My uncle died a while ago and he was quite interested in bikes. Unfortunately I know very little. We have come across lots of, what look like, very old bike parts and I am wondering if I can get some help just knowing what they are and, potentially, if they are worth something.

The first is this. It is marked (as best as I can figure out) ARROW COASTER then under that AN?DBRAKE (Handbrake?) under that Patented then on the extension arm Made in USA. Any help is greatly appreciated.

Thanks