The "EXE" 2 1/2 in. Bar Bed Lathe.
This small lathe is of high grade construction, but somewhat unusual in design.
The V belt drive is one feature of this interesting tool.
There are 2 distinct co-operative elements; the bed is an accurate cylindrical bar; next a flat bar that acts as a guide below the round bar, and between them is the lead screw.
The extra pully gives the effect of a back-gearand has a " flywheel effect" which conduces to steady running.

Source; The simple lathe, book.