origin of trapezoidal screw?

Anyone happen to know who invented trapezoidal profile lead screw? Or for that matter, where it was originally invented?

Original trapezoidal profile is US ACME 29° thread in late 19th century.
Nowadays when someone speak of trapezoidal profile it is usually the 30° metric profile, but the ACME profile is still widely used worldwide.

The origin of the ACME thread is that the previous leadscrew profile, squared thread, is difficult to manufacture as the smallest deviation will bind it.

alj_rprp Wrote:
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> Original trapezoidal profile is US ACME 29°
> thread in late 19th century.
> Nowadays when someone speak of trapezoidal profile
> it is usually the 30° metric profile, but the
> ACME profile is still widely used worldwide.
>
> The origin of the ACME thread is that the previous
> leadscrew profile, squared thread, is difficult to
> manufacture as the smallest deviation will bind
> it.

ah... Thanks. I was aware metric trapezoidal was the child of ACME, and that ACME was designed back in the late 1800s, but I wasn't aware that it was a US invention. Interesting.