sharrow propeller. a revolution?

[wkearney99]

Might make any Sharrow patents validity questionable.

Before throwing out uninformed speculation, at least do a basic patent search. Patents don't get issued without a fair degree of research, and many clearly cite prior art. Use just 'sharrow' on that link and you'll find quite a few relating to the props, among other tech.

US-D988967-S is but one of several

 

[Hippocampus]

Couldn't you equally tune a conventional prop for some specific operating point?

Doesn’t that operating point vary fairly frequently? Isn’t the idea of a CPP is to follow exhaust temp as an indirect measurement of load. So vary pitch to produce that ideal amount of load. I also don’t understand why CPP are still employed when engines are now common rail in the sizes employed for recreational trawlers. I know we are a small market but to my understanding sharrow makes none suitable for us let alone large vessels. Am I wrong in that? Are ships using them?

 

[OldDan1943]

Why not return to a variable pitch prop?

 

[Hippocampus]

Expense.


Looked in to it. As a retrofit expense couldn’t be justified.

 

[twistedtree]

Doesn’t that operating point vary fairly frequently? Isn’t the idea of a CPP is to follow exhaust temp as an indirect measurement of load. So vary pitch to produce that ideal amount of load. I also don’t understand why CPP are still employed when engines are now common rail in the sizes employed for recreational trawlers. I know we are a small market but to my understanding sharrow makes none suitable for us let alone large vessels. Am I wrong in that? Are ships using them?

Sorry, I thought you were also talking about tuning the Sharrow to a particular operating point. In that case, I don't see the difference between it and a conventional prop, other than any fundamental efficiency improvement.

 

[DDW]

Before throwing out uninformed speculation, at least do a basic patent search. Patents don't get issued without a fair degree of research, and many clearly cite prior art. Use just 'sharrow' on that link and you'll find quite a few relating to the props, among other tech.

US-D988967-S is but one of several

Not uninformed really. My own name is on something like 17 patents so I am pretty familiar with the process and the basics of patent law. Patents DO get issued without a very knowledgable search of prior art, and with dubious claims. There are hundreds of patents issued for perpetual motion machines for example.

 

[wkearney99]

Not uninformed really. My own name is on something like 17 patents so I am pretty familiar with the process and the basics of patent law.

If you know the process then why the throw-away sort of diss toward it? There's enough of that nonsense going around these days, why add to it?

 

[DDW]

If you know the process then why the throw-away sort of diss toward it? There's enough of that nonsense going around these days, why add to it?

Wasn't a diss was it? Just citing prior art. Now the patent you referenced claims only the ornamental design and nothing else. Not a super valuable patent, and even then one might challenge how novel it is. They have other patents with more substantial claims, however certainly some of the more general claims might be challenged on prior art. The more specific ones might stand, as you probably know that is why claims are normally written in the bizarre way they are, to keep the baby and the bathwater separate. Searches for prior patents can often miss prior art.

 

[wkearney99]

If you put half the effort into actually checking the patents as you have otherwise, the conversation would have had that much the better content. Instead...

 

[Island Cessna]

Sharrow in a Museum?

Everything that's old is new again?

Spotted today

I saw this today in a maritime museum in Bellingham WA. Startling similarity to the picture Simi posted above.
I spoke with the fellow who owned it, and he bought it used without knowing its heritage, but it sure appears old enough to belong in a museum! Also appears to be “prior art” to any current patents.

 

[RT Firefly]

Greetings,
Mr. IC. I think the earliest screw "propeller" is noted here: https://en.wikipedia.org/wiki/SS_Archimedes. The Wiki article mentions it had 2 full turns.

 

[moparharn]

Sharrow

I think MIT has a patent on this as well. Again, I think the two of them were in some legal discussion and possibly now are working cooperatively. It is a great design that will be the norm once the cost of production comes down. Eventually prop shops will be able to repair them and tune them as well. As of this moment it is hard to justify the return on investment. I see them much like the early days of any new tech. Too expensive at first, but the tech is too good to fade away.

 

[High Wire]

for a planing hull like a 250hp outboard center console, $5000 each. Ouch! A guy on my dock in Cape May has a pair of them. He said they deliver all that they promise but loooonnggg time for ROI.

 

[twistedtree]

Not sure if other know, but Sharrow and Veem have an exclusive arrangement for inboard propellers.


https://veem.com.au/exclusive-agree...ercialise-revolutionary-new-propeller-design/