When searching patents sometimes, it may be useful to search by class and subclass in
addition to searching based on keywords. Of course, to search by classification you
need to know where the invention you are searching for is classified. When searching
U.S. patents, you may want to refer to the US Classification Manual. Each class and
subclass has a definition (although some times the definitions are a bit obtuse), which
can be found by clicking on the class or subclass in the online version of the US
Classification Manual. Finding a class in the classification is somewhat cumbersome,
because sometimes it may be difficult to figure out which class a particular subject may
be found if there is no class with that title. However, that is what the classification index
is for. The classification index lists topics in alphabetical order according to subject. So
you may want to consult the classification index before consulting the Classification
Manual.
After determining a class and subclass where you believe you invention is located at you
may want to ask the Examiner that examines that subclass for searching advice.
When searching PCTs and European patents, the International Patent classification may
be useful.
The classification system is hierarchical. Under each major subclass one can generally
find indented subclasses, which are subcategories of the major subclass. When two
subclasses are at the same hierarchical level, the one that is higher up in the hierarchy is
more general than the one lower than in the hierarchy. The classes and subclasses
generally are classify devices according to their structural features and classify methods
according to their steps. In general the classifications are not based on the usage. So
two devices that have nearly the same structure should classified the same subclass even
if the two devices are used for totally different purposes. More information about the
classification system may be found in the Examiner's handbook.
Some links that are related to searching
that you may want to consult are:
that you may want to consult are:
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A few words about searching
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