05 August 2024

Summertime reading - Patent classification and how searches were done in a paper world

Why do we have patent "classes" and why don't we use tags? Why do the classes have hierarchical numbering? 

How were searches done when the prior art was on paper (mostly older patents)? 

There is a very nice photo on the internet of the EPO search archive in the days of  paper prior art and cupboards: 


(I don't embed it here to avoid any copyright issues)

There is also a very interesting photo, "Employees in the patent office file room ca. 1940"

J Ferrel, Should I have a patent search performed? (no date)
"The other reliability problem associated with searching is that the available search tools are not perfect. Until very recently, patent searches were performed largely by professional searchers in tennis shoes who would race through the millions of shelved patents in the Patent Office, searching through stacks of documents for specific related art. Trained searchers could proficiently scan quickly through boxes of patents, rapidly checking titles, abstracts and figures for hints of a specific invention. These traditional searches, although time consuming, produced surprisingly good results. The problem with these manual searches, however, was that if specific patents were missing from the shelves being searched, significant searching errors could occur. Keeping the patent stacks in pristine condition for searching has always been a losing battle for the Patent Office."




History of the United States Patent Office - The Patent Office Pony - A History of the Early Patent Office - Chapter 31 -- The End of the First Century of the Patent Office

Printing patents had an interesting and lasting effect on the furniture which was required by the Patent Office. Before patent drawings were printed, examiners, while searching patents, had to look at the original drawings in the draftsman's office in large portfolio cases, such as those shown in the illustration from 1869 on page 173. There were 777 folio cases of original drawings which were safely removed from the draftsman's office in the fire of 1877. But when the drawings, and especially the entire patents, were printed, they were available for search in the examiners' rooms and soon in the new public search room. The necessary new filing system was provided by the shoe cases still in use in today's Patent and Trademark Office. The origin of the term shoe is lost, although every patent examiner knows where his shoes are. Some have attributed the term to Thomas Jefferson, suggesting that he stored his patents in shoe boxes. But we know that the drawings kept in the Patent Office in the preprinting days were of varying sizes and were kept in portfolios from the earliest days. Shoes, as we know them, could only have arisen after all patents were available in small, uniform sizes and could be kept in small, uniform boxes. A complete inventory of the moveable property in the Patent Office was made in 1870, [footnote 1] including numerous portfolio cases, portfolio racks, portfolio drawers, and cases for models, 22,000 volumes of books and 300 spittoons, but no shoes. Augustus Burgdorf, livery stable operator, undertaker and cabinet-maker of Washington, sold portfolios and cases to the Patent Office in 1878. [footnote 2] The first known mention of shoes was on March 28, 1879, when he sold shoe drawers to the Patent Office for $115. [footnote 3] What were called shoe drawers would now be called shoes. Among the many possible origins of the term is that preferred by your guide. Perhaps file cabinets suitable for holding bundles of patents while allowing easy access to search through them were already available before they were needed. Perhaps shoe shops of the day kept their supply of ready-made shoes in wood cabinets containing numerous drawers of just the right size to hold patents, and when the Patent Office wanted to order its first drawers, it ordered shoe drawers from Augustus Burgdorf. Or maybe not.


J. Rolnicki, Outline Of The U.S. Patent Office Patent Examination Process, 22 May 2017 
I was a Primary Examiner with the U.S. Patent and Trademark Office many years ago. Much has changed at the Patent Office since I served as an Examiner. For example, when I was an Examiner, prior art searching or patentability searching was done manually. After reviewing a patent application that I was examining, I would then go to the appropriate file room or search room for the subject matter or technology of the patent application. In the search room, there were rows of file cabinets. Each file cabinet had a stack of small drawers called shoes. I think because they resembled small shoe boxes. Each shoe was dimensioned to hold a small stack of patents. There were no U.S. published patent applications back then. Each shoe contained a chronologically ordered stack of U.S. Patents that pertained to the technology I was searching. The same shoes also contained foreign patents and published foreign patent applications. I would pull up a chair in front of the file cabinet, and then pull out the first shoe and manually thumb through the stack of patents in the shoe. This was continued until all of the patents in the file cabinet shoes pertaining to the technology that I was searching were reviewed.

Photo of the US Patent Offices with stacks of files: 

I assume the CPC patent classes started as the numbering of the physical boxes holding the patents about a specific topic. But perhaps one of the valued readers of this blog still remembers?


No comments:

Post a Comment

Do not use hyperlinks in comment text or user name. Comments are welcome, even though they are strictly moderated (no politics). Moderation can take some time.