At least one

[Sabachka]

How does everyone feel about using "at least one" in a claim?  e.g., comprising "a" first component and "at least one" second component.

I don't see what it adds, except maybe emphasis.

It seems to me that "a" and "at least one" in my example claim are equivalent. "at least one" is interpreted to mean that there could be only one or or more than one. See Kestler Instrumente AG v. US (Ct. Cl. 1980), cited in Rhine v. Casio (CAFC 1999).  "a" or "an" is interpreted to mean "one or more" in open-ended claims containing the transistional phrase "comprising" unless there is a clean intent to disclaim the plural. See KCJ Corp. v. Kinetic Concepts (CAFC 2000).

   

[JimIvey]

I don't have any citations handy, but I believe you are mostly correct about the law, except that it's a claim interpretation guideline rather than a hard and fast rule.  In other words, if the other claims, specification, and/or prosecution history suggest that "a/an" means "one and only one", the court is free to interpret the claim that way.  My preference is to try to be clear and use either "one or more" or "exactly one".

Regards.

[Sabachka]

Thank you for your response, Jim. I think your suggestion to be clear and use “one or more” or “exactly one” is a good one.

I haven’t done an exhaustive review of the case law, but here is what the CAFC said in Kinetic Concepts: “This court has repeatedly emphasized that an indefinite article ‘a’ or ‘an’ in patent parlance carries the meaning ‘one or more’ in open-ended claims containing the transitional phrase ‘comprising.’ [citations omitted] Unless the claim is specific as to the number of elements, the article ‘a’ receives a singular interpretation only in rare circumstances when the patentee evinces a clear intent to so limit the article.” The court notes that the written description or prosecution history may support an interpretation that the plural has been disclaimed. Later the court says “Thus, under the general rules of claim construction, this court presumes the customary meaning of ‘a’ - one or more.”

I don’t often see “exactly one” in claims. This is probably because it is often not desired to claim exactly one, but it could also be that the claim drafter mistakenly assumes that “a” means “exactly one.”

Based on what seems to be a strong claim interpretation guideline, it seems relatively safe to use “a” to refer to the plural rather than “at least one” or “one or more,” even though this may not be quite as clear. And if the singular is intended, “exactly one”, or perhaps just “one”, should be used.

[TataBox]

I use it.  And I think it is because it plays a role in damages calculations, not necessarily in patentability.  Of course it depends on the circumstances.  I will find the cite when I get the chance.

[JimIvey]

I don’t often see “exactly one” in claims. This is probably because it is often not desired to claim exactly one, but it could also be that the claim drafter mistakenly assumes that “a” means “exactly one.”

I believe the reason that you don't see "exactly one" in the claims much is that it's very rare that adding a second of whatever should avoid infringement.  I doubt I've used the phrase in more than 1% of my applications.  Each time I use "a/an", I try to consider whether addition of another one of those things should also infringe.  It's all part of being attentive while crafting claims.

Regards.

[klaviernista]

BTW, I have to give props to the OP for picking a good nick.  My first dog as a child was named Sabachka (Sa-Bah-Ka), which means
"little dog" in Russian.  Ah, the memories.

-Klav

kolik dřeva by svišť hodit jestliže svišť by mohly vyvolat dřevo

[patentsusa]

How does everyone feel about using "at least one" in a claim?  e.g., comprising "a" first component and "at least one" second component.

I don't see what it adds, except maybe emphasis.

It seems to me that "a" and "at least one" in my example claim are equivalent. "at least one" is interpreted to mean that there could be only one or or more than one. See Kestler Instrumente AG v. US (Ct. Cl. 1980), cited in Rhine v. Casio (CAFC 1999).  "a" or "an" is interpreted to mean "one or more" in open-ended claims containing the transistional phrase "comprising" unless there is a clean intent to disclaim the plural. See KCJ Corp. v. Kinetic Concepts (CAFC 2000).

   

So if you say "at least one" for the second component, does that imply that there has to be "exactly one" of everything else recited in the claim for there to be infringement?  Opposing counsel could argue in litigation that you must mean something different for elements where you didn't specify "at least one."

You could say "at least one" for every single component in the claim, but then you have to show multiple of everything in the drawings since everything recited in each claim has to be shown in the drawings. 

The transition word "comprising" should mean that you never need to say "at least one" in the claims. 
On the other hand, it can be useful to describe alternatives in the specification.

[ChrisWhewell]

Does "at least one" include pi  ,   3.14159&cet.  ?

In the case of a vehicle braking system claimed as having "at least one" brake shoe per wheel, does it include the number pi of brake shoes ?  If so, I'd say the spec is probably non enabling.   How does one have 3.14 brake shoes ?    Does "at least one" include 1279 brake shoes  ?  I think it would be desirable to include lang in the spec describing some features about what "at least one" means.

