Patent Searching

Patent searching on the web

Note that recently the patent office switched the way it displays patent images.  The images are now pdfs instead of tiffs! You probably won’t need a special plug in to display the image as you did in the past.

The simplest search is where you already know the patent number. You can enter the patent number at

The next simplest search is when you are looking for a tool patent that has already been entered into Datamp stands for Directory of American Tool and Machinery Patents. Patents are searchable there by inventor, manufacturer, issue date- include a partial date, etc. The date formats and the date wildcards allowed are explained here. Links on the datamp site can take you to the US Patent Office site for a particular patent found in datamp.

Google has recently gotten into the patent game. Their advanced search page is at They offer searching on a number of different fields. The down side is that their data was scanned from patent documents. Their text recognition is not 100% accurate. An uppercase M can be misidentified as the three letter combination I V I. Example: Patent 748460’s title should be BULLET-MOLD, instead google lists it as BULLET-IVIOLD. Your search for BULLET MOLD in the title would not find this patent. You may have to try multiple searches using different fields to find the patent you are looking for. Still this is better than the limited searching available at the US Patent site. Here’s an example of patent I found using google patents. I was looking for a motorcycle patent issued to Edwin Himes. I entered Himes in the inventor field and motorcycle in the title. Nothing. I tried motorcyle in the all words box. Nothing. It wasn’t until I tried motorcycle in the exact phrase box that I found patent 1039943. Google has the title as MOTOR OYXLE. I wasn’t able to find this patent at the US Patent office using the tips below as I thought the patent was issued a year later than it actually was. Thank you Google!

Using the advanced search page at the US Patent site can be a little more difficult. Here’s the breakdown of the searches available:

  • Patents issued in 1976 and beyond are fully searchable. Examples: by inventor, inventor’s city
  • Patents issued before 1976 are searchable by issue date and patent classification
  • Patents issued in 1920 and beyond are searchable by inventor. On the advanced search page a search for IN/BAILEY in the entire database will return patents from 1920 and beyond where the patentee is named Baily. Currently 5,262 patents are returned.Here are some tips when using the US Patent office site:
    • Patents issued in 1848 and beyond were generally issued on a Tuesday. You can use a perpetual calendar to try to figure out an issue date. Sometimes it can be difficult to tell the difference between an 8 or 6 on a tool.
    • You can truncate the issue date if you are not sure of the complete date. The issue date search is isd/YYYYMMDD or isd/MM/DD/YYYY. The wildcard character is a dollar sign and has to be at the end of the search. Ex: isd/189905$ would return any patent issued in May 1899.
    • You can use the keywords AND and OR in your searches. Examples: in/Fegley or in/Leopold would return patents where the patentee is either Fegley or Leopold. A search for In/Fegley AND in/Leopold would return patents where both men were patentees on the same patent. The issue date can also be included: (in/Fegley or in/Leopold) and isd/193$ This would limit the search to patents issued between 1930 and 1939 where either man was a patentee. The searches can be as complex as you want to make them.
    • There are 490 or so patent classifications. The common tool ones are 7- Compound (combination) tools, 30 – Cutlery (where hand planes are), 33 Geometrical Instruments and 81 Tools. You specify a class and subclass in the ccl search. It’s best to wildcard the subclass. A search of ccl/33/$ and isd/19300520 would return all the patents issued on May 20, 1930 where the class is Geometrical Instrument and any subclass.
    • You can search the modern (1976 and beyond) patents or use datamp to determine a likely patent classification. Here’s what I did when I was looking for a cloths pin patent. I did a title search on the USPTO site for clothes pin in the “modern” patents (1976 on). The search criteria was: ttl/”clothes pin” (in English that’s a title search for clothes pins) Eleven patents were returned. I clicked on 4,945,613 to find its Current U.S. Classes: 24/501; 24/511 Step two: Issue a search in the non-modern (pre-1976) section where the only criteria allowed are patent number, classification and issue date. The patent I was looking for was issued on November 9, 1915. My search string was “isd/11/9/1915 and ccl/24/$” In English that’s a patent issued on November 9, 1915 that’s in classification 24 with any sub classification. Fourteen patents were returned. A few clicks later I found the patent I was looking for: 1159804.


Useful links when searching for patents: