Vented Plunger
Original Design
The Problem
If this looks like a high schooler’s project, well, that’s because it is. A lot of people don’t like thinking about plunging the toilet, but that was even more reason to look into it: plunging is unpleasant so it should be possible to improve it and not many people choose to tackle the problem because the subject matter isn’t appealing.
The problem I saw was that the act of plunging wasn’t the worst part. The worst part was the first plunge, when an air bubble would release from the plunger “cup” and cause an unsanitary splash at the surface. Lowering the plunger into the water at an angle reduced the size of the bubble, but, due to the cup’s shape, there was no way to eliminate the bubble altogether. So the problem I chose to solve was the bubble in the cup.
The Design
Proof of Concept Design
The design called for a vented plunger. Ideally, I wanted it to act passively - no specific actions required by the user. Just plunge like normal but now no more bubble. This design would be possible with a water check valve coupled to the cup at one end and a channel at the other. This would allow the air to flow out but no water. Since we can’t assume the water’s clean, we don’t want anything getting stuck in the valve so the channel would have to extend above the water level when plunging. This would ensure air on one end of the valve and water at the other, preventing water ingress. The channel should be hooked back to face the water, should the valve inexplicably fail (don’t want the plunger to turn into a toilet water gun facing the user). This was a little complicated to just test the concept so instead a simpler design, requiring user action, was built.
The proof-of-concept design made use of a manually operated vent. The user would open the vent when the plunger entered the water, and close the vent thereafter. The plunger could then be used as a normal plunger would. To build it, I bought a standard plunger and removed the cup from the handle. I drilled a hole through the top of the cup and attached it to a 90° valve. In this configuration, the valve handle axis was inline with the plunger handle axis. The handle was removed and a metal rod was attached in its place. A piece of pipe and a fitting were attached to the valve over the rod. A cap over the free end of the pipe and a handle for the free end of the rod completed the prototype.
The Results
So how’d it work? It worked exactly as planned. The bubble exited through the valve and the plunger plunged as expected. Plunging was a little nicer without that bubble to stand back from, although obviously still not particularly pleasant. Knowing that the concept worked, I decided to take a look at patents and see if anyone else had thought to eliminate this bubble. Unfortunately, someone had. A Wallace Schneider in New York had been granted US Patent 6,684,417 B1 for a vented toilet plunger in 2002. After learning that, and at the time not knowing exactly how patents worked, I figured I couldn’t carry on and stopped working on the project. The prototype plunger is actually still in use as of 2019, 10 years after it was built.