Air ventilated planing hull design

Discussion in 'Boat Design' started by Kraftzion, Jun 11, 2011.

  1. Squidly-Diddly
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    Squidly-Diddly Senior Member

    Tom, it is probably a "defensive patent" where they get their design

    and features into a Patent, mostly so someone else can't patent it.

    For instance, someone might takeout a Patent on "A Planing Hull with forced air supplied by fan driven by 3-phase motor" and even though using ANY sort of electric motor would be "obvious" a patent dispute could cost them a lot of money to even think and worry about, and muddy the water and scare of customers and investors.
     
  2. tom28571
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    tom28571 Senior Member

    My point was that I did not see anything that could be patented. Everything I saw is in the public domain or patented by someone else. The nearest thing I saw was a patent issued quite a few years back for CAT or Controlled Air Technique which works exactly like that with chine walls. The use of a water ballast tube in combination with the forced air channel is new as far as I know and maybe that is what they patented but both are already out there in common use. I think the patent claim is mainly a promotional gimmick.

    Walt Schultz of Shannon Yachts got a patent on his "reverse deadrise hull" but I and others have been using that previously too. Sloppy work by some cheap patent attorney maybe.
     
  3. Squidly-Diddly
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    Squidly-Diddly Senior Member

    I couldn't find any US patent under "beneteau" and "hull"

    But I didn't try an EU search.
     
  4. DCockey
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    DCockey Senior Member

    A patent attorney explained to me that patent examiners only average a few hours on each patent application they examine. They look to see if the idea has been previously patented but don't generally go looking for a prior execution of the same idea. If they don't see a reason not to issue the patent then it's issued. So it's quite possible to get a patent for something which has previously been done.

    Depending on the intentions it may have been very good work by a patent attorney.
     
  5. philSweet
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    philSweet Senior Member

    So what do we think is going on in the Beneteau example? We have an apparently passive air ventilation system that claims to reduce power requirements. The promo video claimed the holeshot boats had different engines; so I'm thinking this has a lot to do with weight and attitude on plane. If the air reduces porpoising and allows a flatter trim, that could be helpful to matching performance with less power. Perhaps this is valid for a narrow range of speeds and weights. Perhaps it is a "fix" to allow old hull designs to continue to be viable with the trend to lower fuel consumption. I'm having a difficult time believing that a passive system can be of much benefit to a clean sheet design under cruise conditions.
     
  6. tom28571
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    tom28571 Senior Member

    That depends entirely on the patent examiner and does not jibe with my experience at all. Perhaps it is sufficient for nuisance patent applications but would never be acceptable for fundamental applications by a large research group. There is too much at risk for that. In my personal experience going back at least 40 years, searches for my patents were very thorough, including foreign patents.

    I was once denied a patent by the finding of a Swiss patent on a similar claim of one year earlier. That was just as well since GPS made both ideas mostly irrelevant a few years later. That system had to do with using electro-magnetic fields for guiding and locating the position of a vehicle or ship along a path. With the internet and digital files available today, even a simple search should reveal a lot. Its not only other patents that are of concern. Even the disclosure of sufficient details of the idea (or whatever) in a public manner is enough to void a later application.

    If Benneteau had a serious patent to protect, they would disclose the patent number, which would offer support to the claim and discourage coppiers.
     
  7. DCockey
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    DCockey Senior Member

    The converstation with the patent attorney took place while I was working for a very large corporation. It was in the context of why some other firms had received patents on things we and/or others had been producing for a number of years and had not patented.

    Our internal folks were very thorough with their searches. They rejected an concept I had for automotive cooling fans on the basis of a 75+ year old patent which was somewhat similar but not that close.
     
  8. messabout
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    messabout Senior Member

    And a patent for anything pertaining to the design of the boat, whether useful or not, is an advantage for the marketing department but not necessarily for the buyer except for his bragging rights at the club bar..
     
  9. DCockey
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    DCockey Senior Member

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  10. tunnels

    tunnels Previous Member

    The thing of skin friction and air ventilated hulls etc etc is all about going fast ,so unless you are doing 60 mph plus anything below that is a waste of time and effort !!. The bubble thing i keep hearing about getting to the propeller is just a matter of lowering the motor 5 mm maybe so the bubbles in the waters surface are just ablove the tips of the prop!! Personally no one really knows !!its all speculation and here say !.
    The most wonderous thing i did to my own boat was to push the motor 450mm back on a new transomcome bracket with a differance and i was able to raise the motor 20 mm above the botton of the hull line !! wow that made it go !! and the trim is beautiful and positive to use .Now i can watch the chine spray out the side of the hull shift from the front to almost the aft corner of the hull at 55 knots plus .its given control to the trim button and can raise the bow effortlessly at just the touch of the button .
    I have only done stage one to my boat so far and when i get back to nz later will do stage two which will be a whole of bottom (chine to keel , bow to stern) modification with wide lifting strakes to get the hull even higher out of the water and go even quicker and stable at speed !!. No i dont want a flat ski pad on the bottom :D
     

  11. Kestrel
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    Kestrel Junior Member

    imo, they actually realized a sort of "swept back step":
    http://www.foils.org/02_Papers dnloads/Clement dynaplane.PDF
    http://www.dynaplaneboat.com/
    and from that comes a good efficiency (high planing surface aspect ratio, less propability to cut spray root by step, at high speed), even if also with a traditional well stepped bottom it's not rare to reach a gain of 20% in efficiency (i.e. expressed as Displ./R). Air ventilation of steps by injection, through tube vents, is a known technic, first was patented (it seems) by Fauber in 1910, and many other variations was proposed around the item in the world,
    http://www.lesliefield.com/other_history/1908_fauber_designed_hydroplane.htm
    here an interesting study:http://202.114.89.60/resource/pdf/1040.pdf
    The afterbody hull, then, works something like a hook cambered bottom, what's is a solution for single stepped hull where something like costant trim attitude is wanted in transition from pre - to planing range.
    In summary it seems a good combination of design factors.
    Yes, tom28571, also imo "nihil novi sub solem".
    K.
     
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