How to make better inventions: Part 2

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By David French

This is the conclusion of a two-part series. Part one introduced patent searching and how inventors can use the “prior art wall” to their advantage.

Whether or not a prefiling patent novelty search establishes that the road is clear for you to attempt to obtain patent rights, there is tremendous value to be obtained by just carrying out the search. In my last post, I explored this premise and started down the path to demonstrate how you can conduct a search of documents that are online at the U.S. Patent Office.

To recap, I shared tips for searching with key words using this page on the U.S. PTO website. As an example, the search was focused on an improved garden rake. Documents relating to rakes were located by initially entering the words “rake” and “handle.” I also suggested that searching can be conducted using the classification system available in the U.S. PTO website, which is what I will explain here today.

Classification searching

There is an index page on the U.S. PTO website that gives access to classification manuals. The documentation surrounding classification is extensive. There are around 1,000 principal classes and within each principal class there are many hundreds of subclasses and sub-sub classes. It is difficult to learn about classification through entering the classification system directly.

Conveniently, every issued patent has a reference to its principal class included on the cover of the printed patent, or on the HTML page for the patent at the U.S. PTO website. In part one, we used keyword searching to locate a relevant patent — U.S. patent 7,987,658, called “Multi-purpose garden tool with pivotable gardening head.” Clicking on this reference takes us to an abstract that describes a garden rake.  There is also a link to images at the top of the screen. (Viewing these images requires a TIF reader, which can be downloaded by clicking the red “Help” link in the yellow bar above the black space where the pictures should be on the “Images” page).

This patent can be used as a root to switch to “classification searching” by clicking back to the patent’s abstract. All U.S. patents are classified according to the focal point or novel feature of the invention. Searching down the screen of our gardening rake patent, we find that it has been classified primarily in U.S. Class 56/400.19. (And it has been cross-classified in U.S. Classes 15/144.1; 16/900; 294/53.5; 56/400.04; all of these other classes would be relevant for an expanded search.)

After a deeper search on the U.S. PTO website, we learn that U.S. Class 56 relates to “HARVESTERS.” Additionally, subclass 400.01 under Class 56 relates to “hand rakes” and subclass 400.19 is a sub-subclass under subclass 400.01 for inventions wherein the novel feature is “adjustable, folding or take-down.”

In this exercise, we need only note the principal class, 56. Using the browser’s “back” button to return to the “Refine Search” box on the search page, we can amend the search string to read as follows:

rake and handle and (claw or hook) and ccl/56/$

(Open and use the “Advanced” red link at the top of the screen if “Refine Search” is not available through a back button from the screen for US patent 7,987,658.)

The search result is as follows:

Results of Search in U.S. Patent Collection db for:
(((rake and handle) and (claw or hook)) and CCL/56/$): 56 patents.

This is a result that is a manageable size.

By the way, the search term “ccl/56/$” stands for “current class/56/any subclass,” where the symbol “$” serves as a wildcard for any of the subclasses under Class 56 — harvesters. When using class as a search term both a class and subclass must be specified. A search using the term “CCL/56/400$” returns 39 hits, with all of the hits qualifying as relating to “hand rakes” under subclasses 400.01 through 400.21.

It’s now time to decide what the invention is that we are searching for. For the purposes of this exercise it could be anything that involves a rake with a handle and a claw or a hook. Perhaps the invention is a rake with a handle that includes both a claw and a hook pointing out at e.g., 45° from the backside of the rake. But that doesn’t matter.

The purpose of this exercise is to show the rich opportunities to learn that can arise by looking at the now truncated list of 56 or 39 patent references related to the search terms that have been employed. This is a very quick way to understand the business of gardening tools. Every one of these patent references has a generous number of drawings and an elaborate description as to which features are important. What a way to get smart fast in the field of your invention!

And here is a bonus. Return to the Refine Search box, which reads, “rake and handle and (claw or hook) and ccl/56/$,” and copy this string. Then go to the top of the search screen and click “Home.” This is not Home for the U.S. PTO website, but Home for the searching tools. On the right side of the Home screen, divided into three parts, is a column referring to “Applications.” This refers to pending applications rather than issued patents. So far, only issued patents have been searched. Under Applications, click “Advanced Search” and paste the above string in the box that is presented under the word “Query” and click “Search.”

The result is a list of applications filed at the U.S. PTO since 2001 that contain the terms of the search string, vis:

Results of Search in AppFT Database for:
rake and handle and (claw or hook) and ccl/56/$: 25 applications.

Every one of these applications is well worth looking at if you are curious to see what other people are doing.

The purpose of this exercise is to demonstrate that patent searching is not just about patenting. It is also about making better inventions! If you want to be a great inventor, don’t leave reviewing the prior art to some professional. Do it yourself and become wiser for it. Any questions?

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