The proof is in the hot dog.
By Harry Urban
This magazine will never endorse a material or machine. Were here to provide an objective report on technologies that are used by secondary plastics processors. Having said that, I was floored by an invention I saw at the recent International Woodworking Fair (which also provides a technological feast for plastics fabricators).
Four entrepreneurs from Portland, Oregon displayed a safety mechanism that is capable of stopping a rotating saw blade instantly when it comes in contact with a users finger. Called the SawStop, it works by recognizing the difference in the electrical properties of wood (or plastics) and a users skin.
According to Stephen Gass, the inventor, the system induces a high-frequency electrical signal on the blade of a table saw and monitors this signal for changes caused by contact between the blade and a users body. The signal remains unchanged when the blade cuts wood or plastics because of the relatively small inherent electrical capacitance and conductivity of the materials. However, when a user contacts the blade while the saw is operating, the electrical signal changes because of the relatively large inherent capacitance of the users body. Once the system detects this change in the electrical signal, it immediately forces a brake into the teeth of the blade. The brake absorbs the energy of the blade, bringing the blade to a complete stop in approximately 2-5 milliseconds.
Placed in the line of fire of a rotating
sawblade, this hot dog was saved by the
||During the show, the invention was demonstrated
by using a hot dog in place of a human finger. A
large crowd gathered for each demonstration and
to my knowledge it worked every time. The hot
dogs that were placed in the line of fire of the
sawblade received only a tiny nick. Not
surprisingly, the SawStop won a coveted
Challengers Award, which is given only to
companies with “new, revolutionary, creative,
ingenious, or forward-thinking technology,
, services, supplies or safety devices that will
advance the industry.”
Another powerful angle to this story is that
Gass and his three partners are also physicists and
patent attorneys to boot. Gass is also a lifelong
woodworker. The partners’ credentials make me
believe that the company probably has all of its
bases covered. Gass said the company’s goal is to
its see its safety system incorporated on every
table saw sold so that the number of debilitating
injuries on table saws can be dramatically reduced.
I spoke to a couple of independent “experts” at
the show and neither could do anything but praise
the entire concept. The technology is practical and
appears to be foolproof. There is little doubt that
the SawStop will save fingers and change the
landscape for future saw injury litigation.
Take a look at the company’s Web site at
www.sawstop.com to see a video demonstration.
Contact Harry Urban, firstname.lastname@example.org for more information.
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