Claim Drafting Exercise
The registration exam tests the MPEP — deadlines, rules, procedure. It barely touches claim drafting. So most newly registered practitioners have never actually written a claim, and nobody has told them the basic rules of how one is put together.
Here are three. Try each one before you open the answer.
1. What’s wrong with the form of this claim?
The invention is a toothbrush. Look at how it’s written, not what it covers.
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A claim is a single sentence. This one is four. It also has none of the structure an examiner expects, and no punctuation doing any work.
a handle;
a head attached to the handle; and
a plurality of bristles extending from the head.
Five rules are doing the work there. A comma after the preamble. A colon after the transitional phrase. A semicolon after each element. The word “and” before the final element. And exactly one period, at the very end. If you found yourself unsure about any of those, you’re in the normal position for someone who just registered.
2. This claim will draw a rejection. Find it.
The form is correct this time. Something else is wrong.
a pair of side rails;
a plurality of steps extending between the side rails; and
a hinge coupling the rungs to the side rails.
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The last element says “the rungs.” Nothing called a rung was ever introduced. The claim called them steps.
This is a lack of antecedent basis, and it’s an indefiniteness rejection under 35 U.S.C. 112(b). The rule underneath it: the first time you name a part, it gets “a” or “an.” Every time after that, it gets “the” — and it has to be the exact same word. Not a synonym, not a better word you thought of halfway through.
Change the last element to:
This is the single most common error in first drafts, and it almost always comes from good writing instinct. You were taught not to repeat yourself. In claims, repetition is the point.
3. One word here costs your client the patent’s value. Which one?
The form is right and every part is properly introduced.
a shaft;
a canopy; and
a plurality of ribs supporting the canopy.
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“Consisting of” is a closed transitional phrase. It means the umbrella has those three parts and nothing else.
So a competitor adds a wrist strap. Now their umbrella has four parts, your claim covers three, and they don’t infringe. You gave away the invention with two words.
Change the transitional phrase to:
“Comprising” is open-ended — it means “including at least these parts.” Adding a wrist strap doesn’t help them. This is why “comprising” appears in the overwhelming majority of claims, and why the handful of situations that call for “consisting of” are worth knowing on purpose rather than by accident.
How did you do?
If some of that was new, that’s expected. The registration exam doesn’t teach much claim drafting and most firms don’t have time to either. These three are the foundation — punctuation and structure, antecedent basis, and transitional phrases — and they’re the first things covered in the claim drafting training.
See the full claim drafting training