[xKarl]

It has been said before, there is a huge gap between the prototype and the product that will be sold. That means that a company powerful enough will be able to sell/patent your invention faster than you do if they can lay their hands on the prototype. You'll be screwed, and there's nothing you'll be able to do about it.

[learc83]

This is just ridiculous. I'm not a fan of most patents, but you don't need to invent a bigcorp bogeyman. You seem to be deteremined to believe that bigcorp can completely screw you regardless of the evidence.

Commercial products are often different than the prototype. However, if it uses the same basic innovation, it's generally not going to be so different that the patent doesn't protect it. Patent protection is generally pretty broad.

If the final product doesn't actually use the novel innovation demonstrated by the prototype what advantage does the prototype offer bigcorp?

For example I invent a screwdriver that can work with any screw without a bit change, and I make the handle from rubber, I then file for a patent and am granted it.

Bigcorp comes along and decides to file a patent for the same thing, but for the production version that uses injection molded plastic instead of rubber.

The patent office will reject bigcorp's patent.