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First off, I'm not talking about those little springs
attached to peoples feet you see in cartoons, or "velocity
stilts" or moon shoes. Iv'e had moon shoes, and they do
not cushion your fall. In fact, they really hurt my ankles.
Anyway, heres how it works: you are standing on a pair
of stilts,
which rest inside of larger stilts. The smaller
stilts are suspended inside the larger ones by an
industrial sized rubber band. The larger stilts are also air
tight, save for a very thin cut running down each side.
These slits can be partially widened or covered up by a
sliding piece of metal to increase or decrease the rate
air can escape. (covered up or closed for low heights,
widened or opened further for high)
Both stilts are strapped to your knees and ankles. Upon
leaving the ground, the larger stilts are pushed by the
industrial sized band away from the smaller stilts, but
cannot simply shoot out. Before impact the stilts should
extend to about twice the length of the users legs. Upon
impact, your fall is cushioned in four ways.
1. As the smaller stilts and your legs fall into the large
ones, the rubber band is stretched.
2. The as the solid platform within the smaller stilt is
pushed into the larger one, the air is compressed, but
allowed to escape through the aforementioned slits in
the larger stilt.
3. When the small stilt pushes all the way through to the
ground, it lands on a soft material (NASA style temper-
pedic pillow fluff?) which is wedged in the very bottom of
the larger stilt.
4. The smaller stilt hits the ground, and you slow the
rest of your momentum with a roll (if necessary)
Using these, you should be able to jump off of really
high stuff, but there are a few dangers to using them.
If you land with the end of the stilts too far apart, (which
is likely if they are too long) then you will be split in half.
If there is no way to lock the smaller stilts in place lower
within the larger ones, it would be very hard to keep you
balance. Such a lock could operate like a gigantic ball
point pen, collapsing the stilts permanently upon impact,
so as not to cause unwanted bounce when walking
You might look funny, but maybe not if you wear really
long pants. (see "pygmy boots")
youtube search for "JUMPING STILTS"
http://www.youtube....s&search_type=&aq=f
Looks like fun . [knowtion, Oct 15 2009, last modified Oct 16 2009]
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If you tether them you can lose the whole split in half problem. |
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I just don't see seeing that screenname over and over again. Prove me wrong? |
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Welcome to the bakery! ok, now I'll read it. Yep, split in half problem is solved. Why not use them to jump really high? The mechanism is somewhat like a pogo-stick.. |
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True, they are pogo stick-ish. However, pogo sticks
cause you to bounce, where as if you are falling from
a high height, then that is the last thing you want.
(impulse equation) The industrial sized rubber band is
mostly for extending the stilts. |
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If you added a third stilt it would be a more stable structure. |
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You could combine them with minature parachutes for ultra-high-speed skydiving. |
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//You could combine them with minature parachutes for ultra-high-speed skydiving.// |
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I have actually put a lot of thought on this subject due to an old book which referenced "spring heeled jack", a murderer who lived around the time of jack the ripper and of course my personal desire to be a super hero and to conquer my fear of heights. |
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So let me stress that for a system to work for any real heights, you need to extend the system from toes to head or at the very least from heels to waist or your knees will HATE you and you may perform the ultimate split. All joints need to be set to guide the body towards a fetal position. This is to avoid the situation where you land and your head hits the ground behind your feet and it also allows you to roll to expend excess energy. Though for that you need sticky "feet" at the ends, so the feet don't slide out. |
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Also some minimal parachute system that will guide your feet to land first is probably also a good idea. |
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Those parcoer (sp?) guys could use something like this. |
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//You might look funny, but maybe not if you wear really long pants// I'm a bit like that anyway... |
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What if one stilt fails to deploy ? |
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Bun for the image of skydivers in tutus. |
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Also, the first result I got for "heel springs" led me
right to spring heeled jack. Has anyone here read
"skulduggery pleasant"?
I was thinking about extending the system to
around the shoulders, so that you hold the small
stilts by hand, giving you more control, but that
increases the weight, and gives your legs less
control as they now have to drag along the extra
long small stilts that reach to your hands. I agree
with the idea that you need to end in the fetal
position, (more parkour) but my original idea was
that these things actually dont stop your fall.
Ideally, you touch the ground through the stilts
with enough momentum to do a roll. (another
reason why extending the system further might
get in the way.) As for a three stilt structure, I
considered that, but it denies you mobility after
jumping, and certainly a roll. |
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However, iv'e discovered another problem...
The rate at which air can escape from the stilts
must be controlled. Higher heights means less
resistance. So... (edits) |
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//The rate at which air can escape from the stilts must be controlled. Higher heights means less resistance.//
Yes, I was going to go into that in the first post. The rubber band thing is inconvenient, as it will continually attempt to deploy every time you lift your foot. What you need is a spring that will keep the system compressed and then either compressed gas(N2), explosive gas(empty handgun cartridges) or my favorite choice for repeated use medium concentration <62% hydrogen peroxide and a catalyst pack to spray thru. The peroxide will fill the cylinders with high pressure steam. The cylinders are vented either thru a blow off valve or a computer controlled release valve to a vent by the soles of your shoes. (so you land in a cool cloud) |
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If you jump from a high height the system will only use the blow off valve as the system will resist to the maximum level your legs can handle set by the blow off valve till you land. If you jump from a low height the computer will sense the excessive resistance and bleed off excess pressure so that you land softly. |
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The extra joints would also be activated by the pressurization of the cylinders and would apply gas pressure to springs that would guide your body into correct alignment. |
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As you can see the peroxide also allows you to reverse the process and jump to high heights in a repeatable fashion. |
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I strongly feel that any of the potential systems should involve telescoping, collapsible cylinders (think tent poles) with sensors and computers and shit. It should look like a person landed from an unseen height riding on the decent of a giant knuckled carbon fiber gorilla's hand. |
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Why do you need sensors again? |
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The rubber band doesn't deploy because of the lock. |
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//Why do you need sensors again?//
Let's say that rigged up, I am a 100kg man. I have strong legs which can lift 300kg. I jump from a high height and deploy the stilts to soften my landing. The system should resist compression with a force of 300kg as this will give me the maximum deceleration my legs can handle. The sensors are necessary get me to actually land if the height was not sufficient to require full deceleration for the whole length. |
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Ok then, add sensors. However, you wouldn't want
the sensors to adjust to the maximum resistance
your legs can handle, as that might cause your upper
body to hit the ground before you finish sinking
through the stilts. Therefore, you have to balance
the resistance with a persons ability not only to
bench press, but to stay upright. |
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The stilts would be rather impressive - 70m/s terminal velocity would have to be brought to a stand-still. With 1g, that's 7 seconds (which is how long it takes to reach terminal velocity, disregarding air resistance). Even if you could stand up to 15g (15x your weight resting on your knees, in my case far over a ton...), the deceleration would take ~ 0.5 seconds, and the stilts would have to be ~12 meters long... |
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//reach terminal velocity, disregarding air
resistance// ... oxymoron? |
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You could arrange to skydive in a vacuum chamber, with radar sensors connected to massive air valves to repressurise the chamber as you hit 70 m/s. That way you would get full 1G acceleration right up to your terminal velocity. |
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