US Government is About to Change Table Saws FOREVER!

[edma194]

The following portion of the SawStop patent shows how well they have locked up the technology. It points out the capacitive coupling system they use, but also that they are patenting the broad concept of detecting contact between a user and a saw blade in order to prevent injury. You cannot make a safety device for a table saw that works by detecting contact between the user and the saw blade without paying SawStop some money, and only if they feel like issuing you a license. Even if the CPSC creates regulations requiring safety devices of this nature I don't know if SawStop can be required to license it in general or to any individual. Bosch has already lost the case here in the US for their Reaxx system.

While one exemplary system and method for detecting contact between the user's body and the blade is described herein, many other systems and methods are available and within the scope of the invention. For example, the detection system may sense the resistance of the human body upon contact between the user's body and the blade to detect contact. As another example, a radio signal may be broadcast near the blade so that the user's body acts as an antenna to change the signal received through the blade when contact is made between the user's body and the blade. Similarly, a signal could be applied to the user's body by virtue of standing on a signal transfer mat or wearing a transmitter and the detection system could monitor for reception of the signal upon contact with or proximity to the cutting tools.
As a further example, a proximity detector may be used as described above. Since brake system 34 is capable of stopping the blade within a few milliseconds, the proximity detector may be set to trigger only upon extremely close positioning of the user's body relative to the blade. This would allow the user to manipulate the work piece close to the blade without triggering the brake system. As another example, the wire-mesh glove detection system described above in connection with the meat cutting equipment may be used. Thus, it will be appreciated that while an exemplary embodiment has been described which uses a capacitive contact detection system, any suitable method of detecting contact or close proximity of the user's body to the blade may be used.

[DLB]

I apologize for the length of this. The Proposed Rule is 31 pages, and not easily summarized.

I was unfavorably impressed by all of the things CPSC can and does estimate, because: "At this time CPSC is not able to estimate the royalty cost for licensing an AIM technology." I submit that they also don't know IF a table saw company will be able to license AIM technology for any price. I suspect saw manufacturers face the same problem. And it is kind of important, even the big boys probably want to know if the compliant products they would develop are going to be competitive in a marketplace consisting of SawStop and a bunch of newly redesigned saws.

Maybe it gets worse, because something CPSC can estimate is: "...the manufacturer would have the challenge of developing its own AIM technology that does not infringe on an existing patent. At a minimum, such an effort would likely cost at least several hundred thousand dollars and perhaps several million dollars, based on the estimated costs of developing the existing technologies." And: "...incorporating AIM technology would require a redesign of each table saw model. Estimates of the redesign and retooling costs ranged from about $100,000 to $700,000 per model. The redesign and retooling process would be expected to take 1 to 3 years depending on the number and severity of problems encountered in the process. The redesign and retooling costs for subsequent models could be less than the costs associated with the first model." And most importantly: "However, there is no certainty that small manufacturers would be able to negotiate acceptable licensing agreements with TTS or another patent holder. If small manufacturers are unable to negotiate acceptable licensing agreements for AIM technology, it is likely they would exit the U.S. table saw market." They go on to kind of water down this impact suggesting that for most of these companies U.S. sales of table saws represent a small percentage of their total business. It's not clear to me if Shopsmith's numbers were included in that, not provide, or excluded for some reason like not supporting the narrative, but I suspect the latter. Of seven small businesses that produce table saws, one reported that table saws represented less than 1% of their total revenue, two between 5% and 8%. No mention of the other four.

Exiting the U.S. table saw market is not consistent with Shopsmith's stated goal of increasing new Mark sales 25X. But for various reasons I think they have the toughest challenge of anyone in the business of meeting the proposed rule with a viable product, even recognizing that in the new market most table saws are going to be significantly more expensive.

Source of my quotes is the Proposed Rule published by the CPSC: https://www.federalregister.gov/documen ... -28-p74928

Despite my criticism, I like the technology and am in favor of the rule. When people hurt themselves, whether due to a momentary lapse of judgment or doing something willfully stupid, we the public tend to shoulder the cost. In this case, however, I think that USG (but not CPSC by themselves) should set the value of the IP and negotiate its sale with SawStop, placing it in the public domain. No sale, no rule.

