Patent Cover Sheet – How Do You Read It?
Patent Cover Sheet
Patent Cover Sheet. Before you read the patent specification, the
patent claims, and review the patent drawings, you are confronted with the
cover sheet. How do you read it?
A patent is made up of several parts. The detailed main body of
the patent is the patent specification. It describes the invention - how to
make it and how to use it. It is used in conjunction with the patent drawings
to help in that description.
But what about that first page - the patent cover sheet.
If you seldom pick up patents to read them the cover sheet may
seem incomprehensible. But it does have much useful information - if you can
sort it out.
Below is the top portion of a U.S. Patent. Across the top you will
see the description United States Patent followed by the
patent number - in this case 7,206,256 B1 and the date of
issue is immediately below that.
Top Portion of a Patent Cover Sheet
What does that B2 mean - that this is an issued patent. An
application that has not yet issued normally ends with an A, not
a B. The number for a utility patent has seven digits, like
this one does. A design patent number has 6 digits preceded by a capital “D”,
such as D142,511. A reissue patent - that has been corrected by the issuance of
a new patent - has a five digit number preceded by “RE”. A reexamination
certificate (a patent that had been reexamined because of newly discovered
prior art) has a seven digit number preceded by “B1" (or “B2" or
“B3", to designate if this was the first,second, or third reexamination),
for example B1 5,123,456.
Let's talk some more about that issue date. This is the date that
the patent issued and the date from which the patent is in force until it
expires. When that expiration date is has become a complicated subject that
will be covered in another article soon. Before June 8, 1995 all U.S. patents
expired 17 years from the issue date. But that changed when US patent law
changed to achieve more harmony with international law. Now the basic
calculation is 20 years from the filing date. But there are so many exceptions
that as I said - I will cover that in another article.
The next thing you may notice on the patent cover sheet is the
peculiar set of numbers all over the cover sheet before each of the individual
items of information. Example - (10) Patent No. or (75) Inventors. By
international agreement, these numbers are used consistently by all countries
on their patent cover sheets. So if you pick up any patent in a language you
cannot read, let's say a German patent - you will still know that (21) is the
original application number. This assures that certain information about the
patent will be available to everyone, even without the ability to read the
language of the patent. Of course you must know the numbering system - but I
keep a little list of the numbers and their meaning around because I often have
to examine foreign language patents for things like their filing date or
Now let's talk about some of the individual items on the patent
cover sheet. I will skip the ones that are rather self-evident. First is (75)
Inventors. The names and hometowns of all inventors of the patented invention
are listed. In the United States, patent applications are filed in the name of
the inventors. In other countries, the owner (assignee) of an invention may
file a patent application in his or her own name, even if he or she is not the
Next is (73) Assignee. This is the name of the person or entity to
which the ownership of the invention has been assigned, most commonly the
company that the inventor works for. If the patent has not been assigned, the
Assignee field will be absent. In order to have an assignee listed on a patent
cover page, the assignment from the inventor to the assignee must be recorded
with the Patent Office.
Note the next line on the patent cover sheet has a ( * ) Notice:
This is a notice that the term of the patent has been extended by 283 days. For
this particular patent the term would have ended 20 years from the filing date
of Feb 16, 2005, but because the patent office took too long to complete the
prosecution they have granted an addition 283 days. In these days of long
delays in the patent office this number can end up being quite large.
The next item is (21) Appl. No. This is the application number
assigned by the Patent Office to the application that eventually issued as this
patent. Patent application numbers are 8 digit numbers beginning with a two
digit number followed by a slash, and then 6 numbers, in this example
11/058,895. Often called the Serial Number.
Now for (22) Filed. This is the date that the application was
filed in the U.S. Patent Office.
And There is More on the Patent Cover Sheet
Sometimes on a patent cover sheet after this there is a (63)
called "Related U.S. Application Data". This is a short paragraph
listing parent applications of this one. This can be rather complicated but
important in that the earlier applications may set an priority date for this
patent. An earlier priority date can be critical in that it defines the scope
of the prior art because art published after the priority date cannot be used
against this patent.
And if you want to get more complicated (with patent rules you can
always get more complicated) a patent may come into the U.S. via the PCT route.
When that happens this " (63) Related U.S. Application Data" will be
replaced by data concerning the PCT application. The cover sheet will list the
filing date of the PCT application (22), the PCT application number (86), the
date the PCT application was entered into the U.S. Patent Office and became a
prior art reference that could be applied against other U.S. patent
applications, the date the PCT application was published, and the publication
number (87). And if the application was filed in a foreign country before the
filing date in the U. S. Patent Office or in the PCT, the cover page will list
(30) Foreign Application Priority Data, showing the date filed, the country in
which it was filed, and the application number in that country.
The next three items are (51) Int. Cl., (52)U.S. Cl., and (58)
Field of Search. These are the International and U.S. classifications that are
related to the field of the invention and the fields that the examiner searched
in examining the patent application. Information regarding the classification
system can be found here. The classification
information is useful when searching for relevant prior art, such as to try to
invalidate a patent or to help in drafting a patent application in a field
similar to this patent.
The next item is (56) References Cited. This is a listing of all
of the publications that were considered by the examiner in deciding whether to
grant the patent. Listed in this example are U.S. Patents, for which the patent
number, issue date, inventor, and U.S. classification are listed. This is
sometimes followed by Foreign Patent Documents, which may include patents and
published patent applications. Finally, Other Publications, typically
scientific articles, are sometimes listed. The listing of cited references on a
patent cover sheet is very important because there is a strong legal
presumption that the patent cannot be invalidated based upon what is disclosed
in the cited references.
Next, the Patent Examiners are listed, followed by the name of the
patent attorney and/or the patent law firm that prosecuted the application. The
next item is  Abstract. This is a short description of the invention and is
similar to the abstract of a scientific article. It permits searching of the
subject matter of the patent.
Following the Abstract is a single line that indicates the number
of claims in the patent and how many Drawing Sheets it contains.
The final item on the patent cover sheet (not shown here)is a
drawing of the patent as representative of the invention.
Probably more than you wanted to know - but you can refer to this
article if any part of the patent cover sheet confuses.