Layman's verison Means plus function

[RIJID]

What is the name of your state? WA

My patent infringement defense struggles have brought me to the means plus function issue.

I think I have a handle on what it means, but....

QUESTIONS :

If an inventor specifies a preferred embodiment and goes on to describe that specific embodiment in his claims is he in fact confined to that particular embodiment?

Example:

Patent owner A has a valve system for brief case. The purpose of the valve is to let air in and out of the case. He goes onto to specify in his claims a specific preferred embodiment, a slide valve that uses the case itself as functional component of the valve system. It is also a manually operated valve. Effectively, there is no way to physically remove the valve from the brief case.

Another inventor B who also holds a patent on a number of different valve types to be used on brief cases. The purpose of the valve differs substantially from that of patent owner A. The specific embodiment specifies a rotational screw in valve operated manually and also claims a self actuating valve. The structure of the valves does NOT include the use of the case itself as a functional component of the valve. The valve can be removed from the brief case.

A is claiming literal infringement.

Any cursory analysis of this scenario in the context of MPF?

 

[divgradcurl]

If an inventor specifies a preferred embodiment and goes on to describe that specific embodiment in his claims is he in fact confined to that particular embodiment?

Not usually. Claims can be limited to the preferred embodiment (or only embodiment) in certain circumstances, but this is by far the exception, and not the rule.

You brought up means plus function (35 U.S.C. 112(6)) claims specifically -- are the claims in question means plus function claims? Do they use the "means for" language? Means plus function claims generally are more limited than general apparatus or method claims -- generally, the "means," or underlying apparatus, that performs the specified function must be described in the specification, and the apparatus is generally limited to the means defined in the spec. But even these means can be broader than the spec, because the means is limited to the means described in the spec, and their equivalents.

If the claims are method or apparatus claims, then only certain specific types of facts will limit the claims to the preferred embodiment.

 

[RIJID]

Yes, the patent in question uses the term "valve means" and then goes on to describe a very specific valve system.

The problem is that the actual function of the valve in this particular application is subject to prior art, meaning a different valve system that performs the same function has already been granted and is now in the public domain.

So this inventor effectively re-arranged the components of a valve system and got a patent using "valve means" in his first claim, then goes onto to specify a very specific valve means.

I am wondering about claims abuse in this case as the inventor thinks he has patented ANY valve used in this particular application.

 

[divgradcurl]

The problem is that the actual function of the valve in this particular application is subject to prior art, meaning a different valve system that performs the same function has already been granted and is now in the public domain.

Okay.

So this inventor effectively re-arranged the components of a valve system and got a patent using "valve means" in his first claim, then goes onto to specify a very specific valve means.

Then the "valve means" may be limited to the "very specific valve" defined in the specification.

I am wondering about claims abuse in this case as the inventor thinks he has patented ANY valve used in this particular application.

Not sure what you mean by "claims abuse."

If the patent holder tries to broaden his claims, one of two things could happen -- at the claims construction phase of the litigation, the court could construe the claim to be limited to the specific embodiment described in the spec -- there is a lot of caselaw on this point. The flip side is that if the patent holder argues for, and is granted, a construction of the claim that is broad enough to also cover prior art, then it may be possible to invalidate the patent at the summary judgment phase. You can't have it both ways -- you can't patent narrowly to avoid prior art, then try and assert broadly.

I realize you probably would like to avoid getting into litigation -- it may be worthwhile to have your attorney try an analyze potential claim construction positions, and prepare a chart showing that the spec and prosecution history only supports a narrow claim construction and therefore claim scope (and then your product doesn't infringe) -- but if you try and claim broadly, then the claim or patent becomes invalid. This is a little different analysis than the one discussed above, but might be a useful analysis for a settlement conference.