Water nozzle patents (very important read!)

[Ben]

Lately I have been reading many patents on various water nozzles. These nozzles usually are not for water guns or necessarily design for maximum range, but they will work very much for our goals. This was not an exhaustive search, or even a search outside of US patents.

Already I have seen new ideas and received explanations for things I previously did not understand. Once I finish reading these patents, I should make an updated "Streams" article to include some ideal nozzle designs and important nozzle features. The updated article should also include links to these patents and thanks to the inventors and researchers! I will give a basic idea of what each patent says in this post. These patents will be put in order of importance from my quick reading of them.

Patent 5,169,065 - Method and apparatus for water jet cutting including improved nozzle - Christopher J. Bloch

While this nozzle was design for extremely high pressure cleaning (i.e. over 2000 psi), it is probably the best nozzle invented for converting highly turbulent flow to laminar flow and then further to streamline flow. The abstract of the patent says "string line flow", but that is most likely a typographical error because string line flow is never mentioned in the patent again.

This nozzle has your basics - linear guidance walls and conical/reducing nozzle design. It should be said that the screens are absent in this design. From my reading of other patents (mostly faucet nozzles), I can easily see that the screens provide little function other than to slow down the stream, which we already know produces more laminar flow. That was my best guess before and I found it to be true. This nozzle is designed better than that. More information on exactly what the screens do will be explained in a future post or article.

One new feature that we have not previously seen makes me very excited. Christopher Bloch breaks down the parts into the pre-nozzle assembly, the nozzle orifice and the post-nozzle assembly. We have not seen a post-nozzle assembly as of yet.

This post-nozzle assembly in short protects the stream (almost like a shield). It creates a vacuum around the stream that protects it from breaking up. Of course, we do not know if this protection will be of much use in our "very low pressure" devices as described by the patent. At higher pressures this post-nozzle assembly may prove to be extremely useful however! This is an unseen technology as of yet. I am going to call this the "Bloch effect" unless it appears that he did not invent this effect himself.

He talks mostly about this nozzle as it is meant to be used, but he also admits that it can be used on "very low pressure" devices and talks about it's use there as well. He gives a good general rule for stream breakup (lets call it "Bloch's rule") - a stream will typically break up in after it travels less than 100 times the nozzle size, depending on the power and other factors. If you think about this, it does work fairly well, but 100 times is far too short for our pressures.

This patent expired on December 11, 1996 due to a failure to pay a maintenance fee. This does mean that the nozzle is open for anyone to use even for profit.



Patent 5,779,099 - Nozzle with turbulence control member for water gun laminar flow ejection - Bruce D'Andrade

This is the famous water gun nozzle patent. This patent was the one that I had found probably over a year ago and posted about. In short, this is your basic Super Soaker nozzle as designed by Bruce D'Andrade, who was instrumental in designing the Super Soakers.

This nozzle has linear guidance walls and screens. That is how simple the Super Soaker nozzle is, likely because it will be easy to manufacture.

Sadly, Bruce is no longer alive, but he certainly has made his way in history! May he rest in peace.

Patent 5,472,145 - Straight stream nozzle

The original nozzle design for range! This nozzle is specifically designed to make a "more highly concentrated stream which produces high impact at a substantial distance." Sounds great to me!

This is a very simply nozzle, and is very similar to the previous Super Soaker nozzle patent except that is lacks screens. The nozzle only has some sort of linear guidance walls, but they are put in an unusual pattern. As opposed to straws or some sort of straight wall, this patent has 5 holes and then 5 curved holes on the outside. This must provide better lamination for low pressure water streams.

Patent 5,242,119 and 4,720,786 - Laminar spout attachment, Low noise, flow limiting, laminar stream spout

Both of these patents are for faucet nozzles. They use screens to reduce stream velocity and reduce the "associated flow noise". This improves stream lamination.

Not much more can be said about these patents. For more information on what exactly the screens do, please read the patents.

There are a few other nozzles which I am still writing the descriptions for. These will be made in a future post soon. What are your thoughts on this new knowledge and technology?

[RacerSoaker445]

Very good post, I wish you could get some pictures, but they will probably be hard to find.

The Straight stream nozzle sounds interesting, 5 curved holes on the outside?

[Ben]

About time that someone posted a reply! You can get the pictures on the US Patent and Trademark Office website. Just do a search by patent number. The interface is the worst on the planet, so admittedly I actually didn't get my copies there.

I think the most promising thing is the shrouded nozzle... we'll see how that invention turns out when applies to water guns.

[RacerSoaker445]

Doing patent searches. Yes you're right, that is THE worst interface I have seen for a long time. Too bad I have to close Opera and view it with IE.

Some of the patents look pretty neat!

[Ben]

Chris Bloch (or someone who appears to know a lot about his patent) has sent me an interesting email! He also has joined our forums and I hope that he can help us all with nozzle designs. Email is quoted below. He explains the string feature I was less excited about because I can't reproduce it in homemade nozzles and also goes into a few other things such as glycerin.

Originally Posted by Chris Bloch

Ben,

My name is Chris Bloch, I am the inventor of the patent referenced on your website. My son that brought your posting to my attention.

Your comments about the application of the "fuzzy nozzle" patent to low pressure flow are correct. The principles taught by the patent equally apply at low pressures. You can demonstrate this effect by placing a paint brush under a faucet. The water that exits the fine hairs of the brush will have very low turbulence and will form a sheet or stream of water that will stay cohearent for some longer period of time. Another example of this effect is a lake on a windy day. The lake surface will be rough exept in areas that have seaweed under or near the surface. In those areas the surface of the lake will appear calm and flat.

This effect is due to the attenuation of random velocity vectors present in the water. Friction between the surface of the strings dampens velocity vectors that are perpendicular to the direction of the strings. It is somewhat like a water laser, all of the velocity vectors of the water are channeled into a single flow direction. The mechanism that breaks a solid stream of water into a stream of small water droplets is retarded by the reduction of internal velocity vectors in the solid stream of water that are perpendicular to the mass direction of flow. This mechanism has to do with the mixing of air at the surface of the solid stream of water "the free jet" into the column of water. As more air is mixed into the free jet, the jet diameter expands. Eventually enough air is mixed into the free jet to result in a phase inversion. When you have a phase inversion, the air bubbles surrounded by the solid column of water break the water column into a column of water droplets surrounded by air. This effect happens in a very short period of time. It is somewhat like a soap bubble where a volume of air is surrounded by a thin film of soapy water. When the soap film breaks, it forms a fine mist of soapy film (and one large drop off the bottom of the bubble) surrounded by air. If you watch a soap bubble burst it happens in a blink of an eye.

In the case of a free jet (a solid column of water), once the phase inversion takes place, the friction between the large surface area of all the fine droplets and the surrounding air will cause the inverted phase jet to lose velocity rapidly.

Another method that is effective in reducing the rate at which air is mixed into a free jet is to add a substance such as glycerin or a water soluble polymer into the water before it exits the nozzle. The higher viscousity reduces the rate of air mixing and holds the film of fluid around the bubbles longer. This effect is also true if you want to make really big, stable bubbles. Add glycerin or a water based polymer to the soapy water used to make the bubbles.

If you load a super soaker water gun with latex paint you will note that you can shot the paint further than if the gun is loaded with plain water.

In any case, whatever you do to reduce air mixing into a free water jet, the longer that jet will hold together.

Best Regards,

Chris Bloch