Naturally it’s fictitious — that is, the examiner’s report is fictitious, and the patent application at issue is adapted from a real patent or application, usually tweaked a bit in order to introduce more errors or uncertainty. The subject matter is usually something simple and mechanical, because the patent agent exams deal with relatively simple mechanical inventions which, in theory, do not require specialized knowledge to understand. (In practice, everybody but the mechanical engineers seems to claim a disadvantage.) So of course, I decided to use a patent for a knitting-related device. The subject matter is simple and mechanical, knitting skill is not actually necessary to be able to understand the invention, and there are few other opportunities to introduce knitting into a patent practice.

The patent I picked on was the one for Knit Klips clips, which were designed for seaming knitted pieces. Unlike the knitting needles with measurement markings, the Knit Klips patent claims generally seem to be fairly true to the product that is actually on the market. (Technically, the patent wasn’t a patent yet when I used it for the exercise — as you can see from the first link, the issue date was in March. But it was on the verge of issuance.)

If you look at a diagram of the clip (especially the ones on the company’s website), it isn’t hard to figure out what how it works.

And, to amuse yourself, before you click the “more” link, ask yourself just what sets these clips apart from any other clips you might have seen in the past. What the inventor (through her agent) and the patent examiner thought were inventive is discussed below the jump.

First, here’s the broadest patent claim that issued:

1. An apparatus which will aid in substantially eliminating misaligned rows when securing adjacent edges of one of knitted and crocheted panels together by securing edges such adjacent edges of a pair of panels of a garment to be darned, said apparatus comprising:
     (a) a first member having a handle portion on a first end and a jaw portion on an opposite end;
     (b) a second member having a handle portion on a first end and a jaw portion on an opposite end, said second member engageable with said first member;
     (c) a securing means engageable with said first member intermediate each end thereof and said second member intermediate each end thereof for securing said second member to said first member;
     (d) an aperture formed through a jaw portion of one of said first member and said second member;
     (e) a post member extending outwardly from an inner surface of an opposite one of said first member and said second member, said post member disposed in a position to extend through said aperture, said post member for engaging such pair of panels to be darned and securing such panels in place where only said post engages such panels; and
     (f) a biasing means engageable with said handle portion of said first member and said handle portion of second member for biasing said apparatus in a closed position.

This is in fact very close to the broadest claim that was originally filed with the application. When the application was originally filed, “post” actually read “post like”, and the phrase “where only said post engages such panels” was not present.

A surprising feature of patents is that sometimes, the simpler the idea, the longer the claims. The fact is, each of the necessary components of a device, and each of the features that distinguishes it over the prior art, needs to be explained. I expect you’re probably thinking “why, this clip here is just a spring-biased clip that opens and closes, dammit, with a substantially smooth post protruding out of one of the clip’s faces, and a hole in the other face for receiving the post, so that layers of fabric pierced by the post can be held together when the clip is closed. And that description’s only about 50 words long, if you drop the ‘dammit’. What’s with all the verbiage?” (Indeed, refraining from even soft profanity is a good tip when drafting patents.)

The problem is, such a description is deficient, patent-wise, as claim. Each element needs to be introduced a first time with an indefinite article; you can’t start calling things the face without first introducing the concept of a face. But if you say “clip”, even if the patent describes one example of a clip, do you mean a paper clip, clothes pin, banana clip, what? If you say “clip” without providing further detail in the claim, are you dooming the patentee to a claim construction that covers only the exact type of clip that was described in the patent and its drawings? And exactly where should the post be positioned with respect to that hole? The claim above, you see, attempts to address these questions.

As a bit of an even further aside before we even get to the prior art, you might be wondering about some of the language chosen for the claim. I did, too. Now, I don’t mean to criticize another person’s patent drafting style, because there is no one “right” way to draft a patent description or claim. (There are lots of right ways, and lots of wrong ways, and while some ways are better than others, you don’t really know if a patent claim is good enough until it gets litigated. If you give a description of an invention to five patent agents, you should wind up with five different sets of claims. If any of the claims are the same, they’re cheating. Different people prefer different terminology and claims structure; that’s just the way it is.)

But still, I found myself wondering if my own knowledge was somehow lacking in respect of the knitting or crafting vernacular, because I had never heard anybody that I’d consider skilled in the art (any knitter, actually) refer to the act of joining two pieces of knitting together as “darning”. “Darning” flaws in fabric already knitted, crocheted, woven, or otherwise manufactured, certainly; but I’ve never seen it as a substitute for “sewing”, “seaming”, or just plain “joining”. The all-seeing, all-knowing, and occasionally unreliable Internet suggests that “darn” is not a substitute for this act of joining. So, why was “darning” chosen as the mot juste when a term like “joining” could be used? Is it not implicitly limiting to describe the act as “darning”? And who chose the term — the patent agent or the client?

Now, on to the prior art. As I said, I picked on this patent because I was preparing an exercise. And as part of this exercise, I needed prior art as a basis for an objection that the clip was not patentable, because it was old or obvious.

I started with the art that was cited in during the prosecution of this particular patent application. There were a number of patents listed, and were mostly directed to clips — clothespins, hair clips, clips for locking various things — but none of them appeared to be too close; in fact, the arguments necessary to overcome these prior art references seemed… well, obvious to me. You can see three examples of the cited prior art located by either the examiner or the inventor to the left. The bottom clip is the one that was used by the examiner to initially reject the patent application’s claims. (It’s actually part of a locking system for securing a portable computer, but arguing that the intended function of a device is different than that of your invention is frequently a non-starter during examination.)

During examination, the examiner concluded that this bottom clip possessed the structural limitations of that claim 1, above. You might not think that this prior clip possesses the “post” and the “aperture” of the claim; it appears to have two teeth that fit together side by side when the clip is closed, so that one tooth on one side of the jaw fits into a void in the opposite jaw. But to the examiner, it was a “post” and “aperture”: the examiner pointed out that there was no positive definition of a “post” and an “aperture” in the patent application, so based on the broadest reasonable interpretation of the claim language, an aperture could be an “opening or open space” (a dictionary definition).

The inventor (through her agent) argued against this, pointing out that the pending claim indicated that the aperture was formed through a jaw portion of the clip, and this was not the case in this prior art clip. (The examiner probably didn’t use the middle clip in the above illustration because it did not open and close the same way as the Knit Klips clip.) In addition, the inventor also pointed out that the post penetrated the knitted panels, and that the interlocking nature of the jaws of the prior art clip would make holding the panels in position difficult. Eventually, the examiner relented and agreed that the fact that only the post in the Knit Klips clip would engage the fabric made it inventive over the prior art clip, where both the “post” and “aperture” engaged the fabric — hence that amendment I mentioned before, which added the phrase “where only said post engages such panels”.

