I printed out the patent drawings and using the photos with the ebay sale as a reference they look to be somewhere around 4" long before folding into a cup.
I can't make the cup link for ebay work. You should be able to do a cut and paste or try looking for the auction # 130706932772. It will tell you something like auction over but they is a place to click something like "look at original listing".
Th Patent date is Sept 22, 1960 and I expect it is still active. I have no idea how long a Patent lasts. I found the Patent using the number (3,087,640)on Google:
Anyway, a person can make something that is covered by a Patent if it is for "their use only", I think.