We're back at it and this week's post will be covering the design and construction of the hub assembly, the central part that connects all the ribs together.
It may seem insignificant to the overall design, in fact we never really thought much about the hub assembly either. In the early days of development, back around early 2015, Kevin and I expected our top hub to be very typical, something similar to everything already on the everyday umbrella. At the end of the day, isn’t it just a plastic piece with slots? Well it all changed when we decided to be the first in the industry to incorporate a fully interchangeable canopy feature (who wouldn’t want more colours and patterns!)
Evolution of the Top Hub Design
The interchangeable canopy feature was very important for us. We know that our umbrella frame can last, but we couldn’t figure out a way to make the canopy last without using extremely thick and heavy fabric. So we decided to make the canopy interchangeable, once a canopy has worn out it could be easily swapped out within minutes. Same applies if you become bored of a certain colour/design, a different canopy can be swapped out to give you a new fresh new look.
The interchangeable canopy feature creates two major challenges. The first challenge is the threaded top cap, which was typically designed to be a one-time-installation performed at the factory. The existing solution is neither ergonomic, nor is it durable. This plastic threads would not hold up after repeated threading and unthreading, and it was very difficult to align everything. Our solution was a metal eyelet swaged on the canopy, sized so it can be easily drop into a counterbore of the hub. This makes aligning the canopy with the top hub a breeze. As for the threads? Both the male and female threads are metal, allowing decades of service before it finally wears out.
Our second challenge was the fabric washer that creates a watertight seal between the top cap and the top hub. With a one-time-installation, this would not be an issue as the washer would forever be connected to the umbrella. However we expect our users to interchange canopies, and an additional loose part would just be another risk of misplacing the part. The solution is quite simple, we increased the size of the top cap just slightly larger than the hub. The result is a “ring” of contact underneath the top cap against the edge of the hub, creating a watertight seal. The overhanging lip on the top cap also allows the top cap to be easily gripped for assembly/disassembly.
Overall, we’re really happy of how our hub assembly turned out. Hope you guys enjoyed this blog post. Be sure to stay tuned for the next one.