"Frank Erskine" wrote in message
news
On Fri, 25 Aug 2006 21:25:47 GMT, "Bazzer Smith"
wrote:


"komodore comrade" wrote in message
groups.com...
i visuallise a lift as a cage; a motor; a cable and a switch. why do
they get stuck?

why do they get stuck in between floors?

do you try to exit lifts stuck between floors? or do you fear
decapitation/amputation from a sudden motion of the lift?

thanks.


Lift have a built in safty mechanism such that if the cable breaks
(ie the lift freefalls, an automatic break is applied. (basically the
tension in the
cable stops some 'rods' from sticking into a 'grid' in the shaft wall..))

Known (at least in mining circles) as a "keps" (probably a corruption
of "keeps"), and usually operated by a centrifugal gizmo.

Yes thats correct, I actually was thinking of some sort of cantilever
system,
where the tension in the cantilevers pulled the rods back (like the tension
in
a pulled longbow makes it shorter), However I was just thinking that if the
bow
'broke' you might be in serious trouble!!
At least that is what I recall seeing on some television program about the
first
lift, where the inventor convinced people of its safety by being in the lift
when
the rope was cut!!!

What you are perhaps describbing is perhaps more similar to this ?
http://science.howstuffworks.com/elevator5.htm

The method I was thinking off doesn't seem to be described there, so maybe
it
is no longer used.
However I guess any method with moving parts can fail, and apparently there
is a
heavy duty shock absorber at the bottom of the shaft "just in case"!!!