Old threshing machine parts

[Sel Larsen]

When I was a kid the neighbors threshed oats. On the feed end there were what I can best describe as revolving cutters (similar to mower sickle bar blades) with hooks whose job was to cut the twine on the bundles as they entered as well as make sure not too much grain went into the separator at once and plugged it. My dad told me the proper name for those "flying hooks/cutters" but I cannot find any diagrams of an old thresher that would label that part of the machine. Do any of you remember what that part was called or what its nickname was?
 

[casecollectorsc]

I've always refered to them as "bandcutters".