PatentHunter Faq

Free 60 Day PatentHunter International Trial!

We are so confident that you will see the benefits of PatentHunter International for your business or law firm that we offer a Free 60 Day Trial! There is no registration required to use this 60 day trial version and it provides you with access to the full power of PatentHunter for your business.

Please note that there is a 50 MB limit on foreign patent downloading in the trial version. Once you've met the maximum foreign downloads or exceeded 60 days, you will need to purchase a subscription to continue using PatentHunter International.

Knowledge Base

Below is a list of answers to commonly asked questions. This should be the first place you look for answers to your questions.

How do I download patent documents after I finish my search?

Answer:After you have completed your search, you can simply double-click on the patent document you’d like to initiate the download. You can also highlight the patent(s) you would like to download, right-click and select “Download Selected Document(s)” to download the patent(s).

How do I download U.S. patent applications?

Answer:To download a U.S. patent application, simply enter the application’s Publication Number into the PatentHunter input box (e.g. 20010000044). Make sure to include the entire Publication Number within the input box. It should be noted that only applications published after March 15, 2001 are available and that not all patent applications are published.

I get the error: “There is no application associated with the given file name extension” when opening the PDF version of my downloaded patent.

Answer:The most common cause for this error is related to a problem with the computers file association. Re-associating the PDF file to the proper application (we suggest Adobe Reader) should correct this issue. To do this complete the following steps:
  1. Open your My Computer.
  2. Select Tools and Folder Options
  3. Under the File Types tab, find the file extension .pdf in the window.
  4. If the Opens with section at the bottom does not say Adobe Reader, press the Change button.
  5. Select Adobe Reader from the list of Programs or browse to your Program Files folder to find the Adobe Reader program and select it.

I have installed PatentHunter, but I cannot download or search patents?

Answer:There are four potential answers to this question. PatentHunter requires access to the Internet and to the USPTO website to perform searches and downloads. If PatentHunter has worked previously upon your computer, the problem is probably one of the four below and not the software. Below are the possible answers and the required solution:
  1. You have incorrectly entered a patent number that does not exist. SOLUTION: Re-enter the patent number correctly.
  2. The patent database section of the USPTO website is having problems. SOLUTION: Attempt to download the patent again or wait a couple of hours for the USPTO to fix the problem. If you are still having problems, you can then attempt to download the patent image during a “non-peak” usage time such as late evening or early morning. QUICK TEST: To see if the USPTO web site is having problems, simply go to and perform a search for your patent number on the “Patent Number Search” page — if you get an error message, the USPTO web site is having problems.
  3. Your Internet service is not working. SOLUTION: Call your Internet Service Provider or Network Administrator.
  4. You have firewall that is “blocking” PatentHunter from accessing the Internet. SOLUTION: Adjust the settings of the firewall software to allow PatentHunter to access the Internet. If you have a software firewall on your computer (e.g. ZONEALARM, NORTON, etc.), you may need to “allow” PatentHunter to access the Internet by adjusting your settings. Contact your software vendor for more information on how to adjust these settings.

I can’t open/view the downloaded patent images?

Answer:1ST STEP: Make sure you have a graphical viewer program that is able to view .PDF files. A PDF file viewer is required to view patents downloaded with PatentHunter (e.g. Adobe Acrobat Reader®). To check if you have Adobe Acrobat Reader, simply go to START-PROGRAMS to see if a folder titled “Adobe” is listed. If so, then make sure that Adobe Acrobat Reader is operating correctly by opening the software directly. If you do not have a PDF viewer installed, please download/install Adobe Reader. 2ND STEP: Make sure you have the PDF viewer program “associated” with a .PDF file extension. To “associate” the PDF viewer program with a .PDF file extension simply go to



A listing of file extensions and the associated program will be displayed. Locate the .PDF file extension and make sure the desired PDF viewer is associated with the .PDF file extension. If no .PDF file extension is listed, you will have to create a new file extension.

Does PatentHunter download the “text” of a patent?

Answer:Yes. PatentHunter downloads both the PDF image and the text of a patent (not for all patents). You can open the text file using any HTML viewer such as Internet Explorer or Google Chrome by simply double-clicking upon the “HTM” icon next to the patent document. You can also right-click upon the patent document and then select “Open HTML Document”. The text can then be copied/pasted into various documents.

How do I open a patent image?

Answer:You can double-click the patent document (or the PDF icon) and the PDF image should load within your PDF viewer separate of PatentHunter or you can right-click the patent then select “Open PDF Document”. If you click on the patent document once, it will open in the preview pane located on the lower right of the PatentHunter software interface.

How do I delete patents from PatentHunter?

