This comment is not legal advice. This comment is merely for educational purposes.

The quote that you have about the 1997 patent, namely "U.S. Pat. No. 5,659,925 teaches a process for adjusting the deposition rate..." is from the specification. That is written by either the inventors or more likely the attorneys filing the application. The specification is not legally enforceable or binding. It is supposed to disclose enough information to let somebody reproduce the claimed invention. As a matter of practice, the specification can say almost anything it wants, including non-enforceable things.

Only the claims are legally enforceable. I suggest taking a closer look at the claims and seeing if these are problematic for your application or not. You may want to consult an attorney if you have further questions.

You can look up the patent examiner's reasoning for allowing the application here:

https://patentcenter.uspto.gov/applications/17667081

Click on "Documents and Transactions" and look for "Notice of Allowance and Fees Due". Also look for the "Non-Final Rejection" for additional information from the examiner from an earlier version of the application.

I should note that it does not appear that the patent examiner considered the 1997 patent directly relevant because they did not cite it in any of the office actions or specifically the PTO-892 forms (search the documents page for 892 to see what I'm talking about). However, they likely did at least look at it since it is listed in the specification.

Again, if you have further questions, you really should consult an attorney. This is not a good forum for this kind of discussion, in my opinion.

Relevant video on the subject, discussing brick layers, and the patents:

https://youtu.be/9IdNA_hWiyE

The real problem is that patent system seems ripe for abuse. Even if the "invention" is not a valid patent, companies want to patent it anyway, as to force the other side to expend resources to prove it's not valid.

There's a couple Bambu Lab patents that probably should not have been granted with prior art in open source.

This post seems very well researched. It's great that OP has brought this up. If we could push further the state of the art in 3D printing, by simply no longer adhering to an (now proven to be invalid) patent, it's a no-brainer to do so.

Non linear slicing is also patent protected but there are some projects that modify slicers to do it.

I did some experiments with bricklaying using a macro in S3D and in all honesty it’s not worth it.

It doesn’t work all the time causes a lot of slicing edge cases on complex models and the cost in print time outweighs any strength gains.

For properly dried filament and a heated chamber the adhesion gains are within the margin of error.

I can also quite confidently say stratasys also currently does not implements it in GrabCAD* which is their slicers/CAM software and I’m not aware of any of their partner slicers/CAMs that do it either.

*There is a chance that they do it as a post processing step in their printers especially the super high end ones either globally or for select locations within the model but I’ve handled quite a few FDM prints on Stratasys machines and I’ve never actually seen it in a production model.

I'm not a lawyer, but have 20+ patents. It's my understanding that if patent A references patent B, it means the examiner thinks that B is not prior art for the claims in A.

Since you wrote

> [...] is a significant limiting factor for the structural integrity of 3d printed parts

I went and checked. There is a youtube called MyTechFun[0] who does proper material testing, and being a patreon I have access to the entire table of his results. The comparison I made is tensile strength vs layer adhesion, which is the same test (basically pull until it breaks), but the sample is printed lying down or standing up. I expressed layer adhesion as a percentage of tensile strength, and sorted by this.

The best three I will show here (tensile and adhesion are in kg):

  Name, Tensile, Adhesion, Percentage
  YXPolyer Nylon[1], 63.1, 66.4, 105
  PolyMaker PLA Pro[2], 56.55, 50.6, 89
  PolyMaker CoPA[3], 66.3, 56.6, 85

[0] https://www.youtube.com/@MyTechFun/videos

[1] https://youtu.be/Q6v4xYrkOnU

[2] https://youtu.be/2dgzwCvSO2k

[3] https://youtu.be/cQb-hbr1KYY

Some related discussion in here:

Ask HN: Why did consumer 3D printing take so long to be invented?

https://news.ycombinator.com/item?id=42079086

For personal stuff you don't have to care about patents anyway. If the slicer can be modded to include this feature then there's nothing stopping people from using it. I'm not sure if just adding the feature in slicers would violate the patent, or using the feature commercially.

Also, if you're printing commercially, I would just go ahead and violate the patent. They are not going to find out, and if they do then just stop using the feature or negotiate a license for the patent.

I'm an attorney who litigates patents. I also write about IP litigation at https://ipde.com.

A patent can be invalidated by a court during litigation or through procedures at the U.S. Patent Office, such as inter partes review or an ex partes reexamination.

When asking whether an earlier patent renders a later patent invalid, the fact finder will generally look at anticipation and obviousness. Anticipation means that every element of the claims is literally present (explicitly or inherently) in the earlier patent, under 35 U.S.C. § 102. Obviousness means that the claimed invention as a whole would have been obvious to a person of skill in the art, under 35 U.S.C. § 103.

How do you figure that out? You have to look at each claim individually. If the fact finder determines that the earlier patent discloses or renders obvious every element of the claim, then the claim is invalid.

This comparison is easier said than done, because it is going to depend on claim construction, meaning how the claims are interpreted. In theory, they are interpreted according to how a person of skill in the art would read them, but in practice there is an art to claim construction, and it can be difficult for anyone to predict how a Court or the U.S. Patent Office will construe claims (especially since it is often judge- or examiner-dependent).

