Window Blind Slat Adjustment Device with Variable Tooth Height
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional window blind slat adjustment devices often damage the teeth of the transmission member due to the uniform height of teeth on the rod, turning member, and transmission member, leading to frequent breakage, especially when the rod is overturned.
Innovation Solution
A device with a rod and transmission member featuring a first rack with teeth of varying heights, where the first and last teeth are shorter than the rest, and a turning member with a gear meshed with the second rack, preventing damage by allowing the teeth to slide between an addendum and pitch circle, providing 'click' feedback for user control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the teeth of the transmission member have uniform height, then the meshing is simple to manufacture, but the first and last teeth are easy to be broken when the rod is overturned
Solution Approach 1:
The patent applies local quality by making the first and last teeth of the transmission member have different heights compared to the intermediate teeth. Specifically, the first and last teeth are designed with shorter addendum lengths, while the intermediate teeth maintain uniform, taller heights. This localized differentiation strengthens the vulnerable end teeth without complicating the manufacturing of the majority of teeth, thus resolving the contradiction between manufacturing simplicity and durability.
2Ease of operation
If the rod is allowed to overturn freely, then the ease of operation is improved, but the teeth of the transmission member are damaged
Solution Approach 1:
The patent implements preliminary anti-action by pre-designing the first and last teeth with reduced heights before the rod can overturn. When the rod is overturned, these shorter teeth make contact with the rod's teeth at a lower level, preventing the rod's teeth from extending into the addendum circles of the intermediate teeth. This preliminary structural arrangement prevents the harmful effect of tooth damage while still allowing the rod to overturn freely.
Data Source
AI summary
A device for adjusting a slat of a window blind including a housing, in which a plurality of frames, a rod, a plurality of transmission members, and a plurality of turning members are provided. The rod is meshed with a first rack of each transmission member, and the turning members are respectively meshed with a second rack of each transmission member. The first rack has a plurality of teeth in a line, and the first and the last teeth are shorter than the rest teeth. Furthermore, the first and the last teeth are designed for ratchet, so that the teeth of the rod will slide on and over the first or the last teeth when the user is overturning the rod to protect the teeth of the first rack of the transmission member.