[R-390] Cosmos PTO, spring-loaded linearizing core?

[Tim Shoppa]

Bill writes:

> OK, the ring is not the main spring. I do see the red part with
> the white dot in Jim's pictures. What I can't see is how to
> remove the coil assembly, with that long steel base that surely
> could contain a spring. The picture with "The two halves of the
> PTO being separated ..." shows what appears to be a wrench flat
> at the end of the "steel" (or some gray metal) base that is close
> to the frame. Have you disassembled it that far?

It's easier than you see.  There are two cheese-head screws (which
you do not see in Jim's photos) that hold the linearizing core base
onto the main plate. It's tight but not too hard to get to those
screws. The material seems to be aluminum for most of the PTO innards
that are not phenolic/ plastic.

> If you do have the coil assembly free of the PTO, can you see a
> way to look in the steel barrel? 

Yeah, I don't see a spring. I see a threaded hole in the base. The
thread on the screw attached to the core threads through that
hole. Current theory is that the threaded hole isn't part of the base
but is part of a sliding cylinder that goes up and down in the base,
and that the cylinder has somehow seized up in mine.

> OTOH, Cosmos didn't machine anything that didn't have to be machined.
> Perhaps the red rod is hollow. The inside end pushes against the
> spring. The outside end pushes against something like a rivet head
> on the end of the inner rod that attaches to the coil slug.

That's a good theory, and it may indeed be what's in other Cosmos
PTO's but that's not what I see in mine.

I am tempted to tear down my other Cosmos PTO (it is actually in
much bigger need of linearization) just to see if
I can slide the core in that one!

I looked at the Cosmos patent #3,098,989 and while the externals
of the linearing inductor match mine, the innards of base #28 and
core #31 do not look like mine.

That's a really well-written patent BTW. Occasionally for work I have
to look at more modern patents and they are written like crap in
comparison.

Tim.