In 1975 to which I had the drawings and all I showed my design for a wheelbarrow that had 2 front wheels on it to a friend of my uncles from the USA they both said that it wouldn't go anywhere, and guess what happened not too long after.
I designed a product that automatically did the 3'-4'-5' which gives 90 degrees c/w a reel that extended the line up to 200'in either direction
I designed a diamond post cleaner for grinding wheels on verticle milling machine in 1973 when I worked for a tool and die maker.That was taken over by him because he stated that anything designed or made in his shop on the clock or off belonged to him.
For those reasons, that is why I believe that inventors and people that think outside of the box like us should be and anyone helping them shouldn't have a problem signing documentation to that fact.
If a person is willing to help anyone and wants a piece of the pie then that should be negotiated with the person beforehand and put in writing one way or another.