Window Actuating Element Cardan Joint Transmission
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Solution Overview
Problem
Existing window and door designs with pivotably mounted sashes and fixed frames face challenges in controlling the operation from outside the building due to lack of accessible surfaces and complex gear arrangements that protrude into the filling element area, making it difficult to mount and secure actuating elements.
Innovation Solution
A second actuating element is positioned on the visible frame surface outside the building, using a cardan joint transmission element that bridges the axial offset, allowing detachable coupling with the espagnolette drive, and featuring a shaft with a self-aligning bearing head piece for secure coupling and alignment, ensuring operation without protruding into the filling element area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If the sash is profiled to cover the frame on the inside and the frame overlaps the sash on the outside, then the aesthetic appearance and sealing performance are improved, but the accessible surface area for mounting external actuating elements is reduced
Solution Approach 1:
The actuating element is mounted on the frame in a different spatial dimension - specifically on the outer visible frame surface rather than on the sash. The cardan joint transmits motion through three-dimensional space, allowing the actuating element to be positioned on the frame while still operating the sash through the offset axis connection.
2Ease of operation
If a gear is used to bridge the axis offset between internal and external actuating elements, then the transmission function is achieved, but the gear protrudes into the filling element area and creates mounting difficulties
Solution Approach 1:
The cardan joint is extracted from the sash structure and mounted independently on the frame. This separates the transmission mechanism from the filling element area, eliminating the protrusion problem while maintaining the axis offset bridging function. The cardan joint's universal joints allow angular misalignment without requiring precise coaxial alignment.
Solution Approach 2:
The cardan joint acts as an intermediary between the external actuating element on the frame and the internal drive mechanism. It mediates the transmission of rotational motion while accommodating the axial and angular offsets, replacing the problematic gear-based solution.
3Manufacturing precision
If a negative backset is provided to shift the drive member axis into the rebate area, then the mounting position is adjusted, but there is still no mounting surface for the external actuating element
Solution Approach 1:
Instead of adjusting the drive member axis position through negative backset, the solution moves the actuating element to a different dimension - the outer visible frame surface. The cardan joint then bridges the spatial gap, utilizing three-dimensional motion transmission rather than linear axis adjustment.
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
Enables operation of the window or door from outside the building with a flat profile design, simplifying assembly and ensuring drive coupling during closure, while maintaining a compact and efficient design by offsetting the connecting rod drive and housing within the filling element plane.
Implementation Method 1
a cardan joint, in particular a detachable cardan joint (20), is used as a transmission element bridging the axial offset
Implementation Method 2
The shaft (21) is aligned in the vertical and horizontal position by the housing (19) and the actuating device 5" has a detent which fixes the position of the shaft 24 assumed when the shaft 21 is decoupled
Data Source
Figure 1
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AI summary
The window or door has a swivellable actuating member (5) attached onto a visible surface toward an inner side. A leaf (1) covers a fixed frame (2) inward of a room, and is overlapped on an outer side of a building by the frame up to a point into an area of a solid pane (7). A connecting rod fitting includes an actuating member that is located on the visible surface of the frame. A swivellable shaft is fixed parallely with respect to another swivellable shaft and detachably coupled to a connecting rod drive by a transmission member that bridges a step joint.