My great grandfather held a patent that was created in 1929. I know the patent is expired, is it possible that the patent was passed on to somebody?
By “passed on to somebody” do you mean the original paper copy? In those days, and even now to a lesser extent, the original ribboned copy was important to physically possess, like a deed or the pink slip for your car. Companies kept them locked in vaults.To sue for infringement you brought it into court. The original can still be important “self authenticating” evidence at trial.
We will not be able to locate that original document. The USPTO has an Office of Recordation were transfers of latent ownership can be filed. On that site it says records before 1980 are in the National Archives. If rights were assigned the ribboned copy should have gone to the new owner. Since it has been worthless since 1946 it may have been disposed of.