First a patent application is written, which is supposed to describe how to make and use
the  invention well enough so that one of ordinary skill working in that area would
understand how to make and use the invention.  At the end of the patent application are
claims. Without going in to the details of how to write a claim, the claims define the
breadth of coverage that applicant seeks for their invention (the best language for
writing a claim and the manner in which the claims are interpreted is dictated a fairly
large body of case law).    

After the application is written, it is filed with the Patent and Trademark Office.  Within
about three months, the Patent and Trademark Office sends a filing receipt, which
includes a foreign filing licence giving the Applicant permission to file the patent
application in another country. However, despite the foreign filing licence it is possible
that another government agency prohibits exporting the technology associated with the
patent application to another country.  

Depending upon the art area into which the application is classified, about a year and a
half after filing the application an Office Action is sent by the US Patent and Trademark
Office.  However, sometimes the first Office Action is received may be sent as early as
six months after filing the application, while at other times the first Office Action may
not be received until four or five years after filing the application.  How long it takes the
US Patent and Trademark Office to send the Office Action varies with the priorities set
by the current presidential administration and according to the backlog of the individual
unit and Examiner handling your application.

The Office Action may include a Notice of Allowance.  More commonly, however, the
Office Action contains one or more rejections of some or all of the claims and/or one or
more objections.  Often all of the claims will be rejected in the first Office Action.  
Since the objective of the claims is to obtain the broadest coverage to which the
Applicant is entitled, a rejection in the first Office Action is not necessarily a bad thing,
because the lack of a rejection in the first Office Action is an indication that the
Applicant may be entitled to broader claims.  

The Applicant is typically given three months within which to reply to the Office
Action.  After the three months, a reply may still be filed if a late fee is paid.  However,
ordinarily a reply may not be filed more than six months after the mailing of the Office

In response to a rejection, the Applicant may amend the claims and the specification
and/or submit  arguments as to why the rejections and/or objections of the Office
Action should be withdrawn.  However, although the wording of the specification may
be amended, no new subject matter may be added to the specification that was not
present in the originally filed application after the application is filed.  After mailing the
response to the Office Action, the Patent and Trademark Office will usually reply within
about three months with another Office Action.  Again, this Office Action may contain
a Notice of Allowance or may contain one or more rejections and/or one or more
objections.  The second Office Action is usually made final.  This means that, although
a response to the final Office Action may contain an amendment,  the entry of the
amendment is at the Examiner's discretion.  After the Final Office Action, the Examiner
will typically only enter amendments that place the application in condition for
allowance without introducing any new issues that require further consideration.  For
example, an amendment that merely cancels rejected claims is likely to be entered, but
an amendment that changes the wording in the claims in a manner that is not suggested
by the Office Action is likely not to be entered.  The Patent and Trademark Office
usually replies to a  response to a Final Office Action by sending an Advisory Office
Action.  The Advisory Office Action is typically very terse, and may only indicate the
status of the claims and whether or not any amendments were entered.  

After the mailing of a Final Office Action, if the Examiner refuses to allow the patent  
application, a continuation or a request for continued examination (with the appropriate
fee) may be filed.  The filing of a continuation is a refiling of the original application,
while retaining the benefits of the filing date of the original application.  The filing of a
request for continued  examination is a filing of a request to continue to examine the
application and send a new nonfinal Office Action in exchange for the payment of a
fee.  The Patent and Trademark Office uses the same set of fees to determine the filing
fee for a continuation as for filing a new application. Filing a continuation or of a
request for continued examination entitles the applicant to amend the application, and
entitles the applicant to another two Office Actions (the second application being made
final).  In this respect filing a continuation or a request for continued application is
almost like filing a new application.

After receiving a second Office Action, the Applicant may file an appeal to the Patent
Trial and Appeals Board, appealing the Examiner's rejection.  If the Patent Trial and
Appeals Board affirms the Examiner's rejection, the Applicant may in at least certain
instances ask the Patent Trial and Appeals Board to reconsider their decision.  

Even if the
Patent Trial and Appeals Board does not change its mind, the Applicant may,
within a narrow period of time, still file a continuation with a new set of claims of a
narrower or of a different scope, but not of a broader scope.  More precisely, there is
nothing stopping the Applicant from filing claims of the same scope or of a broader
scope, but such claims will be rejected, and the rejection of these claims may be made
final on the first Office Action on the basis that the
Patent Trial and Appeals Board has
already determined these claims to be unpatentable.  However, if the Applicant wishes
to file a continuation, the continuation ordinarily must be filed prior to the issuing of a
decision by the
Patent Trial and Appeals Board. (In my opinion that should be changed,
and the Applicant should be given two months within which to file a continuation after
receiving a decision from the
Patent Trial and Appeals Board, because it is unfair to
force the Applicant to decide whether to file a continuation prior to receiving a decision
before the Patent Trial and Appeals Board).   

The decision of the
Patent Trial and Appeals Board may be appealed to the Court of
Appeals of the Federal Circuit (CAFC).  After receiving a decision from the
Patent Trial
and Appeals Board, the Applicant ordinarily has two months within which to file an
appeal to the CAFC. A decision by the CAFC may be appealed to the Supreme Court.  
However, the Supreme Court does not accept many patent cases.  Consequently, the
CAFC is usually the highest court to which an application can be appealed.  Further,
only a relatively small percentage of applications filed  are appealed to the CAFC.

The above overview is not intended to give a complete description of all that may occur
during the pendency of a patent application.  The above is just an overview, there are
many other possible nuances to the entire process.            
An Overview of the Process of Obtaining a