The patent was only applied for, but not proceeded with. Still an interesting read, though. PDF [274kB] attached.
Dunno about the practicality of this setup; it would have taken up quite a bit of room under the blade carrier disc, and restricted the maximum cutting height considerably.
The inventor's timing was a bit late in the day too; he put this gadget on the market after Victa had come up with their own solution to worn bolt heads and the complex bush/washer system; the shouldered bolt, with a diamond-shaped boss to engage the matching carrier hole. Which they have used ever since...
Cheers, Gadge
"ODK Mods can explain it to you, but they can't understand it for you..."
"Crazy can be medicated, ignorance can be educated - but there is no cure for stupid..."