Instructables

I'd like ideas for a domestic ejection-seat, any about?


For artistic purposes, "we" are interested in making an ejection mechanism to remove a person from a household arm chair.
I've thought of>
Springs
Gas-rams
Sealed gas-struts (car tailgate)

My main sticking points are: pushing the thing down if not using active gas-power, and the hassle of gas valves etc.

All suggestions welcome

noahh3 years ago
Springs and a pivot seem like the easiest way to go.
lemonie (author)  noahh3 years ago

Do you have something you could put in a diagram/picture?

L
noahh lemonie3 years ago
Sure, here you go. The idea is that the springs will be in a compressed state and held in place by some sort of catch. When triggered, the springs would expand to their normal state, and the chair would swing forward on its pivot. It would be a very violent forward-jerking motion as opposed to the "up and out" motion that I assume you're thinking of, though. I'm not sure if any of it would work, but it's just an idea.

-Noahh
chair.jpg
lemonie (author)  noahh3 years ago

I'm judging this to be the best answer given. The problem I have with this type of mechanism is the force needed to compress the springs, still I suppose two people could set the thing.
Thanks

L
iceng noahh3 years ago
springs must be able to lift your wight plus chair plus 20 %.
someone will have to help you compress them

A
noahh iceng3 years ago
That's true, but Lemonie said that it's not necessarily going to be used with anyone in it, so the springs wouldn't have to be able to lift a human's weight.
iceng noahh3 years ago
Also True.... I thought you might ketch me there.

Lemonie is very proper centric.
But to be realistic in the sense of a MythBuster
You got to get Dangerous :-)

A
iceng noahh3 years ago
How heavy are you ?
In my case it will take pneumatics :-ß
iceng3 years ago
Let me present, this electrically driven chair to launch crock man. A
lemonie (author)  iceng3 years ago

Strange, if it could go a bit quicker at it...

L
iceng lemonie3 years ago
Sure I can double the motor speed and cut frames from the film.
Work for you ? A
lemonie (author)  iceng3 years ago

"Real chair with fast-eject" is in my mind.

L
iceng lemonie3 years ago
I know.... but couldn't let this self rising chair be, and yea it was slow and mellow.
You realize... aww Steve already said it.

Do you watch the Myth Busters ?
They did a rocket chair, four rockets, one per chair leg.
The chair dummy got flipped and killed.
There was no balancing four chemical rates of burn !

A
lemonie (author)  iceng3 years ago
Hm, I missed that

:(


L
How about a chair with an iron under the seat that turns on when someone seats on it? Not exactly what you wanted, but more realistic and rather artistic.
I'd be really careful putting enough force on someone to eject them, because you are going to hurt them badly if you aren't very careful.
lemonie (author)  steveastrouk3 years ago

The motivation is to make it, rather than use it.

L
If your not going to actually use it then a BIG SPRING Wile E Coyote style
rickharris3 years ago
It would be easier to drop them onto the floor rather than eject. Less force required.
lemonie (author)  rickharris3 years ago

That'd be a rocking-chair type tip, and that had been thought of - how might the tip be driven without tipping the whole chair?

L
I was actually thinking of a drop seat - Ducking stool style.
drop seat.jpg
put a airbag with a triggure under the cussion then when the unsuspecting victim sits in thechair that person gets blown away
lemonie (author)  knexinventer3 years ago

I had thought of that (more like seatbelt pre-tensioners) but these things are hazardous and I don't know whether they are left in at car salvage yards.
Also, they only work once.
Thanks for the suggestion though.

L
"For artistic purposes", I suspect that's as good an answer as you're going to get.

For practical purposes, I suspect there is no good answer.
I think this would be the easiest, most efficient route to take. They're pretty cheap, too($5-$20).

For artistic purposes, I'd uses compressed air to move the chair at a 45 degree angle to the base with a force of around 40-50 lbs more than the chair. Use slides/rails to provide positive stops and to keep the chair and base connected. Even if it doesn't "eject" a person, the sound will make them move.

Qa

jimc45673 years ago
Do a search on motorized lift chairs. Here's one from a medical supply company. They are not cheap.

http://www.usmedicalsupplies.com/Lift-Chairs.htm?utm_source=business&utm_medium=cpc&utm_content=default&utm_campaign=liftchairs
rickharris3 years ago
It's going to cost you. Do you really want to spend just for a whim?
lemonie (author)  rickharris3 years ago

For artistic purposes, there's an idea behind it (a joke if you prefer).

L
Hmm, think I'd prefer a joke...

But...

My mum uses a riser(?) chair that simply has a lever - in the locked position, it's a normal chair, but dis-engage it, and the springs inside will push you and the seat up.

The lever is then used to assist in sitting back down - which also helps compress the springs before latching the lever back in place.

I don't know about the internal construction, but there may be a possibility of swapping the springs for stronger ones, though that would make the lever harder to operate (even if you lengthened it, probably).

But for artistic purposes the riser(?) chair may be too much of an obvious cliche.
My parents had an arm chair that was sprung to assist standing from the sitting position. When empty it reset to horizontal.
Vyger3 years ago
Simply asking often works pretty good.
Non forceful or non powered things that would work could be really bad smells and sounds that would cause a person to quickly move.
There are a lot of assist chairs on the market, they all use motors. Motors are slow enough so any kind of injury is often avoided. A chair that simply "stands up" leaving no place to sit on it would be pretty interesting. A slow motion eviction. Also a slow motion set of spikes coming up through the cushion would get attention, eventually. That would be fun to do with a dog.
If you are talking about ejection as in thrown out, its a bad idea inside a house. With low ceilings any kind of abrupt powered device is likely to throw someone into the ceiling and could cause pretty serious injury including broken necks and even death. Hmmmm a new and interesting form of execution? "Have seat, the executioner will be with you shortly"
Mythbusters did a segment on car ejection seats. They used compresed air and it worked better than they thought it would. It launched Buster quite a distance. (Buster is a test dummy)
lemonie (author)  Vyger3 years ago

For artistic purposes, a proper throw-out/off is what's required. Perhaps only for demonstration purposes without the full lifting force.

L