Back to my fictitious examiner’s report. I needed to guard against clever students who, given a copy of a modified Knit Klips patent application (with all ownership and serial number information removed), would search for and locate the real thing, and find a “right” answer by copying the arguments that had really been submitted. Plus, since the arguments to be made over this prior art seemed pretty easy to figure out, I set out to look for something else. After some unenthusiastic searching of tool and medical equipment websites, I started looking through patents and came up with this:

It’s from a patent for a shower curtain ring. The circle marked 14 is a cross-sectional view of a shower curtain rod; the vertical bit marked 12 is the shower curtain. Like the Knit Klips clip, you can squeeze the finger grips to open it, and now you have some protuberance — not a straight post — emerging from one side of the jaw, that does fit into a hole in the other side of the jaw. When this clip is closed, the bit of the protuberance labelled 50 is still exposed, and the shower curtain 12 can be suspended from that bit.

So the exercise left to the reader, essentially, is this: you can imagine that if this shower curtain clip were used to hold two pieces of knitted fabric together, they would be suspended from the bit of the protuberance 50, which as shown here, is curved. Thus, this shower curtain clip does not suffer the same problem as the previous prior art clip; only the “post”, curved though it is, engages the panels to be “darned”. Given this fact, does the claim reproduced above adequately distinguish the knit clip over this piece of prior art, or what amendments must be made to the claim?

And remember, there is no one right answer.

I won’t pretend to understand Japanese, so here’s the English translation of the abstract:

PROBLEM TO BE SOLVED: To obtain a jacket keeping the shoulder warm at a low cost for keeping the whole shoulder including the neck warm at bedtime through improving productivity.

SOLUTION: This jacket 10 keeping the shoulder warm is obtained by knitting and weaving a surface with regular texture and a rear face with pile stitch while forming a bottom 12c and a neckline 13 of a body from one cuff 11a through the body 12 toward the other cuff 11b, and connecting a turtleneck 14 to the neckline 13. The jacket is set, if necessary, with a knitted texture of polyurethane threads as an intermediate layer formed between the knitted textures of the surface and the rear face of both the sleeves 11 and the body 12, and a pocket 16 to hold a scent bag 15.

And here you thought that shrugs and boobholders were all about keeping glamorously warm. It’s not about your looks; it’s about your productivity, people!

I still feel the same about the aesthetic merits of such garments. But when you present it to me as a technical solution to the problem of maintaining productivity at bedtime, that’s different. And note the pocket for holding a scent bag!

(What you say? Oh, sorry, that should have read, “keeping warm… through improving productivity.” All your shoulder-warmers are belong to us.)

Don’t leap to the conclusion that a grant of this patent, should it be found patentable, would result in an embargo on all shrugs and shoulder-covering delicacies. First of all, patents are only supposed to be granted for new inventions. We’ve seen before that sometimes it’s not so easy to find prior art in a field like knitting. It’s easier for machine knitting-related development, since they’re more likely to be documented. But a patent should not prohibit others from doing something that really and truly was publicly known by others before the patent application was filed. (Sometimes it happens. And when it does, corrective measures can be taken, either by the patentee or by a prospective infringer.) Thus, for example, I should still be able to knit and wear any pre-2003 cropped sweater pattern in Japan, even if a patent did issue on this patent application (I didn’t see any foreign patent applications in my cursory search, but I wasn’t looking very hard).

Secondly, I assume from the abstract that the patent claims, which define the exclusive rights in the invention, do not simply cover a cropped, short-sleeved garment. That’s a big assumption, considering I can’t read the claims.

Instead, I’m guessing that if there’s anything patentable here, it would involve at the very least either the scent pocket or the intermediate layer of polyurethane fabric between the inner and outer faces of the fabric making up the garment, or perhaps the actual method of construction. The abstract itself describes that the garment is made of a fabric formed “by knitting and weaving a surface with regular texture and a rear face with pile stitch” which, in the absence of further detail in the application that I can’t read, sounds like a lot of machine-made fabric.

I do wonder, though: where does the scent pocket go in the women’s version? Right under the neck?

In the meantime, Kate wrote to tell me about some 40s-era Patons publications she had obtained that described the “Beehive Aladdin Heel” and the “Beehive Innovation Sock”; the latter she described as having an instep and three sides of the ankle worked flat, stitches picked up for the heel, and the sole and back of the ankle knitted and seamed to the first place; in short, a replaceable heel.

She asked how one might go about finding out whether a patent had actually issued. And thus begins the lecture. So, instead of writing only about afterthought heels, first I’ll write about the type that requires forethought.

If you’re minded to go searching for such things, the most advanced patent offices have online databases that allow for searching their issued patents and their published applications. This means that within certain limitations, you can not only locate issued patents that could potentially be enforced against infringers, but you can also find out what some inventors or applicants think might be patentable. The databases are also (again, within certain limitations) text-searchable, so you can search by patent owner name, or keyword, and that the very least the patent/application title or abstract will be searched along with other bibliographic data. Most countries now publish pending applications eighteen months after filing; the U.S. started doing this significantly later than other countries did (about ten years after Canada, for example). These applications are searchable the way patents are searchable as well. (This is not retroactive; old patent applications that never issued to patent are not publicly available unless something else happened to cause their publication.)

Patents and applications are searchable not only based on text fields, but also according to classfication. When a professional patent search is done to determine what patents or applications might exist in a given field, it is typically (or should be) conducted by searching the most appropriate art classes for that field. Text searches are very unreliable, and are the most common flaw in, er… self-prescribed or amateur searches: just because you call something a toothbrush doesn’t mean that everyone else calls it a toothbrush. So, if you’ve invented an improvement on a toothbrush and you’re trying to figure out if it’s patentable, searching every single published patent and application for “toothbrush” to see if anyone else ever described your idea is not only insufficient, it’s inefficient as well. For starters, the patent drafter may have decided to call a previous invention a “dental brush” or “bristled dental cleaning instrument”, and never used the word toothbrush at all. Plus, searching for a common term like “toothbrush” will pull up a lot of chaff that is probably wholly irrelevant and a waste of time to review. For example, try searching for “knitting” in the abstract of issued U.S. patents. You will find some highly relevant and interesting patents, but not a lot; you will find a lot of machine knitting patents, some of which are interesting to the hand knitter as well; and you will find a lot of patents that don’t actually have anything to do with two sticks and string (or a knitting machine and string), but make legitimate use of the word “knitting” as well. In short, keyword text searches are only good for turning up previously published patents and applications if you know exactly what you’re looking for, and you know that it already exists, and uses those keywords to describe it. (Patent databases can propagate misspellings of inventors’ names, too.)

In addition to the inadequacy of text searching, there are some other issues to keep in mind if you’re looking for something in a patent database:

First, the older the document, the harder it is to search by text keyword. The U.S. patent database, for example, is only searchable by patent number and classification for patents issued before 1976, and not by text (including bibliographic data such as owner or inventor). However, esp@cenet, the database maintained by the European Patent Office, does have bibliographic data for older U.S. patents. The amount of data can vary; it may only be a title, and not the inventor. Similarly, older Canadian patents only provide a title and owner/inventor information, and so the abstracts are not searchable. But in brief, if you search only one free online database for patents and applications, I’d suggest esp@cenet.

