Contents ••••••• Most of the body of a patent is written in plain English. The exception is the claims section, which is the section of primary legal importance. The claims determine what aspects of the invention are protected by the patent. Attorneys write claims in claim language, a special style of writing. Claims are difficult to read when you are new to the patenting process and don't understand the basic structure and semantics of claim language.
I will do my best to demystify claim language by explaining the basic vocabulary and structure of a claim. In the examples that follow, I italicize those words that are common elements of claim language. Claim language is actually simple to write and to decipher once you get the hang of it. To teach the style of claims, I will take a simple invention—the indictable ham sandwich-and write the claims for it in the broadest possible style.
But first, heed this important disclaimer: I am not an attorney The knowledge that I can impart is purely experiential and informal. Feel free to use my advice in constructing a draft of your patent, but make sure to consult with your attorney on what you've written prior to filing any formal documents.
Writing Broad Claims
Neoplasticist Piet Mondrian said that the most difficult brushstroke in a painting is the first one because it is unconstrained. Once placed, it implies limitations on the subsequent brushstrokes, which then become easier to place.
Writing a set of claims is a similar proposition. The first claim is an independent claim, which means that it stands on its own and makes no use of other claims. Claims that make use of a prior claim are called dependent claims. The claims on which they depend are called antecedent claims. Constructing the first claim will set the direction and mood as to how its dependent claims will flow. The dependent claims are said to be limitations on the claims on which they depend. That means that they further specify or define (limit) something that was claimed more broadly in an antecedent claim. You can use a chain of dependent claims to further limit and define a specific invention.
Initially, you should try for the broadest claim possible in an independent claim, and then narrow it down using dependent claims. The patent examiner might not allow your broadest possible claim. In this event, you need to “roll up” the dependent claims into their antecedents to narrow down what you are claiming.
In the following example, I use a style that is as broad as possible to construct claims for a ham sandwich. These claims are probably too broad, and an alert patent examiner should not accept them. But they will illustrate the basic vocabulary and structure of claims. Each claim must be written as a single sentence, although it can have multiple clauses separated by semicolons.
I start by writing 10 method claims and then 10 apparatus claims in direct correspondence to the method claims. Each apparatus claim will describe the sandwich made in accordance with the method described in its corresponding method claim.
Method Claims
A method claim generally starts with the words method for, so that it is easily identifiable as a method claim. A physical entity in a claim is generally referred to as a means, or as an apparatus. Methods are usually written to include one or more steps.
Claim 1 will be the broadest possible claim that describes a method for making a ham sandwich. To make it as broad as possible, I will neither restrict the content of the sandwich to be ham, nor will I restrict the sandwich to have bread on both sides (because it could be an open-faced sandwich), nor will I restrict the sandwich to be made out of bread. This is overreaching on the generality of a ham sandwich. As such, it is a gambit put out to the patent examiner to test his mettle. If allowed, this will be a very powerful claim, but it might not stand up in court if subsequently challenged.
In claim language, when the claim uses multiple objects or steps, you can distinguish them by referring to them as “a first object (or step)” and” a second object (or step).” In the broadest manner, we can write claim 1 this way:
1. Method for making a sandwich, including the step of placing a second means on top of a first means.
We can then write claim 2 as a dependent claim in which we limit the first claim by adding another step—in this case by adding another piece of bread. But to make it general, we will not restrict the added piece to be bread, or even to be the same as anything yet in the sandwich. A dependent method claim usually starts with the wording “The method according to claim [insert the antecedent claim number here], further including the step(s) of … “
Whenever you refer to an object (called a means or an apparatus in claim language) or a method (or step) that the claim already describes, you should identify it as already having been described by calling it a said means or a said step. If you do not flag this by using the modifier said, the patent examiner might become confused, and think that you are introducing a new entity or step. You should write the claim to make it clear which previously described object is being referred to when you use the modifier said. Claim 2 is then
2. The method according to Claim 1, further including the step of placing a third means on top of the said second means.
So we have added a step to the prior claim, introduced a third means, and positioned the new (third) means relative to an object that was already described—the said second means. Now we can add a new dependent claim that further restricts what we have done so far by requiring that the outer layers of the sandwich both be made of the same thing (which will eventually become bread in a later claim). We will use claim 2 as our point of departure, and declare that the various means used are of certain types. Note that we are not adding any steps for the time being; we are merely placing restrictions on the items that have been placed so far. Claim 3 is then
3. The method of Claim 2 in which the said first means and the said third means are both of a first type and the said second means is of a second type.
This is a very generic sandwich. We have outer layers of a first type (which we will further restrict to be bread in the next claim) and an inner layer of a second type (which will eventually become ham in a later claim). Claim 4 introduces the bread:
4. The method of Claim 3 in which the said first type is bread.
Now I will generalize the sandwich so that it can have more than just one slice of ham in it, as well as having other things in addition to ham. Note that when I am broadening a definition to allow multiple entities, the words used are typically “one or more [things]” (which is the most general), or “at least one [thing]” (which focuses on one thing, but does not preclude more than one thing), or sometimes “a multiplicity of [things]” which does not include the case of a single thing. Be careful in your selection of words here.
I will write claim 5 relative to claim 3 (not claim 4) so as not to restrict outer layers of the sandwich to be bread:
5. The method of Claim 3 in which the said second means includes one or more layers.
So now the inside of the sandwich can contain more than one thing, and more than one layer of any particular thing. I next introduce ham for the first time:
6. The method of Claim 5 in which at least one of the said layers is ham.
Next, I allow cheese to be put into the sandwich. In this example, I immediately restrict the types of cheese by listing them explicitly. But by referring back to claim 5 (and not claim 6), I do not require ham to be in the sandwich. Claim 7 can be just a cheese sandwich. I am pulling a fast one here:
7. The method of Claim 5 in which at least one of the said layers is cheese, said cheese being any of: cheddar, Muenster, Swiss, or provolone.
