Window Gearbox Ratio Change for Correct Handle Alignment
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Solution Overview
Problem
Existing window mechanisms experience misalignment of the handle due to mechanical play in the kinematic chain, causing the handle to lag behind the desired position when operated by a drive, particularly when reversing movements, leading to an aesthetically displeasing skewed handle orientation.
Innovation Solution
The gearbox is modified by increasing the transmission ratio between functional positions, specifically greater than 5.0 degrees per 1 millimeter stroke of the push rod, to compensate for mechanical play, ensuring the handle reaches the desired position, such as vertical orientation when closed, by adapting the gear and/or rack elements with increased angular distances and material modifications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the transmission ratio in the gearbox is increased to compensate for mechanical play, then the handle alignment precision is improved, but the device complexity increases due to modified gear and rack elements
Solution Approach 1:
The patent changes the transmission ratio parameter of the gearbox from the standard 5 degrees per 1mm to a higher value (greater than 5.0 degrees per 1mm stroke). This parameter modification compensates for mechanical play in the kinematic chain, ensuring the handle reaches the desired vertical position when the window is closed, without requiring fundamental structural changes to the gearbox architecture.
2Manufacturing precision
If the gear and rack elements are modified with increased angular distances, then the handle reaches the desired position accurately, but the manufacturing precision requirements increase
Solution Approach 1:
The patent modifies the gear and rack elements by increasing the angular distance between teeth, which changes the transmission ratio. This parameter change allows the handle to overcome mechanical play and reach the correct vertical position, while the modifications can be implemented through standard manufacturing processes with adjusted dimensional specifications.
3Measurement precision
If the transmission ratio is increased to compensate for mechanical play, then the handle orientation is corrected, but the device complexity increases due to non-standard gear components
Solution Approach 1:
The patent implements a non-standard transmission ratio (greater than 5.0 degrees per 1mm stroke) by modifying the gear and rack tooth geometry. This parameter change enables the handle to achieve accurate vertical orientation despite mechanical play in the kinematic chain, while the modified components can still be manufactured using conventional techniques.
Data Source
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AI summary
The invention relates to a method for correcting the handle position of a manually and motor-operated window, which has a handle whose manual rotation is translated by means of a gearbox into a pushing movement of a push rod having at least one locking element, wherein the gearbox has as translating gearbox elements at least a gear connected to the handle and a rack meshing with the gear and connected to the push rod, and which has a drive with which, by applying force to a push rod lying in a fitting groove of the sash frame, the push rod is pushed in active operation and the handle is turned indirectly via the gearbox, wherein at least one of the translating gearbox elements in the gearbox is exchanged for a replacement element and thereby the gearbox with the at least one replacement element achieves a higher gear ratio.The invention also relates to a window of the aforementioned type, in which the gear ratio between two operating positions is greater than 5.0 degrees per 1 millimeter of stroke of the push rod, in particular greater than 5.1 degrees per 1 millimeter of stroke of the push rod, in particular greater than 5.25 degrees per 1 millimeter of stroke of the push rod, and more preferably greater than 5.35 degrees per 1 millimeter of stroke of the push rod. The invention also relates to a set comprising a window drive for installation in the frame of a window and a replacement gear element.