- David

[thedovetailjoint]

Sounds like an urban myth to me!!!

That's what happened.

[RFGuy]

Sounds like an urban myth to me!!!

That's what happened.

Scott,

Okay, I'll play along. Where are the pics of the flipped over Mark V? Any other details for how this happened, i.e. what was being tested specifically? Up above, you can see where I posted a video of the Bosch Reaxx (small, light portable contractor TS) when it had a trigger event causing the cartridge to activate and stopping the blade. Also, SawStop has smaller footprint saws of the contractor TS variety now as well. IF a light saw like this can stop a blade without flipping over, what was so different about this special test at Shopsmith that caused a beefy Mark V to tip over when these other saws do NOT? Hopefully those of you with critical thinking skills can understand my reasoning for calling this out. IF what you say happened was real, then they were doing something far different than just trying to slow/stop a sawblade on that Mark V. Now, if a 10 ft. long steel bar was attached to the sawblade in an attempt to stop it, then yes, I would believe it flipped the Mark V over during this Friday afternoon of fun at Shopsmith HQ.

BOSCH REAXX VIDEO:
viewtopic.php?p=313611#p313611

[DLB]

That's what happened.

Good to know that SS has studied the problem. Makes sense, as the CPSC has been working on it for 20+ years. If the proposed rule becomes the rule, I'd think lowering the center of mass and/or widening the stance of this future Mark is trivial compared to otherwise meeting the new safety requirement. And could sell as an upgrade on its own . A deeper, heavier stronger bench compatible with the existing DT upper assembly? Simple to do, and the DT makes for a simple interface of two steel pins and landings (for vertical operations) between the bench and everything else. A bench redesign could include height adjust for owners that would like a taller lathe and shorter TS, among other 'new' features.

- David

[edma194]

Up above, you can see where I posted a video of the Bosch Reaxx (small, light portable contractor TS) when it had a trigger event causing the cartridge to activate and stopping the blade.

There is no video of a Reaxx table saw stopping the blade:

The Bosch saw retracts the blade below the table, but unlike SawStop, it does not stop or damage the blade.

The SawStop uses the momentum that results from stopping the blade to retract it below the table.

The manufacturer states the saw stops in less than five milliseconds,[1] and angular momentum retracts the blade into the table.

[HopefulSSer]

Even Bosch, a 3rd tier woodworking company today, can get this right on a contractor TS and without it flipping upside down apparently.

2 things worth noting:
1. As stated above, the Reaxx system doesn't stop the blade
2. You can't buy a new Reaxx saw today because Sawstop sued Bosch for patent infringement

IANAL but it certainly seems that the patents are broad enough so that if this goes through, and you want to make a power tool (not just a table saw) with blade-contact detection, Sawstop gets a cut. (See what I did there? ;-)

EDIT: The way Sawstop is acting makes me think of the story of Lee DeForest, who in 1907 invented the vacuum tube amplifier then supposedly used the technology to defraud investors.

[BuckeyeDennis]

US patents expire 20 years (or less, in certain cases) after their application date (not issuance date). Should SawStop's original patents not be expired by now? No doubt they have others, but those would almost certainly contain claims related to secondary/detail issues, which cannot extend the protection period for the claims in the original patents.

[twistsol]

There isn't a requirement that the blade below the table if it can be stopped quickly enough with a brake. That is a feature Sawstop introduced and if I recall correctly, Reaxx improved upon by using only the drop method instead of a brake which preserves the blade.

Combining a brake to stop the blade and a shear pin in the blade arbor would significantly reduce the torque from a sudden stop by allowing the motor to continue to spin and the only mass coming to a sudden stop would be the blade itself. I think any attempt to suddenly raise the table would be as or more dangerous than contact with a blade.

Sawstop did say they would license necessary patents on FRAND basis if the rule were to pass.

[JPG]

I would prefer SawStop commit to a FRAND-Z agreement.


BTW anyone ever see a movie about the Texas Table Saw Massacre.








I find it interesting that Gass numbed his finger before gingerly touching the blade.


Any one ever feed a workpiece gingerly?