Two provisional patents covering the same product in the same way?

[Jason Gladstone]

Hello,

I have an idea for a product that I would like to pursue.  I have drafted a provisional application that covers the details of how the product would work (for an end user) but it does not cover how to construct the product.  How to construct the product will be learned when a prototype is built.   

I was thinking I should file this basic provisional application now to have some protection while the prototype is being built.  I'll refile an expanded, detailed provisional application once I have learned how to construction the product during the prototype build phase.  Once the detailed provisional application is filed, I will push the product to the marketplace and if there is interest, I will file for a utility patent. 

What do you think of this strategy?  Are there drawbacks to this strategy that could negatively impact me/my idea?

[Brad]

This is a good strategy and something I use all the time.    You essentially use multiple provisionals as your "building blocks" for the full utility patent application and you can link your full utility application back to all of the provisionals (as long as they are all within that 1-year period).    The biggest drawback is the money since every time you file a new provisional you have to pay a new filing fee with the USPTO.

*Make sure you file your full utility application within 12 months of your first provisional.