Secondly, as mentioned above, patent applications filed within the last eighteen months have not yet been published, unless the applicant specifically requested early publication. In fact, the U.S. even plays favourites: under certain conditions, a U.S. inventor who does not seek patent protection in an other country that publishes patent applications can even request that the U.S. application not be published until patent grant. Also, these publication rules do not necessarily apply to design patents or industrial designs, just to utility patents. If you’re looking for bleeding edge technological development this way, you’re probably looking at a year-and-a-half time lag.

And, by the way, if you are searching for applications or patents for the purpose of trying to determine whether it is likely that you may be infringing on someone else’s rights now or in the future, do not rely on the status of the patent or application as reported online (whether it is still in force, or lapsed, or expired, or dead). Yes, it’s pretty blatantly obvious when an old patent has expired. But databases can store inaccurate information; you might think that an application has gone abandoned for failure to pay the annual maintenance fees that some countries require, but it could be that the online database isn’t updated as regularly as a patent office’s internal database. (In this country, for example, you really need to call the patent office to find out if a fee due last month was actually paid on time.)

Also remember that even the best searches may miss relevant art, even if you do a comprehensive classification search and a keyword search combined. Sometimes the patent office doesn’t classify an invention in the right categories.

Here endeth the lesson.

To find out whether this knitting patent ever issued, the first question to answer is, “where would they have filed?” This being Patons, the likeliest suspects were the U.S., Canada, and Great Britain. The one database that covers all three countries the best is esp@acenet, but instead, I searched Canada first by searching for Patons and Baldwins as owner. (A patent or application can be assigned to another entity after filing, but the Canadian database does update owner information if assignments are registered with the patent office, and I figured chances are the patent application would have been filed in the name of the owner rather than the inventor. And bingo, I found the patent. Its application was filed in 1942, so now I had a framework for searching the U.S. database, if I chose. But I did not choose to do so, remembering that it would be more efficient to search esp@cenet. This I did, and I found the corresponding U.S. and British patents. You can download these patents yourself, of course (the Canadian patent number is 433936; U.S., 2372468; GB, 559487), but I’ve regurgitated the text and drawings of the Canadian patent here (although it has the drawings from the U.S. patent, because they’re cleaner; I think the text of the Canadian and U.S. patents are the same, but I haven’t double-checked). To save you trouble, I put the British patent here [PDF], because interestingly it includes explicit directions for knitting the sock and replacement heel — a knitting pattern, in a patent. This content did not make it into the Canadian or U.S. versions. In comparing the text of the patents, I think that the patent application was initially prepared by a Canadian or British agent; when redrafted for filing in Canada and the U.S., a single version was prepared in which the unnecessary content was cut (free sock knitting pattern!) and the rest revised in accordance with U.S. requirements: there is no “u” in “color” in either the Canadian or the U.S. patent.

This particular method of making a sock with a replaceable heel was invented by a Toronto woman named Nora Jarvis Allen, and assigned to related Patons and Baldwins companies, depending on the country (for the U.S. patent, Patons and Baldwins Inc. in New Jersey; for Canada, Patons & Baldwins Limited, a British company with a Toronto address; and for the British patent, the same Limited company, but with an address in Yorkshire).

Briefly, the description starts out with the first step of the quasi-afterthought technique that can be used not only for sock heels, but also for glove and mitten thumbs, buttonholes, and pockets, and anything that requires severing knitted fabric along a section of a row: namely, the use of a separate length of yarn (preferably in a contrasting colour) to work a portion of a row, so that this separate length can be picked out after the fact to yield two edges with loops to be picked up and worked. (If you behave in true afterthought fashion, you would not think ahead to use contrasting yarn; you’d simply snip a strand in the middle of the row section that you planned to unravel, and you’d carefully unpick the stitches and place them on the needles.)

In the case of this method of working a sock heel, a typical top-down sock pattern is used (cuff to toe); once the top of the heel flap is reached, it is worked flat towards the toe, with selvedges; the last row of the heel flap, though, is worked with the separate (contrast) length of yarn. Once that last row is worked, the main sock yarn is used to continue the sock; however, the stitches are not picked up along the heel flap selvedges to continue the instep. Instead, stitches are cast on to either edge of the set of instep stitches, which are then worked in the round with the heel stitches towards the toe.

In another variant, three pieces of contrasting yarn are cut. After the heel is shaped, one final row is worked across the heel stitches in contrast yarn. Then, stitches are picked up on either side of the heel flap with the other pieces of contrast yarn, and the work proceeds from there. Thus, in this variant, there are three stretches of contrasting stitches. (Actually, there are four if you follow along with the British patent — this variant is the first set of verbose instructions provided — because the British patent knitting instructions suggest that contrast yarn also be used to graft the toe to make unpicking the seam for mending easier.)

To replace the heel, the contrasting stitches are picked out, the heel ripped back up to the beginning of the heel flap, the live stitches placed on the needle and a new heel flap worked in its place. When finished, the flap must be sewn to the instep and grafted to the foot edge. (Do read the patents for detail, and do follow along by reading the knitting instructions in the British patent if you need more than vague hand-waving.)

This appears to be the likeliest candidate for a patent on the so-called “Innovation Sock” or “Aladdin Heel”; in fact, this is the only patent issued to Patons and Baldwin on a hand knitted sock.

These Beehive publications also granted a peculiar licence:

BEEHIVE INNOVATION SOCK. An application for patent has been filed and although Patons & Baldwins Limited welcome the use of this invention by persons knitting socks by hand with Patons & Baldwins’ yarn, other persons should not use or imitate this invention without first obtaining a licence in writing from Patons & Baldwins Limited. (this example is from Men’s Socks by Beehive, Series No. 62)

BEEHIVE ‘ALADDIN’ HEEL. By making the replacement of heels in socks a simple and practical operation, Patons & Baldwins Limited are glad to offer this contribution toward your personal economy. An application for patent has been filed [etc.] (e.g. Hand Knit Socks by Beehive, Series no, 37)

It is interesting that Patons & Baldwin saw fit to file a patent application, and moreover how they thought to enforce their rights. Their goal was likely to prevent competitors from selling patterns embodying this technique, but note the language of the licence: permission was granted to those knitting by hand, using only their brand of yarn. These days, if such a term survived the enforcement laugh test (could you imagine how difficult it would be to pursue your sock-knitting customers for breach of such a term, assuming that there was a binding contract?) the enforcer would likely face antitrust tying allegations from the allegedly infringing defendant-customer. (This does not necessarily mean that a patent would be categorically invalid or unenforceable.) I do wonder if they did ever make use of their patent to at least prevent a competitor from publishing patterns with similar techniques. (In case you’re wondering, the latest of these three patents would have expired in the 1960s.)

You’ll note that although I invoked the “afterthought” concept in describing the technique, this patent describes nothing of the sort: it requires planning. A true “afterthought” heel would require cutting a stitch at the heel, unravelling, then picking up and working the heel. Like in U.S. Patent No. 315,043, the “Art of Knitting Stockings”: literally, part of a row is cut and raveled in a knitted tube at the location of the heel; the live loops are picked up near either raw edge and half-heel flaps are knit, first by working a short portion even then by decreasing one stitch at each end of every other row; then joining the remaining live loops and the selvedges of the heel flaps. In this particular invention, the method was meant to be implemented using a machine for knitting the flat heel flaps that could also work decreases (“narrowing”); the heel was to be finished by either hand or machine. As well — perhaps given the finer gauge at which the machine-made sock was made (the patent for Young’s knitting machine, referenced in this patent, does not give dimensions or gauges) — the stitches picked up after raveling the partial row were not picked up right at the severed edge, but rather three rows (“courses”) away, in order to ensure a neat product. The remaining rows at the severed edge would be raveled and cut during finishing.

