I wanted to patent something but found that it already existed on google patents. Now I would like to get in touch with whomever patented it to see if I can use the patent -- but I am not sure how to find the person or manufacturer. Does anyone know how I can contact or find them based on the patent itself? Or are there any other ways/sites to get in touch?
George makes a good point, you can identify the person or firm that prosecuted the patent in question by reviewing the materials in the image file wrapper that is available via Public PAIR. Then, you can reach out to the patent owner's representative.
Another option is to go to the USPTO's "Assignments on the Web" site at http://assignments.uspto.gov/assignments/?db=pat. Then, enter the patent number and hit the "search" button to identify the owner. Note, however, this works only if the patent owner has recorded an assignment.