On Mon, 16 May 2005 08:56:44 -0400, "Peter Olcott" <olcott@att.net>
wrote:
Let me see if I understand this correctly. If a dependent claim gets past
prior art, and the independent claim that it depends upon can not possibly
get past prior art, then the verbatim wording of these two claims can be
combined such that the newly created independent claim retains the full
range of the doctrine of equivalents as the original dependent claim. Is
this correct?
I don't think I can answer your question very well without knowing
something about how it arose, but it appears to me that your inquiry
has gone far astray.
The doctrine of equivalents states that if something does the same
thing as a claimed invention, in the same way, yielding the same
result, then it is within the scope of the claim, even if a literal
reading of the claim does not encompass it.
One situation in which the doctrine of equivalents is often invoked is
where the patent claim does not read onto some piece of technology
solely because that technology did not exist when the claim was
written.
To give an entirely imaginary example, suppose I had a patent for a
jukebox, filed in 1975, which speaks of storing, moving and playing
"phonograph records." It is now 1985, and I want to enforce my patent
against a competitor whose product is identical except that it plays
CDs, which were introduced in 1983. I would probably invoke the
doctrine of equivalents to argue that for the purposes of my invention
a CD is equivalent to a phonograph record, and my patent's claims
therefore cover CDs, although they only mention phonograph records.
The principle of file wrapper estoppel says that if I narrow the scope
of a claim in a patent application to avoid a rejection based on prior
art, I cannot later use the doctrine of equivalents to broaden it
again.
Neither principle has anything to do with dependent and independent
claims.
My email address is LLM041103 at earthlink dot net.
