with an upright rib protruding from one longitudinal side only. This asymmetry creates a stop that prevents over-rotation and ensures proper engagement direction, thereby improving the reliability of the closure mechanism between leaves.
2Reliability
If fixed locking pieces and sliding fittings are mounted in the same fitting groove to improve closure, then the connection between leaves is better, but the device complexity increases
Solution Approach 1:
The operating lever integrates multiple functions into a single component: it provides both the sliding action for the latch and the locking action through its connecting arm. This merging reduces the number of separate fittings needed in the groove while maintaining reliable leaf connection.
Solution Approach 2:
The operating lever serves multiple purposes: it operates the latch, provides a stopping mechanism via the upright rib, and enables secure closure through the connecting arm. This multi-functionality reduces overall system complexity while improving closure reliability.
3Ease of operation
If operating levers are mounted in the fitting groove of the secondary leaf to enable operation, then the secondary leaf can be operated, but the operating levers become visible and may compromise security
Solution Approach 1:
The operating lever is designed to nest within the fitting groove when in the closed position. The oblong body fits into the groove, and the upright rib aligns with the groove's contour, making the lever invisible from the outside while remaining fully functional for operation.
4Object-affected harmful factors
If the operating lever is designed with an upright rib to prevent unauthorized access, then burglar-proofing is improved, but the device complexity increases
Solution Approach 1:
The upright rib is added only to the longitudinal side of the oblong body that faces the exterior, providing burglar-proofing exactly where it is needed. The rest of the lever maintains a simple structure for ease of manufacture and operation.
Data Source
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AI summary
The invention provides for a set of two asymmetric operating levers (9a,b) for mounting on a secondary leaf of a casement window. Each operating lever can be coupled to a slideable upper latch and lower latch, whereby, in mounted condition on the secondary leaf, the operating levers of the set are coupled with the slideable upper latch and lower latch respectively and the operating lever coupled to the upper latch is configured in a mirrored way relative to the operating lever coupled to the lower latch.