Given the machinery suggested for working the heel flaps, the options of working short rows or an afterthought heel in the round were not given — I am guessing that these would have been advantages more readily achievable by hand, although machines for knitting tubular items were available at the time. But it seems to me that those knitters who turn their minds to knitting socks are a resourceful and inventive bunch — note, I’m not one of them, having never knit a sock.

If you’re a designer who is planning to file and prosecute your own trademark application, especially in the US, you really should think about what you supply as a specimen of use in support of your application. Not only should you ask yourself, “will this specimen prove that I’m using the trademark?” — which is something your specimen needs to do — but you should also ask yourself “do I want to put this on the public record?”

When you seek registered intellectual property rights — patent or trademark — what you submit to an intellectual property office becomes part of the public record, at some time or other, and it becomes accessible to the public, somehow. In the case of a US trademark application submitted electronically, that’s immediately and online.

(In the case of a patent application, with a few exceptions your application is published eighteen months after filing. Many patent offices publish the patent application online; the US and the European Patent Office now make the entire up-to-date patent file history, including the applicant’s submissions, easily accessible online. This is a terrific tool. Not only can you track your own patent applications as they wend their way through the system, but you can keep very close tabs on competitors, too.)

So, if your example of trademark use is a knitting pattern bearing your trademark, and you choose to provide the USPTO with a full copy of that pattern bearing your trademark as a specimen, then your complete pattern will be uploaded to the USPTO website and made available for download, for free, to anybody who knows where to look. Perhaps a knitting pattern might be your only appropriate specimen, but if that’s the case and it’s a multi-page publication, consider carefully whether you actually need to supply all pages as a specimen. It may well be that the first page or the cover page will be sufficient. And that way, you would avoid turning a document that you normally offer for sale into a free download.

If it turns out that you did do just that, I’m not certain there is a way to withdraw the specimen of use so that it no longer appears online. Conceivably parts of a file could be sealed by a confidentiality order, but a specimen of use cannot, and in a case like this a confidentiality order would have to be after the fact and if you’ve let the cat out of the bag yourself, it’s often hard to lock the barn door. (Please don’t cry over spilt milk. Just deplore my mixed metaphors.)

By engaging the patent or trademark system, you are at least implicitly giving the government permission to deal with your submitted work, even if protected by copyright, in a manner consistent with its legal obligations to the public.

Standard warning: just in case you start getting ideas, the fact that you, a user, manage to download a file with the apparent blessing of a government entity doesn’t mean that you have the right to start distributing the file to whomever you please. Copyright doesn’t explode into nothingness just because something’s on the net. Thank you.

Yes, I am being deliberately coy.

Today, though, a historical tidbit that’s been sitting on my hard drive for a few years. It has become especially relevant now, though, since Kory Stamper’s article on knitting two socks at once on dpns was published in Knitty. That knitting parlour trick, briefly described in Leo Tolstoy’s War and Peace, is a perfect example for a discussion of prior art and enabling disclosure:

The melancholy silence that followed was broken by the sounds of the children’s voices and laughter from the next room. Evidently some jolly excitement was going on there.

“Finished, finished!” little Natasha’s gleeful yell rose above them all.

Pierre exchanged glances with Countess Mary and Nicholas (Natasha he never lost sight of) and smiled happily.

“That’s delightful music!” said he.

“It means that Anna Makarovna has finished her stocking,” said Countess Mary.

“Oh, I’ll go and see,” said Pierre, jumping up. “You know,” he added, stopping at the door, “why I’m especially fond of that music? It is always the first thing that tells me all is well. When I was driving here today, the nearer I got to the house the more anxious I grew. As I entered the anteroom I heard Andrusha’s peals of laughter and that meant that all was well.”

“I know! I know that feeling,” said Nicholas. “But I mustn’t go there- those stockings are to be a surprise for me.”
Pierre went to the children, and the shouting and laughter grew still louder.

“Come, Anna Makarovna,” Pierre’s voice was heard saying, “come here into the middle of the room and at the word of command, ‘One, two,’ and when I say ‘three’… You stand here, and you in my arms- well now! One, two!…” said Pierre, and a silence followed: “three!” and a rapturously breathless cry of children’s voices filled the room. “Two, two!” they shouted.

This meant two stockings, which by a secret process known only to herself Anna Makarovna used to knit at the same time on the same needles, and which, when they were ready, she always triumphantly drew, one out of the other, in the children’s presence.

War and Peace was first published in Russian in the 1860s. The fact that Tolstoy wrote about two stockings being knit at once suggests that this was a technique handed down in Russia (unless we are to suppose that Tolstoy developed the idea himself), if not Europe, that therefore must have antedated the publication of War and Peace. And

But a patent application for accomplishing Anna’s “secret process” was filed in the United States by Frederich Polle, Louisa Keisker, and Sallie Polle on October 24, 1874; their patent issued as U.S. Patent No. 167,563 on September 7, 1875. If you’d like to read the text and see all the figures of this patent, they’re reproduced below the jump.

Polle et al. describe the rudiments of knitting two layers at once using a technique that we’d call “double knitting” today — the variant with two separate ends of yarn, without exchanging the ends, so that the fabric layers always remain separate. Interestingly, Polle et al. only describe the easier part of working the stockings; if you read through the description, you’ll see that there is no discussion about how to shape toes or heels. The only reference made to shaping stitches is this:

By means of this improvement… uniformity of size is secured without the usual comparing of one article with the other, when dropping or taking up stitches in the act of reducing or increasing the diameter of the knit article.

… yet there is no explanation provided as to how to reduce or increase, although this is the trickiest part of the double-knit sock trick (read the Knitty article to find out how to do this).

On the other hand, Polle et al. go to different extremes: they don’t stop at double knitting; they go on to describe knitting four layers at once!

Thus, in simultaneously knitting four stockings, we cast onto the needle C a stitch from the first yarn, A, then one from the second, B, one from the third, C, one from the fourth, D, until the required number of stitches is set up on the needles. Then, after knitting the first yarn, A, we pass it outside of the needles, where it will always remain during the work. Next, pull up the second yarn, B, from underneath the first, knit it, and pull it down. This yarn will continue to be between the first and second garments throughout the work. Then knit the third yarn, C, reversing the stitch to make the right side of this garment face toward the right sides of the other two, keeping this yarn inside of the needles, where it will always remain, the nearest yarn to the knitter. Next, pull up the fourth yarn, D, from underneath the third, and knit it, reversing the stitch. This yarn should always be kept between the third and fourth garments.

The one claim of Polle et al.’s patent is to “[t]he improvement in the art of knitting two or more garments at the same time upon the same set of needles, the same consisting in setting up on the needles the loops of each garment, so that they alternate one with the other, and in removing them in the same order, substantially as described [in the patent description].” (Today, one would not rely on a single patent claim as breezily worded as this; the rules of claim construction have evolved over time.)