Answer:You can right-click upon the patent then select “Delete Documents”. If you want to delete all of the patents in a folder of PatentHunter, you can press CTRL-A when in the directory, then right-click and select “Delete Documents”. NOTE: By deleting the patents listed on PatentHunter, the associated .PDF (graphic file) and HTML files will also be deleted from your hard drive.

When I perform a patent search with PatentHunter, no patents are found. What am I doing wrong?

Answer:If you are having a difficult time searching for patents using PatentHunter, the USPTO website could be having problems (see top of this page for considerations) or the search query you are entering may not be proper. Below are some suggestions on how to enter search queries into PatentHunter.
  • Use Various Terms. It is important to not limit your search to only a few search terms. You should attempt to search for any possible variation of a specific term. For example, if your search query includes the term pipe, you will want to also search for synonyms of the word pipe such as but not limited to tubular structure, or tube, or conduit. We recommend using when searching for different words. Remember, a patent will not be located by your search if your search query utilizes word(s) that are different from the patent.
  • Use Words Similar to Those Found in Patents. After you locate a few patents that relate to your invention, attempt to utilize words in your search query that reflect the terminology utilized within these patents. Often times a particular prior art (or patent attorneys) will utilize a common terminology that you may not be familiar with. Remember, a patent will not be located by your search if your search query utilizes word(s) that are different from the patent.
  • Phrase Searching. Phrase searching can also help locate specific patents. PatentHunter automatically searches for phrases when more than one word is entered without a connector. This allows you to search for a multi-word phrase rather than specifying each word as a separate term. Utilizing the search query ergonomic computer mouse obviously will receive a narrower search result than simply computer and mouse .
  • Using Boolean Expressions (Simple & Advanced). You can use Boolean operators (or, and, andnot) within your searches. Some of the below examples are taken from the USPTO web site. Example #1: printer and laser – Entering this query will retrieve a list of all patents that contain both the terms printer and laser anywhere in the document. Example #2: printer or laser – Entering this query will retrieve a list of all patents that contain either the term printer or laser anywhere in the document.

How do I know if a patent has expired because the owner never paid the maintenance fee?

Answer:To verify the status of a patent with regard to the payment of patent maintenance fees, simply right-click upon the patent and select “View Maintenance Fee Status at USPTO”. This will open a separate internet browser window showing the current maintenance fee status of said patent at the USPTO. Alternatively, you can call USPTO Maintenance Fee Customer Service at (571) 272-6500 or send an e-mail to

What are the different United States patent documents I can download?

Answer:The following different series of U.S. patents are being or in the past have been issued. See USPTO Website for more information.
  • X-Series. These are the approximately 10,000 patents issued between 1790 and July 4, 1836. They were not originally numbered, but have since been assigned numbers in the sequence in which they were issued. The number should not be cited. When copies are ordered, the patentee’s name and date of issue suffice for identification.
  • 1836 Series. The mechanical, electrical, and chemical patents issued since 1836 and frequently designated as “utility” patents are included in this series. A citation by number only is understood to refer to this series. This series comprises the bulk of all U.S. patents issued. Some U.S. patents issued in 1861 bear two numbers but only the larger number should be cited.
  • Reissue Series. Reissue patents (MPEP § 1401) have been given a separate series of numbers preceded by “Re.” In citing, the letters and the number must be given, e.g., Re. 1776. The date that it is effective as a reference is the effective date of the original patent application, not the filing date of the reissue application.Design reissue patents are numbered with the same number series as “utility” reissue patents. The letter prefix does, however, indicate them to be design reissues.
  • A.I. Series. From 1838 to 1861, patents covering an inventor’s improvement on his or her own patented device were given a separate series of numbers preceded by “A.I.” to indicate Additional Improvement. In citing, the letters and the number must be given, e.g., A.I. 113. About 300 such patents were issued.
  • Plant Patent Series. When the statutes were amended to provide for patenting certain types of plants (see MPEP Chapter 1600) these patents were given a separate series of numbers. In citing, the letters “P.P.” and the number must be given, e.g., P.P. 13.
  • Design Patents. Patents for designs (see MPEP Chapter 1500) are issued under a separate series of numbers preceded by “D.” In citing, the letter “D” and the number must be given, e.g., D. 140,000.

What are the different foreign patent documents I can download?

Answer: PatentHunter provides you with the ability to download PCT applications as well as foreign patent documents (e.g. PCT, EP, GB, JP, AU , CA, CN – see EPO Country List for complete listing)

What is a U.S. Patent Search?

Answer:A U.S. patent search is a patent search by a patent searcher for granted United States patents and published United States patent applications.
If you haven’t yet found the solution to your problem please visit our Support Page and fill out the form to further detail the issue you are running into.