7 ms·

All of those differ from the one in this ad.

• beambot 4y ago
  They are very similar, just with more toroids attached to the central shaft. They also render the patent completely invalid by way of prior art.
  • maxerickson 4y ago
    Filing date was November 2017.
    • beambot 4y ago
      If you look at computer case fans, you can find commercial examples dating back to at least 2012 that are specifically meant to curb noise: https://www.overclock.net/threads/noiseblocker-nb-eloop-120mm-bionic-loop-propeller-fans.1289723/ https://www.overclock.net/threads/noiseblocker-nb-eloop-120m...
      • maxerickson 4y ago
        Yeah, I missed the 2012 in the other comment.