If we assume that it was known to knit two garments, such as socks, at once in the manner described by Polle et al., prior to 1874, and if we assume that this knowledge was not commonly known, but was known by a select bunch of knitters who passed on the technique orally — both of which are assumptions that we are making based only on a passing reference by Tolstoy — then how is it possible for a patent to be granted?

Easy. Early in U.S. patent law history, applications for patent were not examined for novelty; by the time this trio applied for their patent, there was an examination process in place. But even so, there are limits to the patent examiner’s ability and resources. In a field such as knitting, where so much was passed on through oral tradition rather than in writing, it is highly possible that a technique could be publicly known, and publicly shared, yet completely miss the examiner’s notice–particularly because the patent office examination for novelty would be restricted to only printed publications. And even today, although so much is recorded in writing, it’s still entirely possible for a publicly available reference to remain “hidden”, only to be unearthed when a defendant or potential defendant in a patent infringement action starts hunting around for prior art (whether printed or practical) to invalidate the patent.

On the other hand, if we were to assume that there was an actual, printed reference that the examiner could have found in 1874 that disclosed this technique of knitting two articles at once, this would not necessarily leave the applicants without a patent: they did, after all, teach how to knit more than two articles, and arguably figuring out how to do this, and where to put all the working ends of yarn, would not have been anticipated (rendered not novel) by a printed publication restricted to two articles.

War and Peace, by itself, could not have been a prior art reference, even if it had been available in the United States in English to the examiner in 1874: while it described the desired result — two stockings knit at once — it was not an enabling disclosure, because that mere description would not have told the reader, even one skilled in the art of knitting socks, how to carry out the method. It doesn’t lead the reader to the method described by Polle et al.; it’s the difference between Poincar?©’s conjecture and Perelman’s work. (No, I don’t use hyperbole in my analogies. They’re both mind-blowing when you see them, right?)

Polle et al. does teach a skilled reader how to knit multiple layers at once, with sufficient detail so that those who came after (like us) can read it and repeat their steps to arrive at the same result. That is the purpose of the description in a patent: the patentee must provide enough detail so that their invention can be replicated by others, once the patent monopoly expires. You’ll note that Polle et al. assumes a certain level of ability in the reader; there are no instructions about how to cast on, or how to form knit stitches. That assumption of a certain level of skill is fine, because patents aren’t directed to the general public, but rather to a notional addressee who is assumed to have the requisite skill set to understand the description.

Thus, when patents are litigated, expert witnesses are commonly called on to explain to the court just what would be understood by the terminology of the patent. I couldn’t say what the pay would be like in the knitting field because, well, this just doesn’t happen; but in other fields, expert remuneration is far more lucrative than, say, designing and publishing patterns.

Improvement in the Art of Knitting Stockings and Other Articles
Specification forming part of Letters Patent No. 167,563, dated September 7, 1875; application filed October 24, 1874.
To all whom it may concern:
Be it known that we, F. W. POLLE, LOUISA KEISKER, and SALLIE POLLE, of Port Gibson, in the county of Claiborne and State of Mississippi, have invented a new and valuable improvement in the art of knitting several articles at one time upon the same set of needles; and we do hereby declare that the following is a full, clear, and exact description of the construction and operation of the same, reference being had to the annexed drawings making a
part of this specification, and to the letters and figures of reference marked thereon.

The figures of the drawings are representations of knitting-work in different stages of construction, according to our improvement.

Our invention has relation to an improvement in knitting; and the novelty consists in knitting two or more stockings or other garments on one set of needles at the same time, and in the manner hereinafter more fully explained.

To knit two stockings simultaneously upon one set of needles, we first cast upon them the stitches alternately from two different balls of yarn, designated in the drawings by the letters A B, using as many stitches of each separate yarn as would be required for each separate garment. Thus, when two stockings are set up on one set of needles, there will be twice as many stitches on the needles as there would be if but one single garment were set
up. The letters C C¹ C² C³ designate the needles, of which as few as four may be used, three to set the work up on, and one to work with. The knitting is then continued as in the ordinary method, taking the stitches of the different yarn alternately, care being taken to keep the ball of yarn of which the outside stocking is being knit always upon the outside of the work, and the yarn of the inside stocking inside of the work to prevent their becoming entangled with each other.


In knitting any number above two of stockings or other similar garments, in order to prevent the different yarns from crossing and interlacing with each other in the work, it is necessary to keep the yarns of the inner garments
each between the garment to which it belongs and the next, keeping always the same order as that in which the work was commenced, pulling up each yarn when required for a new stitch, and when this stitch is knit pulling it down again under the work, so that when the next stitch of that particular garment is to be taken its yarn will cross underneath to it in a straight line without interfering with any yarn of another garment. Thus, in simultaneously knitting four stockings, we cast onto the needle C a stitch from the first yarn, A, then one from the second, B, one from the third, C, one from the fourth, D, until the required number of stitches is set up on the needles. Then, after knitting the first yarn, A, we pass it outside of the needles, where it will always remain during the work. Next, pull up the second yarn, B, from underneath the first, knit it, and pull it down. This yarn will continue to be between the first and second garments throughout the work. Then knit the third yarn, C, reversing the stitch to make the right side of this garment face toward the right sides of the other two, keeping this yarn inside of the needles, where it will always remain, the nearest yarn to the knitter. Next, pull up the fourth yarn, D, from underneath the third, and knit it, reversing the stitch. This yarn should always be kept between the third and fourth garments. This process is to be again and again gone through until the garments are ready for finishing or “binding off,” always keeping the yarns in the order described. When there are a number of stitches to be bound off we work around one entire garment, carrying the loop of yarn along on the working-needle to each stitch, alternating the stitches of the other garments to the end. The garment will still be held by the needles upon which it was set up. Then bind off the remaining garments in the same manner, after which pull out all the needles upon which the several garments were set up, and the garments will appear perfectly independent of each other.

Any single garment that can be knit singly may be knit in duplicate upon one set of needles at the same time.

By means of this improvement, while the same set of needles can be used to knit two or more articles of the same pattern and at the same time, uniformity of size is secured without the usual comparing of one article with the other, when dropping or taking up stitches in the act of reducing or increasing the diameter of the knit article.

What we claim as new is –

The improvement in the art of knitting two or more garments at the same time upon the same set of needles, the same consisting in setting up on the needles the loops of each garment, so that they alternate one with the
other, and in removing them in the same order, substantially as described.

In testimony that we claim the above we have hereunto subscribed our names in the presence of two witnesses.

F. W. POLLE.
LOUISA KEISKER.
SALLIE POLLE.

Witnesses:
HERMANN GOEPEL,
SOLN. UNGER.