I won't get further into burdens of proof and legal standards, but both anticipation and obviousness tend to be a high bar.

From a very quick review of the two patents you posted, it looks like claim 1 the second patent claims, for example, "lowering the vertical axis of the bead height of a bead disposed between a bead on either side thereof." From a quick look at the specification, this may refer to staggering the vertical size of the beads themselves in each row.

It looks like the earlier patent discloses staggering the alignment of the columns of beads, but I don't see (from a quick glance) whether or not it discloses staggering the size of the beads. If it doesn't disclose that element of claim 1 (however the court or PTO interprets it), then it can't anticipate that claim of the second patent. Of course, it could still render it obvious if, for example, there is another prior art patent that discloses varying the beads in the claimed way, and if a person of skill in the art would have been motivated to combine them (assuming the combination also meets all of the other elements).

Each claim in the second patent will need to be looked at individually. Even if claim 1 were invalid, for example, other independent claims may not be.

Keep in mind that everything in this post is hypothetical and I am not your attorney. If you want to try to invalidate the patent, you'll need to get your own attorney involved or otherwise get one to take up the cause, including to take a real look at the patents and prior art and to figure out how best to proceed. It is not a small task.

Apart from the patent issues.

There has been some tinkering with this technique in the community.

From what I could gather this sort of bricklayer interlocking does basically nothing to help part strength.

And you can not do it on the outside walls because they would not be smooth.

Which means you would need to transition half way in the wall from stacked to interlocked which is possible but needs a very well tuned printer laying lines a fraction of the nozzle diameter.

All in all does not look like it's worth the effort.

The only thing that matters are the claims. You have to read and analyze them in order to understand where the legal IP fence is being built. If you are not used to reading and dissecting patents the claims can be difficult to understand.

I’m not sure but this may be of interest to the Electronic Frontier Foundation https://www.eff.org/pages/legal-cases

Can't you request a separate patent if you're making substantial improvements to it? No idea if that's what happened here, but I'm just saying it's not surprising that a new patent would reference old patents.

I assume that for most things the current tech is durable enough. If it needs to be more durable, going with cast, forged, or even mim metal instead of geometry changes would be better. If you really want geometry stuff, just design one yourself. Use three nozzles - a primary vertical down, two trailing secondaries opposing each other on slightly doward angles and slightly above the primary. Put all the nozzles on the same head but with steppers driving eccentrics to adjust height for each nozzle for areas where only a combination or single nozzle can be used. You'll effectively build a three layered wall with offset layers. Simultaneous printing allows better adhesion by row, and the staggered design provides increased interconnectivity between each strand.

Can't you request a separate patent if you're making substantial improvements to it? No idea if that's what happened here, but I'm just saying it's not surprising that a new patent would reference old patents.

Edit: sorry, seems to be a dupe.

disclaimer, I am not an expert in patent litigation but have been involved in and hold several patents) also, hold my beer and watch this.

Having read the claims on both patents (US2023/11813789B2, US1997/5653925A) , it still seems pretty sus to me on both sides of the fence.

The basic concept of of the geometric layer pattern is identical in the claims and illustrations in both patents, but the expired patent mentions this in the context of "density" and "porosity", while the newer patent describes the identical process for for the effect of interlayer adhesion. This -might- be enough to make a meaningful distinction.

The new patent fills in a little bit more detail on the process, and is much more narrow in scope. But...the expired patent claims -do- specifically mention strength in terms of density in claim 6: "the pressurizing Supply source is adjusted to provide a porosity in the article of between 1% and 9%, so as to form an article of a strength sufficient to maintain the integrity of the article."

Claim 6 refers to claim 3 which refers back to the primary claim of modifying density through the feed pressure and geometric distribution (specifically brick-like, as depicted in figure 2 - preferred embodiment) deposition of the filament.

In all, it is surprising to me that the patent was granted as is. I have had filings rejected for much weaker similarities to existing art when basing a patent on new applications of existing processes... and this is arguably not even a new application.

The described process (hexagonal or brick-like bead geometry) is identical to the process shown in figure 2 of the expired patent and described in the preferred embodiment.

What is missing from the expired patent is a specific claim on the geometry of the preferred embodiment given in figure 2. This could be construed in a sense to say that the preferred embodiment itself was not the subject of the patent, i guess?

In any rate, the 2023 patent clearly does not describe any actual innovation, but rather an attempt to lock down a competitive advantage by locking everyone else out of an invention that has been clearly documented since 1997 and released into the public domain for 6 years prior to this patent.

Although the patent holder appears to be using the patent in a proprietary, in house process, this still smacks a bit of troll dung.

It doesn't take a rocket scientist to see that there was exactly zero innovation here, and the patent applicant was clearly aware of the prior art, perhaps even being inspired by ambitious nonspecificity of the expired patent. His figures 1 and 2 (the primary basis of the new patent) could just have well been lifted directly from the Stratasys patent.

This might be one for the courts. What we need is someanon to fork slic3r with this feature added and dump it on torrent.