In bio practice, "said matrix comprising an effective biocatalytic amount of at least one apolipoprotein selected from the group consisting of: x,y,z, p,d,q , and mixtures thereof" may work.   Some arts and contexts are more conducive to that lang having concrete meaning but I think its always good to have it covered in the spec in various ways to afford flexibility in prosecution, since one never knows what prior art the Office may find that you weren't aware of.

[smgsmc]

You could say "at least one" for every single component in the claim, but then you have to show multiple of everything in the drawings since everything recited in each claim has to be shown in the drawings. 

Is this true?  I didn't think there's a requirement that everything recited in a claim must be shown in a drawing.  Regardless, if the spec reads:  "In the embodiment shown in Fig. 1, a communications system with a single router is shown.  In other embodiments, a communications system includes multiple routers.", you could then claim,

A communications system comprising:

    at least one router ...

without problems, couldn't you?  With a complicated system, drawings often get too messy if you show multiples of every component and clouds explanation of the underlying principles.

[smgsmc]

Does "at least one" include pi  ,   3.14159&cet.  ?

In the case of a vehicle braking system claimed as having "at least one" brake shoe per wheel, does it include the number pi of brake shoes ?  If so, I'd say the spec is probably non enabling.   How does one have 3.14 brake shoes ?    Does "at least one" include 1279 brake shoes  ?  I think it would be desirable to include lang in the spec describing some features about what "at least one" means.

In bio practice, "said matrix comprising an effective biocatalytic amount of at least one apolipoprotein selected from the group consisting of: x,y,z, p,d,q , and mixtures thereof" may work.   Some arts and contexts are more conducive to that lang having concrete meaning but I think its always good to have it covered in the spec in various ways to afford flexibility in prosecution, since one never knows what prior art the Office may find that you weren't aware of.

Are you saying that the spec needs to explicitly define "at least one" or "one or more" as meaning an integral count?  I don't see that as a problem with tires, brake shoes, cars, transmitters, radios ...Maybe an issue in cases such as "a weight of at least one kilogram".  Are you allowing 1.316 kg?  Or is the weight quantized in units of one kilogram?  And what's wrong with a claim including 1279 brake shoes?

[johnif]

I've had this conversation before in the office, but I'm curious what others have to say: does the use of "one or more" introduce ambiguity because it's not clear whether you're attempting to claim "one" or attempting to claim "more than one"?

There are few instances where I need to specifically recite one or more items in a claim, but when I do, I prefer "at least one" to avoid any ambiguity in the language.

One example I can think of is a when claiming computer inventions where I want to make sure and cover a dual-processor (a true dual processor machine, not just a dual/quad/oct core) or a distributed processing environment.  In that case, I've been instructed to claim:

A system comprising:
one or more processors; and
a memory coupled to the one or more processors, the memory including instructions, which when executed by the one or more processors, cause the one or more processors to:
<< insert steps >>

Thoughts?

[JimIvey]

I've had this conversation before in the office, but I'm curious what others have to say: does the use of "one or more" introduce ambiguity because it's not clear whether you're attempting to claim "one" or attempting to claim "more than one"?

I've heard smart people suggest that "or" is always ambiguous, but I think that's silly.  Can anyone truly and honestly say that, if I asked them to go get me one or more pencils, they wouldn't be able to comply with my instructions because they're confusing?

From another perspective, is "at least one" any less ambiguous?  Does that mean "one" or "more than one"?  Of course, the answer is "both."

While alternative phrasing can sometimes be vague and/or ambiguous and run afoul of Section 112, it's certainly not always the case.  The biggest problem with alternative phrasing is that invalidation for any of the alternatives invalidates all alternatives.

Regards.

[BobRoberts]

"Does "at least one" include 1279 brake shoes  ?  I think it would be desirable to include lang in the spec describing some features about what "at least one" means."

A method of baking, comprising:
replacing a brake shoe of a braking system with a (at least one?!?) pie, and
driving around the block, wherein the driving includes utilizing the braking system.

You may have something there, Chris...

I would think that if you have 3.14, or 1279 of something, it seems that you have at least one.

"How does one have 3.14 brake shoes ?"  if you have four brake shoes that are each worn to .785 of their original capacity?

[BobRoberts]

Oh, and for what it's worth, "at least one of" appears to be a completely different story...

[ChrisWhewell]

Are you saying that the spec needs to explicitly define "at least one" or "one or more" as meaning an integral count?  I don't see that as a problem with tires, brake shoes, cars, transmitters, radios ...Maybe an issue in cases such as "a weight of at least one kilogram".  Are you allowing 1.316 kg?  Or is the weight quantized in units of one kilogram?  And what's wrong with a claim including 1279 brake shoes?

maybe    Its case-specific and how one of ordinary skill would interpret.  Some would argue that 1279 brake shoes are included by at least one and that number might well be.  I've used "any integral number of feature x between p and q, including p and q" and also "according to structure XnYm wherein the sum of n+m is any number in the range between about o and r, including all values and ranges of values therebetween".   At least one language is usually not a problem, just be careful about falling into habits and not thinking about detrimental ways it could be interpreted.