Support : Dialog Search Aids : Patent Family Searching Using DWPI

Patent Family Searching Using Derwent World Patents Index

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What is a Patent Family?

Because patent protection is country specific, a company or an individual that wants to protect its invention in a particular country must apply for patent protection in that country — either by filing national patent applications, or by making the application via one of the multi-national routes (e.g. an EP or a PCT application). If protection is sought in more than one country, or through more than one patenting authority, this will result in what is known as a family of patents.

Derwent gathers all of the patent documents relating to an invention into a single database record. In general, one record in Derwent WPI (Files 350/351/352) on Dialog represents one invention and shows you all the patent documents that Derwent has collected relating to that invention.

Why are Patent Families Important?

By looking at the patent family, you can see the global picture of where the company or individual has chosen to seek protection for an invention. This is important from a legal point-of-view and can also tell you a great deal about the owner's plans for the eventual marketing of the product.

In the context of a Derwent WPI search on Dialog, the key thing to know is that the patent family has been gathered together for you — usually into just one database record; thus, when you display your search results, everything is there for you to see without the need for extensive further research. However, exceptions do exist. In some cases, such as families involving patents with divisions and/or continuations-in-part with multiple priorities, there may be several DWPI records. If you see multiple priorities, or the filing details indicate divisions or continuations, there are likely to be additional relevant records. To get a complete picture of the patenting activity, it is essential that you gather together all of these records.

Step 1: When gathering together family member records, retrieve the record containing the patent that you already know about; in this example, the Great Britain patent number 2276006.

Step 2: Use Dialog's powerful MAP command, which allows you to extract all of the priority data (ANPRYY) from this record (or from this set of records), automatically save it and re-search it. The letter "T" within the command means that the strategy will be saved temporarily; it will disappear a week after logoff and will, therefore, incur no storage charges.

Step 3: Use the EXS command which allows you to execute the search you just saved. The search has been given a serial number by Dialog — TD256 — but it can be omitted when the search is executed immediately. Dialog searches the whole DWPI database for records containing the priority data extracted from the original record. There are two database records sharing this priority data.

Step 4: Repeat the process, extracting the priority data from these records and searching for further matches. If no additional records are retrieved, all family members have been located.

Family Searching on Dialog

Members of a "scattered" patent family will have at least one priority in common, so to gather the family members together, it is important to look for records with matching priority data. The search technique is illustrated below.

In this example, it took two iterations of the mapping process to retrieve all records related to this particular family. It may take more than two iterations in particularly complex cases to locate all records for the patent family; however, the MAP command makes it easy!