Here are the broadest claims that issued. Yes, they’re long. Read them anyway. You may find that some figures will help:

1. A method for measuring the dimensions of a knitted work-piece during the fabrication thereof, said method comprising the steps of:
      obtaining a pair of identical knitting needles, a first needle and a second needle, each of said needles comprising
           an elongated member substantially circular in cross section and having a proximal end and a distal end, the proximal end being substantially pointed;
           head means permanently disposed at the distal end of the elongated member, said head means being larger in circumference than the elongated member for preventing stitches held on the elongated member from sliding off the elongated member at its distal end;
           at least one measuring scale permanently applied longitudinally to the surface of the elongated member, said at least one measuring scale having as its zero point the distal end of the head means and being marked in equidistant intervals numbered consecutively toward the proximal end;
      obtaining necessary yarn and instructions to construct the work-piece;
      casting on the requisite number of stitches and proceeding to knit a portion of the work-piece;
      completing a row so that the first needle holds the entire work-piece and the second needle does not hold any stitches; spreading the work-piece evenly along the first needle;
      maintaining the first needle in a horizontal orientation;
      holding the second needle in a vertical orientation with the proximal end pointed downward and bringing the distal end of the second needle upward to the first needle until the distal end of the head means touches the first needle and the second needle is adjacent to and parallel with a vertical edge the work-piece; and
      measuring the length of the work-piece using the at least one measuring scale on the second needle.

I broke up this first claim with carriage returns to try to make it a little easier to read. This first claim appears to be directed to the method of measuring the length of the work as it hangs from the needles: the first needle, holding the “entire work-piece”, is held in a “horizontal orientation”, and the second needle, which “does not hold any stitches”, is held in a “vertical orientation with the proximal end pointed downward and bringing the distal end of the second needle upward to the first needle” until the distal end of the head of the second needle touches the first needle, and the second needle is “parallel with a vertical edge of the work-piece”; then a measuring scale on the second needle is used to measure the length of the work, since the “zero point” of the measuring scale is at the distal end of the head.

4. A craft needle for use in the fabrication of a work-piece from a continuous filament, said needle comprising: an elongated member substantially circular in cross section and having a proximal end and a distal end; and at least one measuring scale, taken from the group consisting of the metric scale and the English scale, permanently applied longitudinally to the surface of the elongated member, said at least one measuring scale having as its zero point one end of said elongated member and being marked in equidistant intervals numbered consecutively toward the opposing end, head means permanently disposed at the distal end of the elongated member, said bead means being larger in circumference than the elongated member for preventing stitches held on the craft needle from sliding off the needle at the distal end; a depression in the distal surface of the head means, said depression conforming to the shape of the elongated member and capable of receiving the elongated member, and the low point of said depression representing the zero point of the at least one measuring scale, whereby the craft needle may be used to measure the dimensions of the work-piece as it is being fabricated.

6. A pair of identical knitting needles for use in the fabrication of a work-piece from a continuous filament, each needle comprising: an elongated member substantially circular in cross section and having a proximal end and a distal end; head means permanently disposed at the distal end of the elongated member, said head means being larger in circumference than the elongated member for preventing stitches held on the elongated member from sliding off the elongated member at the distal end; and at least one measuring scale permanently applied longitudinally to the surface of the elongated member, said at least one measuring scale having as its zero point the distal end of the head means and being marked in equidistant intervals numbered consecutively toward the proximal end; whereby the knitting needles may be used to measure the length and width of the work-piece as it is being fabricated.

Two things spring to mind when reading this: first — and please don’t think that I’m construing these patent claims or providing a legal opinion, here — it seems that these claims specifically exclude circular needles, which of course have no head means, and secondly, the zero point has to be aligned with a specific position on the needle, such as that shown here:

or in Figure 10, at that “low point” of the depression.

For interest’s sake (because of course I am interested by this sort of thing), I took a peek at the claims that had been rejected by the Examiner. Here are some examples:

The original claim 1, as filed, read:

1. A craft needle for use in the fabrication of a work-piece from a continuous filament, said needle comprising:
      an elongated member substantially circular in cross-section and having a proximal end and a distal end; and
      at least one measuring scale permanently applied longitudinally to the surface of the elongated member, said at least one measuring scale having as its zero point one end of said elongated member and being marked in equidistant intervals numbered consecutively toward the opposing end;
      whereby the craft needle may be used to measure the dimensions of the work-piece as it is being fabricated.

This seems a little more familiar, doesn’t it? In this claim, the zero point is “one end” of the needle.
This claim was rejected by the Examiner, who cited Kohler, US Patent No. 2,187,039. This is basically what the invention in that patent looked like:

In response, claim 1 was amended by the inventor to read:

1. A craft needle for use in the fabrication of a work-piece from a continuous filament, said needle comprising:
an elongated member substantially circular in cross section and having a proximal end and a distal end; and
at least one measuring scale, taken from the group consisting of the metric scale and the English scale, permanently applied longitudinally to the surface of the elongated member, said at least one measuring scale having at its zero point one end of said elongated member and being marked in equidistant intervals numbered consecutively toward the opposing end;
whereby the craft needle may be used to measure the dimensions of the work-piece as it is being fabricated.

As you can see, the metric/English scale limitation was added, and it was argued that Kohler didn’t teach that the markings on the needle were numbered consecutively, or with any numbered scale. Kohler does actually state that the markings could be “spaced one inch apart” with “half-inch markings” in between, and even with “intermediate quarter-inch markings”, but Kohler doesn’t actually describe a needle with numbers on it. But the Examiner didn’t buy that argument, and issued a final rejection against that claim, and against some others that were dependent on it. However, the Examiner did allow the claim that I reproduced at the beginning as issued claim 1, as well as a dependent claim based on that. So, in response to the final rejection, the set of claims based on this rejected claim 1 was cancelled by the inventor, and she stuck with the two claims that the Examiner allowed (and added four more, including the issued claims 4 and 6 that I also reproduced).

So there you have it, a brief, albeit incomplete, examination of a patent file history. You can wake up now.

Among the other things I had said earlier when I put up that patent from the 50s, if you recall, was that “for all I know the Knit Stix patent application claims exclusivity over some other aspect that isn’t readily apparent from their product description, although I can’t imagine what that could be…” And see? I didn’t imagine what that could be. And in my defence, it wasn’t in their product description, either; the product they’re offering for sale doesn’t have the features recited in the claims that were allowed. If the pictures on the order page are accurate, then you can see that the zero point is located below the needle head, and there is no depression or other shape in the head that is shaped to receive the “elongated member” of the other needle. The needles that Knit Stix is currently selling seem to have more of a resemblance to Hadler, except the scale runs from head to tip, not from tip to head. Helen Jost has apparently devised an improvement on an old device to improve the accuracy of measurement.

I do wonder about the feasibility of manufacturing needles with a precisely positioned zero point; if you look at the examples on the ordering page, the zero point on the lavendar pair is closer to the head than on the golden yellow pair; what if the heads of the needles, which here are made from a different material, were mounted at varying depths on various needles? Could this imprecision be avoided if the needles were manufactured from a single material, say, molded from plastic?

Patents don’t depend on whether the invention is actually made or used; it can’t be invalidated on that basis (as long as it’s possible to reproduce the invention described and claimed in the patent; there’s a case in Canada in which an applicant was required to submit an actual, working model of his so-called invention, a death ray gun, because the Examiner didn’t believe it would actually work. He didn’t, so he didn’t get a patent). But unless someone actually makes the article that is described by the claims, then there wouldn’t be any infringement. So, I guess it remains to be seen if someone will actually practise the claimed invention.

