Mechanical device to lower a raised weight

[suryag]

Hi,

I am trying to design a small machine that lowers a raised weight slowly. For example if i raise the weight by 10 metres and allowed there it should start descending at 0.1m/hour. Initially i thought of a windup mechanism but i don't know how to control the rate of descent with a windup mechanism. Btw, i can't use any electrical energy.

TIA Surya

 

[sardonicus]

Try an escarpment mechanism like that of a clock or lighthouse motor maybe.

 

[Danger]

Sardonicus has a good approach there. As to the actual hoisting (de-hoisting?) mechanism, I have a strong preference for lead-screws, or screw-jacks, or whatever they're called in your area. I have toyed with hydraulics, pneumatics, and even a few "ics" that I made up myself... but I've never found anything that provides a smoother consistent movement than a lead-screw. They also have the advantage of being irreversible. No matter how heavy the load is, it cannot force itself down faster than the screw is calibrated for. The screw mechanism can involve an escapement as Sardonicus mentioned, or an intermediate gearbox. Both approaches will work fine with a clockwork or weight activated power source.