I filed a simple provisional application on an idea, weeks later i realized that i can do better with this invention, added new material, new attachment, added a catch, and added an other uses for the invention. do you file another provisional on a new invention or do you file an improvement provisional with reference to serial number to your already filed application?
Provisional applications cannot claim priority to any earlier-filed applications of any type (provisional or non-provisional). But they are, as you mention, extremely useful in establishing an earlier priority date for a later-filed nonprovisional application. One strategy some low-budget clients pursue is to put everything in a single application--even if that application potentially contains two inventions. Then, you can draft claims that primarily pursue one invention but still treat the other novel aspect as an additional feature, e.g., as a "dependent claim." This allows the applicant to gauge the USPTO's position on both the first feature's and the second feature's patentability (novelty, etc.). If the PTO responds favorably, you can then file a second application which separately claims the second feature. This is not legal advice, and I am no expert. Before taking any action, all of this strategy and information should be discussed with a patent attorney or patent agent who is an expert in the laws and strategic approaches. For example, this sort of approach could result in the USPTO requiring you to sign a "terminal disclaimer," which limits the lifetime of the second patent to the term of the first patent. As another example, if this is not done without care, there might also be a possibility that the first patent can be used as "prior art" against the second patent. These are just some of the reasons to acquire legal advice from a registered patent agent or patent attorney.
I am no expert, and this response is for informational purposes only and not for the purpose of providing legal advice. You should contact your attorney or legal expert to obtain advice with respect to any particular issue or problem. Laws can differ dramatically from country to country, state to state, and technology field to technology field.
From another source of information i found the answer to my question and i will share it for others. if your invention is substantially different in the improvements then your first original filing, and you want the benefit of the first filing date you should mention it in your second provisional application, but if you don't need the benefit of the earlier filing date don't mention it.when filing your NON-provisional application you can incorporate the two provisional's into the NON-provisional. they are not two separate entity, one would infringe on the other.