Aermotor flapper yoke

[NV-WindmillProject]

Around what year did Aermotor scrap the flapper yoke and start using the oil ring?

Thanks in advance

[Windcatcher530 Dan]

Venn it was used on the model 502 in 1915 and was found to be a failure so they came out with the model 602 with the oil ring. But apparently they decided they had to much leftover stock of the flipper design yoke and flipper and decided to use it on some of their early model 602s . Don't know how long they did this i have a 602 with a flipper but no date on the mill to tell. !!

[CTXmiller]

Flippers were on the first generation 602 made from 1916 and seemingly into 1918. Those were gearboxes with the flat bottom for the mast pipe washer and the center drain plug. The early 602 parts list reflects the 509 and 524 yoke on it. Finding a patent date for the oil ring might pin point the month/year better.

[NV-WindmillProject]

Thanks guys, I'll look up a patent

[NV-WindmillProject]

Found this one - 1341080
Filed December 8, 1919, and patented May 25, 1920.

The oil ring is Part 21.

US1341080 page 2.png

US1341080 page 1.png

[CTXmiller]

I was thinking it might be 1918, but 1919 it is. I’d imagine Aermotor sent oil rings out to owners, sort of like an internal recall or marketed upgrade because of complaints, etc. with the flipper.

[Ron Stauffer]

In the pile of first generation 602, I have one that is stamped on shaft end 10 19 or Oct 1919. It was still original with the oil flipper and 524 yoke.

It is interesting in the patent drawings that the oil ring and yoke are the only upgrades. The flat bottom case, bottom drain plug and flat strap pitman arms are shown in the patent. These were changes that came right after the oil ring. It is probably doubtful that the cupped bottom case, side drain plug and strut pitmans were patented but Venn needs.a project to see if they were...

I have seen more of these first generation 602 with still the flipper and 524 yoke than having an oil ring and 624 yoke. I have seen them with oil ring and 624 with the remnants of the flipper pin at the base of the hoop to know it was done. There are not enough of the upgraded ones out there to say that Aermotor upgraded all the early ones. Also, there must not have been instant failure of the flipper from the mill turning backwards with the flipper being used for a year in the 502 and at least 4 years in the 602.

Ron Stauffer
Montrose CO

[NV-WindmillProject]

Thanks for the great info Ron

[Windcatcher530 Dan]

Tried to send pics but won't let me?