Mechanisms

http://kmoddl.library.cornell.edu/model.php?m=467

This mechanism first caught my eye because when I first played the video I thought it could be used as a way to pull up a bucket of water or an elevator. But as I read the way it worked, I realized that this mechanism actually is limited to a certain range of linear motion but it delivers a much more powerful force downwards every time the piston rod goes down. This is due to the transfer of high speed turns of the larger wheel to the slower turns of the large gears. The strong force created by the straight line drive used to be used for steam engines but I think it could also be used for machines that crush objects.

http://kmoddl.library.cornell.edu/model.php?m=451

Special mention: I thought that this out of line drive was so cool since it only works when the two shafts are at the same angle but I did not really understand how the two tubes were able to rotate each other. 

This is a straight line drive which transforms a rotational motion into linear motion. The rotating motion is created by a large wheel with a small gear in its center, a larger gear sits on top of the smaller gear and another larger gear is right next to the larger gear on top of the small gear. The large wheel is turned which then causes the small gear to rotate which then makes the larger gear on top of it to turn and then the larger gear besides it turns as well. This turning motion is converted into linear motion by two cranks, each attached to one of the larger gears on one end and the other attached to one beam which is attached to the piston rod, that turn with the larger gears causing the piston rod to move up and down.