If you want to look up the history of this patent application, it’s available online. Go here, and type in 11/217,874 as the application number, then select the tab “Image File Wrapper”.

At this point, we don’t even know if a corresponding application has been filed in any other countries because if it had been, it would still be confidential until March 2007: it’s possible to find out if she filed an application elsewhere claiming priority to this US application, but likely not without spending money, and I’m not going to do that.

And for the record, I am still totally against blindly measuring your work with a measuring guide of any sort while it’s still on the needles. If all you need is an estimated length, fine; but if you’re knitting to match a specific length, I’m still firmly on the know-your-gauge-and-count-row side.

First, a comment from one of the women behind Knit Stix, Aleta Frost, stating that they had a design patent, that they expect to receive a utility patent, that their product was patented, and inviting me to contact her for more details.

Secondly, a comment from Charlotte, who used to have some of these old calibrated needles in her possession, so they were produced and the markings were sufficiently durable, contrary to my speculation.

In response to the first comment, I sent an e-mail to Ms. Frost asking for details and explaining where I found the prior art patent. She did drop me a note this morning to thank me for my continued interest, but I didn’t get any more details — she just said they’ve contacted their lawyers about what I wrote. (Understandable — if the applications were filed this year, they’d most likely still be unpublished, and you’d want to consult your lawyer before divulging information about an unpublished application.)

The product in question was Knit Stix: straight knitting needles in colourful shades of anodized aluminum with 12 inches’ worth of ruler markings. The product review gushed about its why-didn’t-I-think-of-that-ness, but I thought, yes, it’s a good idea (although I probably wouldn’t avail myself of their benefits because I’m strictly a circular needle type, with the odd recourse to double points), but haven’t I seen that before? (Not in Kim’s recollection of photographs of striped DPNs circa WWII, but rather in one of my patent forages.)

And indeed, I had…

U.S. Patent No. 2,748,582, patented in 1956, entitled “Calibrated Knitting Needle.” Now that you’ve seen those drawings, there really isn’t much else to explain. And if it wasn’t obvious from the year, that patent has long since expired; it would have expired in 1973.

The patent described more features than merely a needle with inch rules. The markings could also be calibrated to match a particular yarn thickness, so that the knitter could tell at a glance how many stitches were on the needle (those finer markings in the drawings aren’t for millimetres, they’re for stitch counts). Also, the head, or whatever you prefer to call the stopper at the end opposite the point, and the needle body could be engaged by threaded means, so that you could unscrew the head and slip the stitches off the needle at that end, or even screw on an extension to make a longer needle. The screw threads are illustrated in Figure 2.

I don’t recall ever hearing of anyone owning such a needle in their vintage collection, so I don’t know if it was ever produced. Perhaps the markings wore off the old ones. Or if they didn’t wear off, perhaps the raised or engraved numbers and ridges made for dissatisfied customers. But with modern manufacturing methods, perhaps the markings can now endure the constant friction of knitting without rubbing off, and don’t annoy by catching fingertips or yarn, so the market is ripe for Knit Stix knitting needles. And fifty years from now, these needles will be on eBay when our children and grandchildren find themselves saddled with a moth-ridden bequest.

I’m happy for the women behind Knit Stix. They had a concept. They ran with it. They found a manufacturer, and they’re now selling their product. Lots of individuals have ideas, and they even consult patent attorneys about them, but only a small fraction of them manage to get past the concept stage because it doesn’t just take money, it takes time and courage for an individual to develop and sell a product they believe in.

But something is bothering me, as it always does. Not the fact that this isn’t a “new” product; as I just said above, it might only be recently that needles could be produced with indestructible yet imperceptible (to the touch) markings. In the meantime, someone without knowledge of Thomas Hadler’s invention developed the same idea, and now the needles can become a commercial success.

It’s not the fact that the Knit Stix website has a subtle little “patent pending” in the banner title. (That’s assuming that the pending trademark application for “Knit Stix” hasn’t been mistakenly described as a patent application; I believe that the businesspeople behind Knit Stix know the difference. That’s also assuming that the patent referred to isn’t a design patent, which covers unique ornamental features.) It’s not unheard of for an inventor to file a patent application, even knowing that the chances of obtaining a patent are slim; saying that you have a pending patent application lends a certain cachet in some customers’ eyes, and bargaining power with investors or buyers. Many inventors also file utility patent applications not even knowing what the likelihood of patentability is at all, because they’d rather spend their money on filing the application than on searching the prior art; or because the best protection available prior to a public inventor’s exhibition is to either have a patent in hand, or to at least have filed the application. And furthermore, for all I know the Knit Stix patent application claims exclusivity over some other aspect that isn’t readily apparent from their product description, although I can’t imagine what that could be — the printing method?

It’s not the fact that INPEX, the company that ran one of the trade shows at which Knit Stix were exhibited, stated in a press release that the product was “patented. ” Technically, it was patented once, just by someone else. And while it’s an offence to mark or advertise something as patented when it really isn’t in order to deceive the public, well, if anyone actually did that, INPEX did.

What bothers me is something that I, as a gauge preacher, cannot allow to pass without warning.

Don’t let your Knit Stix knitting needles lull you into a false sense of security about your swatching. You won’t get an accurate measure of a gauge swatch while it’s still on the needles. Measure your swatches off the needles, after laundering and blocking, or suffer the consequences you so richly deserve.

Actually, that brings to mind something that has bothered me for as long as I’ve been aware of the concept of gauge: if row gauge changes after blocking, why do some people prefer patterns that instruct them to “knit until work is 14 inches from beginning” over “knit 84 rows”? If you hold up your measuring tape or Knit Stix needle to your knitting to measure it, you’re measuring the pre-blocked length which means you have to either mentally adjust the measured number, or physically stretch your knitting as you measure. Either alternative sounds more difficult than using a row counter.

In any event, you’ve been warned, so now I can live peaceably with these knitting needles.

Ouch.

The idea was to provide a more tactile experience for the knitter in order to reduce the incidence of dropped stitches, because, you know, pulling the yarn through those little loops by dragging the tip of one needle against the shaft of the other is so hard. As you can guess from the graphic illustrations, the yarn is caught beneath the head as the stitch is completed.

(Stop thinking that.)

Oh, look, you can still buy a kit to make the needle case. It’s on this page.

(I said STOP!!!)

On a serious note, it was meant to enable the knitter to work by feel alone. I wonder how this type of needle would fare with a yarn like Kidsilk Haze and similarly fine yarns, which can be frustrating to knit if you’re not watching your stitches. The yarn is so fine, you can barely feel it.

However, there’s a practical difficulty: this tip might be fine for the needle drawing the loop, but having that tip on the needle holding the live stitches might mess up the gauge. The stitch about to be knit would be near the narrow portion of the neck; a loop is drawn through, and then the original stitch needs to be lifted over that protruding head. Perhaps that’s why we don’t see this type of needle in any vintage collections.

