INVENTIONS BY BRUNO LEGAIGNOUX
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High Pressure kite. 

THE CONCEPT.

​There were 3 main types of kites marketed today. By chronological order :
Picture
  • ram air kite (similar to paraglider)
Picture
  • inflatable kite (shaped frame) divided in C-shape kite, Bow kite and mix of both
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  • monoskin kite (first marketed in 2017)
Each one has its pros and cons (see here-under chart). 
There has been a few attempts to make high pressure inflatable kites. None went to market.
Although my concept may seem very simple, almost “obvious”, those who attempted to develop a high pressure kite didn't come to the same solutions and failed. Today November 25th 2018, there is no high pressure kite on the market.

The first idea was to find a way to make cheaper kites for the kitesurf market.
  • shaped tubes are expensive to manufacture, are heavy and their weak point always is the seam.
  • replacing the "classic" inflatable frame by one made of hoses produced industrially would be cheaper
  • there would be no seam so it would be possible to inflate at much higher pressure in order to narrow the diameter, reducing the drag and weight

How to achieve it ? By purchasing custom made rolls of “hose” and making the frame by cutting the roll in parts. The hose frame should have enough flexibility to follow the kite shape.
The “High Pressure kite” concept was born ! 

I based the design of my prototypes on two additional ideas :
  • it's a technical feat to be able to get a monoskin kite flying at a low angle of attack without any kind of frame and I congratulate the guys who developped this concept. These kites are super-light and cheap. However they have limitations : they don't relaunch from water, have lower upwind ability and depower. Adding to a monoskin kite a very thin inflatable frame would solve these problems.

  • the frame goes all around the kite. Having a Trailing Edge (TE) tube has several benefits : it makes the whole kite stiffer and above all it limits the risk of frontal collapse (look here-under how hang-gliders solved the deadly frontal collapse problem – check the lines that start from the top of the mast and end at the end of 4 struts – you can see that these lines keep the TE “solid” whatever the angle of attack of the profile)​
         
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The TE  hose may be smaller in diameter than the Leading Edge (LE) one. ​
If you place the TE hose above the skin, there is not much added drag, the air flow on the rear part of the extrados being always turbulent there, TE hose or not.

​So let's take a mono-skin kite, let's remove its complex LE and let's put high pressure hoses that are so thin that they bend and follow the shape given by the bridles. There is no reason in theory that it doesn't fly better than a monoskin kite, right ? So here it is !


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Why the new kite will revolutionize the market :

Value
classic inflatable
ram air kite
mono skin kite
high pressure kite
Depower
*****
****
**
*****
Upwind efficiency
****
*****
****
*****
​Loop speed/power
*****
***
**
****
​Price
***
*
****
****
​Light wind flight
**
****
*****
****
Relaunch in light wind
***
**
*
****
Packed size and weight
**
****
*****
****
Handling
***
****
****
***
Average/10
7.2
6.6
6.2
8.5
This chart takes in account the needs of the average kitesurfer
Different coefficients have been attributed to the abilities


The price of the equipment is the main brake to a market size rise. Making a kite 40% cheaper than an inflatable could multiply the market size by 2 if the brands also offer cheaper bars.
Weight comparison.
Size 7.5m²
KG
Value
​HP kite rough proto
1.9
 ​soon best for water  ;-)
Monoskin Gin Shaman
1.2
best for snow freeride
ram air kite Flysurfer Sonic
1.8
best for racers (price & relaunch don't matter)
​inflatable
2.8 to 3.5
best for water freeride
​1-strut inflat. Airush Ultra
2.2
​best for water in light wind
Copyright © 2018
  • Home
  • Inventions
    • Homemade dinghy
    • Tree tent
    • Turn Accelerator
    • Auto-zenith kite
    • High Pressure kite >
      • Presentation
      • Concept
      • Design
      • Development
      • Manufacturing
  • Book
  • Contact