"Ken Moon" wrote: (clip) it sounds like they may have been doing something
along the line of the current vane type compressors, or the princle of the
sliding vanes in Mazdas rotary engines. The vanes are embedded in a
cylinder and rotated inside a oviod shaped enclosure.
^^^^^^^^^^^^^^^^^
Actually, the familiar Gast vacuum pump does this, but the chamber is
cylindrical, and the rotor is eccentrically positioned. The Mazda rotary
engine--more properly, the Wankel, is quite different. It uses a cavity
shaped sort of like a figure "8," and the rotor orbits through both lobes of
the "8" as it spins. The earliest application of this was as a compressor,
which, of course, is very like a vacuum pump.

The obvious problem with this whole idea is that you can't stop the lathe
without losing the vacuum.