Why does a patent not give us the right to use our invention?

I also would add that while counselor Kolitch is correct, another easy way to think about your rights under a patent is to remember that the Patent Act grants you the right to EXCLUDE others from making, using, and selling YOUR patented invention. This is what makes your patent useful. YOUR rights to make a product that relates to the claims in your patent, may nonetheless infringe another person's patent. In my example, consider further that if your new widget contains A +B +C elements, where C is new and not found in the prior art, your application may likely be issued a patent if it is new, useful, and non-obvious, after examination. However, in my example, if someone else holds a patent to the combination of A+B, your invention is patentable since it has new element C but you will need a license to the patent covering A+B to keep from infringing this patent. Presumably, your patent is valuable because it gives you the exclusive right to exclude others from making a product that infringes one or more of YOUR claims in your patent that include elements A+B+C. You may have to pay a license fee to the A+B patent owner but presumably the feature C which you have patented is a valuable variation to the industry that customers will want. If so, this could make your A+B+C patent valuable even though you pay license fees. Hope this helps.