Are there other constant force springs or devices available besides these types?

Constant Force Spring - Vulcan Spring (http://www.vulcanspring.com/mechanical/conf.html)

Thanks,
Joe

There is no conceptual spring as constant force. Each spring is elastic in its nature, as you apply some force on it, it elongates. Now you could have linear or non-linear behavior of spring force-elongation curve. For ex. Consider a spring which elongates by 1 mm after an application of 1 N, this is linear behavior, contrary to this; consider spring which elongates first 1mm, then .5mm, then .25, etc, the behavior is non-linear.

In conclusion, at any given force, spring would elongate, and based on application of the force spring length will change. So, point is you couldn't really have constant force spring. There are heavy duty springs which applies constant force/dissipate similar amount of energy, but they need a static or dynamic equilibrium, which is very difficult to obtain. Anyway, hope this helps.

I guess I understand from a typical spring F=kx relationship, but if you look at the vulcan springs website it talks of constant force springs that do in fact provide a constant force as they move along and uncoil or coil back up. Please explain how these work and if there are any problems associated with these types of springs.
Thanks,
Joe


There is no conceptual spring as constant force. Each spring is elastic in its nature, as you apply some force on it, it elongates. Now you could have linear or non-linear behavior of spring force-elongation curve. For ex. consider a spring which elongates by 1 mm after an application of 1 N, this is linear behavior, contrary to this; consider spring which elongates first 1mm, then .5mm, then .25,, etc, the behavior is non-linear.

In conclusion, at any given force, spring would elongate, and based on application of the force spring length will change. So, point is you couldnt really have constant force spring. There are heavy duty springs which applies constant force/dissipate similar amount of energy, but they need a static or dynamic equilibrium, which is very difficult to obtain. Anyway, hope this helps.