Yale Sewing Machine??

It says Yale on it, that's about all I know. It has a patent date stamped on it and possibly a serial number (899681 I think) as well. Just trying to find out where to learn more about this machine. Have had it for 15 years or so. Has all kinds of accessories and stuff with it. Has what appears to be a leather belt that attached the upper and lower pulleys to each other to operate it while pumping the pedal.