I will now do the same trick with veggies:
8. The method of Claim 5 in which at least one of the said layers is vegetables, said vegetables being any of: lettuce, sliced tomato, sliced pickle, sliced onion, sliced avocado, or sprouts.
I can then add a spread to the sandwich. For breadth, I will apply this to claim 2:
9. The method of Claim 2 further including the step of spreading a spreadable means on at least one side of at least one of said first means or said third means.
And finally, I will restrict the spreads being applied to the sandwich:
10. The method of Claim 9 in which said spreadable means is any combination of: mustard, mayonnaise, or salad dressing.
Rolling Up Claims into their Antecedents
Note that I do not have—nor do I need—any claim in which both ham andbread are required. The chain that eventually arrives at ham as a filling (claim 6 depending on claim 5, depending on claim 3, depending on claim 2, depending on claim 1) does not contain the claim in which the first type (including the first means and the third means) is limited to be bread (claim 4). Therefore in claim 6, what we have is a general claim to a method for putting ham (and perhaps other things) between any two things of an unspecified type.
If the patent examiner allowed this, claim 6 would certainly cover the specific case of an edible sandwich in which the two things are slices of bread. I would also own the method of putting ham between two books, between two bath towels, between your hands, and so on. This would be a broad claim. If allowed, it would be powerful. An alert examiner should force the independent claims to be more specific.
For example, if the examiner decides to allow claim 6, but not allow any of its antecedents (the chain of claims 5, 3, 2, and 1), we can rewrite claim 6 by “rolling up” the entire chain. A claim is always written as a single sentence. It can have arbitrarily many steps and components. Semicolons generally separate each step or component, but there is only one period—at the end of the claim. So I could write the rolled-up chain of claims 6, 5, 3, 2, and 1 as a basic concatenation of these claims. For example:
A method for making a sandwich, including the step of placing a second means of a second type on top of a first means of a first type, and further including the step of placing a third means also of a first type on top of the said second means, in which the said second means includes one or more layers, in which at least one of said layers is ham.
For multiple clauses separated by semi-colons, you can write the clauses to start on new lines to make the claim structure clearer, which improves its readability.
I could go on to write more method claims using further variations on these combinations, further limiting the invention into a sensible realm. That is, I have not yet exhaustively covered all possible permutations, and could continue writing method claims if I wanted to. The purpose here was just to get started and to introduce some of the basic vocabulary of claims.
Apparatus Claims
Now I will construct apparatus claims directly from the method claims. The apparatus claims will be constructed in direct correspondence: 1 to 11, 2 to 12, and so on. This can be done in a fairly straightforward manner. Recall claim 1 (a method claim):
1. Method for making a sandwich, including the step of placing a second means on top of a first means.
I can construct the corresponding apparatus claim directly from this method claim. In this case, the first apparatus will be a compound means, which is not to be confused with the various simple means that it comprises. (Equivalently, I could have just called it an apparatus. I also could have just used the word sandwich.) Since I am going to claim several apparatuses (sandwiches), the first one is a first compound means:
11. A first compound means including a first means and a second means, said second means being on top of said first means.
This is a structural definition of what the method of claim 1 produces. In this case, I have identified its components and their relative placements, and I am calling the aggregation (sandwich) a first compound means. Recall claim 2 (a method claim):
2. The method according to Claim 1, further including the step of placing a third means on top of the said second means.
The corresponding apparatus claim is then
12. A second compound means including the apparatus of Claim 11, and further including a third means, said third means being on top of said first compound means.
For completeness, I write the remaining apparatus claims (claims 13 to 20) to be in direct correspondence to the method claims (claims 3 to 10).
13. The apparatus of Claim 12 in which the said third means and the said first means of the said first compound means are both of a first substance.
14. The apparatus of Claim 13 in which said first substance is bread.
15. The apparatus of Claim 13 in which the said second means of the said first compound means includes one or more layers.
16. The apparatus of Claim 15 in which at least one of said layers is ham.
17. The apparatus of Claim 15 in which at least one of said layers is cheese; said cheese being any of: cheddar, Muenster, Swiss, or provolone.
18. The apparatus of Claim 15 in which at least one of said layers is vegetables; said vegetables being any of: lettuce, sliced tomato, sliced pickle, sliced onion, sliced avocado, or sprouts.
19. The apparatus of Claim 12 in which at least one of said third means and said first means of said first compound means has a second substance spread on at least one side.
20 The apparatus of Claim 19 in which said second substance is any combination of: mustard, mayonnaise, or salad dressing.
There need not be a direct correspondence between the apparatus and the method claims in a finished patent, because this might not be exactly what you want covered. But it makes a convenient starting point to write your apparatus claims in this way. Then go back, and decide whether these apparatus claims are exactly the ones that you want.
Other Styles for Writing Claims
As previously stated, I wrote these 20 claims in an extremely general manner, to be as broad as possible. This is one style of writing claims. If allowed, these claims are general and, hence, powerful. But because they are very general, they are more subject to being overturned if eventually challenged.
There are (at least) two other styles of writing claims. One is a more direct style that more explicitly defines all of the steps and means, which are therefore not as open to interpretation (and not as general). The other is the style of the submarine claim, a claim written for something not yet invented. Each of these three styles is suited to a different approach in how you anticipate the tactical use of your patent.