In Patent-Speak: When is a Brassiere an N95 Mask?

In these especially challenging times, one must be able to see through the fog of distracting information.

The same holds true for the bureaucratic process of filing for a patent. A case in point is a 3M Company patent (U.S. Patent No 3,064,329) for a molded nonwoven fabric article and related manufacturing process for making items such as porous breath-filtering face masks used by surgeons, physicians, and nurses subjected to contaminated atmospheres. Nowadays, we might call such items N95 masks. 

Back in 1959, 3M equated their masks to women’s undergarments.  But notwithstanding the distracting patent illustrations, this U.S. patent is not what some may think of when considering N95 masks.  Why is that?

The U.S. Patent & Trademark Office (USPTO) uses an arcane classification system to pigeon-hole patent applications into the proper “bucket” of technology.  Although the original patent classification of this 3M patent has changed during reclassification efforts of the last 60 years, this patent is currently classified in U.S. patent class 450, subclass 39.  Here, the USPTO classifies inventions that include “breast or chest, e.g., brassieres; molded preshaped shell-like cup, e.g., plastic latex”. 

Interestingly, the broadest claims of this patent actually make no mention of breasts or brassieres.  Rather, brassieres are buried in two short claims towards the end of the list of claims.  So how can a brassiere patent not be a brassiere patent, and why would 3M or any patent applicant obfuscate the intended invention?

The answer can be as simple as the first rule of any good persuasive writing:  write for your audience.

The USPTO includes over 8,000 patent examiners that review patent applications in discrete buckets of technology. Over time, each examiner becomes expert in reviewing their own peculiar area of inventions. This pejoratively means that each examiner knows a lot about very little.

One way that seasoned patent practitioners have learned to use this to their advantage is to draft a patent application broadly enough to cover the intended commercial product, but simultaneously insert enough flavour into the application to shepherd the case into a preferred bucket of technology.  In the case of the 3M patent, it is likely that the examiner who reviewed and granted that brassiere patent was expert in women’s undergarments rather than N95 masks.  In theory, this can make a patent practitioner’s job a little easier when trying to persuade a USPTO examiner that an invention is new and nonobvious.

Knowing how to effectively navigate the USPTO patent classification system to get a patent application under the right examiner’s nose can often affect the outcome of negotiations.  So, when is a brassiere not a brassiere: when the patent applicant calls it an N95 mask. 

Indeed, a rose by any other name would smell as sweet!