The 'modern' history of the EUREKA Gear-Tooth Relieving Attachment began, I believe in the mid-late 1980's arising from an M.E. PostBag letter [someone confirm the date/Issue No.] from a New Zealand (my country!) reader including a copy of a page from a very old machinists' tools catalogue [does anyone have that copy?] and accompanied by that old chestnut; "What is it?"
The M.E. brains trust (Professor D.H.Chaddock & Ivan Law) got to work to crack the puzzle and eventually nutted out how the thing worked ….. and the rest, as they say, was history. now a widely disseminated and equally widely used device.
But insofar as I know, no-one ever did solve the actual mystery of ther true origin of this most ingenious attachment. As far as I know, no Patent has ever surfaced, no country of origin, no confirmed dates and of course, no inventor's name!
Or am I wrong? Can anyone fill-in these missing historical blanks as it seems to me to be rather odd to be using a device for which no-one seems to have bothered to dig-up the appropriate attributions to its rightful creator.
I confess to teasing you a little. It seems to have had its origins with the Balzer Rotary Milling Cutter Relieving Attachment:-
https://www.csparks.com/VanDervoort/index.xhtml
His corresponding Patent refers:-
https://patents.google.com/patent/US535127?oq=535127
…. but still, I'm not quite sure. It's certainly not identical. Can anyone zero-in on the true history. Answers please………