The Secret Life of Sewing Machines -- video
Here is a 3 part youtube video showing how sewing machines work. It's pretty interesting. I don't know when this footage was made but looks sort of 1970's-ish.
Part 1:
http://www.youtube.com/watch?v=JKkrA...e_gdata_player
Part 2:
http://www.youtube.com/watch?v=JKkrA...e_gdata_player
Part 3:
http://www.youtube.com/watch?v=4bpDX...feature=relmfu