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Very curious, since there were commercialized versions reported back in 2019. https://www.boatindustry.com/news/32122/sharrow-amazing-propeller-geometry-to-opt

Very curious, since there were commercialized versions reported back in 2019. https://www.boatindustry.com/news/32122/sharrow-amazing-propeller-geometry-to-optimize-performance https://www.boatindustry.com/news/32122/sharrow-amazing-prop... https://boattest.com/Sharrow-Propeller https://boattest.com/Sharrow-Propeller And there are examples from online forums dating back to 2012: https://www.boatdesign.net/threads/strange-propeller.44740/ https://www.boatdesign.net/threads/strange-propeller.44740/

BuckyBeaver 4y ago
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.
bdowling 4y ago
> Very curious, since there were commercialized versions reported back in 2019. (1) Their patent application was filed on 11/6/2017. https://patents.google.com/patent/US10836466B2 https://patents.google.com/patent/US10836466B2 (2) This propeller is different from those propellers, and the patent office found that the differences were patentably new and non-obvious. Claim 1 is representative: > 1. Toroidal propeller comprising: a hub supporting a plurality of elongate propeller elements in which a tip of a leading propeller element curves into contact with a trailing propeller element to form a closed structure with increased stiffness and reduced acoustic signature. The element "in which a tip of a leading propeller element curves into contact with a trailing propeller element" seems to be common to all the independent claims of the patent.

BuckyBeaver 4y ago

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.

bdowling 4y ago

> Very curious, since there were commercialized versions reported back in 2019. (1) Their patent application was filed on 11/6/2017. https://patents.google.com/patent/US10836466B2 https://patents.google.com/patent/US10836466B2 (2) This propeller is different from those propellers, and the patent office found that the differences were patentably new and non-obvious. Claim 1 is representative: > 1. Toroidal propeller comprising: a hub supporting a plurality of elongate propeller elements in which a tip of a leading propeller element curves into contact with a trailing propeller element to form a closed structure with increased stiffness and reduced acoustic signature. The element "in which a tip of a leading propeller element curves into contact with a trailing propeller element" seems to be common to all the independent claims of the patent.