The United States works differently than other countries when it comes to giving patents. In U.S., it doesn't necessarily matter who first applied for patent (the process may take up to a year to complete).
What does matter, however, is who came up with original composite for invention first. If an inventor can prove that s/he came up with a tangible product before someone else, then they will be granted right to patent.
It's best, given information above, to sketch your idea for a product with descriptions on how it works. Then, inventor, along with two witnesses should sign and date it in front of an official notary.
Following, keep composite in a safe location while you are applying for provisional or regular patent, while working on your invention.
A provisional patent application from U.S. Patent and Trademark Office provides a confirmation to date when invention was first invented, or when composite was completed. This way inventor doesn't have to necessarily have completed invention in its entirety.
The inventor needs to file a regular patent application with USPTO within one year of provisional application.
An inventor, once ready to fully patent his invention, may have to hire an official patent attorney or agent. Then, patent attorney or agent can conduct a search which checks to see that invention is original, and that it hasn't already been filed. Once uniqueness of new invention is confirmed, inventor has to fill out a specification (or description), two or more composites and an official claim form.