It would be safer to get a non-disclosure signed. Keep in mind as well that US patent laws changed significantly with the America Invents Act. It used to be beneficial for the invention priority date to keep dated records showing time of invention. Now, the US is a first-to-file jurisdiction. If you came up with the idea six months ago and I came up with it yesterday, but I file a patent application tomorrow and you file in another month, I am entitled to the patent rights and you are not. If you are concerned about getting a patent, I would do what you need to do to get a provisional patent application filed as soon as the machine concept is complete enough to put something on file. Having a provisional application on file is safer than an executed non-disclosure for patent right purposes.
Answered on Nov 05th, 2013 at 8:32 AM