How to get a patent

First, there’s some background information here. Note the bit about the requirements that the invention must be new, useful, and non-obvious. Those standards are assessed (depending on what country’s patent laws apply) as of the date the patent application was first filed, or the date of invention. In other words, the test for whether an invention is “inventive” (a circular description, to be sure) is not considered as of today; it’s considered as of the earliest date that the inventor can legally claim.

That background information also mentions that the patent application undergoes an examination process. In particular, the patent claims — the numbered paragraphs consisting of run-on sentences — are examined to ensure that they cover only new and inventive subject matter, and that whatever they cover, it was sufficiently described in the rest of the patent application. The rest of the patent application can describe much more than the invention, but the claims themselves must read only on something new and inventive, because this is the part of the patent that defines the exclusive rights that are going to be granted. The rest of the patent application must give enough information to allow a worker skilled in the relevant field to make the invention described in the claims. (Some information can be assumed, based on the level of knowledge that the reader is expected to have; not everything has to be explained. For example, if the invention involves a circuit, the patent application doesn’t have to explain what a transistor is.)

So, during the examination process, the patent examiner focuses on the scope of the claims. The examiner will search the prior art (usually published patents and patent applications, hopefully from more than one country; sometimes published articles) that seems relevant to the invention claimed in the patent. The examiner will also make sure that the claims are supported by the description in the patent application.

Often, the examiner will raise objections against the patentability of the claims on the basis of prior art. For example, the examiner can conclude that the claimed invention isn’t new, because he or she found a published document that discloses the very same thing. Or, the examiner can conclude that the claimed invention is obvious (i.e. not “inventive”), because the various parts of the claims are found in a number of prior art documents, and an uninventive person who had knowledge in that field of technology or art could have put them together to arrive at the claimed invention. If the examiner comes to this kind of conclusion, he or she issues a rejection of some or all of the claims. It’s up to the applicant (or the applicant’s patent agent) to either amend the claims to avoid this objection (often the claims are originally drafted too broadly at the outset, so they cover prior art and therefore need to be revised during examination), or to argue against the examiner’s conclusion. If the amendment or argument is successful and there are no further objections, then the patent application will be allowed and will be issued as a patent, with the content of the patent application as amended during examination. Of course, this whole process isn’t free or instantaneous. It can take at least one year, usually two, and often much longer, for a patent to issue from an application. And most steps taken during the process cost money — either paid to the patent agent for doing work, or paid to the patent office for official fees.

Now, in many countries, the burden can be on the examiner to find all the relevant prior art that should be considered. Because every examiner is expected to examine a number of applications while maintaining some decent level of productivity, they can’t track down every single reference that might possibly exist. They’re limited by the resources that are available to them.

In the United States, there is an obligation on a patent applicant to disclose any prior art publications that were known to the applicant, the inventor, or the patent agent that are relevant to the invention. In other countries, the examiner may be able to requisition the applicant to disclose any prior art that was cited in related patent applications in other countries. That helps cut down on the burden of searching. But there are still limitations — folk wisdom or common sense that wasn’t actually recorded in a meaningful way isn’t going to be available to the examiner; and an examiner can’t (or shouldn’t) simply rely on “common sense” without any documentary backup to reject a claim.

How to bust a patent

Short, cynical answer: got money?

In order of decreasing cost and risk, here are the ways that patents usually get invalidated (this is a generalized overview of procedures in more than one country, so not everything described here will literally apply in a single country):

1. Infringer gets sued for infringement; infringer challenges validity of patent in defence and also seeks impeachment of patent in a counterclaim.
2. An interested party brings an action to impeach the patent (there may be some legal requirement to demonstrate status as an interested party); if party is a potential infringer, patentee may counterclaim for patent infringement.
3. A party applies to the patent office for a re-examination of the patent in view of published prior art documents.

The first two options involve court actions (quite expensive). The third option doesn’t involve the court — at least, not right away — and depending on the process before the relevant patent office, is often less expensive, although there are specific procedures to be followed.

In a patent office re-exam, the examination board is usually restricted to considering novelty and obviousness in view of printed prior art publications (the scope of the inquiry can vary from country to country, but note again that folk wisdom or common sense that is undocumented may not be accepted), and the patentee may have the opportunity to submit replacement claims that will avoid the prior art and still cover the invention. The challenger is permitted to make written arguments against the patent. So, while it’s lower cost for the challenger, it’s also lower risk for the patentee, because at the end of the re-examination the patent may still stand, with either the same or narrower claims. If the challenger’s goal was simply to get the claims narrowed so that the challenger could avoid infringing them, that could be considered a success.

And when I say “lower cost”, it’s a relative term: re-examination fees payable to the patent office can range from about $1K to almost $9K. As much could be spent again on patent agent fees, if one is retained by the challenger to do the work. And the patentee or challenger may have rights of appeal if they’re not happy with the decision.

In a court action, while the costs and risks are higher for the challenger, the risks are higher for the patentee, too. Other grounds for invalidity besides prior art can be raised, such as procedural and equitable issues, like a failure to pay appropriate fees, abuse of patent rights, or failure to act in good faith before the patent office; but most patents are invalidated on the grounds of novelty and inventiveness in view of prior art, not on technical grounds (however, a court can consider non-documentary evidence of prior use or knowledge). And the court doesn’t have the power to “fix” the patent so that it is no longer invalid, so if it turns out that there is prior art that is covered by some or all of the claims, those claims will be invalid — no chance for the patentee to fix them.

Things can get more complicated if, during an infringement/impeachment action, the patentee or the infringer applies to the patent office for a re-examination.

In some countries, there’s an opportunity for other parties to write to the patent office before the patent is granted to protest against the application. You can submit prior art and arguments why the prior art invalidates the proposed claims. But the examiner may not be required to respond to your submissions; they’ll get considered, for what they’re worth, and your arguments may or may not wind up being used.

Obviously, if avoiding infringement of someoone else’s patent is of concern to you, it goes without saying that it is strongly recommended that you consult a patent attorney. The actual rules of interpretation of patent claims and the rules for determining whether a seemingly different device or method can be captured by those interpreted claims are extremely complicated. Even if it seems that the language of the claims is comprehensible to you, the meaning that you might happen to attribute to them isn’t necessarily the legal meaning. (To make reference to other impeachment-related proceedings, it really does matter what your meaning of the word “is” is.)

As a general comment, it’s a lot easier for laypeople to dismiss the invention claimed in a patent as “not new” or “obvious” than it is for the people who have to scrutinize the patent and evaluate its validity. Years after the patent application was filed, and the patentee starts enforcing its patent against others, it’s easy for commentators to say “yeah, well, that’s old hat — look at any university textbook.” Well, perhaps it’s old news now — but the body of knowledge by which inventiveness and novelty is measured isn’t the standard you would apply now, it’s the knowledge that a person skilled in the art would have had back then. It’s also easy to dismiss the invention as merely being the application of plain common sense, which any uninventive drone could have done, but proving that is a challenge. In other words, hindsight is 20/20: it’s easier to look back from today’s date and say “well of course, this is how you’d do it!” than it is to place yourself in the position of someone at the patent application filing date or invention date and look forward.