Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Patent]

I am reading a patent which claims "about 50%" of an ingredient in composition.  What would be the range of it?  The specification does not define what the about term stands for.  Are there any guidelines to this term?

[Isaac]

Your correct about the way to resolve this.  I'd comment that
leaving this particular kind of thing to the prosecution history
should probably not happen unless the explanation of what
"about" meant could be determined from the prior art by a skilled artisan.

Otherwise, it would be difficult to justify not requiring an
amendment to the spec during prosecution.  And the hypothetical
spec would not support the "clarification" of about making the
application fatally vague.

[Patent]

Thanks for the comments. However, I am still confused.

Based on your suggestions, I checked the specification and it had examples using both 50 and 70% of that ingredient.  Also, there is a dependent claim which is dependent from the independent claim (which claims "about 50%") claiming "about 70%" of the same ingredient.

Can the term "about" mean to indicate such a large range of 50 to 70%?  So should I interpret the term about as "+/- 20%?

In that case is the independent claim mean 30 to 70%?

And the dependent claim mean from 50 to 90%?

But that interpretation is leading me to interpret dependent claim having range outside the independent claim it is dependent upon.

[Jonathan]

From what you have typed, it does not appear that they are claiming ranges. Therefore the independent claim is for the embodiment of about 50% and the dependent claim is for about 70%. If it was a range claim, it would say as such - for example, ingredient x in the range of about 50 to 70%.

While relative terms can perhaps cause some confusion, they are valuable tools in claim drafting. For example, if one skilled in this particular art would probably say that this composition with 49.9% of the ingredient is pretty much the same as one with 50% of the ingredient. If that 'about' is not in that claim, then the 49.9% would most likely not be deemed as infringing. This is just an example, of course. It could be very likely that in this art a 0.1 % difference is quite significant.

[Isaac]

I'm having a difficult time picturing how a claim
covering about 70% of X could depend from a claim covering
about 50% of X.

How about some example claim language with the element names changed
to protect the innocent?

[Patent]

Independent claim:

5. A … composition … comprising:

..about 50% by weight x ..

Dependent claim:

10. A … composition according to claim 5, wherein ….. comprises about 70% by weight X …..

The confusion I have is what is the broadest meaning one can give to this term "about"? From above dependent claim can one interpret it to be +/- 20%?  Or does it have to be much smaller range such as +/-1%?

Thanks very much.

[Jonathan]

Unfortunately, no one here can give you a black and white answer as to what range 'about' should be given.

As others have previously posted, there are a few ways to determine this. You already looked at the specification and said it did not speak to it. This is not too surprising cause relative terms are used ubiquitously in claims. The next step is to look at the prosecution history. Finally, and I think probably is the defining way to answer your question, how would one skilled in this art interpret it? Can this invention be practiced as claimed and described at 49.5%? 49%?
48%? Obviously this type of question is highly dependent on the field.

Regarding your question if the dependent claim should be interpreted as a range, no it definitely sounds like the inventor is claiming embodiments of about 50% and about 70%. He is not claiming the range inbetween. Perhaps his invention works well at 50 and 70 % but not that well inbetween, so he didn't claim the range.

[eric stasik]

Hi All,

Great Discussion. Nice pointer by RogersDA.

I think this is a doctrine of equivalents issue.

Before Festo became the focus of doctrine of equivalents, Hilton Davis was what everyone was talking about. The claim at issue was for a process for manufacturing dye:

"In a process for the purification of a dye . . . the improvement which comprises: subjecting an aqueous solution . . . to ultrafiltration through a membrane having a nominal pore diameter of 5-15 Angstroms under a hydrostatic pressure of approximately 200 to 400 p.s.i.g., at a pH from approximately 6.0 to 9.0, to thereby cause separation of said impurities from said dye . . . ."

The inventors added the phrase "at a pH from approximately 6.0 to 9.0" during patent prosecution. At a minimum, this phrase was added to distinguish a previous patent that disclosed an ultrafiltration process operating at a pH above 9.0. The parties disagree as to why the low end pH limit of 6.0 was included as part of the claim.

In 1986, Warner Jenkinson developed an ultrafiltration process that operated with membrane pore diameters assumed to be 5-15 Angstroms, at pressures of 200 to nearly 500 p.s.i.g., and at a pH of 5.0.

Hilton Davis sued Warner Jenkinson for patent infringement and won. Although there was no literal infringement, the district court jury found that a pH of 5.0 infringed under the doctrine of equivalents even though the patent clearly said at "a pH from approximately 6.0 to 9.0."

Warner Jenkinson appealed to the CAFC who affirmed the decision in a divided decision. The appeal was heard by the US Supreme court who reversed the decision.

"We do, however, share the concern of the dissenters below that the doctrine of equivalents, as it has come to be applied since Graver Tank, has taken on a life of its own, unbounded by the patent claims. There can be no denying that the doctrine of equivalents, when applied broadly, conflicts with the definitional and public notice functions of the statutory claiming requirement."

With Hilton Davis, the US Supreme court began rolling back the doctrine of equivalents. After Festo, Hilton Davis would not have even been able to apply the doctrine of equivalents.

The other responses were right that there is no bright line as to what "about" or "approximately" means. What does seem clear is that the US courts are giving patent owners a lot less DOE wiggle room than they have had in the past.

Regards,

eric stasik

[Isaac]

There may be DOE considerations here, but we're having trouble just
figuring out the literal scope of the claims.

If the invention really did not work with values between
50 and 70 percent, maybe the idea is that it would not take
undue experimentation to sort out which values around 50 and
70 percent make the invention work.

I haven't looked at many composition patents.  I can construct an
argument that the 70% claim is a proper dependent claim but
my own argument does not convince me.  Anybody got an explanation?

[JimIvey]

I've only got two possible explanations for proper dependence of Claim 10 from Claim 5 in the cited example claims.

1.  There's an omitted "at least" preceding the quoted "about 50%" in Claim 5.

2.  This is an example of human fallibility in the human-implemented patent system we have.  I find it hard to believe that "about 70%" further limits "about 50%" but instead modifies "about 50%".  I think Claim 10 (assuming no "at least" omitted from the quote) is properly a separate independent claim rather than a dependent claim.  

Of course, this is based on a very limited view of the patent in question.  Knowing the full context might illuminate another possible interpretation.

Regards.

[Patent]

Thanks for all the comments.  Just to clarify, there is no omitted "at least" in Claim 5.  However, as an expert in the field, I believe that "at least about" in claim 5 makes a lot of sense and in fact if I had to guess, there is an error in the claim 5.

Other patents by the same inventors and patent firm had many spelling mistakes in their claims and hence makes me think that error in the claim is a good possibility.  Infact, the errors are so bad that made me wonder if any one has read the claims! Errors like "thiss" instead of "this".  I guess the result of such errors in claims is a matter of another discussion.

[hridayabhiranjan]

If term about is not defined then is it a defective and idefinate claim !

[JimIvey]

Sometimes there are printing errors.  If you really want to know, get the file history and compare the claims as actually allowed to the printed, issued claims.

Claims are also interpreted in the context of the other claims and it's possible, to support the presumed validity of the claims, that a court would impute the missing "at least" in Claim 5.  Possible, but far from certain.

The file history can give much better insight into what happened and what Claim 5 really meant to cover.

Regards.