Switchable Planetary Gear Stage for Blind Speed Control
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Solution Overview
Problem
Conventional planetary gears in drive devices for venetian blinds face a trade-off between high output speed for quick curtain movement and low speed for precise slat adjustment, making it difficult to achieve both simultaneously.
Innovation Solution
Incorporating a switchable additional gear stage that can be engaged or disengaged using a helical spring mechanism, allowing for high initial speed when moving the curtain and reduced speed for adjusting slats, with the gear stage automatically switching based on the position of the blind.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the initial speed is reduced to enable finer adjustment of the slats, then the manufacturing precision is improved, but the productivity deteriorates due to increased time required to move the curtain
Solution Approach 1:
The planetary gear transmission employs a dynamically switchable additional gear stage that can be engaged or disengaged during operation. A coil spring mechanism automatically engages the additional gear stage when the blind reaches the end position, reducing speed for slat adjustment, and disengages it when moving in the opposite direction, enabling high-speed curtain movement. This dynamic reconfiguration resolves the contradiction between fine adjustment precision and productivity.
2Productivity
If a high drive speed is used to achieve high approach speed for moving the curtain, then the productivity is improved, but the manufacturing precision deteriorates as fine adjustment of slats becomes difficult
Solution Approach 1:
The system dynamically adjusts the gear ratio by engaging or disengaging the additional gear stage based on operational requirements. During approach movement, the additional gear stage is disengaged to provide high drive speed. Upon reaching the end position, the coil spring mechanism automatically engages the additional gear stage to reduce speed for precise slat adjustment, thus resolving the contradiction between productivity and precision.
Solution Approach 2:
The coil spring mechanism automatically engages and disengages the additional gear stage based on the position of the blind without external control. When the blind reaches the end position, the spring mechanism self-activates to engage the gear stage for speed reduction. When moving in the opposite direction, it automatically disengages to restore high speed, enabling the system to serve itself and resolve the speed-precision contradiction autonomously.
3Manufacturing precision
If the additional gear stage is continuously engaged to enable fine adjustment, then the manufacturing precision is improved, but the productivity deteriorates due to reduced approach speed
Solution Approach 1:
The additional gear stage is designed to be dynamically engaged only when needed for fine adjustment of slats at the end positions. The coil spring mechanism automatically engages the gear stage upon reaching the end position and disengages it during reverse movement. This dynamic engagement strategy maintains fine adjustment capability while maximizing approach speed during the majority of the movement cycle, resolving the contradiction between precision and productivity.
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 faster curtain movement while allowing for precise slat adjustments, reducing the time required to reach the desired blind position by dynamically adjusting the gear stage engagement.
Implementation Method 1
the coil spring has a bent first end which behind the tang, and the coil spring has an inturned second end which is drivable by the carrier tang
Data Source
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AI summary
The invention relates to a planetary gear drive for drive motors, in particular for roller shutters, blinds, awnings, gates, doors and the like, the speed of which is reduced by multi-stage planet gears (5, 6, 7) that mesh in a ring gear (11). The invention lies in the fact that at least one selectable gear stage (11, 12, 13) is arranged for higher or lower output speeds.